diff.con commit diff --stat-count: finishing touches (e5f85df)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        if (!o->irreversible_delete)
 585                print_line_count(o->file, lc_a);
 586        else
 587                fprintf(o->file, "?,?");
 588        fprintf(o->file, " +");
 589        print_line_count(o->file, lc_b);
 590        fprintf(o->file, " @@%s\n", reset);
 591        if (lc_a && !o->irreversible_delete)
 592                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 593        if (lc_b)
 594                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 595        if (textconv_one)
 596                free((char *)data_one);
 597        if (textconv_two)
 598                free((char *)data_two);
 599}
 600
 601struct diff_words_buffer {
 602        mmfile_t text;
 603        long alloc;
 604        struct diff_words_orig {
 605                const char *begin, *end;
 606        } *orig;
 607        int orig_nr, orig_alloc;
 608};
 609
 610static void diff_words_append(char *line, unsigned long len,
 611                struct diff_words_buffer *buffer)
 612{
 613        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 614        line++;
 615        len--;
 616        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 617        buffer->text.size += len;
 618        buffer->text.ptr[buffer->text.size] = '\0';
 619}
 620
 621struct diff_words_style_elem {
 622        const char *prefix;
 623        const char *suffix;
 624        const char *color; /* NULL; filled in by the setup code if
 625                            * color is enabled */
 626};
 627
 628struct diff_words_style {
 629        enum diff_words_type type;
 630        struct diff_words_style_elem new, old, ctx;
 631        const char *newline;
 632};
 633
 634static struct diff_words_style diff_words_styles[] = {
 635        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 636        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 637        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 638};
 639
 640struct diff_words_data {
 641        struct diff_words_buffer minus, plus;
 642        const char *current_plus;
 643        int last_minus;
 644        struct diff_options *opt;
 645        regex_t *word_regex;
 646        enum diff_words_type type;
 647        struct diff_words_style *style;
 648};
 649
 650static int fn_out_diff_words_write_helper(FILE *fp,
 651                                          struct diff_words_style_elem *st_el,
 652                                          const char *newline,
 653                                          size_t count, const char *buf,
 654                                          const char *line_prefix)
 655{
 656        int print = 0;
 657
 658        while (count) {
 659                char *p = memchr(buf, '\n', count);
 660                if (print)
 661                        fputs(line_prefix, fp);
 662                if (p != buf) {
 663                        if (st_el->color && fputs(st_el->color, fp) < 0)
 664                                return -1;
 665                        if (fputs(st_el->prefix, fp) < 0 ||
 666                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 667                            fputs(st_el->suffix, fp) < 0)
 668                                return -1;
 669                        if (st_el->color && *st_el->color
 670                            && fputs(GIT_COLOR_RESET, fp) < 0)
 671                                return -1;
 672                }
 673                if (!p)
 674                        return 0;
 675                if (fputs(newline, fp) < 0)
 676                        return -1;
 677                count -= p + 1 - buf;
 678                buf = p + 1;
 679                print = 1;
 680        }
 681        return 0;
 682}
 683
 684/*
 685 * '--color-words' algorithm can be described as:
 686 *
 687 *   1. collect a the minus/plus lines of a diff hunk, divided into
 688 *      minus-lines and plus-lines;
 689 *
 690 *   2. break both minus-lines and plus-lines into words and
 691 *      place them into two mmfile_t with one word for each line;
 692 *
 693 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 694 *
 695 * And for the common parts of the both file, we output the plus side text.
 696 * diff_words->current_plus is used to trace the current position of the plus file
 697 * which printed. diff_words->last_minus is used to trace the last minus word
 698 * printed.
 699 *
 700 * For '--graph' to work with '--color-words', we need to output the graph prefix
 701 * on each line of color words output. Generally, there are two conditions on
 702 * which we should output the prefix.
 703 *
 704 *   1. diff_words->last_minus == 0 &&
 705 *      diff_words->current_plus == diff_words->plus.text.ptr
 706 *
 707 *      that is: the plus text must start as a new line, and if there is no minus
 708 *      word printed, a graph prefix must be printed.
 709 *
 710 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 711 *      *(diff_words->current_plus - 1) == '\n'
 712 *
 713 *      that is: a graph prefix must be printed following a '\n'
 714 */
 715static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 716{
 717        if ((diff_words->last_minus == 0 &&
 718                diff_words->current_plus == diff_words->plus.text.ptr) ||
 719                (diff_words->current_plus > diff_words->plus.text.ptr &&
 720                *(diff_words->current_plus - 1) == '\n')) {
 721                return 1;
 722        } else {
 723                return 0;
 724        }
 725}
 726
 727static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 728{
 729        struct diff_words_data *diff_words = priv;
 730        struct diff_words_style *style = diff_words->style;
 731        int minus_first, minus_len, plus_first, plus_len;
 732        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 733        struct diff_options *opt = diff_words->opt;
 734        struct strbuf *msgbuf;
 735        char *line_prefix = "";
 736
 737        if (line[0] != '@' || parse_hunk_header(line, len,
 738                        &minus_first, &minus_len, &plus_first, &plus_len))
 739                return;
 740
 741        assert(opt);
 742        if (opt->output_prefix) {
 743                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 744                line_prefix = msgbuf->buf;
 745        }
 746
 747        /* POSIX requires that first be decremented by one if len == 0... */
 748        if (minus_len) {
 749                minus_begin = diff_words->minus.orig[minus_first].begin;
 750                minus_end =
 751                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 752        } else
 753                minus_begin = minus_end =
 754                        diff_words->minus.orig[minus_first].end;
 755
 756        if (plus_len) {
 757                plus_begin = diff_words->plus.orig[plus_first].begin;
 758                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 759        } else
 760                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 761
 762        if (color_words_output_graph_prefix(diff_words)) {
 763                fputs(line_prefix, diff_words->opt->file);
 764        }
 765        if (diff_words->current_plus != plus_begin) {
 766                fn_out_diff_words_write_helper(diff_words->opt->file,
 767                                &style->ctx, style->newline,
 768                                plus_begin - diff_words->current_plus,
 769                                diff_words->current_plus, line_prefix);
 770                if (*(plus_begin - 1) == '\n')
 771                        fputs(line_prefix, diff_words->opt->file);
 772        }
 773        if (minus_begin != minus_end) {
 774                fn_out_diff_words_write_helper(diff_words->opt->file,
 775                                &style->old, style->newline,
 776                                minus_end - minus_begin, minus_begin,
 777                                line_prefix);
 778        }
 779        if (plus_begin != plus_end) {
 780                fn_out_diff_words_write_helper(diff_words->opt->file,
 781                                &style->new, style->newline,
 782                                plus_end - plus_begin, plus_begin,
 783                                line_prefix);
 784        }
 785
 786        diff_words->current_plus = plus_end;
 787        diff_words->last_minus = minus_first;
 788}
 789
 790/* This function starts looking at *begin, and returns 0 iff a word was found. */
 791static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 792                int *begin, int *end)
 793{
 794        if (word_regex && *begin < buffer->size) {
 795                regmatch_t match[1];
 796                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 797                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 798                                        '\n', match[0].rm_eo - match[0].rm_so);
 799                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 800                        *begin += match[0].rm_so;
 801                        return *begin >= *end;
 802                }
 803                return -1;
 804        }
 805
 806        /* find the next word */
 807        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 808                (*begin)++;
 809        if (*begin >= buffer->size)
 810                return -1;
 811
 812        /* find the end of the word */
 813        *end = *begin + 1;
 814        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 815                (*end)++;
 816
 817        return 0;
 818}
 819
 820/*
 821 * This function splits the words in buffer->text, stores the list with
 822 * newline separator into out, and saves the offsets of the original words
 823 * in buffer->orig.
 824 */
 825static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 826                regex_t *word_regex)
 827{
 828        int i, j;
 829        long alloc = 0;
 830
 831        out->size = 0;
 832        out->ptr = NULL;
 833
 834        /* fake an empty "0th" word */
 835        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 836        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 837        buffer->orig_nr = 1;
 838
 839        for (i = 0; i < buffer->text.size; i++) {
 840                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 841                        return;
 842
 843                /* store original boundaries */
 844                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 845                                buffer->orig_alloc);
 846                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 847                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 848                buffer->orig_nr++;
 849
 850                /* store one word */
 851                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 852                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 853                out->ptr[out->size + j - i] = '\n';
 854                out->size += j - i + 1;
 855
 856                i = j - 1;
 857        }
 858}
 859
 860/* this executes the word diff on the accumulated buffers */
 861static void diff_words_show(struct diff_words_data *diff_words)
 862{
 863        xpparam_t xpp;
 864        xdemitconf_t xecfg;
 865        mmfile_t minus, plus;
 866        struct diff_words_style *style = diff_words->style;
 867
 868        struct diff_options *opt = diff_words->opt;
 869        struct strbuf *msgbuf;
 870        char *line_prefix = "";
 871
 872        assert(opt);
 873        if (opt->output_prefix) {
 874                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 875                line_prefix = msgbuf->buf;
 876        }
 877
 878        /* special case: only removal */
 879        if (!diff_words->plus.text.size) {
 880                fputs(line_prefix, diff_words->opt->file);
 881                fn_out_diff_words_write_helper(diff_words->opt->file,
 882                        &style->old, style->newline,
 883                        diff_words->minus.text.size,
 884                        diff_words->minus.text.ptr, line_prefix);
 885                diff_words->minus.text.size = 0;
 886                return;
 887        }
 888
 889        diff_words->current_plus = diff_words->plus.text.ptr;
 890        diff_words->last_minus = 0;
 891
 892        memset(&xpp, 0, sizeof(xpp));
 893        memset(&xecfg, 0, sizeof(xecfg));
 894        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 895        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 896        xpp.flags = 0;
 897        /* as only the hunk header will be parsed, we need a 0-context */
 898        xecfg.ctxlen = 0;
 899        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 900                      &xpp, &xecfg);
 901        free(minus.ptr);
 902        free(plus.ptr);
 903        if (diff_words->current_plus != diff_words->plus.text.ptr +
 904                        diff_words->plus.text.size) {
 905                if (color_words_output_graph_prefix(diff_words))
 906                        fputs(line_prefix, diff_words->opt->file);
 907                fn_out_diff_words_write_helper(diff_words->opt->file,
 908                        &style->ctx, style->newline,
 909                        diff_words->plus.text.ptr + diff_words->plus.text.size
 910                        - diff_words->current_plus, diff_words->current_plus,
 911                        line_prefix);
 912        }
 913        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 914}
 915
 916/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 917static void diff_words_flush(struct emit_callback *ecbdata)
 918{
 919        if (ecbdata->diff_words->minus.text.size ||
 920            ecbdata->diff_words->plus.text.size)
 921                diff_words_show(ecbdata->diff_words);
 922}
 923
 924static void free_diff_words_data(struct emit_callback *ecbdata)
 925{
 926        if (ecbdata->diff_words) {
 927                diff_words_flush(ecbdata);
 928                free (ecbdata->diff_words->minus.text.ptr);
 929                free (ecbdata->diff_words->minus.orig);
 930                free (ecbdata->diff_words->plus.text.ptr);
 931                free (ecbdata->diff_words->plus.orig);
 932                if (ecbdata->diff_words->word_regex) {
 933                        regfree(ecbdata->diff_words->word_regex);
 934                        free(ecbdata->diff_words->word_regex);
 935                }
 936                free(ecbdata->diff_words);
 937                ecbdata->diff_words = NULL;
 938        }
 939}
 940
 941const char *diff_get_color(int diff_use_color, enum color_diff ix)
 942{
 943        if (diff_use_color)
 944                return diff_colors[ix];
 945        return "";
 946}
 947
 948static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 949{
 950        const char *cp;
 951        unsigned long allot;
 952        size_t l = len;
 953
 954        if (ecb->truncate)
 955                return ecb->truncate(line, len);
 956        cp = line;
 957        allot = l;
 958        while (0 < l) {
 959                (void) utf8_width(&cp, &l);
 960                if (!cp)
 961                        break; /* truncated in the middle? */
 962        }
 963        return allot - l;
 964}
 965
 966static void find_lno(const char *line, struct emit_callback *ecbdata)
 967{
 968        const char *p;
 969        ecbdata->lno_in_preimage = 0;
 970        ecbdata->lno_in_postimage = 0;
 971        p = strchr(line, '-');
 972        if (!p)
 973                return; /* cannot happen */
 974        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 975        p = strchr(p, '+');
 976        if (!p)
 977                return; /* cannot happen */
 978        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 979}
 980
 981static void fn_out_consume(void *priv, char *line, unsigned long len)
 982{
 983        struct emit_callback *ecbdata = priv;
 984        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 985        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 986        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 987        struct diff_options *o = ecbdata->opt;
 988        char *line_prefix = "";
 989        struct strbuf *msgbuf;
 990
 991        if (o && o->output_prefix) {
 992                msgbuf = o->output_prefix(o, o->output_prefix_data);
 993                line_prefix = msgbuf->buf;
 994        }
 995
 996        if (ecbdata->header) {
 997                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 998                strbuf_reset(ecbdata->header);
 999                ecbdata->header = NULL;
1000        }
1001        *(ecbdata->found_changesp) = 1;
1002
1003        if (ecbdata->label_path[0]) {
1004                const char *name_a_tab, *name_b_tab;
1005
1006                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1007                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1008
1009                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1010                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1011                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1012                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1013                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1014        }
1015
1016        if (diff_suppress_blank_empty
1017            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1018                line[0] = '\n';
1019                len = 1;
1020        }
1021
1022        if (line[0] == '@') {
1023                if (ecbdata->diff_words)
1024                        diff_words_flush(ecbdata);
1025                len = sane_truncate_line(ecbdata, line, len);
1026                find_lno(line, ecbdata);
1027                emit_hunk_header(ecbdata, line, len);
1028                if (line[len-1] != '\n')
1029                        putc('\n', ecbdata->opt->file);
1030                return;
1031        }
1032
1033        if (len < 1) {
1034                emit_line(ecbdata->opt, reset, reset, line, len);
1035                if (ecbdata->diff_words
1036                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1037                        fputs("~\n", ecbdata->opt->file);
1038                return;
1039        }
1040
1041        if (ecbdata->diff_words) {
1042                if (line[0] == '-') {
1043                        diff_words_append(line, len,
1044                                          &ecbdata->diff_words->minus);
1045                        return;
1046                } else if (line[0] == '+') {
1047                        diff_words_append(line, len,
1048                                          &ecbdata->diff_words->plus);
1049                        return;
1050                }
1051                diff_words_flush(ecbdata);
1052                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1053                        emit_line(ecbdata->opt, plain, reset, line, len);
1054                        fputs("~\n", ecbdata->opt->file);
1055                } else {
1056                        /* don't print the prefix character */
1057                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1058                }
1059                return;
1060        }
1061
1062        if (line[0] != '+') {
1063                const char *color =
1064                        diff_get_color(ecbdata->color_diff,
1065                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1066                ecbdata->lno_in_preimage++;
1067                if (line[0] == ' ')
1068                        ecbdata->lno_in_postimage++;
1069                emit_line(ecbdata->opt, color, reset, line, len);
1070        } else {
1071                ecbdata->lno_in_postimage++;
1072                emit_add_line(reset, ecbdata, line + 1, len - 1);
1073        }
1074}
1075
1076static char *pprint_rename(const char *a, const char *b)
1077{
1078        const char *old = a;
1079        const char *new = b;
1080        struct strbuf name = STRBUF_INIT;
1081        int pfx_length, sfx_length;
1082        int len_a = strlen(a);
1083        int len_b = strlen(b);
1084        int a_midlen, b_midlen;
1085        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1086        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1087
1088        if (qlen_a || qlen_b) {
1089                quote_c_style(a, &name, NULL, 0);
1090                strbuf_addstr(&name, " => ");
1091                quote_c_style(b, &name, NULL, 0);
1092                return strbuf_detach(&name, NULL);
1093        }
1094
1095        /* Find common prefix */
1096        pfx_length = 0;
1097        while (*old && *new && *old == *new) {
1098                if (*old == '/')
1099                        pfx_length = old - a + 1;
1100                old++;
1101                new++;
1102        }
1103
1104        /* Find common suffix */
1105        old = a + len_a;
1106        new = b + len_b;
1107        sfx_length = 0;
1108        while (a <= old && b <= new && *old == *new) {
1109                if (*old == '/')
1110                        sfx_length = len_a - (old - a);
1111                old--;
1112                new--;
1113        }
1114
1115        /*
1116         * pfx{mid-a => mid-b}sfx
1117         * {pfx-a => pfx-b}sfx
1118         * pfx{sfx-a => sfx-b}
1119         * name-a => name-b
1120         */
1121        a_midlen = len_a - pfx_length - sfx_length;
1122        b_midlen = len_b - pfx_length - sfx_length;
1123        if (a_midlen < 0)
1124                a_midlen = 0;
1125        if (b_midlen < 0)
1126                b_midlen = 0;
1127
1128        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1129        if (pfx_length + sfx_length) {
1130                strbuf_add(&name, a, pfx_length);
1131                strbuf_addch(&name, '{');
1132        }
1133        strbuf_add(&name, a + pfx_length, a_midlen);
1134        strbuf_addstr(&name, " => ");
1135        strbuf_add(&name, b + pfx_length, b_midlen);
1136        if (pfx_length + sfx_length) {
1137                strbuf_addch(&name, '}');
1138                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1139        }
1140        return strbuf_detach(&name, NULL);
1141}
1142
1143struct diffstat_t {
1144        int nr;
1145        int alloc;
1146        struct diffstat_file {
1147                char *from_name;
1148                char *name;
1149                char *print_name;
1150                unsigned is_unmerged:1;
1151                unsigned is_binary:1;
1152                unsigned is_renamed:1;
1153                uintmax_t added, deleted;
1154        } **files;
1155};
1156
1157static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1158                                          const char *name_a,
1159                                          const char *name_b)
1160{
1161        struct diffstat_file *x;
1162        x = xcalloc(sizeof (*x), 1);
1163        if (diffstat->nr == diffstat->alloc) {
1164                diffstat->alloc = alloc_nr(diffstat->alloc);
1165                diffstat->files = xrealloc(diffstat->files,
1166                                diffstat->alloc * sizeof(x));
1167        }
1168        diffstat->files[diffstat->nr++] = x;
1169        if (name_b) {
1170                x->from_name = xstrdup(name_a);
1171                x->name = xstrdup(name_b);
1172                x->is_renamed = 1;
1173        }
1174        else {
1175                x->from_name = NULL;
1176                x->name = xstrdup(name_a);
1177        }
1178        return x;
1179}
1180
1181static void diffstat_consume(void *priv, char *line, unsigned long len)
1182{
1183        struct diffstat_t *diffstat = priv;
1184        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1185
1186        if (line[0] == '+')
1187                x->added++;
1188        else if (line[0] == '-')
1189                x->deleted++;
1190}
1191
1192const char mime_boundary_leader[] = "------------";
1193
1194static int scale_linear(int it, int width, int max_change)
1195{
1196        /*
1197         * make sure that at least one '-' is printed if there were deletions,
1198         * and likewise for '+'.
