diff.con commit diff: add configuration option for disabling diff prefixes. (f89504d)
   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 = 200;
  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;
  34
  35static char diff_colors[][COLOR_MAXLEN] = {
  36        GIT_COLOR_RESET,
  37        GIT_COLOR_NORMAL,       /* PLAIN */
  38        GIT_COLOR_BOLD,         /* METAINFO */
  39        GIT_COLOR_CYAN,         /* FRAGINFO */
  40        GIT_COLOR_RED,          /* OLD */
  41        GIT_COLOR_GREEN,        /* NEW */
  42        GIT_COLOR_YELLOW,       /* COMMIT */
  43        GIT_COLOR_BG_RED,       /* WHITESPACE */
  44        GIT_COLOR_NORMAL,       /* FUNCINFO */
  45};
  46
  47static void diff_filespec_load_driver(struct diff_filespec *one);
  48static size_t fill_textconv(struct userdiff_driver *driver,
  49                            struct diff_filespec *df, char **outbuf);
  50
  51static int parse_diff_color_slot(const char *var, int ofs)
  52{
  53        if (!strcasecmp(var+ofs, "plain"))
  54                return DIFF_PLAIN;
  55        if (!strcasecmp(var+ofs, "meta"))
  56                return DIFF_METAINFO;
  57        if (!strcasecmp(var+ofs, "frag"))
  58                return DIFF_FRAGINFO;
  59        if (!strcasecmp(var+ofs, "old"))
  60                return DIFF_FILE_OLD;
  61        if (!strcasecmp(var+ofs, "new"))
  62                return DIFF_FILE_NEW;
  63        if (!strcasecmp(var+ofs, "commit"))
  64                return DIFF_COMMIT;
  65        if (!strcasecmp(var+ofs, "whitespace"))
  66                return DIFF_WHITESPACE;
  67        if (!strcasecmp(var+ofs, "func"))
  68                return DIFF_FUNCINFO;
  69        return -1;
  70}
  71
  72static int git_config_rename(const char *var, const char *value)
  73{
  74        if (!value)
  75                return DIFF_DETECT_RENAME;
  76        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  77                return  DIFF_DETECT_COPY;
  78        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  79}
  80
  81/*
  82 * These are to give UI layer defaults.
  83 * The core-level commands such as git-diff-files should
  84 * never be affected by the setting of diff.renames
  85 * the user happens to have in the configuration file.
  86 */
  87int git_diff_ui_config(const char *var, const char *value, void *cb)
  88{
  89        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  90                diff_use_color_default = git_config_colorbool(var, value, -1);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.renames")) {
  94                diff_detect_rename_default = git_config_rename(var, value);
  95                return 0;
  96        }
  97        if (!strcmp(var, "diff.autorefreshindex")) {
  98                diff_auto_refresh_index = git_config_bool(var, value);
  99                return 0;
 100        }
 101        if (!strcmp(var, "diff.mnemonicprefix")) {
 102                diff_mnemonic_prefix = git_config_bool(var, value);
 103                return 0;
 104        }
 105        if (!strcmp(var, "diff.noprefix")) {
 106                diff_no_prefix = git_config_bool(var, value);
 107                return 0;
 108        }
 109        if (!strcmp(var, "diff.external"))
 110                return git_config_string(&external_diff_cmd_cfg, var, value);
 111        if (!strcmp(var, "diff.wordregex"))
 112                return git_config_string(&diff_word_regex_cfg, var, 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        return git_color_default_config(var, value, cb);
 149}
 150
 151static char *quote_two(const char *one, const char *two)
 152{
 153        int need_one = quote_c_style(one, NULL, NULL, 1);
 154        int need_two = quote_c_style(two, NULL, NULL, 1);
 155        struct strbuf res = STRBUF_INIT;
 156
 157        if (need_one + need_two) {
 158                strbuf_addch(&res, '"');
 159                quote_c_style(one, &res, NULL, 1);
 160                quote_c_style(two, &res, NULL, 1);
 161                strbuf_addch(&res, '"');
 162        } else {
 163                strbuf_addstr(&res, one);
 164                strbuf_addstr(&res, two);
 165        }
 166        return strbuf_detach(&res, NULL);
 167}
 168
 169static const char *external_diff(void)
 170{
 171        static const char *external_diff_cmd = NULL;
 172        static int done_preparing = 0;
 173
 174        if (done_preparing)
 175                return external_diff_cmd;
 176        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 177        if (!external_diff_cmd)
 178                external_diff_cmd = external_diff_cmd_cfg;
 179        done_preparing = 1;
 180        return external_diff_cmd;
 181}
 182
 183static struct diff_tempfile {
 184        const char *name; /* filename external diff should read from */
 185        char hex[41];
 186        char mode[10];
 187        char tmp_path[PATH_MAX];
 188} diff_temp[2];
 189
 190typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 191
 192struct emit_callback {
 193        int color_diff;
 194        unsigned ws_rule;
 195        int blank_at_eof_in_preimage;
 196        int blank_at_eof_in_postimage;
 197        int lno_in_preimage;
 198        int lno_in_postimage;
 199        sane_truncate_fn truncate;
 200        const char **label_path;
 201        struct diff_words_data *diff_words;
 202        int *found_changesp;
 203        FILE *file;
 204        struct strbuf *header;
 205};
 206
 207static int count_lines(const char *data, int size)
 208{
 209        int count, ch, completely_empty = 1, nl_just_seen = 0;
 210        count = 0;
 211        while (0 < size--) {
 212                ch = *data++;
 213                if (ch == '\n') {
 214                        count++;
 215                        nl_just_seen = 1;
 216                        completely_empty = 0;
 217                }
 218                else {
 219                        nl_just_seen = 0;