1199         */
1200        if (max_change < 2)
1201                return it;
1202        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1203}
1204
1205static void show_name(FILE *file,
1206                      const char *prefix, const char *name, int len)
1207{
1208        fprintf(file, " %s%-*s |", prefix, len, name);
1209}
1210
1211static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1212{
1213        if (cnt <= 0)
1214                return;
1215        fprintf(file, "%s", set);
1216        while (cnt--)
1217                putc(ch, file);
1218        fprintf(file, "%s", reset);
1219}
1220
1221static void fill_print_name(struct diffstat_file *file)
1222{
1223        char *pname;
1224
1225        if (file->print_name)
1226                return;
1227
1228        if (!file->is_renamed) {
1229                struct strbuf buf = STRBUF_INIT;
1230                if (quote_c_style(file->name, &buf, NULL, 0)) {
1231                        pname = strbuf_detach(&buf, NULL);
1232                } else {
1233                        pname = file->name;
1234                        strbuf_release(&buf);
1235                }
1236        } else {
1237                pname = pprint_rename(file->from_name, file->name);
1238        }
1239        file->print_name = pname;
1240}
1241
1242static void show_stats(struct diffstat_t *data, struct diff_options *options)
1243{
1244        int i, len, add, del, adds = 0, dels = 0;
1245        uintmax_t max_change = 0, max_len = 0;
1246        int total_files = data->nr;
1247        int width, name_width, count;
1248        const char *reset, *add_c, *del_c;
1249        const char *line_prefix = "";
1250        int extra_shown = 0;
1251        struct strbuf *msg = NULL;
1252
1253        if (data->nr == 0)
1254                return;
1255
1256        if (options->output_prefix) {
1257                msg = options->output_prefix(options, options->output_prefix_data);
1258                line_prefix = msg->buf;
1259        }
1260
1261        width = options->stat_width ? options->stat_width : 80;
1262        name_width = options->stat_name_width ? options->stat_name_width : 50;
1263        count = options->stat_count ? options->stat_count : data->nr;
1264
1265        /* Sanity: give at least 5 columns to the graph,
1266         * but leave at least 10 columns for the name.
1267         */
1268        if (width < 25)
1269                width = 25;
1270        if (name_width < 10)
1271                name_width = 10;
1272        else if (width < name_width + 15)
1273                name_width = width - 15;
1274
1275        /* Find the longest filename and max number of changes */
1276        reset = diff_get_color_opt(options, DIFF_RESET);
1277        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1278        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1279
1280        for (i = 0; (i < count) && (i < data->nr); i++) {
1281                struct diffstat_file *file = data->files[i];
1282                uintmax_t change = file->added + file->deleted;
1283                if (!data->files[i]->is_renamed &&
1284                         (change == 0)) {
1285                        count++; /* not shown == room for one more */
1286                        continue;
1287                }
1288                fill_print_name(file);
1289                len = strlen(file->print_name);
1290                if (max_len < len)
1291                        max_len = len;
1292
1293                if (file->is_binary || file->is_unmerged)
1294                        continue;
1295                if (max_change < change)
1296                        max_change = change;
1297        }
1298        count = i; /* min(count, data->nr) */
1299
1300        /* Compute the width of the graph part;
1301         * 10 is for one blank at the beginning of the line plus
1302         * " | count " between the name and the graph.
1303         *
1304         * From here on, name_width is the width of the name area,
1305         * and width is the width of the graph area.
1306         */
1307        name_width = (name_width < max_len) ? name_width : max_len;
1308        if (width < (name_width + 10) + max_change)
1309                width = width - (name_width + 10);
1310        else
1311                width = max_change;
1312
1313        for (i = 0; i < count; i++) {
1314                const char *prefix = "";
1315                char *name = data->files[i]->print_name;
1316                uintmax_t added = data->files[i]->added;
1317                uintmax_t deleted = data->files[i]->deleted;
1318                int name_len;
1319
1320                if (!data->files[i]->is_renamed &&
1321                         (added + deleted == 0)) {
1322                        total_files--;
1323                        continue;
1324                }
1325                /*
1326                 * "scale" the filename
1327                 */
1328                len = name_width;
1329                name_len = strlen(name);
1330                if (name_width < name_len) {
1331                        char *slash;
1332                        prefix = "...";
1333                        len -= 3;
1334                        name += name_len - len;
1335                        slash = strchr(name, '/');
1336                        if (slash)
1337                                name = slash;
1338                }
1339
1340                if (data->files[i]->is_binary) {
1341                        fprintf(options->file, "%s", line_prefix);
1342                        show_name(options->file, prefix, name, len);
1343                        fprintf(options->file, "  Bin ");
1344                        fprintf(options->file, "%s%"PRIuMAX"%s",
1345                                del_c, deleted, reset);
1346                        fprintf(options->file, " -> ");
1347                        fprintf(options->file, "%s%"PRIuMAX"%s",
1348                                add_c, added, reset);
1349                        fprintf(options->file, " bytes");
1350                        fprintf(options->file, "\n");
1351                        continue;
1352                }
1353                else if (data->files[i]->is_unmerged) {
1354                        fprintf(options->file, "%s", line_prefix);
1355                        show_name(options->file, prefix, name, len);
1356                        fprintf(options->file, "  Unmerged\n");
1357                        continue;
1358                }
1359
1360                /*
1361                 * scale the add/delete
1362                 */
1363                add = added;
1364                del = deleted;
1365                adds += add;
1366                dels += del;
1367
1368                if (width <= max_change) {
1369                        add = scale_linear(add, width, max_change);
1370                        del = scale_linear(del, width, max_change);
1371                }
1372                fprintf(options->file, "%s", line_prefix);
1373                show_name(options->file, prefix, name, len);
1374                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1375                                added + deleted ? " " : "");
1376                show_graph(options->file, '+', add, add_c, reset);
1377                show_graph(options->file, '-', del, del_c, reset);
1378                fprintf(options->file, "\n");
1379        }
1380        for (i = count; i < data->nr; i++) {
1381                uintmax_t added = data->files[i]->added;
1382                uintmax_t deleted = data->files[i]->deleted;
1383                if (!data->files[i]->is_renamed &&
1384                         (added + deleted == 0)) {
1385                        total_files--;
1386                        continue;
1387                }
1388                adds += added;
1389                dels += deleted;
1390                if (!extra_shown)
1391                        fprintf(options->file, "%s ...\n", line_prefix);
1392                extra_shown = 1;
1393        }
1394        fprintf(options->file, "%s", line_prefix);
1395        fprintf(options->file,
1396               " %d files changed, %d insertions(+), %d deletions(-)\n",
1397               total_files, adds, dels);
1398}
1399
1400static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1401{
1402        int i, adds = 0, dels = 0, total_files = data->nr;
1403
1404        if (data->nr == 0)
1405                return;
1406
1407        for (i = 0; i < data->nr; i++) {
1408                if (!data->files[i]->is_binary &&
1409                    !data->files[i]->is_unmerged) {
1410                        int added = data->files[i]->added;
1411                        int deleted= data->files[i]->deleted;
1412                        if (!data->files[i]->is_renamed &&
1413                            (added + deleted == 0)) {
1414                                total_files--;
1415                        } else {
1416                                adds += added;
1417                                dels += deleted;
1418                        }
1419                }
1420        }
1421        if (options->output_prefix) {
1422                struct strbuf *msg = NULL;
1423                msg = options->output_prefix(options,
1424                                options->output_prefix_data);
1425                fprintf(options->file, "%s", msg->buf);
1426        }
1427        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1428               total_files, adds, dels);
1429}
1430
1431static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1432{
1433        int i;
1434
1435        if (data->nr == 0)
1436                return;
1437
1438        for (i = 0; i < data->nr; i++) {
1439                struct diffstat_file *file = data->files[i];
1440
1441                if (options->output_prefix) {
1442                        struct strbuf *msg = NULL;
1443                        msg = options->output_prefix(options,
1444                                        options->output_prefix_data);
1445                        fprintf(options->file, "%s", msg->buf);
1446                }
1447
1448                if (file->is_binary)
1449                        fprintf(options->file, "-\t-\t");
1450                else
1451                        fprintf(options->file,
1452                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1453                                file->added, file->deleted);
1454                if (options->line_termination) {
1455                        fill_print_name(file);
1456                        if (!file->is_renamed)
1457                                write_name_quoted(file->name, options->file,
1458                                                  options->line_termination);
1459                        else {
1460                                fputs(file->print_name, options->file);
1461                                putc(options->line_termination, options->file);
1462                        }
1463                } else {
1464                        if (file->is_renamed) {
1465                                putc('\0', options->file);
1466                                write_name_quoted(file->from_name, options->file, '\0');
1467                        }
1468                        write_name_quoted(file->name, options->file, '\0');
1469                }
1470        }
1471}
1472
1473struct dirstat_file {
1474        const char *name;
1475        unsigned long changed;
1476};
1477
1478struct dirstat_dir {
1479        struct dirstat_file *files;
1480        int alloc, nr, percent, cumulative;
1481};
1482
1483static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1484                unsigned long changed, const char *base, int baselen)
1485{
1486        unsigned long this_dir = 0;
1487        unsigned int sources = 0;
1488        const char *line_prefix = "";
1489        struct strbuf *msg = NULL;
1490
1491        if (opt->output_prefix) {
1492                msg = opt->output_prefix(opt, opt->output_prefix_data);
1493                line_prefix = msg->buf;
1494        }
1495
1496        while (dir->nr) {
1497                struct dirstat_file *f = dir->files;
1498                int namelen = strlen(f->name);
1499                unsigned long this;
1500                char *slash;
1501
1502                if (namelen < baselen)
1503                        break;
1504                if (memcmp(f->name, base, baselen))
1505                        break;
1506                slash = strchr(f->name + baselen, '/');
1507                if (slash) {
1508                        int newbaselen = slash + 1 - f->name;
1509                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1510                        sources++;
1511                } else {
1512                        this = f->changed;
1513                        dir->files++;
1514                        dir->nr--;
1515                        sources += 2;
1516                }
1517                this_dir += this;
1518        }
1519
1520        /*
1521         * We don't report dirstat's for
1522         *  - the top level
1523         *  - or cases where everything came from a single directory
1524         *    under this directory (sources == 1).
1525         */
1526        if (baselen && sources != 1) {
1527                int permille = this_dir * 1000 / changed;
1528                if (permille) {
1529                        int percent = permille / 10;
1530                        if (percent >= dir->percent) {
1531                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1532                                        percent, permille % 10, baselen, base);
1533                                if (!dir->cumulative)
1534                                        return 0;
1535                        }
1536                }
1537        }
1538        return this_dir;
1539}
1540
1541static int dirstat_compare(const void *_a, const void *_b)
1542{
1543        const struct dirstat_file *a = _a;
1544        const struct dirstat_file *b = _b;
1545        return strcmp(a->name, b->name);
1546}
1547
1548static void show_dirstat(struct diff_options *options)
1549{
1550        int i;
1551        unsigned long changed;
1552        struct dirstat_dir dir;
1553        struct diff_queue_struct *q = &diff_queued_diff;
1554
1555        dir.files = NULL;
1556        dir.alloc = 0;
1557        dir.nr = 0;
1558        dir.percent = options->dirstat_percent;
1559        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1560
1561        changed = 0;
1562        for (i = 0; i < q->nr; i++) {
1563                struct diff_filepair *p = q->queue[i];
1564                const char *name;
1565                unsigned long copied, added, damage;
1566                int content_changed;
1567
1568                name = p->two->path ? p->two->path : p->one->path;
1569
1570                if (p->one->sha1_valid && p->two->sha1_valid)
1571                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1572                else
1573                        content_changed = 1;
1574
1575                if (!content_changed) {
1576                        /*
1577                         * The SHA1 has not changed, so pre-/post-content is
1578                         * identical. We can therefore skip looking at the
1579                         * file contents altogether.
1580                         */
1581                        damage = 0;
1582                        goto found_damage;
1583                }
1584
1585                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1586                        /*
1587                         * In --dirstat-by-file mode, we don't really need to
1588                         * look at the actual file contents at all.
1589                         * The fact that the SHA1 changed is enough for us to
1590                         * add this file to the list of results
1591                         * (with each file contributing equal damage).
1592                         */
1593                        damage = 1;
1594                        goto found_damage;
1595                }
1596
1597                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1598                        diff_populate_filespec(p->one, 0);
1599                        diff_populate_filespec(p->two, 0);
1600                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1601                                               &copied, &added);
1602                        diff_free_filespec_data(p->one);
1603                        diff_free_filespec_data(p->two);
1604                } else if (DIFF_FILE_VALID(p->one)) {
1605                        diff_populate_filespec(p->one, 1);
1606                        copied = added = 0;
1607                        diff_free_filespec_data(p->one);
1608                } else if (DIFF_FILE_VALID(p->two)) {
1609                        diff_populate_filespec(p->two, 1);
1610                        copied = 0;
1611                        added = p->two->size;
1612                        diff_free_filespec_data(p->two);
1613                } else
1614                        continue;
1615
1616                /*
1617                 * Original minus copied is the removed material,
1618                 * added is the new material.  They are both damages
1619                 * made to the preimage.
1620                 * If the resulting damage is zero, we know that
1621                 * diffcore_count_changes() considers the two entries to
1622                 * be identical, but since content_changed is true, we
1623                 * know that there must have been _some_ kind of change,
1624                 * so we force all entries to have damage > 0.
1625                 */
1626                damage = (p->one->size - copied) + added;
1627                if (!damage)
1628                        damage = 1;
1629
1630found_damage:
1631                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1632                dir.files[dir.nr].name = name;
1633                dir.files[dir.nr].changed = damage;
1634                changed += damage;
1635                dir.nr++;
1636        }
1637
1638        /* This can happen even with many files, if everything was renames */
1639        if (!changed)
1640                return;
1641
1642        /* Show all directories with more than x% of the changes */
1643        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1644        gather_dirstat(options, &dir, changed, "", 0);
1645}
1646
1647static void free_diffstat_info(struct diffstat_t *diffstat)
1648{
1649        int i;
1650        for (i = 0; i < diffstat->nr; i++) {
1651                struct diffstat_file *f = diffstat->files[i];
1652                if (f->name != f->print_name)
1653                        free(f->print_name);
1654                free(f->name);
1655                free(f->from_name);
1656                free(f);
1657        }
1658        free(diffstat->files);
1659}
1660
1661struct checkdiff_t {
1662        const char *filename;
1663        int lineno;
1664        int conflict_marker_size;
1665        struct diff_options *o;
1666        unsigned ws_rule;
1667        unsigned status;
1668};
1669
1670static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1671{
1672        char firstchar;
1673        int cnt;
1674
1675        if (len < marker_size + 1)
1676                return 0;
1677        firstchar = line[0];
1678        switch (firstchar) {
1679        case '=': case '>': case '<': case '|':
1680                break;
1681        default:
1682                return 0;
1683        }
1684        for (cnt = 1; cnt < marker_size; cnt++)
1685                if (line[cnt] != firstchar)
1686                        return 0;
1687        /* line[1] thru line[marker_size-1] are same as firstchar */
1688        if (len < marker_size + 1 || !isspace(line[marker_size]))
1689                return 0;
1690        return 1;
1691}
1692
1693static void checkdiff_consume(void *priv, char *line, unsigned long len)
1694{
1695        struct checkdiff_t *data = priv;
1696        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1697        int marker_size = data->conflict_marker_size;
1698        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1699        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1700        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1701        char *err;
1702        char *line_prefix = "";
1703        struct strbuf *msgbuf;
1704
1705        assert(data->o);
1706        if (data->o->output_prefix) {
1707                msgbuf = data->o->output_prefix(data->o,
1708                        data->o->output_prefix_data);
1709                line_prefix = msgbuf->buf;
1710        }
1711
1712        if (line[0] == '+') {
1713                unsigned bad;
1714                data->lineno++;
1715                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1716                        data->status |= 1;
1717                        fprintf(data->o->file,
1718                                "%s%s:%d: leftover conflict marker\n",
1719                                line_prefix, data->filename, data->lineno);
1720                }
1721                bad = ws_check(line + 1, len - 1, data->ws_rule);
1722                if (!bad)
1723                        return;
1724                data->status |= bad;
1725                err = whitespace_error_string(bad);
1726                fprintf(data->o->file, "%s%s:%d: %s.\n",
1727                        line_prefix, data->filename, data->lineno, err);
1728                free(err);
1729                emit_line(data->o, set, reset, line, 1);
1730                ws_check_emit(line + 1, len - 1, data->ws_rule,
1731                              data->o->file, set, reset, ws);
1732        } else if (line[0] == ' ') {
1733                data->lineno++;
1734        } else if (line[0] == '@') {
1735                char *plus = strchr(line, '+');
1736                if (plus)
1737                        data->lineno = strtol(plus, NULL, 10) - 1;
1738                else
1739                        die("invalid diff");
1740        }
1741}
1742
1743static unsigned char *deflate_it(char *data,
1744                                 unsigned long size,
1745                                 unsigned long *result_size)
1746{
1747        int bound;
1748        unsigned char *deflated;
1749        z_stream stream;
1750
1751        memset(&stream, 0, sizeof(stream));
1752        deflateInit(&stream, zlib_compression_level);
1753        bound = deflateBound(&stream, size);
1754        deflated = xmalloc(bound);
1755        stream.next_out = deflated;
1756        stream.avail_out = bound;
1757
1758        stream.next_in = (unsigned char *)data;
1759        stream.avail_in = size;
1760        while (deflate(&stream, Z_FINISH) == Z_OK)
1761                ; /* nothing */
1762        deflateEnd(&stream);
1763        *result_size = stream.total_out;
1764        return deflated;
1765}
1766
1767static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1768{
1769        void *cp;
1770        void *delta;
1771        void *deflated;
1772        void *data;
1773        unsigned long orig_size;
1774        unsigned long delta_size;
1775        unsigned long deflate_size;
1776        unsigned long data_size;
1777
1778        /* We could do deflated delta, or we could do just deflated two,
1779         * whichever is smaller.
1780         */
1781        delta = NULL;
1782        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1783        if (one->size && two->size) {
1784                delta = diff_delta(one->ptr, one->size,
1785                                   two->ptr, two->size,
1786                                   &delta_size, deflate_size);
1787                if (delta) {
1788                        void *to_free = delta;
1789                        orig_size = delta_size;
1790                        delta = deflate_it(delta, delta_size, &delta_size);
1791                        free(to_free);
1792                }
1793        }
1794
1795        if (delta && delta_size < deflate_size) {
1796                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1797                free(deflated);
1798                data = delta;
1799                data_size = delta_size;
1800        }
1801        else {
1802                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1803                free(delta);
1804                data = deflated;
1805                data_size = deflate_size;
1806        }
1807
1808        /* emit data encoded in base85 */
1809        cp = data;
1810        while (data_size) {
1811                int bytes = (52 < data_size) ? 52 : data_size;
1812                char line[70];
1813                data_size -= bytes;
1814                if (bytes <= 26)
1815                        line[0] = bytes + 'A' - 1;
1816                else
1817                        line[0] = bytes - 26 + 'a' - 1;
1818                encode_85(line + 1, cp, bytes);
1819                cp = (char *) cp + bytes;
1820                fprintf(file, "%s", prefix);
1821                fputs(line, file);
1822                fputc('\n', file);
1823        }
1824        fprintf(file, "%s\n", prefix);
1825        free(data);
1826}
1827
1828static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1829{
1830        fprintf(file, "%sGIT binary patch\n", prefix);
1831        emit_binary_diff_body(file, one, two, prefix);
1832        emit_binary_diff_body(file, two, one, prefix);
1833}
1834
1835static void diff_filespec_load_driver(struct diff_filespec *one)
1836{
1837        /* Use already-loaded driver */
1838        if (one->driver)
1839                return;
1840
1841        if (S_ISREG(one->mode))
1842                one->driver = userdiff_find_by_path(one->path);
1843
1844        /* Fallback to default settings */
1845        if (!one->driver)
1846                one->driver = userdiff_find_by_name("default");
1847}
1848
1849int diff_filespec_is_binary(struct diff_filespec *one)
1850{
1851        if (one->is_binary == -1) {
1852                diff_filespec_load_driver(one);
1853                if (one->driver->binary != -1)
1854                        one->is_binary = one->driver->binary;
1855                else {
1856                        if (!one->data && DIFF_FILE_VALID(one))
1857                                diff_populate_filespec(one, 0);
1858                        if (one->data)
1859                                one->is_binary = buffer_is_binary(one->data,
1860                                                one->size);
1861                        if (one->is_binary == -1)
1862                                one->is_binary = 0;
1863                }
1864        }
1865        return one->is_binary;
1866}
1867
1868static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1869{
1870        diff_filespec_load_driver(one);
1871        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1872}
1873
1874static const char *userdiff_word_regex(struct diff_filespec *one)
1875{
1876        diff_filespec_load_driver(one);
1877        return one->driver->word_regex;
1878}
1879
1880void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1881{
1882        if (!options->a_prefix)
1883                options->a_prefix = a;
1884        if (!options->b_prefix)
1885                options->b_prefix = b;
1886}
1887
1888struct userdiff_driver *get_textconv(struct diff_filespec *one)
1889{
1890        if (!DIFF_FILE_VALID(one))
1891                return NULL;
1892
1893        diff_filespec_load_driver(one);
1894        if (!one->driver->textconv)
1895                return NULL;
1896
1897        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1898                struct notes_cache *c = xmalloc(sizeof(*c));
1899                struct strbuf name = STRBUF_INIT;
1900
1901                strbuf_addf(&name, "textconv/%s", one->driver->name);
1902                notes_cache_init(c, name.buf, one->driver->textconv);
1903                one->driver->textconv_cache = c;
1904        }
1905
1906        return one->driver;
1907}
1908
1909static void builtin_diff(const char *name_a,
1910                         const char *name_b,
1911                         struct diff_filespec *one,
1912                         struct diff_filespec *two,
1913                         const char *xfrm_msg,
1914                         int must_show_header,
1915                         struct diff_options *o,
1916                         int complete_rewrite)
1917{
1918        mmfile_t mf1, mf2;
1919        const char *lbl[2];
1920        char *a_one, *b_two;
1921        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1922        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1923        const char *a_prefix, *b_prefix;
1924        struct userdiff_driver *textconv_one = NULL;
1925        struct userdiff_driver *textconv_two = NULL;
1926        struct strbuf header = STRBUF_INIT;
1927        struct strbuf *msgbuf;
1928        char *line_prefix = "";
1929
1930        if (o->output_prefix) {
1931                msgbuf = o->output_prefix(o, o->output_prefix_data);
1932                line_prefix = msgbuf->buf;
1933        }
1934
1935        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1936                        (!one->mode || S_ISGITLINK(one->mode)) &&
1937                        (!two->mode || S_ISGITLINK(two->mode))) {
1938                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1939                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1940                show_submodule_summary(o->file, one ? one->path : two->path,
1941                                one->sha1, two->sha1, two->dirty_submodule,
1942                                del, add, reset);
1943                return;
1944        }
1945
1946        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1947                textconv_one = get_textconv(one);
1948                textconv_two = get_textconv(two);
1949        }
1950
1951        diff_set_mnemonic_prefix(o, "a/", "b/");
1952        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1953                a_prefix = o->b_prefix;
1954                b_prefix = o->a_prefix;
1955        } else {
1956                a_prefix = o->a_prefix;
1957                b_prefix = o->b_prefix;
1958        }
1959
1960        /* Never use a non-valid filename anywhere if at all possible */
1961        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1962        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1963
1964        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1965        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1966        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1967        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1968        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1969        if (lbl[0][0] == '/') {
1970                /* /dev/null */
1971                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1972                if (xfrm_msg)
1973                        strbuf_addstr(&header, xfrm_msg);
1974                must_show_header = 1;
1975        }
1976        else if (lbl[1][0] == '/') {
1977                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1978                if (xfrm_msg)
1979                        strbuf_addstr(&header, xfrm_msg);
1980                must_show_header = 1;
1981        }
1982        else {
1983                if (one->mode != two->mode) {
1984                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1985                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1986                        must_show_header = 1;
1987                }
1988                if (xfrm_msg)
1989                        strbuf_addstr(&header, xfrm_msg);
1990
1991                /*
1992                 * we do not run diff between different kind
1993                 * of objects.
1994                 */
1995                if ((one->mode ^ two->mode) & S_IFMT)
1996                        goto free_ab_and_return;
1997                if (complete_rewrite &&
1998                    (textconv_one || !diff_filespec_is_binary(one)) &&
1999                    (textconv_two || !diff_filespec_is_binary(two))) {
2000                        fprintf(o->file, "%s", header.buf);
2001                        strbuf_reset(&header);
2002                        emit_rewrite_diff(name_a, name_b, one, two,
2003                                                textconv_one, textconv_two, o);
2004                        o->found_changes = 1;
2005                        goto free_ab_and_return;
2006                }
2007        }
2008
2009        if (o->irreversible_delete && lbl[1][0] == '/') {
2010                fprintf(o->file, "%s", header.buf);
2011                strbuf_reset(&header);
2012                goto free_ab_and_return;
2013        } else if (!DIFF_OPT_TST(o, TEXT) &&
2014            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2015              (!textconv_two && diff_filespec_is_binary(two)) )) {
2016                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2017                        die("unable to read files to diff");
2018                /* Quite common confusing case */
2019                if (mf1.size == mf2.size &&
2020                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2021                        if (must_show_header)
2022                                fprintf(o->file, "%s", header.buf);
2023                        goto free_ab_and_return;
2024                }
2025                fprintf(o->file, "%s", header.buf);
2026                strbuf_reset(&header);
2027                if (DIFF_OPT_TST(o, BINARY))
2028                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2029                else
2030                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2031                                line_prefix, lbl[0], lbl[1]);
2032                o->found_changes = 1;
2033        } else {
2034                /* Crazy xdl interfaces.. */
2035                const char *diffopts = getenv("GIT_DIFF_OPTS");
2036                xpparam_t xpp;
2037                xdemitconf_t xecfg;
2038                struct emit_callback ecbdata;
2039                const struct userdiff_funcname *pe;
2040
2041                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2042                        fprintf(o->file, "%s", header.buf);
2043                        strbuf_reset(&header);
2044                }
2045
2046                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2047                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2048
2049                pe = diff_funcname_pattern(one);
2050                if (!pe)
2051                        pe = diff_funcname_pattern(two);
2052
2053                memset(&xpp, 0, sizeof(xpp));
2054                memset(&xecfg, 0, sizeof(xecfg));
2055                memset(&ecbdata, 0, sizeof(ecbdata));
2056                ecbdata.label_path = lbl;
2057                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2058                ecbdata.found_changesp = &o->found_changes;
2059                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2060                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2061                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2062                ecbdata.opt = o;
2063                ecbdata.header = header.len ? &header : NULL;
2064                xpp.flags = o->xdl_opts;
2065                xecfg.ctxlen = o->context;
2066                xecfg.interhunkctxlen = o->interhunkcontext;
2067                xecfg.flags = XDL_EMIT_FUNCNAMES;
2068                if (pe)
2069                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2070                if (!diffopts)
2071                        ;
2072                else if (!prefixcmp(diffopts, "--unified="))
2073                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2074                else if (!prefixcmp(diffopts, "-u"))
2075                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2076                if (o->word_diff) {
2077                        int i;
2078
2079                        ecbdata.diff_words =
2080                                xcalloc(1, sizeof(struct diff_words_data));
2081                        ecbdata.diff_words->type = o->word_diff;
2082                        ecbdata.diff_words->opt = o;
2083                        if (!o->word_regex)
2084                                o->word_regex = userdiff_word_regex(one);
2085                        if (!o->word_regex)
2086                                o->word_regex = userdiff_word_regex(two);
2087                        if (!o->word_regex)
2088                                o->word_regex = diff_word_regex_cfg;
2089                        if (o->word_regex) {
2090                                ecbdata.diff_words->word_regex = (regex_t *)
2091                                        xmalloc(sizeof(regex_t));
2092                                if (regcomp(ecbdata.diff_words->word_regex,
2093                                                o->word_regex,
2094                                                REG_EXTENDED | REG_NEWLINE))
2095                                        die ("Invalid regular expression: %s",
2096                                                        o->word_regex);
2097                        }
2098                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2099                                if (o->word_diff == diff_words_styles[i].type) {
2100                                        ecbdata.diff_words->style =
2101                                                &diff_words_styles[i];
2102                                        break;
2103                                }
2104                        }
2105                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2106                                struct diff_words_style *st = ecbdata.diff_words->style;
2107                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2108                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2109                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2110                        }
2111                }
2112                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2113                              &xpp, &xecfg);
2114                if (o->word_diff)
2115                        free_diff_words_data(&ecbdata);
2116                if (textconv_one)
2117                        free(mf1.ptr);
2118                if (textconv_two)
2119                        free(mf2.ptr);
2120                xdiff_clear_find_func(&xecfg);
2121        }
2122
2123 free_ab_and_return:
2124        strbuf_release(&header);
2125        diff_free_filespec_data(one);
2126        diff_free_filespec_data(two);
2127        free(a_one);
2128        free(b_two);
2129        return;
2130}
2131
2132static void builtin_diffstat(const char *name_a, const char *name_b,
2133                             struct diff_filespec *one,
2134                             struct diff_filespec *two,
2135                             struct diffstat_t *diffstat,
2136                             struct diff_options *o,
2137                             int complete_rewrite)
2138{
2139        mmfile_t mf1, mf2;
2140        struct diffstat_file *data;
2141
2142        data = diffstat_add(diffstat, name_a, name_b);
2143
2144        if (!one || !two) {
2145                data->is_unmerged = 1;
2146                return;
2147        }
2148
2149        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2150                data->is_binary = 1;
2151                data->added = diff_filespec_size(two);
2152                data->deleted = diff_filespec_size(one);
2153        }
2154
2155        else if (complete_rewrite) {
2156                diff_populate_filespec(one, 0);
2157                diff_populate_filespec(two, 0);
2158                data->deleted = count_lines(one->data, one->size);
2159                data->added = count_lines(two->data, two->size);
2160        }
2161
2162        else {
2163                /* Crazy xdl interfaces.. */
2164                xpparam_t xpp;
2165                xdemitconf_t xecfg;
2166
2167                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2168                        die("unable to read files to diff");
2169
2170                memset(&xpp, 0, sizeof(xpp));
2171                memset(&xecfg, 0, sizeof(xecfg));
2172                xpp.flags = o->xdl_opts;
2173                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2174                              &xpp, &xecfg);
2175        }
2176
2177        diff_free_filespec_data(one);
2178        diff_free_filespec_data(two);
2179}
2180
2181static void builtin_checkdiff(const char *name_a, const char *name_b,
2182                              const char *attr_path,
2183                              struct diff_filespec *one,
2184                              struct diff_filespec *two,
2185                              struct diff_options *o)
2186{
2187        mmfile_t mf1, mf2;
2188        struct checkdiff_t data;
2189
2190        if (!two)
2191                return;
2192
2193        memset(&data, 0, sizeof(data));
2194        data.filename = name_b ? name_b : name_a;
2195        data.lineno = 0;
2196        data.o = o;
2197        data.ws_rule = whitespace_rule(attr_path);
2198        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2199
2200        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2201                die("unable to read files to diff");
2202
2203        /*
2204         * All the other codepaths check both sides, but not checking
2205         * the "old" side here is deliberate.  We are checking the newly
2206         * introduced changes, and as long as the "new" side is text, we
2207         * can and should check what it introduces.