 220                        completely_empty = 0;
 221                }
 222        }
 223        if (completely_empty)
 224                return 0;
 225        if (!nl_just_seen)
 226                count++; /* no trailing newline */
 227        return count;
 228}
 229
 230static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 231{
 232        if (!DIFF_FILE_VALID(one)) {
 233                mf->ptr = (char *)""; /* does not matter */
 234                mf->size = 0;
 235                return 0;
 236        }
 237        else if (diff_populate_filespec(one, 0))
 238                return -1;
 239
 240        mf->ptr = one->data;
 241        mf->size = one->size;
 242        return 0;
 243}
 244
 245static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 246{
 247        char *ptr = mf->ptr;
 248        long size = mf->size;
 249        int cnt = 0;
 250
 251        if (!size)
 252                return cnt;
 253        ptr += size - 1; /* pointing at the very end */
 254        if (*ptr != '\n')
 255                ; /* incomplete line */
 256        else
 257                ptr--; /* skip the last LF */
 258        while (mf->ptr < ptr) {
 259                char *prev_eol;
 260                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 261                        if (*prev_eol == '\n')
 262                                break;
 263                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 264                        break;
 265                cnt++;
 266                ptr = prev_eol - 1;
 267        }
 268        return cnt;
 269}
 270
 271static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 272                               struct emit_callback *ecbdata)
 273{
 274        int l1, l2, at;
 275        unsigned ws_rule = ecbdata->ws_rule;
 276        l1 = count_trailing_blank(mf1, ws_rule);
 277        l2 = count_trailing_blank(mf2, ws_rule);
 278        if (l2 <= l1) {
 279                ecbdata->blank_at_eof_in_preimage = 0;
 280                ecbdata->blank_at_eof_in_postimage = 0;
 281                return;
 282        }
 283        at = count_lines(mf1->ptr, mf1->size);
 284        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 285
 286        at = count_lines(mf2->ptr, mf2->size);
 287        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 288}
 289
 290static void emit_line_0(FILE *file, const char *set, const char *reset,
 291                        int first, const char *line, int len)
 292{
 293        int has_trailing_newline, has_trailing_carriage_return;
 294        int nofirst;
 295
 296        if (len == 0) {
 297                has_trailing_newline = (first == '\n');
 298                has_trailing_carriage_return = (!has_trailing_newline &&
 299                                                (first == '\r'));
 300                nofirst = has_trailing_newline || has_trailing_carriage_return;
 301        } else {
 302                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 303                if (has_trailing_newline)
 304                        len--;
 305                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 306                if (has_trailing_carriage_return)
 307                        len--;
 308                nofirst = 0;
 309        }
 310
 311        if (len || !nofirst) {
 312                fputs(set, file);
 313                if (!nofirst)
 314                        fputc(first, file);
 315                fwrite(line, len, 1, file);
 316                fputs(reset, file);
 317        }
 318        if (has_trailing_carriage_return)
 319                fputc('\r', file);
 320        if (has_trailing_newline)
 321                fputc('\n', file);
 322}
 323
 324static void emit_line(FILE *file, const char *set, const char *reset,
 325                      const char *line, int len)
 326{
 327        emit_line_0(file, set, reset, line[0], line+1, len-1);
 328}
 329
 330static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 331{
 332        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 333              ecbdata->blank_at_eof_in_preimage &&
 334              ecbdata->blank_at_eof_in_postimage &&
 335              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 336              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 337                return 0;
 338        return ws_blank_line(line, len, ecbdata->ws_rule);
 339}
 340
 341static void emit_add_line(const char *reset,
 342                          struct emit_callback *ecbdata,
 343                          const char *line, int len)
 344{
 345        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 346        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 347
 348        if (!*ws)
 349                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 350        else if (new_blank_line_at_eof(ecbdata, line, len))
 351                /* Blank line at EOF - paint '+' as well */
 352                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 353        else {
 354                /* Emit just the prefix, then the rest. */
 355                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 356                ws_check_emit(line, len, ecbdata->ws_rule,
 357                              ecbdata->file, set, reset, ws);
 358        }
 359}
 360
 361static void emit_hunk_header(struct emit_callback *ecbdata,
 362                             const char *line, int len)
 363{
 364        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 365        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 366        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 367        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 368        static const char atat[2] = { '@', '@' };
 369        const char *cp, *ep;
 370
 371        /*
 372         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 373         * it always is at least 10 bytes long.