2208         */
2209        if (diff_filespec_is_binary(two))
2210                goto free_and_return;
2211        else {
2212                /* Crazy xdl interfaces.. */
2213                xpparam_t xpp;
2214                xdemitconf_t xecfg;
2215
2216                memset(&xpp, 0, sizeof(xpp));
2217                memset(&xecfg, 0, sizeof(xecfg));
2218                xecfg.ctxlen = 1; /* at least one context line */
2219                xpp.flags = 0;
2220                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2221                              &xpp, &xecfg);
2222
2223                if (data.ws_rule & WS_BLANK_AT_EOF) {
2224                        struct emit_callback ecbdata;
2225                        int blank_at_eof;
2226
2227                        ecbdata.ws_rule = data.ws_rule;
2228                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2229                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2230
2231                        if (blank_at_eof) {
2232                                static char *err;
2233                                if (!err)
2234                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2235                                fprintf(o->file, "%s:%d: %s.\n",
2236                                        data.filename, blank_at_eof, err);
2237                                data.status = 1; /* report errors */
2238                        }
2239                }
2240        }
2241 free_and_return:
2242        diff_free_filespec_data(one);
2243        diff_free_filespec_data(two);
2244        if (data.status)
2245                DIFF_OPT_SET(o, CHECK_FAILED);
2246}
2247
2248struct diff_filespec *alloc_filespec(const char *path)
2249{
2250        int namelen = strlen(path);
2251        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2252
2253        memset(spec, 0, sizeof(*spec));
2254        spec->path = (char *)(spec + 1);
2255        memcpy(spec->path, path, namelen+1);
2256        spec->count = 1;
2257        spec->is_binary = -1;
2258        return spec;
2259}
2260
2261void free_filespec(struct diff_filespec *spec)
2262{
2263        if (!--spec->count) {
2264                diff_free_filespec_data(spec);
2265                free(spec);
2266        }
2267}
2268
2269void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2270                   unsigned short mode)
2271{
2272        if (mode) {
2273                spec->mode = canon_mode(mode);
2274                hashcpy(spec->sha1, sha1);
2275                spec->sha1_valid = !is_null_sha1(sha1);
2276        }
2277}
2278
2279/*
2280 * Given a name and sha1 pair, if the index tells us the file in
2281 * the work tree has that object contents, return true, so that
2282 * prepare_temp_file() does not have to inflate and extract.
2283 */
2284static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2285{
2286        struct cache_entry *ce;
2287        struct stat st;
2288        int pos, len;
2289
2290        /*
2291         * We do not read the cache ourselves here, because the
2292         * benchmark with my previous version that always reads cache
2293         * shows that it makes things worse for diff-tree comparing
2294         * two linux-2.6 kernel trees in an already checked out work
2295         * tree.  This is because most diff-tree comparisons deal with
2296         * only a small number of files, while reading the cache is
2297         * expensive for a large project, and its cost outweighs the
2298         * savings we get by not inflating the object to a temporary
2299         * file.  Practically, this code only helps when we are used
2300         * by diff-cache --cached, which does read the cache before
2301         * calling us.
2302         */
2303        if (!active_cache)
2304                return 0;
2305
2306        /* We want to avoid the working directory if our caller
2307         * doesn't need the data in a normal file, this system
2308         * is rather slow with its stat/open/mmap/close syscalls,
2309         * and the object is contained in a pack file.  The pack
2310         * is probably already open and will be faster to obtain
2311         * the data through than the working directory.  Loose
2312         * objects however would tend to be slower as they need
2313         * to be individually opened and inflated.
2314         */
2315        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2316                return 0;
2317
2318        len = strlen(name);
2319        pos = cache_name_pos(name, len);
2320        if (pos < 0)
2321                return 0;
2322        ce = active_cache[pos];
2323
2324        /*
2325         * This is not the sha1 we are looking for, or
2326         * unreusable because it is not a regular file.
2327         */
2328        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2329                return 0;
2330
2331        /*
2332         * If ce is marked as "assume unchanged", there is no
2333         * guarantee that work tree matches what we are looking for.
2334         */
2335        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2336                return 0;
2337
2338        /*
2339         * If ce matches the file in the work tree, we can reuse it.
2340         */
2341        if (ce_uptodate(ce) ||
2342            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2343                return 1;
2344
2345        return 0;
2346}
2347
2348static int populate_from_stdin(struct diff_filespec *s)
2349{
2350        struct strbuf buf = STRBUF_INIT;
2351        size_t size = 0;
2352
2353        if (strbuf_read(&buf, 0, 0) < 0)
2354                return error("error while reading from stdin %s",
2355                                     strerror(errno));
2356
2357        s->should_munmap = 0;
2358        s->data = strbuf_detach(&buf, &size);
2359        s->size = size;
2360        s->should_free = 1;
2361        return 0;
2362}
2363
2364static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2365{
2366        int len;
2367        char *data = xmalloc(100), *dirty = "";
2368
2369        /* Are we looking at the work tree? */
2370        if (s->dirty_submodule)
2371                dirty = "-dirty";
2372
2373        len = snprintf(data, 100,
2374                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2375        s->data = data;
2376        s->size = len;
2377        s->should_free = 1;
2378        if (size_only) {
2379                s->data = NULL;
2380                free(data);
2381        }
2382        return 0;
2383}
2384
2385/*
2386 * While doing rename detection and pickaxe operation, we may need to
2387 * grab the data for the blob (or file) for our own in-core comparison.
2388 * diff_filespec has data and size fields for this purpose.
2389 */
2390int diff_populate_filespec(struct diff_filespec *s, int size_only)
2391{
2392        int err = 0;
2393        if (!DIFF_FILE_VALID(s))
2394                die("internal error: asking to populate invalid file.");
2395        if (S_ISDIR(s->mode))
2396                return -1;
2397
2398        if (s->data)
2399                return 0;
2400
2401        if (size_only && 0 < s->size)
2402                return 0;
2403
2404        if (S_ISGITLINK(s->mode))
2405                return diff_populate_gitlink(s, size_only);
2406
2407        if (!s->sha1_valid ||
2408            reuse_worktree_file(s->path, s->sha1, 0)) {
2409                struct strbuf buf = STRBUF_INIT;
2410                struct stat st;
2411                int fd;
2412
2413                if (!strcmp(s->path, "-"))
2414                        return populate_from_stdin(s);
2415
2416                if (lstat(s->path, &st) < 0) {
2417                        if (errno == ENOENT) {
2418                        err_empty:
2419                                err = -1;
2420                        empty:
2421                                s->data = (char *)"";
2422                                s->size = 0;
2423                                return err;
2424                        }
2425                }
2426                s->size = xsize_t(st.st_size);
2427                if (!s->size)
2428                        goto empty;
2429                if (S_ISLNK(st.st_mode)) {
2430                        struct strbuf sb = STRBUF_INIT;
2431
2432                        if (strbuf_readlink(&sb, s->path, s->size))
2433                                goto err_empty;
2434                        s->size = sb.len;
2435                        s->data = strbuf_detach(&sb, NULL);
2436                        s->should_free = 1;
2437                        return 0;
2438                }
2439                if (size_only)
2440                        return 0;
2441                fd = open(s->path, O_RDONLY);
2442                if (fd < 0)
2443                        goto err_empty;
2444                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2445                close(fd);
2446                s->should_munmap = 1;
2447
2448                /*
2449                 * Convert from working tree format to canonical git format
2450                 */
2451                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2452                        size_t size = 0;
2453                        munmap(s->data, s->size);
2454                        s->should_munmap = 0;
2455                        s->data = strbuf_detach(&buf, &size);
2456                        s->size = size;
2457                        s->should_free = 1;
2458                }
2459        }
2460        else {
2461                enum object_type type;
2462                if (size_only) {
2463                        type = sha1_object_info(s->sha1, &s->size);
2464                        if (type < 0)
2465                                die("unable to read %s", sha1_to_hex(s->sha1));
2466                } else {
2467                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2468                        if (!s->data)
2469                                die("unable to read %s", sha1_to_hex(s->sha1));
2470                        s->should_free = 1;
2471                }
2472        }
2473        return 0;
2474}
2475
2476void diff_free_filespec_blob(struct diff_filespec *s)
2477{
2478        if (s->should_free)
2479                free(s->data);
2480        else if (s->should_munmap)
2481                munmap(s->data, s->size);
2482
2483        if (s->should_free || s->should_munmap) {
2484                s->should_free = s->should_munmap = 0;
2485                s->data = NULL;
2486        }
2487}
2488
2489void diff_free_filespec_data(struct diff_filespec *s)
2490{
2491        diff_free_filespec_blob(s);
2492        free(s->cnt_data);
2493        s->cnt_data = NULL;
2494}
2495
2496static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2497                           void *blob,
2498                           unsigned long size,
2499                           const unsigned char *sha1,
2500                           int mode)
2501{
2502        int fd;
2503        struct strbuf buf = STRBUF_INIT;
2504        struct strbuf template = STRBUF_INIT;
2505        char *path_dup = xstrdup(path);
2506        const char *base = basename(path_dup);
2507
2508        /* Generate "XXXXXX_basename.ext" */
2509        strbuf_addstr(&template, "XXXXXX_");
2510        strbuf_addstr(&template, base);
2511
2512        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2513                        strlen(base) + 1);
2514        if (fd < 0)
2515                die_errno("unable to create temp-file");
2516        if (convert_to_working_tree(path,
2517                        (const char *)blob, (size_t)size, &buf)) {
2518                blob = buf.buf;
2519                size = buf.len;
2520        }
2521        if (write_in_full(fd, blob, size) != size)
2522                die_errno("unable to write temp-file");
2523        close(fd);
2524        temp->name = temp->tmp_path;
2525        strcpy(temp->hex, sha1_to_hex(sha1));
2526        temp->hex[40] = 0;
2527        sprintf(temp->mode, "%06o", mode);
2528        strbuf_release(&buf);
2529        strbuf_release(&template);
2530        free(path_dup);
2531}
2532
2533static struct diff_tempfile *prepare_temp_file(const char *name,
2534                struct diff_filespec *one)
2535{
2536        struct diff_tempfile *temp = claim_diff_tempfile();
2537
2538        if (!DIFF_FILE_VALID(one)) {
2539        not_a_valid_file:
2540                /* A '-' entry produces this for file-2, and
2541                 * a '+' entry produces this for file-1.
2542                 */
2543                temp->name = "/dev/null";
2544                strcpy(temp->hex, ".");
2545                strcpy(temp->mode, ".");
2546                return temp;
2547        }
2548
2549        if (!remove_tempfile_installed) {
2550                atexit(remove_tempfile);
2551                sigchain_push_common(remove_tempfile_on_signal);
2552                remove_tempfile_installed = 1;
2553        }
2554
2555        if (!one->sha1_valid ||
2556            reuse_worktree_file(name, one->sha1, 1)) {
2557                struct stat st;
2558                if (lstat(name, &st) < 0) {
2559                        if (errno == ENOENT)
2560                                goto not_a_valid_file;
2561                        die_errno("stat(%s)", name);
2562                }
2563                if (S_ISLNK(st.st_mode)) {
2564                        struct strbuf sb = STRBUF_INIT;
2565                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2566                                die_errno("readlink(%s)", name);
2567                        prep_temp_blob(name, temp, sb.buf, sb.len,
2568                                       (one->sha1_valid ?
2569                                        one->sha1 : null_sha1),
2570                                       (one->sha1_valid ?
2571                                        one->mode : S_IFLNK));
2572                        strbuf_release(&sb);
2573                }
2574                else {
2575                        /* we can borrow from the file in the work tree */
2576                        temp->name = name;
2577                        if (!one->sha1_valid)
2578                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2579                        else
2580                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2581                        /* Even though we may sometimes borrow the
2582                         * contents from the work tree, we always want
2583                         * one->mode.  mode is trustworthy even when
2584                         * !(one->sha1_valid), as long as
2585                         * DIFF_FILE_VALID(one).