 374         */
 375        if (len < 10 ||
 376            memcmp(line, atat, 2) ||
 377            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 378                emit_line(ecbdata->file, plain, reset, line, len);
 379                return;
 380        }
 381        ep += 2; /* skip over @@ */
 382
 383        /* The hunk header in fraginfo color */
 384        emit_line(ecbdata->file, frag, reset, line, ep - line);
 385
 386        /* blank before the func header */
 387        for (cp = ep; ep - line < len; ep++)
 388                if (*ep != ' ' && *ep != '\t')
 389                        break;
 390        if (ep != cp)
 391                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 392
 393        if (ep < line + len)
 394                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 395}
 396
 397static struct diff_tempfile *claim_diff_tempfile(void) {
 398        int i;
 399        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 400                if (!diff_temp[i].name)
 401                        return diff_temp + i;
 402        die("BUG: diff is failing to clean up its tempfiles");
 403}
 404
 405static int remove_tempfile_installed;
 406
 407static void remove_tempfile(void)
 408{
 409        int i;
 410        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 411                if (diff_temp[i].name == diff_temp[i].tmp_path)
 412                        unlink_or_warn(diff_temp[i].name);
 413                diff_temp[i].name = NULL;
 414        }
 415}
 416
 417static void remove_tempfile_on_signal(int signo)
 418{
 419        remove_tempfile();
 420        sigchain_pop(signo);
 421        raise(signo);
 422}
 423
 424static void print_line_count(FILE *file, int count)
 425{
 426        switch (count) {
 427        case 0:
 428                fprintf(file, "0,0");
 429                break;
 430        case 1:
 431                fprintf(file, "1");
 432                break;
 433        default:
 434                fprintf(file, "1,%d", count);
 435                break;
 436        }
 437}
 438
 439static void emit_rewrite_lines(struct emit_callback *ecb,
 440                               int prefix, const char *data, int size)
 441{
 442        const char *endp = NULL;
 443        static const char *nneof = " No newline at end of file\n";
 444        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 445        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 446
 447        while (0 < size) {
 448                int len;
 449
 450                endp = memchr(data, '\n', size);
 451                len = endp ? (endp - data + 1) : size;
 452                if (prefix != '+') {
 453                        ecb->lno_in_preimage++;
 454                        emit_line_0(ecb->file, old, reset, '-',
 455                                    data, len);
 456                } else {
 457                        ecb->lno_in_postimage++;
 458                        emit_add_line(reset, ecb, data, len);
 459                }
 460                size -= len;
 461                data += len;
 462        }
 463        if (!endp) {
 464                const char *plain = diff_get_color(ecb->color_diff,
 465                                                   DIFF_PLAIN);
 466                emit_line_0(ecb->file, plain, reset, '\\',
 467                            nneof, strlen(nneof));
 468        }
 469}
 470
 471static void emit_rewrite_diff(const char *name_a,
 472                              const char *name_b,
 473                              struct diff_filespec *one,
 474                              struct diff_filespec *two,
 475                              struct userdiff_driver *textconv_one,
 476                              struct userdiff_driver *textconv_two,
 477                              struct diff_options *o)
 478{
 479        int lc_a, lc_b;
 480        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 481        const char *name_a_tab, *name_b_tab;
 482        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 483        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 484        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 485        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 486        const char *a_prefix, *b_prefix;
 487        char *data_one, *data_two;
 488        size_t size_one, size_two;
 489        struct emit_callback ecbdata;
 490
 491        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 492                a_prefix = o->b_prefix;
 493                b_prefix = o->a_prefix;
 494        } else {
 495                a_prefix = o->a_prefix;
 496                b_prefix = o->b_prefix;
 497        }
 498
 499        name_a += (*name_a == '/');
 500        name_b += (*name_b == '/');
 501        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 502        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 503
 504        strbuf_reset(&a_name);
 505        strbuf_reset(&b_name);
 506        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 507        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 508
 509        size_one = fill_textconv(textconv_one, one, &data_one);
 510        size_two = fill_textconv(textconv_two, two, &data_two);
 511
 512        memset(&ecbdata, 0, sizeof(ecbdata));
 513        ecbdata.color_diff = color_diff;
 514        ecbdata.found_changesp = &o->found_changes;
 515        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 516        ecbdata.file = o->file;
 517        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 518                mmfile_t mf1, mf2;
 519                mf1.ptr = (char *)data_one;
 520                mf2.ptr = (char *)data_two;
 521                mf1.size = size_one;
 522                mf2.size = size_two;
 523                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 524        }
 525        ecbdata.lno_in_preimage = 1;
 526        ecbdata.lno_in_postimage = 1;
 527
 528        lc_a = count_lines(data_one, size_one);
 529        lc_b = count_lines(data_two, size_two);
 530        fprintf(o->file,
 531                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 532                metainfo, a_name.buf, name_a_tab, reset,
 533                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 534        print_line_count(o->file, lc_a);
 535        fprintf(o->file, " +");
 536        print_line_count(o->file, lc_b);
 537        fprintf(o->file, " @@%s\n", reset);
 538        if (lc_a)
 539                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 540        if (lc_b)
 541                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 542        if (textconv_one)
 543                free((char *)data_one);
 544        if (textconv_two)
 545                free((char *)data_two);
 546}
 547
 548struct diff_words_buffer {
 549        mmfile_t text;
 550        long alloc;
 551        struct diff_words_orig {
 552                const char *begin, *end;
 553        } *orig;
 554        int orig_nr, orig_alloc;
 555};
 556
 557static void diff_words_append(char *line, unsigned long len,
 558                struct diff_words_buffer *buffer)
 559{
 560        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 561        line++;
 562        len--;
 563        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 564        buffer->text.size += len;
 565        buffer->text.ptr[buffer->text.size] = '\0';
 566}
 567
 568struct diff_words_data {
 569        struct diff_words_buffer minus, plus;
 570        const char *current_plus;
 571        FILE *file;
 572        regex_t *word_regex;
 573};
 574
 575static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 576{
 577        struct diff_words_data *diff_words = priv;
 578        int minus_first, minus_len, plus_first, plus_len;
 579        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 580
 581        if (line[0] != '@' || parse_hunk_header(line, len,
 582                        &minus_first, &minus_len, &plus_first, &plus_len))
 583                return;
 584
 585        /* POSIX requires that first be decremented by one if len == 0... */
 586        if (minus_len) {
 587                minus_begin = diff_words->minus.orig[minus_first].begin;
 588                minus_end =
 589                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 590        } else
 591                minus_begin = minus_end =
 592                        diff_words->minus.orig[minus_first].end;
 593
 594        if (plus_len) {
 595                plus_begin = diff_words->plus.orig[plus_first].begin;
 596                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 597        } else
 598                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 599
 600        if (diff_words->current_plus != plus_begin)
 601                fwrite(diff_words->current_plus,
 602                                plus_begin - diff_words->current_plus, 1,
 603                                diff_words->file);
 604        if (minus_begin != minus_end)
 605                color_fwrite_lines(diff_words->file,
 606                                diff_get_color(1, DIFF_FILE_OLD),
 607                                minus_end - minus_begin, minus_begin);
 608        if (plus_begin != plus_end)
 609                color_fwrite_lines(diff_words->file,
 610                                diff_get_color(1, DIFF_FILE_NEW),
 611                                plus_end - plus_begin, plus_begin);
 612
 613        diff_words->current_plus = plus_end;
 614}
 615
 616/* This function starts looking at *begin, and returns 0 iff a word was found. */
 617static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 618                int *begin, int *end)
 619{
 620        if (word_regex && *begin < buffer->size) {
 621                regmatch_t match[1];
 622                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 623                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 624                                        '\n', match[0].rm_eo - match[0].rm_so);
 625                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 626                        *begin += match[0].rm_so;
 627                        return *begin >= *end;
 628                }
 629                return -1;
 630        }
 631
 632        /* find the next word */
 633        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 634                (*begin)++;
 635        if (*begin >= buffer->size)
 636                return -1;
 637
 638        /* find the end of the word */
 639        *end = *begin + 1;
 640        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 641                (*end)++;
 642
 643        return 0;
 644}
 645
 646/*
 647 * This function splits the words in buffer->text, stores the list with
 648 * newline separator into out, and saves the offsets of the original words
 649 * in buffer->orig.
 650 */
 651static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 652                regex_t *word_regex)
 653{
 654        int i, j;
 655        long alloc = 0;
 656
 657        out->size = 0;
 658        out->ptr = NULL;
 659
 660        /* fake an empty "0th" word */
 661        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 662        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 663        buffer->orig_nr = 1;
 664
 665        for (i = 0; i < buffer->text.size; i++) {
 666                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 667                        return;
 668
 669                /* store original boundaries */
 670                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 671                                buffer->orig_alloc);
 672                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 673                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 674                buffer->orig_nr++;
 675
 676                /* store one word */
 677                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 678                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 679                out->ptr[out->size + j - i] = '\n';
 680                out->size += j - i + 1;
 681
 682                i = j - 1;
 683        }
 684}
 685
 686/* this executes the word diff on the accumulated buffers */
 687static void diff_words_show(struct diff_words_data *diff_words)
 688{
 689        xpparam_t xpp;
 690        xdemitconf_t xecfg;
 691        mmfile_t minus, plus;
 692
 693        /* special case: only removal */
 694        if (!diff_words->plus.text.size) {
 695                color_fwrite_lines(diff_words->file,
 696                        diff_get_color(1, DIFF_FILE_OLD),
 697                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 698                diff_words->minus.text.size = 0;