2586                         */
2587                        sprintf(temp->mode, "%06o", one->mode);
2588                }
2589                return temp;
2590        }
2591        else {
2592                if (diff_populate_filespec(one, 0))
2593                        die("cannot read data blob for %s", one->path);
2594                prep_temp_blob(name, temp, one->data, one->size,
2595                               one->sha1, one->mode);
2596        }
2597        return temp;
2598}
2599
2600/* An external diff command takes:
2601 *
2602 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2603 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2604 *
2605 */
2606static void run_external_diff(const char *pgm,
2607                              const char *name,
2608                              const char *other,
2609                              struct diff_filespec *one,
2610                              struct diff_filespec *two,
2611                              const char *xfrm_msg,
2612                              int complete_rewrite)
2613{
2614        const char *spawn_arg[10];
2615        int retval;
2616        const char **arg = &spawn_arg[0];
2617
2618        if (one && two) {
2619                struct diff_tempfile *temp_one, *temp_two;
2620                const char *othername = (other ? other : name);
2621                temp_one = prepare_temp_file(name, one);
2622                temp_two = prepare_temp_file(othername, two);
2623                *arg++ = pgm;
2624                *arg++ = name;
2625                *arg++ = temp_one->name;
2626                *arg++ = temp_one->hex;
2627                *arg++ = temp_one->mode;
2628                *arg++ = temp_two->name;
2629                *arg++ = temp_two->hex;
2630                *arg++ = temp_two->mode;
2631                if (other) {
2632                        *arg++ = other;
2633                        *arg++ = xfrm_msg;
2634                }
2635        } else {
2636                *arg++ = pgm;
2637                *arg++ = name;
2638        }
2639        *arg = NULL;
2640        fflush(NULL);
2641        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2642        remove_tempfile();
2643        if (retval) {
2644                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2645                exit(1);
2646        }
2647}
2648
2649static int similarity_index(struct diff_filepair *p)
2650{
2651        return p->score * 100 / MAX_SCORE;
2652}
2653
2654static void fill_metainfo(struct strbuf *msg,
2655                          const char *name,
2656                          const char *other,
2657                          struct diff_filespec *one,
2658                          struct diff_filespec *two,
2659                          struct diff_options *o,
2660                          struct diff_filepair *p,
2661                          int *must_show_header,
2662                          int use_color)
2663{
2664        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2665        const char *reset = diff_get_color(use_color, DIFF_RESET);
2666        struct strbuf *msgbuf;
2667        char *line_prefix = "";
2668
2669        *must_show_header = 1;
2670        if (o->output_prefix) {
2671                msgbuf = o->output_prefix(o, o->output_prefix_data);
2672                line_prefix = msgbuf->buf;
2673        }
2674        strbuf_init(msg, PATH_MAX * 2 + 300);
2675        switch (p->status) {
2676        case DIFF_STATUS_COPIED:
2677                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2678                            line_prefix, set, similarity_index(p));
2679                strbuf_addf(msg, "%s\n%s%scopy from ",
2680                            reset,  line_prefix, set);
2681                quote_c_style(name, msg, NULL, 0);
2682                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2683                quote_c_style(other, msg, NULL, 0);
2684                strbuf_addf(msg, "%s\n", reset);
2685                break;
2686        case DIFF_STATUS_RENAMED:
2687                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2688                            line_prefix, set, similarity_index(p));
2689                strbuf_addf(msg, "%s\n%s%srename from ",
2690                            reset, line_prefix, set);
2691                quote_c_style(name, msg, NULL, 0);
2692                strbuf_addf(msg, "%s\n%s%srename to ",
2693                            reset, line_prefix, set);
2694                quote_c_style(other, msg, NULL, 0);
2695                strbuf_addf(msg, "%s\n", reset);
2696                break;
2697        case DIFF_STATUS_MODIFIED:
2698                if (p->score) {
2699                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2700                                    line_prefix,
2701                                    set, similarity_index(p), reset);
2702                        break;
2703                }
2704                /* fallthru */
2705        default:
2706                *must_show_header = 0;
2707        }
2708        if (one && two && hashcmp(one->sha1, two->sha1)) {
2709                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2710
2711                if (DIFF_OPT_TST(o, BINARY)) {
2712                        mmfile_t mf;
2713                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2714                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2715                                abbrev = 40;
2716                }
2717                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2718                            find_unique_abbrev(one->sha1, abbrev));
2719                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2720                if (one->mode == two->mode)
2721                        strbuf_addf(msg, " %06o", one->mode);
2722                strbuf_addf(msg, "%s\n", reset);
2723        }
2724}
2725
2726static void run_diff_cmd(const char *pgm,
2727                         const char *name,
2728                         const char *other,
2729                         const char *attr_path,
2730                         struct diff_filespec *one,
2731                         struct diff_filespec *two,
2732                         struct strbuf *msg,
2733                         struct diff_options *o,
2734                         struct diff_filepair *p)
2735{
2736        const char *xfrm_msg = NULL;
2737        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2738        int must_show_header = 0;
2739
2740        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2741                pgm = NULL;
2742        else {
2743                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2744                if (drv && drv->external)
2745                        pgm = drv->external;
2746        }
2747
2748        if (msg) {
2749                /*
2750                 * don't use colors when the header is intended for an
2751                 * external diff driver
2752                 */
2753                fill_metainfo(msg, name, other, one, two, o, p,
2754                              &must_show_header,
2755                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2756                xfrm_msg = msg->len ? msg->buf : NULL;
2757        }
2758
2759        if (pgm) {
2760                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2761                                  complete_rewrite);
2762                return;
2763        }
2764        if (one && two)
2765                builtin_diff(name, other ? other : name,
2766                             one, two, xfrm_msg, must_show_header,
2767                             o, complete_rewrite);
2768        else
2769                fprintf(o->file, "* Unmerged path %s\n", name);
2770}
2771
2772static void diff_fill_sha1_info(struct diff_filespec *one)
2773{
2774        if (DIFF_FILE_VALID(one)) {
2775                if (!one->sha1_valid) {
2776                        struct stat st;
2777                        if (!strcmp(one->path, "-")) {
2778                                hashcpy(one->sha1, null_sha1);
2779                                return;
2780                        }
2781                        if (lstat(one->path, &st) < 0)
2782                                die_errno("stat '%s'", one->path);
2783                        if (index_path(one->sha1, one->path, &st, 0))
2784                                die("cannot hash %s", one->path);
2785                }
2786        }
2787        else
2788                hashclr(one->sha1);
2789}
2790
2791static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2792{
2793        /* Strip the prefix but do not molest /dev/null and absolute paths */
2794        if (*namep && **namep != '/') {
2795                *namep += prefix_length;
2796                if (**namep == '/')
2797                        ++*namep;
2798        }
2799        if (*otherp && **otherp != '/') {
2800                *otherp += prefix_length;
2801                if (**otherp == '/')
2802                        ++*otherp;
2803        }
2804}
2805
2806static void run_diff(struct diff_filepair *p, struct diff_options *o)
2807{
2808        const char *pgm = external_diff();
2809        struct strbuf msg;
2810        struct diff_filespec *one = p->one;
2811        struct diff_filespec *two = p->two;
2812        const char *name;
2813        const char *other;
2814        const char *attr_path;
2815
2816        name  = p->one->path;
2817        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2818        attr_path = name;
2819        if (o->prefix_length)
2820                strip_prefix(o->prefix_length, &name, &other);
2821
2822        if (DIFF_PAIR_UNMERGED(p)) {
2823                run_diff_cmd(pgm, name, NULL, attr_path,
2824                             NULL, NULL, NULL, o, p);
2825                return;
2826        }
2827
2828        diff_fill_sha1_info(one);
2829        diff_fill_sha1_info(two);
2830
2831        if (!pgm &&
2832            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2833            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2834                /*
2835                 * a filepair that changes between file and symlink
2836                 * needs to be split into deletion and creation.
2837                 */
2838                struct diff_filespec *null = alloc_filespec(two->path);
2839                run_diff_cmd(NULL, name, other, attr_path,
2840                             one, null, &msg, o, p);
2841                free(null);
2842                strbuf_release(&msg);
2843
2844                null = alloc_filespec(one->path);
2845                run_diff_cmd(NULL, name, other, attr_path,
2846                             null, two, &msg, o, p);
2847                free(null);
2848        }
2849        else
2850                run_diff_cmd(pgm, name, other, attr_path,
2851                             one, two, &msg, o, p);
2852
2853        strbuf_release(&msg);
2854}
2855
2856static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2857                         struct diffstat_t *diffstat)
2858{
2859        const char *name;
2860        const char *other;
2861        int complete_rewrite = 0;
2862
2863        if (DIFF_PAIR_UNMERGED(p)) {
2864                /* unmerged */
2865                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2866                return;
2867        }
2868
2869        name = p->one->path;
2870        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2871
2872        if (o->prefix_length)
2873                strip_prefix(o->prefix_length, &name, &other);
2874
2875        diff_fill_sha1_info(p->one);
2876        diff_fill_sha1_info(p->two);
2877
2878        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2879                complete_rewrite = 1;
2880        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2881}
2882
2883static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2884{
2885        const char *name;
2886        const char *other;
2887        const char *attr_path;
2888
2889        if (DIFF_PAIR_UNMERGED(p)) {
2890                /* unmerged */
2891                return;
2892        }
2893
2894        name = p->one->path;
2895        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2896        attr_path = other ? other : name;
2897
2898        if (o->prefix_length)
2899                strip_prefix(o->prefix_length, &name, &other);
2900
2901        diff_fill_sha1_info(p->one);
2902        diff_fill_sha1_info(p->two);
2903
2904        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2905}
2906
2907void diff_setup(struct diff_options *options)
2908{
2909        memcpy(options, &default_diff_options, sizeof(*options));
2910
2911        options->file = stdout;
2912
2913        options->line_termination = '\n';
2914        options->break_opt = -1;
2915        options->rename_limit = -1;
2916        options->dirstat_percent = 3;
2917        options->context = 3;
2918
2919        options->change = diff_change;
2920        options->add_remove = diff_addremove;
2921        if (diff_use_color_default > 0)
2922                DIFF_OPT_SET(options, COLOR_DIFF);
2923        options->detect_rename = diff_detect_rename_default;
2924
2925        if (diff_no_prefix) {
2926                options->a_prefix = options->b_prefix = "";
2927        } else if (!diff_mnemonic_prefix) {
2928                options->a_prefix = "a/";
2929                options->b_prefix = "b/";
2930        }
2931}
2932
2933int diff_setup_done(struct diff_options *options)
2934{
2935        int count = 0;
2936
2937        if (options->output_format & DIFF_FORMAT_NAME)
2938                count++;
2939        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2940                count++;
2941        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2942                count++;
2943        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2944                count++;
2945        if (count > 1)
2946                die("--name-only, --name-status, --check and -s are mutually exclusive");
2947
2948        /*
2949         * Most of the time we can say "there are changes"
2950         * only by checking if there are changed paths, but
2951         * --ignore-whitespace* options force us to look
2952         * inside contents.
2953         */
2954
2955        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2956            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2957            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2958                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2959        else
2960                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2961
2962        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2963                options->detect_rename = DIFF_DETECT_COPY;
2964
2965        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2966                options->prefix = NULL;
2967        if (options->prefix)
2968                options->prefix_length = strlen(options->prefix);
2969        else
2970                options->prefix_length = 0;
2971
2972        if (options->output_format & (DIFF_FORMAT_NAME |
2973                                      DIFF_FORMAT_NAME_STATUS |
2974                                      DIFF_FORMAT_CHECKDIFF |
2975                                      DIFF_FORMAT_NO_OUTPUT))
2976                options->output_format &= ~(DIFF_FORMAT_RAW |
2977                                            DIFF_FORMAT_NUMSTAT |
2978                                            DIFF_FORMAT_DIFFSTAT |
2979                                            DIFF_FORMAT_SHORTSTAT |
2980                                            DIFF_FORMAT_DIRSTAT |
2981                                            DIFF_FORMAT_SUMMARY |
2982                                            DIFF_FORMAT_PATCH);
2983
2984        /*
2985         * These cases always need recursive; we do not drop caller-supplied
2986         * recursive bits for other formats here.
2987         */
2988        if (options->output_format & (DIFF_FORMAT_PATCH |
2989                                      DIFF_FORMAT_NUMSTAT |
2990                                      DIFF_FORMAT_DIFFSTAT |
2991                                      DIFF_FORMAT_SHORTSTAT |
2992                                      DIFF_FORMAT_DIRSTAT |
2993                                      DIFF_FORMAT_SUMMARY |
2994                                      DIFF_FORMAT_CHECKDIFF))
2995                DIFF_OPT_SET(options, RECURSIVE);
2996        /*
2997         * Also pickaxe would not work very well if you do not say recursive
2998         */
2999        if (options->pickaxe)
3000                DIFF_OPT_SET(options, RECURSIVE);
3001        /*
3002         * When patches are generated, submodules diffed against the work tree
3003         * must be checked for dirtiness too so it can be shown in the output
3004         */
3005        if (options->output_format & DIFF_FORMAT_PATCH)
3006                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3007
3008        if (options->detect_rename && options->rename_limit < 0)
3009                options->rename_limit = diff_rename_limit_default;
3010        if (options->setup & DIFF_SETUP_USE_CACHE) {
3011                if (!active_cache)
3012                        /* read-cache does not die even when it fails
3013                         * so it is safe for us to do this here.  Also
3014                         * it does not smudge active_cache or active_nr
3015                         * when it fails, so we do not have to worry about
3016                         * cleaning it up ourselves either.
3017                         */
3018                        read_cache();
3019        }
3020        if (options->abbrev <= 0 || 40 < options->abbrev)
3021                options->abbrev = 40; /* full */
3022
3023        /*
3024         * It does not make sense to show the first hit we happened
3025         * to have found.  It does not make sense not to return with
3026         * exit code in such a case either.