 699                return;
 700        }
 701
 702        diff_words->current_plus = diff_words->plus.text.ptr;
 703
 704        memset(&xpp, 0, sizeof(xpp));
 705        memset(&xecfg, 0, sizeof(xecfg));
 706        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 707        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 708        xpp.flags = XDF_NEED_MINIMAL;
 709        /* as only the hunk header will be parsed, we need a 0-context */
 710        xecfg.ctxlen = 0;
 711        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 712                      &xpp, &xecfg);
 713        free(minus.ptr);
 714        free(plus.ptr);
 715        if (diff_words->current_plus != diff_words->plus.text.ptr +
 716                        diff_words->plus.text.size)
 717                fwrite(diff_words->current_plus,
 718                        diff_words->plus.text.ptr + diff_words->plus.text.size
 719                        - diff_words->current_plus, 1,
 720                        diff_words->file);
 721        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 722}
 723
 724/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 725static void diff_words_flush(struct emit_callback *ecbdata)
 726{
 727        if (ecbdata->diff_words->minus.text.size ||
 728            ecbdata->diff_words->plus.text.size)
 729                diff_words_show(ecbdata->diff_words);
 730}
 731
 732static void free_diff_words_data(struct emit_callback *ecbdata)
 733{
 734        if (ecbdata->diff_words) {
 735                diff_words_flush(ecbdata);
 736                free (ecbdata->diff_words->minus.text.ptr);
 737                free (ecbdata->diff_words->minus.orig);
 738                free (ecbdata->diff_words->plus.text.ptr);
 739                free (ecbdata->diff_words->plus.orig);
 740                free(ecbdata->diff_words->word_regex);
 741                free(ecbdata->diff_words);
 742                ecbdata->diff_words = NULL;
 743        }
 744}
 745
 746const char *diff_get_color(int diff_use_color, enum color_diff ix)
 747{
 748        if (diff_use_color)
 749                return diff_colors[ix];
 750        return "";
 751}
 752
 753static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 754{
 755        const char *cp;
 756        unsigned long allot;
 757        size_t l = len;
 758
 759        if (ecb->truncate)
 760                return ecb->truncate(line, len);
 761        cp = line;
 762        allot = l;
 763        while (0 < l) {
 764                (void) utf8_width(&cp, &l);
 765                if (!cp)
 766                        break; /* truncated in the middle? */
 767        }
 768        return allot - l;
 769}
 770
 771static void find_lno(const char *line, struct emit_callback *ecbdata)
 772{
 773        const char *p;
 774        ecbdata->lno_in_preimage = 0;
 775        ecbdata->lno_in_postimage = 0;
 776        p = strchr(line, '-');
 777        if (!p)
 778                return; /* cannot happen */
 779        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 780        p = strchr(p, '+');
 781        if (!p)
 782                return; /* cannot happen */
 783        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 784}
 785
 786static void fn_out_consume(void *priv, char *line, unsigned long len)
 787{
 788        struct emit_callback *ecbdata = priv;
 789        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 790        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 791        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 792
 793        if (ecbdata->header) {
 794                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 795                strbuf_reset(ecbdata->header);
 796                ecbdata->header = NULL;
 797        }
 798        *(ecbdata->found_changesp) = 1;
 799
 800        if (ecbdata->label_path[0]) {
 801                const char *name_a_tab, *name_b_tab;
 802
 803                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 804                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 805
 806                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 807                        meta, ecbdata->label_path[0], reset, name_a_tab);
 808                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 809                        meta, ecbdata->label_path[1], reset, name_b_tab);
 810                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 811        }
 812
 813        if (diff_suppress_blank_empty
 814            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 815                line[0] = '\n';
 816                len = 1;
 817        }
 818
 819        if (line[0] == '@') {
 820                if (ecbdata->diff_words)
 821                        diff_words_flush(ecbdata);
 822                len = sane_truncate_line(ecbdata, line, len);
 823                find_lno(line, ecbdata);
 824                emit_hunk_header(ecbdata, line, len);
 825                if (line[len-1] != '\n')
 826                        putc('\n', ecbdata->file);
 827                return;
 828        }
 829
 830        if (len < 1) {
 831                emit_line(ecbdata->file, reset, reset, line, len);
 832                return;
 833        }
 834
 835        if (ecbdata->diff_words) {
 836                if (line[0] == '-') {
 837                        diff_words_append(line, len,
 838                                          &ecbdata->diff_words->minus);
 839                        return;
 840                } else if (line[0] == '+') {
 841                        diff_words_append(line, len,
 842                                          &ecbdata->diff_words->plus);
 843                        return;
 844                }
 845                diff_words_flush(ecbdata);
 846                line++;
 847                len--;
 848                emit_line(ecbdata->file, plain, reset, line, len);
 849                return;
 850        }
 851
 852        if (line[0] != '+') {
 853                const char *color =
 854                        diff_get_color(ecbdata->color_diff,
 855                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 856                ecbdata->lno_in_preimage++;
 857                if (line[0] == ' ')
 858                        ecbdata->lno_in_postimage++;
 859                emit_line(ecbdata->file, color, reset, line, len);
 860        } else {
 861                ecbdata->lno_in_postimage++;
 862                emit_add_line(reset, ecbdata, line + 1, len - 1);
 863        }
 864}
 865
 866static char *pprint_rename(const char *a, const char *b)
 867{
 868        const char *old = a;
 869        const char *new = b;
 870        struct strbuf name = STRBUF_INIT;
 871        int pfx_length, sfx_length;
 872        int len_a = strlen(a);
 873        int len_b = strlen(b);
 874        int a_midlen, b_midlen;
 875        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 876        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 877
 878        if (qlen_a || qlen_b) {
 879                quote_c_style(a, &name, NULL, 0);
 880                strbuf_addstr(&name, " => ");
 881                quote_c_style(b, &name, NULL, 0);
 882                return strbuf_detach(&name, NULL);
 883        }
 884
 885        /* Find common prefix */
 886        pfx_length = 0;
 887        while (*old && *new && *old == *new) {
 888                if (*old == '/')
 889                        pfx_length = old - a + 1;
 890                old++;
 891                new++;
 892        }
 893
 894        /* Find common suffix */
 895        old = a + len_a;
 896        new = b + len_b;
 897        sfx_length = 0;
 898        while (a <= old && b <= new && *old == *new) {
 899                if (*old == '/')
 900                        sfx_length = len_a - (old - a);
 901                old--;
 902                new--;
 903        }
 904
 905        /*
 906         * pfx{mid-a => mid-b}sfx
 907         * {pfx-a => pfx-b}sfx
 908         * pfx{sfx-a => sfx-b}
 909         * name-a => name-b
 910         */
 911        a_midlen = len_a - pfx_length - sfx_length;
 912        b_midlen = len_b - pfx_length - sfx_length;
 913        if (a_midlen < 0)
 914                a_midlen = 0;
 915        if (b_midlen < 0)
 916                b_midlen = 0;
 917
 918        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 919        if (pfx_length + sfx_length) {
 920                strbuf_add(&name, a, pfx_length);
 921                strbuf_addch(&name, '{');
 922        }
 923        strbuf_add(&name, a + pfx_length, a_midlen);
 924        strbuf_addstr(&name, " => ");
 925        strbuf_add(&name, b + pfx_length, b_midlen);
 926        if (pfx_length + sfx_length) {
 927                strbuf_addch(&name, '}');
 928                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 929        }
 930        return strbuf_detach(&name, NULL);
 931}
 932
 933struct diffstat_t {
 934        int nr;
 935        int alloc;
 936        struct diffstat_file {
 937                char *from_name;
 938                char *name;
 939                char *print_name;
 940                unsigned is_unmerged:1;
 941                unsigned is_binary:1;
 942                unsigned is_renamed:1;
 943                uintmax_t added, deleted;
 944        } **files;
 945};
 946
 947static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 948                                          const char *name_a,
 949                                          const char *name_b)
 950{
 951        struct diffstat_file *x;
 952        x = xcalloc(sizeof (*x), 1);
 953        if (diffstat->nr == diffstat->alloc) {
 954                diffstat->alloc = alloc_nr(diffstat->alloc);
 955                diffstat->files = xrealloc(diffstat->files,
 956                                diffstat->alloc * sizeof(x));
 957        }
 958        diffstat->files[diffstat->nr++] = x;
 959        if (name_b) {
 960                x->from_name = xstrdup(name_a);
 961                x->name = xstrdup(name_b);
 962                x->is_renamed = 1;
 963        }
 964        else {
 965                x->from_name = NULL;
 966                x->name = xstrdup(name_a);
 967        }
 968        return x;
 969}
 970
 971static void diffstat_consume(void *priv, char *line, unsigned long len)
 972{
 973        struct diffstat_t *diffstat = priv;
 974        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 975
 976        if (line[0] == '+')
 977                x->added++;
 978        else if (line[0] == '-')
 979                x->deleted++;
 980}
 981
 982const char mime_boundary_leader[] = "------------";
 983
 984static int scale_linear(int it, int width, int max_change)
 985{
 986        /*
 987         * make sure that at least one '-' is printed if there were deletions,
 988         * and likewise for '+'.
 989         */
 990        if (max_change < 2)
 991                return it;
 992        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 993}
 994
 995static void show_name(FILE *file,
 996                      const char *prefix, const char *name, int len)
 997{
 998        fprintf(file, " %s%-*s |", prefix, len, name);
 999}
1000
1001static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1002{
1003        if (cnt <= 0)
1004                return;
1005        fprintf(file, "%s", set);
1006        while (cnt--)
1007                putc(ch, file);
1008        fprintf(file, "%s", reset);
1009}
1010
1011static void fill_print_name(struct diffstat_file *file)
1012{
1013        char *pname;
1014
1015        if (file->print_name)
1016                return;
1017
1018        if (!file->is_renamed) {
1019                struct strbuf buf = STRBUF_INIT;
1020                if (quote_c_style(file->name, &buf, NULL, 0)) {
1021                        pname = strbuf_detach(&buf, NULL);
1022                } else {
1023                        pname = file->name;
1024                        strbuf_release(&buf);
1025                }
1026        } else {
1027                pname = pprint_rename(file->from_name, file->name);
1028        }
1029        file->print_name = pname;
1030}
1031
1032static void show_stats(struct diffstat_t *data, struct diff_options *options)
1033{
1034        int i, len, add, del, adds = 0, dels = 0;
1035        uintmax_t max_change = 0, max_len = 0;
1036        int total_files = data->nr;
1037        int width, name_width;
1038        const char *reset, *set, *add_c, *del_c;
1039
1040        if (data->nr == 0)
1041                return;
1042
1043        width = options->stat_width ? options->stat_width : 80;
1044        name_width = options->stat_name_width ? options->stat_name_width : 50;
1045
1046        /* Sanity: give at least 5 columns to the graph,
1047         * but leave at least 10 columns for the name.