3027         */
3028        if (DIFF_OPT_TST(options, QUICK)) {
3029                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3030                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3031        }
3032
3033        return 0;
3034}
3035
3036static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3037{
3038        char c, *eq;
3039        int len;
3040
3041        if (*arg != '-')
3042                return 0;
3043        c = *++arg;
3044        if (!c)
3045                return 0;
3046        if (c == arg_short) {
3047                c = *++arg;
3048                if (!c)
3049                        return 1;
3050                if (val && isdigit(c)) {
3051                        char *end;
3052                        int n = strtoul(arg, &end, 10);
3053                        if (*end)
3054                                return 0;
3055                        *val = n;
3056                        return 1;
3057                }
3058                return 0;
3059        }
3060        if (c != '-')
3061                return 0;
3062        arg++;
3063        eq = strchr(arg, '=');
3064        if (eq)
3065                len = eq - arg;
3066        else
3067                len = strlen(arg);
3068        if (!len || strncmp(arg, arg_long, len))
3069                return 0;
3070        if (eq) {
3071                int n;
3072                char *end;
3073                if (!isdigit(*++eq))
3074                        return 0;
3075                n = strtoul(eq, &end, 10);
3076                if (*end)
3077                        return 0;
3078                *val = n;
3079        }
3080        return 1;
3081}
3082
3083static int diff_scoreopt_parse(const char *opt);
3084
3085static inline int short_opt(char opt, const char **argv,
3086                            const char **optarg)
3087{
3088        const char *arg = argv[0];
3089        if (arg[0] != '-' || arg[1] != opt)
3090                return 0;
3091        if (arg[2] != '\0') {
3092                *optarg = arg + 2;
3093                return 1;
3094        }
3095        if (!argv[1])
3096                die("Option '%c' requires a value", opt);
3097        *optarg = argv[1];
3098        return 2;
3099}
3100
3101int parse_long_opt(const char *opt, const char **argv,
3102                   const char **optarg)
3103{
3104        const char *arg = argv[0];
3105        if (arg[0] != '-' || arg[1] != '-')
3106                return 0;
3107        arg += strlen("--");
3108        if (prefixcmp(arg, opt))
3109                return 0;
3110        arg += strlen(opt);
3111        if (*arg == '=') { /* sticked form: --option=value */
3112                *optarg = arg + 1;
3113                return 1;
3114        }
3115        if (*arg != '\0')
3116                return 0;
3117        /* separate form: --option value */
3118        if (!argv[1])
3119                die("Option '--%s' requires a value", opt);
3120        *optarg = argv[1];
3121        return 2;
3122}
3123
3124static int stat_opt(struct diff_options *options, const char **av)
3125{
3126        const char *arg = av[0];
3127        char *end;
3128        int width = options->stat_width;
3129        int name_width = options->stat_name_width;
3130        int count = options->stat_count;
3131        int argcount = 1;
3132
3133        arg += strlen("--stat");
3134        end = (char *)arg;
3135
3136        switch (*arg) {
3137        case '-':
3138                if (!prefixcmp(arg, "-width")) {
3139                        arg += strlen("-width");
3140                        if (*arg == '=')
3141                                width = strtoul(arg + 1, &end, 10);
3142                        else if (!*arg && !av[1])
3143                                die("Option '--stat-width' requires a value");
3144                        else if (!*arg) {
3145                                width = strtoul(av[1], &end, 10);
3146                                argcount = 2;
3147                        }
3148                } else if (!prefixcmp(arg, "-name-width")) {
3149                        arg += strlen("-name-width");
3150                        if (*arg == '=')
3151                                name_width = strtoul(arg + 1, &end, 10);
3152                        else if (!*arg && !av[1])
3153                                die("Option '--stat-name-width' requires a value");
3154                        else if (!*arg) {
3155                                name_width = strtoul(av[1], &end, 10);
3156                                argcount = 2;
3157                        }
3158                } else if (!prefixcmp(arg, "-count")) {
3159                        arg += strlen("-count");
3160                        if (*arg == '=')
3161                                count = strtoul(arg + 1, &end, 10);
3162                        else if (!*arg && !av[1])
3163                                die("Option '--stat-count' requires a value");
3164                        else if (!*arg) {
3165                                count = strtoul(av[1], &end, 10);
3166                                argcount = 2;
3167                        }
3168                }
3169                break;
3170        case '=':
3171                width = strtoul(arg+1, &end, 10);
3172                if (*end == ',')
3173                        name_width = strtoul(end+1, &end, 10);
3174                if (*end == ',')
3175                        count = strtoul(end+1, &end, 10);
3176        }
3177
3178        /* Important! This checks all the error cases! */
3179        if (*end)
3180                return 0;
3181        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3182        options->stat_name_width = name_width;
3183        options->stat_width = width;
3184        options->stat_count = count;
3185        return argcount;
3186}
3187
3188int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3189{
3190        const char *arg = av[0];
3191        const char *optarg;
3192        int argcount;
3193
3194        /* Output format options */
3195        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3196                options->output_format |= DIFF_FORMAT_PATCH;
3197        else if (opt_arg(arg, 'U', "unified", &options->context))
3198                options->output_format |= DIFF_FORMAT_PATCH;
3199        else if (!strcmp(arg, "--raw"))
3200                options->output_format |= DIFF_FORMAT_RAW;
3201        else if (!strcmp(arg, "--patch-with-raw"))
3202                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3203        else if (!strcmp(arg, "--numstat"))
3204                options->output_format |= DIFF_FORMAT_NUMSTAT;
3205        else if (!strcmp(arg, "--shortstat"))
3206                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3207        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3208                options->output_format |= DIFF_FORMAT_DIRSTAT;
3209        else if (!strcmp(arg, "--cumulative")) {
3210                options->output_format |= DIFF_FORMAT_DIRSTAT;
3211                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3212        } else if (opt_arg(arg, 0, "dirstat-by-file",
3213                           &options->dirstat_percent)) {
3214                options->output_format |= DIFF_FORMAT_DIRSTAT;
3215                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3216        }
3217        else if (!strcmp(arg, "--check"))
3218                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3219        else if (!strcmp(arg, "--summary"))
3220                options->output_format |= DIFF_FORMAT_SUMMARY;
3221        else if (!strcmp(arg, "--patch-with-stat"))
3222                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3223        else if (!strcmp(arg, "--name-only"))
3224                options->output_format |= DIFF_FORMAT_NAME;
3225        else if (!strcmp(arg, "--name-status"))
3226                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3227        else if (!strcmp(arg, "-s"))
3228                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3229        else if (!prefixcmp(arg, "--stat"))
3230                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3231                return stat_opt(options, av);
3232
3233        /* renames options */
3234        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3235                 !strcmp(arg, "--break-rewrites")) {
3236                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3237                        return error("invalid argument to -B: %s", arg+2);
3238        }
3239        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3240                 !strcmp(arg, "--find-renames")) {
3241                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3242                        return error("invalid argument to -M: %s", arg+2);
3243                options->detect_rename = DIFF_DETECT_RENAME;
3244        }
3245        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3246                options->irreversible_delete = 1;
3247        }
3248        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3249                 !strcmp(arg, "--find-copies")) {
3250                if (options->detect_rename == DIFF_DETECT_COPY)
3251                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3252                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3253                        return error("invalid argument to -C: %s", arg+2);
3254                options->detect_rename = DIFF_DETECT_COPY;
3255        }
3256        else if (!strcmp(arg, "--no-renames"))
3257                options->detect_rename = 0;
3258        else if (!strcmp(arg, "--relative"))
3259                DIFF_OPT_SET(options, RELATIVE_NAME);
3260        else if (!prefixcmp(arg, "--relative=")) {
3261                DIFF_OPT_SET(options, RELATIVE_NAME);
3262                options->prefix = arg + 11;
3263        }
3264
3265        /* xdiff options */
3266        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3267                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3268        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3269                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3270        else if (!strcmp(arg, "--ignore-space-at-eol"))
3271                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3272        else if (!strcmp(arg, "--patience"))
3273                DIFF_XDL_SET(options, PATIENCE_DIFF);
3274
3275        /* flags options */
3276        else if (!strcmp(arg, "--binary")) {
3277                options->output_format |= DIFF_FORMAT_PATCH;
3278                DIFF_OPT_SET(options, BINARY);
3279        }
3280        else if (!strcmp(arg, "--full-index"))
3281                DIFF_OPT_SET(options, FULL_INDEX);
3282        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3283                DIFF_OPT_SET(options, TEXT);
3284        else if (!strcmp(arg, "-R"))
3285                DIFF_OPT_SET(options, REVERSE_DIFF);
3286        else if (!strcmp(arg, "--find-copies-harder"))
3287                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3288        else if (!strcmp(arg, "--follow"))
3289                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3290        else if (!strcmp(arg, "--color"))
3291                DIFF_OPT_SET(options, COLOR_DIFF);
3292        else if (!prefixcmp(arg, "--color=")) {
3293                int value = git_config_colorbool(NULL, arg+8, -1);
3294                if (value == 0)
3295                        DIFF_OPT_CLR(options, COLOR_DIFF);
3296                else if (value > 0)
3297                        DIFF_OPT_SET(options, COLOR_DIFF);
3298                else
3299                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3300        }
3301        else if (!strcmp(arg, "--no-color"))
3302                DIFF_OPT_CLR(options, COLOR_DIFF);
3303        else if (!strcmp(arg, "--color-words")) {
3304                DIFF_OPT_SET(options, COLOR_DIFF);
3305                options->word_diff = DIFF_WORDS_COLOR;
3306        }
3307        else if (!prefixcmp(arg, "--color-words=")) {
3308                DIFF_OPT_SET(options, COLOR_DIFF);
3309                options->word_diff = DIFF_WORDS_COLOR;
3310                options->word_regex = arg + 14;
3311        }
3312        else if (!strcmp(arg, "--word-diff")) {
3313                if (options->word_diff == DIFF_WORDS_NONE)
3314                        options->word_diff = DIFF_WORDS_PLAIN;
3315        }
3316        else if (!prefixcmp(arg, "--word-diff=")) {
3317                const char *type = arg + 12;
3318                if (!strcmp(type, "plain"))
3319                        options->word_diff = DIFF_WORDS_PLAIN;
3320                else if (!strcmp(type, "color")) {
3321                        DIFF_OPT_SET(options, COLOR_DIFF);
3322                        options->word_diff = DIFF_WORDS_COLOR;
3323                }
3324                else if (!strcmp(type, "porcelain"))
3325                        options->word_diff = DIFF_WORDS_PORCELAIN;
3326                else if (!strcmp(type, "none"))
3327                        options->word_diff = DIFF_WORDS_NONE;
3328                else
3329                        die("bad --word-diff argument: %s", type);
3330        }
3331        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3332                if (options->word_diff == DIFF_WORDS_NONE)
3333                        options->word_diff = DIFF_WORDS_PLAIN;
3334                options->word_regex = optarg;
3335                return argcount;
3336        }
3337        else if (!strcmp(arg, "--exit-code"))
3338                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3339        else if (!strcmp(arg, "--quiet"))
3340                DIFF_OPT_SET(options, QUICK);
3341        else if (!strcmp(arg, "--ext-diff"))
3342                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3343        else if (!strcmp(arg, "--no-ext-diff"))
3344                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3345        else if (!strcmp(arg, "--textconv"))
3346                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3347        else if (!strcmp(arg, "--no-textconv"))
3348                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3349        else if (!strcmp(arg, "--ignore-submodules")) {
3350                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3351                handle_ignore_submodules_arg(options, "all");
3352        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3353                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3354                handle_ignore_submodules_arg(options, arg + 20);
3355        } else if (!strcmp(arg, "--submodule"))
3356                DIFF_OPT_SET(options, SUBMODULE_LOG);
3357        else if (!prefixcmp(arg, "--submodule=")) {
3358                if (!strcmp(arg + 12, "log"))
3359                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3360        }
3361
3362        /* misc options */
3363        else if (!strcmp(arg, "-z"))
3364                options->line_termination = 0;
3365        else if ((argcount = short_opt('l', av, &optarg))) {
3366                options->rename_limit = strtoul(optarg, NULL, 10);
3367                return argcount;
3368        }
3369        else if ((argcount = short_opt('S', av, &optarg))) {
3370                options->pickaxe = optarg;
3371                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3372                return argcount;
3373        } else if ((argcount = short_opt('G', av, &optarg))) {
3374                options->pickaxe = optarg;
3375                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3376                return argcount;
3377        }
3378        else if (!strcmp(arg, "--pickaxe-all"))
3379                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3380        else if (!strcmp(arg, "--pickaxe-regex"))
3381                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3382        else if ((argcount = short_opt('O', av, &optarg))) {
3383                options->orderfile = optarg;
3384                return argcount;
3385        }
3386        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3387                options->filter = optarg;
3388                return argcount;
3389        }
3390        else if (!strcmp(arg, "--abbrev"))
3391                options->abbrev = DEFAULT_ABBREV;
3392        else if (!prefixcmp(arg, "--abbrev=")) {
3393                options->abbrev = strtoul(arg + 9, NULL, 10);
3394                if (options->abbrev < MINIMUM_ABBREV)
3395                        options->abbrev = MINIMUM_ABBREV;
3396                else if (40 < options->abbrev)
3397                        options->abbrev = 40;
3398        }
3399        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3400                options->a_prefix = optarg;
3401                return argcount;
3402        }
3403        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3404                options->b_prefix = optarg;
3405                return argcount;
3406        }
3407        else if (!strcmp(arg, "--no-prefix"))
3408                options->a_prefix = options->b_prefix = "";
3409        else if (opt_arg(arg, '\0', "inter-hunk-context",
3410                         &options->interhunkcontext))
3411                ;
3412        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3413                options->file = fopen(optarg, "w");
3414                if (!options->file)
3415                        die_errno("Could not open '%s'", optarg);
3416                options->close_file = 1;
3417                return argcount;
3418        } else
3419                return 0;
3420        return 1;
3421}
3422
3423int parse_rename_score(const char **cp_p)
3424{
3425        unsigned long num, scale;
3426        int ch, dot;
3427        const char *cp = *cp_p;
3428
3429        num = 0;
3430        scale = 1;
3431        dot = 0;
3432        for (;;) {
3433                ch = *cp;
3434                if ( !dot && ch == '.' ) {
3435                        scale = 1;
3436                        dot = 1;
3437                } else if ( ch == '%' ) {
3438                        scale = dot ? scale*100 : 100;
3439                        cp++;   /* % is always at the end */
3440                        break;
3441                } else if ( ch >= '0' && ch <= '9' ) {
3442                        if ( scale < 100000 ) {
3443                                scale *= 10;
3444                                num = (num*10) + (ch-'0');
3445                        }
3446                } else {
3447                        break;
3448                }
3449                cp++;
3450        }
3451        *cp_p = cp;
3452
3453        /* user says num divided by scale and we say internally that
3454         * is MAX_SCORE * num / scale.
3455         */
3456        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3457}
3458
3459static int diff_scoreopt_parse(const char *opt)
3460{
3461        int opt1, opt2, cmd;
3462
3463        if (*opt++ != '-')
3464                return -1;
3465        cmd = *opt++;
3466        if (cmd == '-') {
3467                /* convert the long-form arguments into short-form versions */
3468                if (!prefixcmp(opt, "break-rewrites")) {
3469                        opt += strlen("break-rewrites");
3470                        if (*opt == 0 || *opt++ == '=')
3471                                cmd = 'B';
3472                } else if (!prefixcmp(opt, "find-copies")) {
3473                        opt += strlen("find-copies");
3474                        if (*opt == 0 || *opt++ == '=')
3475                                cmd = 'C';
3476                } else if (!prefixcmp(opt, "find-renames")) {
3477                        opt += strlen("find-renames");
3478                        if (*opt == 0 || *opt++ == '=')
3479                                cmd = 'M';
3480                }
3481        }
3482        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3483                return -1; /* that is not a -M, -C nor -B option */
3484
3485        opt1 = parse_rename_score(&opt);
3486        if (cmd != 'B')
3487                opt2 = 0;
3488        else {
3489                if (*opt == 0)
3490                        opt2 = 0;
3491                else if (*opt != '/')
3492                        return -1; /* we expect -B80/99 or -B80 */
3493                else {
3494                        opt++;
3495                        opt2 = parse_rename_score(&opt);
3496                }
3497        }
3498        if (*opt != 0)
3499                return -1;
3500        return opt1 | (opt2 << 16);
3501}
3502
3503struct diff_queue_struct diff_queued_diff;
3504
3505void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3506{
3507        if (queue->alloc <= queue->nr) {
3508                queue->alloc = alloc_nr(queue->alloc);
3509                queue->queue = xrealloc(queue->queue,
3510                                        sizeof(dp) * queue->alloc);
3511        }
3512        queue->queue[queue->nr++] = dp;
3513}
3514
3515struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3516                                 struct diff_filespec *one,
3517                                 struct diff_filespec *two)
3518{
3519        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3520        dp->one = one;
3521        dp->two = two;
3522        if (queue)
3523                diff_q(queue, dp);
3524        return dp;
3525}
3526
3527void diff_free_filepair(struct diff_filepair *p)
3528{
3529        free_filespec(p->one);
3530        free_filespec(p->two);
3531        free(p);
3532}
3533
3534/* This is different from find_unique_abbrev() in that
3535 * it stuffs the result with dots for alignment.
3536 */
3537const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3538{
3539        int abblen;
3540        const char *abbrev;
3541        if (len == 40)
3542                return sha1_to_hex(sha1);
3543
3544        abbrev = find_unique_abbrev(sha1, len);
3545        abblen = strlen(abbrev);
3546        if (abblen < 37) {
3547                static char hex[41];
3548                if (len < abblen && abblen <= len + 2)
3549                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3550                else
3551                        sprintf(hex, "%s...", abbrev);
3552                return hex;
3553        }
3554        return sha1_to_hex(sha1);
3555}
3556
3557static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3558{
3559        int line_termination = opt->line_termination;
3560        int inter_name_termination = line_termination ? '\t' : '\0';
3561        if (opt->output_prefix) {
3562                struct strbuf *msg = NULL;
3563                msg = opt->output_prefix(opt, opt->output_prefix_data);
3564                fprintf(opt->file, "%s", msg->buf);
3565        }
3566
3567        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3568                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3569                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3570                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3571        }
3572        if (p->score) {
3573                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3574                        inter_name_termination);
3575        } else {
3576                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3577        }
3578
3579        if (p->status == DIFF_STATUS_COPIED ||
3580            p->status == DIFF_STATUS_RENAMED) {
3581                const char *name_a, *name_b;
3582                name_a = p->one->path;
3583                name_b = p->two->path;
3584                strip_prefix(opt->prefix_length, &name_a, &name_b);
3585                write_name_quoted(name_a, opt->file, inter_name_termination);
3586                write_name_quoted(name_b, opt->file, line_termination);
3587        } else {
3588                const char *name_a, *name_b;
3589                name_a = p->one->mode ? p->one->path : p->two->path;
3590                name_b = NULL;
3591                strip_prefix(opt->prefix_length, &name_a, &name_b);
3592                write_name_quoted(name_a, opt->file, line_termination);
3593        }
3594}
3595
3596int diff_unmodified_pair(struct diff_filepair *p)
3597{
3598        /* This function is written stricter than necessary to support
3599         * the currently implemented transformers, but the idea is to
3600         * let transformers to produce diff_filepairs any way they want,
3601         * and filter and clean them up here before producing the output.
3602         */
3603        struct diff_filespec *one = p->one, *two = p->two;
3604
3605        if (DIFF_PAIR_UNMERGED(p))
3606                return 0; /* unmerged is interesting */
3607
3608        /* deletion, addition, mode or type change
3609         * and rename are all interesting.
3610         */
3611        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3612            DIFF_PAIR_MODE_CHANGED(p) ||
3613            strcmp(one->path, two->path))
3614                return 0;
3615
3616        /* both are valid and point at the same path.  that is, we are
3617         * dealing with a change.
3618         */
3619        if (one->sha1_valid && two->sha1_valid &&
3620            !hashcmp(one->sha1, two->sha1) &&
3621            !one->dirty_submodule && !two->dirty_submodule)
3622                return 1; /* no change */
3623        if (!one->sha1_valid && !two->sha1_valid)
3624                return 1; /* both look at the same file on the filesystem. */
3625        return 0;
3626}
3627
3628static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3629{
3630        if (diff_unmodified_pair(p))
3631                return;
3632
3633        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3634            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3635                return; /* no tree diffs in patch format */
3636
3637        run_diff(p, o);
3638}
3639
3640static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3641                            struct diffstat_t *diffstat)
3642{
3643        if (diff_unmodified_pair(p))
3644                return;
3645
3646        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3647            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3648                return; /* no useful stat for tree diffs */
3649
3650        run_diffstat(p, o, diffstat);
3651}
3652
3653static void diff_flush_checkdiff(struct diff_filepair *p,
3654                struct diff_options *o)
3655{
3656        if (diff_unmodified_pair(p))
3657                return;
3658
3659        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3660            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3661                return; /* nothing to check in tree diffs */
3662
3663        run_checkdiff(p, o);
3664}
3665
3666int diff_queue_is_empty(void)
3667{
3668        struct diff_queue_struct *q = &diff_queued_diff;
3669        int i;
3670        for (i = 0; i < q->nr; i++)
3671                if (!diff_unmodified_pair(q->queue[i]))
3672                        return 0;
3673        return 1;
3674}
3675
3676#if DIFF_DEBUG
3677void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3678{
3679        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3680                x, one ? one : "",
3681                s->path,
3682                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3683                s->mode,
3684                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3685        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3686                x, one ? one : "",
3687                s->size, s->xfrm_flags);
3688}
3689
3690void diff_debug_filepair(const struct diff_filepair *p, int i)
3691{
3692        diff_debug_filespec(p->one, i, "one");
3693        diff_debug_filespec(p->two, i, "two");
3694        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3695                p->score, p->status ? p->status : '?',
3696                p->one->rename_used, p->broken_pair);
3697}
3698
3699void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3700{
3701        int i;
3702        if (msg)
3703                fprintf(stderr, "%s\n", msg);
3704        fprintf(stderr, "q->nr = %d\n", q->nr);
3705        for (i = 0; i < q->nr; i++) {
3706                struct diff_filepair *p = q->queue[i];
3707                diff_debug_filepair(p, i);
3708        }
3709}
3710#endif
3711
3712static void diff_resolve_rename_copy(void)
3713{
3714        int i;
3715        struct diff_filepair *p;
3716        struct diff_queue_struct *q = &diff_queued_diff;
3717
3718        diff_debug_queue("resolve-rename-copy", q);
3719
3720        for (i = 0; i < q->nr; i++) {
3721                p = q->queue[i];
3722                p->status = 0; /* undecided */
3723                if (DIFF_PAIR_UNMERGED(p))
3724                        p->status = DIFF_STATUS_UNMERGED;
3725                else if (!DIFF_FILE_VALID(p->one))
3726                        p->status = DIFF_STATUS_ADDED;
3727                else if (!DIFF_FILE_VALID(p->two))
3728                        p->status = DIFF_STATUS_DELETED;
3729                else if (DIFF_PAIR_TYPE_CHANGED(p))
3730                        p->status = DIFF_STATUS_TYPE_CHANGED;
3731
3732                /* from this point on, we are dealing with a pair
3733                 * whose both sides are valid and of the same type, i.e.
3734                 * either in-place edit or rename/copy edit.
3735                 */
3736                else if (DIFF_PAIR_RENAME(p)) {
3737                        /*
3738                         * A rename might have re-connected a broken
3739                         * pair up, causing the pathnames to be the
3740                         * same again. If so, that's not a rename at
3741                         * all, just a modification..
3742                         *
3743                         * Otherwise, see if this source was used for
3744                         * multiple renames, in which case we decrement
3745                         * the count, and call it a copy.
3746                         */
3747                        if (!strcmp(p->one->path, p->two->path))
3748                                p->status = DIFF_STATUS_MODIFIED;
3749                        else if (--p->one->rename_used > 0)
3750                                p->status = DIFF_STATUS_COPIED;
3751                        else
3752                                p->status = DIFF_STATUS_RENAMED;
3753                }
3754                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3755                         p->one->mode != p->two->mode ||
3756                         p->one->dirty_submodule ||
3757                         p->two->dirty_submodule ||
3758                         is_null_sha1(p->one->sha1))
3759                        p->status = DIFF_STATUS_MODIFIED;
3760                else {
3761                        /* This is a "no-change" entry and should not
3762                         * happen anymore, but prepare for broken callers.
3763                         */
3764                        error("feeding unmodified %s to diffcore",
3765                              p->one->path);
3766                        p->status = DIFF_STATUS_UNKNOWN;
3767                }
3768        }
3769        diff_debug_queue("resolve-rename-copy done", q);
3770}
3771
3772static int check_pair_status(struct diff_filepair *p)
3773{
3774        switch (p->status) {
3775        case DIFF_STATUS_UNKNOWN:
3776                return 0;
3777        case 0:
3778                die("internal error in diff-resolve-rename-copy");
3779        default:
3780                return 1;
3781        }
3782}
3783
3784static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3785{
3786        int fmt = opt->output_format;
3787
3788        if (fmt & DIFF_FORMAT_CHECKDIFF)
3789                diff_flush_checkdiff(p, opt);
3790        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3791                diff_flush_raw(p, opt);
3792        else if (fmt & DIFF_FORMAT_NAME) {
3793                const char *name_a, *name_b;
3794                name_a = p->two->path;
3795                name_b = NULL;
3796                strip_prefix(opt->prefix_length, &name_a, &name_b);
3797                write_name_quoted(name_a, opt->file, opt->line_termination);
3798        }
3799}
3800
3801static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3802{
3803        if (fs->mode)
3804                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3805        else
3806                fprintf(file, " %s ", newdelete);
3807        write_name_quoted(fs->path, file, '\n');
3808}
3809
3810
3811static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3812                const char *line_prefix)
3813{
3814        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3815                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3816                        p->two->mode, show_name ? ' ' : '\n');
3817                if (show_name) {
3818                        write_name_quoted(p->two->path, file, '\n');
3819                }
3820        }
3821}
3822
3823static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3824                        const char *line_prefix)
3825{
3826        char *names = pprint_rename(p->one->path, p->two->path);
3827
3828        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3829        free(names);
3830        show_mode_change(file, p, 0, line_prefix);
3831}
3832
3833static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3834{
3835        FILE *file = opt->file;
3836        char *line_prefix = "";
3837
3838        if (opt->output_prefix) {
3839                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3840                line_prefix = buf->buf;
3841        }
3842
3843        switch(p->status) {
3844        case DIFF_STATUS_DELETED:
3845                fputs(line_prefix, file);
3846                show_file_mode_name(file, "delete", p->one);
3847                break;
3848        case DIFF_STATUS_ADDED:
3849                fputs(line_prefix, file);
3850                show_file_mode_name(file, "create", p->two);
3851                break;
3852        case DIFF_STATUS_COPIED:
3853                fputs(line_prefix, file);
3854                show_rename_copy(file, "copy", p, line_prefix);
3855                break;
3856        case DIFF_STATUS_RENAMED:
3857                fputs(line_prefix, file);
3858                show_rename_copy(file, "rename", p, line_prefix);
3859                break;
3860        default:
3861                if (p->score) {
3862                        fprintf(file, "%s rewrite ", line_prefix);
3863                        write_name_quoted(p->two->path, file, ' ');
3864                        fprintf(file, "(%d%%)\n", similarity_index(p));
3865                }
3866                show_mode_change(file, p, !p->score, line_prefix);
3867                break;
3868        }
3869}
3870
3871struct patch_id_t {
3872        git_SHA_CTX *ctx;
3873        int patchlen;
3874};
3875
3876static int remove_space(char *line, int len)
3877{
3878        int i;
3879        char *dst = line;
3880        unsigned char c;
3881
3882        for (i = 0; i < len; i++)
3883                if (!isspace((c = line[i])))
3884                        *dst++ = c;
3885
3886        return dst - line;
3887}
3888
3889static void patch_id_consume(void *priv, char *line, unsigned long len)
3890{
3891        struct patch_id_t *data = priv;
3892        int new_len;
3893
3894        /* Ignore line numbers when computing the SHA1 of the patch */
3895        if (!prefixcmp(line, "@@ -"))
3896                return;
3897
3898        new_len = remove_space(line, len);
3899
3900        git_SHA1_Update(data->ctx, line, new_len);
3901        data->patchlen += new_len;
3902}
3903
3904/* returns 0 upon success, and writes result into sha1 */
3905static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3906{
3907        struct diff_queue_struct *q = &diff_queued_diff;
3908        int i;
3909        git_SHA_CTX ctx;
3910        struct patch_id_t data;
3911        char buffer[PATH_MAX * 4 + 20];
3912
3913        git_SHA1_Init(&ctx);
3914        memset(&data, 0, sizeof(struct patch_id_t));
3915        data.ctx = &ctx;
3916
3917        for (i = 0; i < q->nr; i++) {
3918                xpparam_t xpp;
3919                xdemitconf_t xecfg;
3920                mmfile_t mf1, mf2;
3921                struct diff_filepair *p = q->queue[i];
3922                int len1, len2;
3923
3924                memset(&xpp, 0, sizeof(xpp));
3925                memset(&xecfg, 0, sizeof(xecfg));
3926                if (p->status == 0)
3927                        return error("internal diff status error");
3928                if (p->status == DIFF_STATUS_UNKNOWN)
3929                        continue;
3930                if (diff_unmodified_pair(p))
3931                        continue;
3932                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3933                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3934                        continue;
3935                if (DIFF_PAIR_UNMERGED(p))
3936                        continue;
3937
3938                diff_fill_sha1_info(p->one);
3939                diff_fill_sha1_info(p->two);
3940                if (fill_mmfile(&mf1, p->one) < 0 ||
3941                                fill_mmfile(&mf2, p->two) < 0)
3942                        return error("unable to read files to diff");
3943
3944                len1 = remove_space(p->one->path, strlen(p->one->path));
3945                len2 = remove_space(p->two->path, strlen(p->two->path));
3946                if (p->one->mode == 0)
3947                        len1 = snprintf(buffer, sizeof(buffer),
3948                                        "diff--gita/%.*sb/%.*s"
3949                                        "newfilemode%06o"
3950                                        "---/dev/null"
3951                                        "+++b/%.*s",
3952                                        len1, p->one->path,
3953                                        len2, p->two->path,
3954                                        p->two->mode,
3955                                        len2, p->two->path);
3956                else if (p->two->mode == 0)
3957                        len1 = snprintf(buffer, sizeof(buffer),
3958                                        "diff--gita/%.*sb/%.*s"
3959                                        "deletedfilemode%06o"
3960                                        "---a/%.*s"
3961                                        "+++/dev/null",
3962                                        len1, p->one->path,
3963                                        len2, p->two->path,
3964                                        p->one->mode,
3965                                        len1, p->one->path);
3966                else
3967                        len1 = snprintf(buffer, sizeof(buffer),
3968                                        "diff--gita/%.*sb/%.*s"
3969                                        "---a/%.*s"
3970                                        "+++b/%.*s",
3971                                        len1, p->one->path,
3972                                        len2, p->two->path,
3973                                        len1, p->one->path,
3974                                        len2, p->two->path);
3975                git_SHA1_Update(&ctx, buffer, len1);
3976
3977                if (diff_filespec_is_binary(p->one) ||
3978                    diff_filespec_is_binary(p->two)) {
3979                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3980                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3981                        continue;
3982                }
3983
3984                xpp.flags = 0;
3985                xecfg.ctxlen = 3;
3986                xecfg.flags = 0;
3987                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3988                              &xpp, &xecfg);
3989        }
3990
3991        git_SHA1_Final(sha1, &ctx);
3992        return 0;
3993}
3994
3995int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3996{
3997        struct diff_queue_struct *q = &diff_queued_diff;
3998        int i;
3999        int result = diff_get_patch_id(options, sha1);
4000
4001        for (i = 0; i < q->nr; i++)
4002                diff_free_filepair(q->queue[i]);
4003
4004        free(q->queue);
4005        DIFF_QUEUE_CLEAR(q);
4006
4007        return result;
4008}
4009
4010static int is_summary_empty(const struct diff_queue_struct *q)
4011{
4012        int i;
4013
4014        for (i = 0; i < q->nr; i++) {
4015                const struct diff_filepair *p = q->queue[i];
4016
4017                switch (p->status) {
4018                case DIFF_STATUS_DELETED:
4019                case DIFF_STATUS_ADDED:
4020                case DIFF_STATUS_COPIED:
4021                case DIFF_STATUS_RENAMED:
4022                        return 0;
4023                default:
4024                        if (p->score)
4025                                return 0;
4026                        if (p->one->mode && p->two->mode &&
4027                            p->one->mode != p->two->mode)
4028                                return 0;
4029                        break;
4030                }
4031        }
4032        return 1;
4033}
4034
4035static const char rename_limit_warning[] =
4036"inexact rename detection was skipped due to too many files.";
4037
4038static const char degrade_cc_to_c_warning[] =
4039"only found copies from modified paths due to too many files.";
4040
4041static const char rename_limit_advice[] =
4042"you may want to set your %s variable to at least "
4043"%d and retry the command.";
4044
4045void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4046{
4047        if (degraded_cc)
4048                warning(degrade_cc_to_c_warning);
4049        else if (needed)
4050                warning(rename_limit_warning);
4051        else
4052                return;
4053        if (0 < needed && needed < 32767)
4054                warning(rename_limit_advice, varname, needed);
4055}
4056
4057void diff_flush(struct diff_options *options)
4058{
4059        struct diff_queue_struct *q = &diff_queued_diff;
4060        int i, output_format = options->output_format;
4061        int separator = 0;
4062
4063        /*
4064         * Order: raw, stat, summary, patch
4065         * or:    name/name-status/checkdiff (other bits clear)
4066         */
4067        if (!q->nr)
4068                goto free_queue;
4069
4070        if (output_format & (DIFF_FORMAT_RAW |
4071                             DIFF_FORMAT_NAME |
4072                             DIFF_FORMAT_NAME_STATUS |
4073                             DIFF_FORMAT_CHECKDIFF)) {
4074                for (i = 0; i < q->nr; i++) {
4075                        struct diff_filepair *p = q->queue[i];
4076                        if (check_pair_status(p))
4077                                flush_one_pair(p, options);
4078                }
4079                separator++;
4080        }
4081
4082        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4083                struct diffstat_t diffstat;
4084
4085                memset(&diffstat, 0, sizeof(struct diffstat_t));
4086                for (i = 0; i < q->nr; i++) {
4087                        struct diff_filepair *p = q->queue[i];
4088                        if (check_pair_status(p))
4089                                diff_flush_stat(p, options, &diffstat);
4090                }
4091                if (output_format & DIFF_FORMAT_NUMSTAT)
4092                        show_numstat(&diffstat, options);
4093                if (output_format & DIFF_FORMAT_DIFFSTAT)
4094                        show_stats(&diffstat, options);
4095                if (output_format & DIFF_FORMAT_SHORTSTAT)
4096                        show_shortstats(&diffstat, options);
4097                free_diffstat_info(&diffstat);
4098                separator++;
4099        }
4100        if (output_format & DIFF_FORMAT_DIRSTAT)
4101                show_dirstat(options);
4102
4103        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4104                for (i = 0; i < q->nr; i++) {
4105                        diff_summary(options, q->queue[i]);
4106                }
4107                separator++;
4108        }
4109
4110        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4111            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4112            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4113                /*
4114                 * run diff_flush_patch for the exit status. setting
4115                 * options->file to /dev/null should be safe, becaue we
4116                 * aren't supposed to produce any output anyway.