1048         */
1049        if (width < 25)
1050                width = 25;
1051        if (name_width < 10)
1052                name_width = 10;
1053        else if (width < name_width + 15)
1054                name_width = width - 15;
1055
1056        /* Find the longest filename and max number of changes */
1057        reset = diff_get_color_opt(options, DIFF_RESET);
1058        set   = diff_get_color_opt(options, DIFF_PLAIN);
1059        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1060        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1061
1062        for (i = 0; i < data->nr; i++) {
1063                struct diffstat_file *file = data->files[i];
1064                uintmax_t change = file->added + file->deleted;
1065                fill_print_name(file);
1066                len = strlen(file->print_name);
1067                if (max_len < len)
1068                        max_len = len;
1069
1070                if (file->is_binary || file->is_unmerged)
1071                        continue;
1072                if (max_change < change)
1073                        max_change = change;
1074        }
1075
1076        /* Compute the width of the graph part;
1077         * 10 is for one blank at the beginning of the line plus
1078         * " | count " between the name and the graph.
1079         *
1080         * From here on, name_width is the width of the name area,
1081         * and width is the width of the graph area.
1082         */
1083        name_width = (name_width < max_len) ? name_width : max_len;
1084        if (width < (name_width + 10) + max_change)
1085                width = width - (name_width + 10);
1086        else
1087                width = max_change;
1088
1089        for (i = 0; i < data->nr; i++) {
1090                const char *prefix = "";
1091                char *name = data->files[i]->print_name;
1092                uintmax_t added = data->files[i]->added;
1093                uintmax_t deleted = data->files[i]->deleted;
1094                int name_len;
1095
1096                /*
1097                 * "scale" the filename
1098                 */
1099                len = name_width;
1100                name_len = strlen(name);
1101                if (name_width < name_len) {
1102                        char *slash;
1103                        prefix = "...";
1104                        len -= 3;
1105                        name += name_len - len;
1106                        slash = strchr(name, '/');
1107                        if (slash)
1108                                name = slash;
1109                }
1110
1111                if (data->files[i]->is_binary) {
1112                        show_name(options->file, prefix, name, len);
1113                        fprintf(options->file, "  Bin ");
1114                        fprintf(options->file, "%s%"PRIuMAX"%s",
1115                                del_c, deleted, reset);
1116                        fprintf(options->file, " -> ");
1117                        fprintf(options->file, "%s%"PRIuMAX"%s",
1118                                add_c, added, reset);
1119                        fprintf(options->file, " bytes");
1120                        fprintf(options->file, "\n");
1121                        continue;
1122                }
1123                else if (data->files[i]->is_unmerged) {
1124                        show_name(options->file, prefix, name, len);
1125                        fprintf(options->file, "  Unmerged\n");
1126                        continue;
1127                }
1128                else if (!data->files[i]->is_renamed &&
1129                         (added + deleted == 0)) {
1130                        total_files--;
1131                        continue;
1132                }
1133
1134                /*
1135                 * scale the add/delete
1136                 */
1137                add = added;
1138                del = deleted;
1139                adds += add;
1140                dels += del;
1141
1142                if (width <= max_change) {
1143                        add = scale_linear(add, width, max_change);
1144                        del = scale_linear(del, width, max_change);
1145                }
1146                show_name(options->file, prefix, name, len);
1147                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1148                                added + deleted ? " " : "");
1149                show_graph(options->file, '+', add, add_c, reset);
1150                show_graph(options->file, '-', del, del_c, reset);
1151                fprintf(options->file, "\n");
1152        }
1153        fprintf(options->file,
1154               " %d files changed, %d insertions(+), %d deletions(-)\n",
1155               total_files, adds, dels);
1156}
1157
1158static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1159{
1160        int i, adds = 0, dels = 0, total_files = data->nr;
1161
1162        if (data->nr == 0)
1163                return;
1164
1165        for (i = 0; i < data->nr; i++) {
1166                if (!data->files[i]->is_binary &&
1167                    !data->files[i]->is_unmerged) {
1168                        int added = data->files[i]->added;
1169                        int deleted= data->files[i]->deleted;
1170                        if (!data->files[i]->is_renamed &&
1171                            (added + deleted == 0)) {
1172                                total_files--;
1173                        } else {
1174                                adds += added;
1175                                dels += deleted;
1176                        }
1177                }
1178        }
1179        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1180               total_files, adds, dels);
1181}
1182
1183static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1184{
1185        int i;
1186
1187        if (data->nr == 0)
1188                return;
1189
1190        for (i = 0; i < data->nr; i++) {
1191                struct diffstat_file *file = data->files[i];
1192
1193                if (file->is_binary)
1194                        fprintf(options->file, "-\t-\t");
1195                else
1196                        fprintf(options->file,
1197                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1198                                file->added, file->deleted);
1199                if (options->line_termination) {
1200                        fill_print_name(file);
1201                        if (!file->is_renamed)
1202                                write_name_quoted(file->name, options->file,
1203                                                  options->line_termination);
1204                        else {
1205                                fputs(file->print_name, options->file);
1206                                putc(options->line_termination, options->file);
1207                        }
1208                } else {
1209                        if (file->is_renamed) {
1210                                putc('\0', options->file);
1211                                write_name_quoted(file->from_name, options->file, '\0');
1212                        }
1213                        write_name_quoted(file->name, options->file, '\0');
1214                }
1215        }
1216}
1217
1218struct dirstat_file {
1219        const char *name;
1220        unsigned long changed;
1221};
1222
1223struct dirstat_dir {
1224        struct dirstat_file *files;
1225        int alloc, nr, percent, cumulative;
1226};
1227
1228static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1229{
1230        unsigned long this_dir = 0;
1231        unsigned int sources = 0;
1232
1233        while (dir->nr) {
1234                struct dirstat_file *f = dir->files;
1235                int namelen = strlen(f->name);
1236                unsigned long this;
1237                char *slash;
1238
1239                if (namelen < baselen)
1240                        break;
1241                if (memcmp(f->name, base, baselen))
1242                        break;
1243                slash = strchr(f->name + baselen, '/');
1244                if (slash) {
1245                        int newbaselen = slash + 1 - f->name;
1246                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1247                        sources++;
1248                } else {
1249                        this = f->changed;
1250                        dir->files++;
1251                        dir->nr--;
1252                        sources += 2;
1253                }
1254                this_dir += this;
1255        }
1256
1257        /*
1258         * We don't report dirstat's for
1259         *  - the top level
1260         *  - or cases where everything came from a single directory
1261         *    under this directory (sources == 1).