4117                 */
4118                if (options->close_file)
4119                        fclose(options->file);
4120                options->file = fopen("/dev/null", "w");
4121                if (!options->file)
4122                        die_errno("Could not open /dev/null");
4123                options->close_file = 1;
4124                for (i = 0; i < q->nr; i++) {
4125                        struct diff_filepair *p = q->queue[i];
4126                        if (check_pair_status(p))
4127                                diff_flush_patch(p, options);
4128                        if (options->found_changes)
4129                                break;
4130                }
4131        }
4132
4133        if (output_format & DIFF_FORMAT_PATCH) {
4134                if (separator) {
4135                        putc(options->line_termination, options->file);
4136                        if (options->stat_sep) {
4137                                /* attach patch instead of inline */
4138                                fputs(options->stat_sep, options->file);
4139                        }
4140                }
4141
4142                for (i = 0; i < q->nr; i++) {
4143                        struct diff_filepair *p = q->queue[i];
4144                        if (check_pair_status(p))
4145                                diff_flush_patch(p, options);
4146                }
4147        }
4148
4149        if (output_format & DIFF_FORMAT_CALLBACK)
4150                options->format_callback(q, options, options->format_callback_data);
4151
4152        for (i = 0; i < q->nr; i++)
4153                diff_free_filepair(q->queue[i]);
4154free_queue:
4155        free(q->queue);
4156        DIFF_QUEUE_CLEAR(q);
4157        if (options->close_file)
4158                fclose(options->file);
4159
4160        /*
4161         * Report the content-level differences with HAS_CHANGES;
4162         * diff_addremove/diff_change does not set the bit when
4163         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4164         */
4165        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4166                if (options->found_changes)
4167                        DIFF_OPT_SET(options, HAS_CHANGES);
4168                else
4169                        DIFF_OPT_CLR(options, HAS_CHANGES);
4170        }
4171}
4172
4173static void diffcore_apply_filter(const char *filter)
4174{
4175        int i;
4176        struct diff_queue_struct *q = &diff_queued_diff;
4177        struct diff_queue_struct outq;
4178        DIFF_QUEUE_CLEAR(&outq);
4179
4180        if (!filter)
4181                return;
4182
4183        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4184                int found;
4185                for (i = found = 0; !found && i < q->nr; i++) {
4186                        struct diff_filepair *p = q->queue[i];
4187                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4188                             ((p->score &&
4189                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4190                              (!p->score &&
4191                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4192                            ((p->status != DIFF_STATUS_MODIFIED) &&
4193                             strchr(filter, p->status)))
4194                                found++;
4195                }
4196                if (found)
4197                        return;
4198
4199                /* otherwise we will clear the whole queue
4200                 * by copying the empty outq at the end of this
4201                 * function, but first clear the current entries
4202                 * in the queue.
4203                 */
4204                for (i = 0; i < q->nr; i++)
4205                        diff_free_filepair(q->queue[i]);
4206        }
4207        else {
4208                /* Only the matching ones */
4209                for (i = 0; i < q->nr; i++) {
4210                        struct diff_filepair *p = q->queue[i];
4211
4212                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4213                             ((p->score &&
4214                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4215                              (!p->score &&
4216                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4217                            ((p->status != DIFF_STATUS_MODIFIED) &&
4218                             strchr(filter, p->status)))
4219                                diff_q(&outq, p);
4220                        else
4221                                diff_free_filepair(p);
4222                }
4223        }
4224        free(q->queue);
4225        *q = outq;
4226}
4227
4228/* Check whether two filespecs with the same mode and size are identical */
4229static int diff_filespec_is_identical(struct diff_filespec *one,
4230                                      struct diff_filespec *two)
4231{
4232        if (S_ISGITLINK(one->mode))
4233                return 0;
4234        if (diff_populate_filespec(one, 0))
4235                return 0;
4236        if (diff_populate_filespec(two, 0))
4237                return 0;
4238        return !memcmp(one->data, two->data, one->size);
4239}
4240
4241static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4242{
4243        int i;
4244        struct diff_queue_struct *q = &diff_queued_diff;
4245        struct diff_queue_struct outq;
4246        DIFF_QUEUE_CLEAR(&outq);
4247
4248        for (i = 0; i < q->nr; i++) {
4249                struct diff_filepair *p = q->queue[i];
4250
4251                /*
4252                 * 1. Entries that come from stat info dirtiness
4253                 *    always have both sides (iow, not create/delete),
4254                 *    one side of the object name is unknown, with
4255                 *    the same mode and size.  Keep the ones that
4256                 *    do not match these criteria.  They have real
4257                 *    differences.
4258                 *
4259                 * 2. At this point, the file is known to be modified,
4260                 *    with the same mode and size, and the object
4261                 *    name of one side is unknown.  Need to inspect
4262                 *    the identical contents.
4263                 */
4264                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4265                    !DIFF_FILE_VALID(p->two) ||
4266                    (p->one->sha1_valid && p->two->sha1_valid) ||
4267                    (p->one->mode != p->two->mode) ||
4268                    diff_populate_filespec(p->one, 1) ||
4269                    diff_populate_filespec(p->two, 1) ||
4270                    (p->one->size != p->two->size) ||
4271                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4272                        diff_q(&outq, p);
4273                else {
4274                        /*
4275                         * The caller can subtract 1 from skip_stat_unmatch
4276                         * to determine how many paths were dirty only
4277                         * due to stat info mismatch.
4278                         */
4279                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4280                                diffopt->skip_stat_unmatch++;
4281                        diff_free_filepair(p);
4282                }
4283        }
4284        free(q->queue);
4285        *q = outq;
4286}
4287
4288static int diffnamecmp(const void *a_, const void *b_)
4289{
4290        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4291        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4292        const char *name_a, *name_b;
4293
4294        name_a = a->one ? a->one->path : a->two->path;
4295        name_b = b->one ? b->one->path : b->two->path;
4296        return strcmp(name_a, name_b);
4297}
4298
4299void diffcore_fix_diff_index(struct diff_options *options)
4300{
4301        struct diff_queue_struct *q = &diff_queued_diff;
4302        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4303}
4304
4305void diffcore_std(struct diff_options *options)
4306{
4307        if (options->skip_stat_unmatch)
4308                diffcore_skip_stat_unmatch(options);
4309        if (!options->found_follow) {
4310                /* See try_to_follow_renames() in tree-diff.c */
4311                if (options->break_opt != -1)
4312                        diffcore_break(options->break_opt);
4313                if (options->detect_rename)
4314                        diffcore_rename(options);
4315                if (options->break_opt != -1)
4316                        diffcore_merge_broken();
4317        }
4318        if (options->pickaxe)
4319                diffcore_pickaxe(options);
4320        if (options->orderfile)
4321                diffcore_order(options->orderfile);
4322        if (!options->found_follow)
4323                /* See try_to_follow_renames() in tree-diff.c */
4324                diff_resolve_rename_copy();
4325        diffcore_apply_filter(options->filter);
4326
4327        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4328                DIFF_OPT_SET(options, HAS_CHANGES);
4329        else
4330                DIFF_OPT_CLR(options, HAS_CHANGES);
4331
4332        options->found_follow = 0;
4333}
4334
4335int diff_result_code(struct diff_options *opt, int status)
4336{
4337        int result = 0;
4338
4339        diff_warn_rename_limit("diff.renamelimit",
4340                               opt->needed_rename_limit,
4341                               opt->degraded_cc_to_c);
4342        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4343            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4344                return status;
4345        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4346            DIFF_OPT_TST(opt, HAS_CHANGES))
4347                result |= 01;
4348        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4349            DIFF_OPT_TST(opt, CHECK_FAILED))
4350                result |= 02;
4351        return result;
4352}
4353
4354/*
4355 * Shall changes to this submodule be ignored?
4356 *
4357 * Submodule changes can be configured to be ignored separately for each path,
4358 * but that configuration can be overridden from the command line.
4359 */
4360static int is_submodule_ignored(const char *path, struct diff_options *options)
4361{
4362        int ignored = 0;
4363        unsigned orig_flags = options->flags;
4364        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4365                set_diffopt_flags_from_submodule_config(options, path);
4366        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4367                ignored = 1;
4368        options->flags = orig_flags;
4369        return ignored;
4370}
4371
4372void diff_addremove(struct diff_options *options,
4373                    int addremove, unsigned mode,
4374                    const unsigned char *sha1,
4375                    const char *concatpath, unsigned dirty_submodule)
4376{
4377        struct diff_filespec *one, *two;
4378
4379        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4380                return;
4381
4382        /* This may look odd, but it is a preparation for
4383         * feeding "there are unchanged files which should
4384         * not produce diffs, but when you are doing copy
4385         * detection you would need them, so here they are"
4386         * entries to the diff-core.  They will be prefixed
4387         * with something like '=' or '*' (I haven't decided
4388         * which but should not make any difference).
4389         * Feeding the same new and old to diff_change()
4390         * also has the same effect.
4391         * Before the final output happens, they are pruned after
4392         * merged into rename/copy pairs as appropriate.
4393         */
4394        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4395                addremove = (addremove == '+' ? '-' :
4396                             addremove == '-' ? '+' : addremove);
4397
4398        if (options->prefix &&
4399            strncmp(concatpath, options->prefix, options->prefix_length))
4400                return;
4401
4402        one = alloc_filespec(concatpath);
4403        two = alloc_filespec(concatpath);
4404
4405        if (addremove != '+')
4406                fill_filespec(one, sha1, mode);
4407        if (addremove != '-') {
4408                fill_filespec(two, sha1, mode);
4409                two->dirty_submodule = dirty_submodule;
4410        }
4411
4412        diff_queue(&diff_queued_diff, one, two);
4413        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4414                DIFF_OPT_SET(options, HAS_CHANGES);
4415}
4416
4417void diff_change(struct diff_options *options,
4418                 unsigned old_mode, unsigned new_mode,
4419                 const unsigned char *old_sha1,
4420                 const unsigned char *new_sha1,
4421                 const char *concatpath,
4422                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4423{
4424        struct diff_filespec *one, *two;
4425
4426        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4427            is_submodule_ignored(concatpath, options))
4428                return;
4429
4430        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4431                unsigned tmp;
4432                const unsigned char *tmp_c;
4433                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4434                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4435                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4436                        new_dirty_submodule = tmp;
4437        }
4438
4439        if (options->prefix &&
4440            strncmp(concatpath, options->prefix, options->prefix_length))
4441                return;
4442
4443        one = alloc_filespec(concatpath);
4444        two = alloc_filespec(concatpath);
4445        fill_filespec(one, old_sha1, old_mode);
4446        fill_filespec(two, new_sha1, new_mode);
4447        one->dirty_submodule = old_dirty_submodule;
4448        two->dirty_submodule = new_dirty_submodule;
4449
4450        diff_queue(&diff_queued_diff, one, two);
4451        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4452                DIFF_OPT_SET(options, HAS_CHANGES);
4453}
4454
4455void diff_unmerge(struct diff_options *options,
4456                  const char *path,
4457                  unsigned mode, const unsigned char *sha1)
4458{
4459        struct diff_filespec *one, *two;
4460
4461        if (options->prefix &&
4462            strncmp(path, options->prefix, options->prefix_length))
4463                return;
4464
4465        one = alloc_filespec(path);
4466        two = alloc_filespec(path);
4467        fill_filespec(one, sha1, mode);
4468        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4469}
4470
4471static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4472                size_t *outsize)
4473{
4474        struct diff_tempfile *temp;
4475        const char *argv[3];
4476        const char **arg = argv;
4477        struct child_process child;
4478        struct strbuf buf = STRBUF_INIT;
4479        int err = 0;
4480
4481        temp = prepare_temp_file(spec->path, spec);
4482        *arg++ = pgm;
4483        *arg++ = temp->name;
4484        *arg = NULL;
4485
4486        memset(&child, 0, sizeof(child));
4487        child.use_shell = 1;
4488        child.argv = argv;
4489        child.out = -1;
4490        if (start_command(&child)) {
4491                remove_tempfile();
4492                return NULL;
4493        }
4494
4495        if (strbuf_read(&buf, child.out, 0) < 0)
4496                err = error("error reading from textconv command '%s'", pgm);
4497        close(child.out);
4498
4499        if (finish_command(&child) || err) {
4500                strbuf_release(&buf);
4501                remove_tempfile();
4502                return NULL;
4503        }
4504        remove_tempfile();
4505
4506        return strbuf_detach(&buf, outsize);
4507}
4508
4509size_t fill_textconv(struct userdiff_driver *driver,
4510                     struct diff_filespec *df,
4511                     char **outbuf)
4512{
4513        size_t size;
4514
4515        if (!driver || !driver->textconv) {
4516                if (!DIFF_FILE_VALID(df)) {
4517                        *outbuf = "";
4518                        return 0;
4519                }
4520                if (diff_populate_filespec(df, 0))
4521                        die("unable to read files to diff");
4522                *outbuf = df->data;
4523                return df->size;
4524        }
4525
4526        if (driver->textconv_cache && df->sha1_valid) {
4527                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4528                                          &size);
4529                if (*outbuf)
4530                        return size;
4531        }
4532
4533        *outbuf = run_textconv(driver->textconv, df, &size);
4534        if (!*outbuf)
4535                die("unable to read files to diff");
4536
4537        if (driver->textconv_cache && df->sha1_valid) {
4538                /* ignore errors, as we might be in a readonly repository */
4539                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4540                                size);
4541                /*
4542                 * we could save up changes and flush them all at the end,
4543                 * but we would need an extra call after all diffing is done.
4544                 * Since generating a cache entry is the slow path anyway,
4545                 * this extra overhead probably isn't a big deal.
4546                 */
4547                notes_cache_write(driver->textconv_cache);
4548        }
4549
4550        return size;
4551}