1262         */
1263        if (baselen && sources != 1) {
1264                int permille = this_dir * 1000 / changed;
1265                if (permille) {
1266                        int percent = permille / 10;
1267                        if (percent >= dir->percent) {
1268                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1269                                if (!dir->cumulative)
1270                                        return 0;
1271                        }
1272                }
1273        }
1274        return this_dir;
1275}
1276
1277static int dirstat_compare(const void *_a, const void *_b)
1278{
1279        const struct dirstat_file *a = _a;
1280        const struct dirstat_file *b = _b;
1281        return strcmp(a->name, b->name);
1282}
1283
1284static void show_dirstat(struct diff_options *options)
1285{
1286        int i;
1287        unsigned long changed;
1288        struct dirstat_dir dir;
1289        struct diff_queue_struct *q = &diff_queued_diff;
1290
1291        dir.files = NULL;
1292        dir.alloc = 0;
1293        dir.nr = 0;
1294        dir.percent = options->dirstat_percent;
1295        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1296
1297        changed = 0;
1298        for (i = 0; i < q->nr; i++) {
1299                struct diff_filepair *p = q->queue[i];
1300                const char *name;
1301                unsigned long copied, added, damage;
1302
1303                name = p->one->path ? p->one->path : p->two->path;
1304
1305                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1306                        diff_populate_filespec(p->one, 0);
1307                        diff_populate_filespec(p->two, 0);
1308                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1309                                               &copied, &added);
1310                        diff_free_filespec_data(p->one);
1311                        diff_free_filespec_data(p->two);
1312                } else if (DIFF_FILE_VALID(p->one)) {
1313                        diff_populate_filespec(p->one, 1);
1314                        copied = added = 0;
1315                        diff_free_filespec_data(p->one);
1316                } else if (DIFF_FILE_VALID(p->two)) {
1317                        diff_populate_filespec(p->two, 1);
1318                        copied = 0;
1319                        added = p->two->size;
1320                        diff_free_filespec_data(p->two);
1321                } else
1322                        continue;
1323
1324                /*
1325                 * Original minus copied is the removed material,
1326                 * added is the new material.  They are both damages
1327                 * made to the preimage. In --dirstat-by-file mode, count
1328                 * damaged files, not damaged lines. This is done by
1329                 * counting only a single damaged line per file.
1330                 */
1331                damage = (p->one->size - copied) + added;
1332                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1333                        damage = 1;
1334
1335                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1336                dir.files[dir.nr].name = name;
1337                dir.files[dir.nr].changed = damage;
1338                changed += damage;
1339                dir.nr++;
1340        }
1341
1342        /* This can happen even with many files, if everything was renames */
1343        if (!changed)
1344                return;
1345
1346        /* Show all directories with more than x% of the changes */
1347        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1348        gather_dirstat(options->file, &dir, changed, "", 0);
1349}
1350
1351static void free_diffstat_info(struct diffstat_t *diffstat)
1352{
1353        int i;
1354        for (i = 0; i < diffstat->nr; i++) {
1355                struct diffstat_file *f = diffstat->files[i];
1356                if (f->name != f->print_name)
1357                        free(f->print_name);
1358                free(f->name);
1359                free(f->from_name);
1360                free(f);
1361        }
1362        free(diffstat->files);
1363}
1364
1365struct checkdiff_t {
1366        const char *filename;
1367        int lineno;
1368        int conflict_marker_size;
1369        struct diff_options *o;
1370        unsigned ws_rule;
1371        unsigned status;
1372};
1373
1374static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1375{
1376        char firstchar;
1377        int cnt;
1378
1379        if (len < marker_size + 1)
1380                return 0;
1381        firstchar = line[0];
1382        switch (firstchar) {
1383        case '=': case '>': case '<': case '|':
1384                break;
1385        default:
1386                return 0;
1387        }
1388        for (cnt = 1; cnt < marker_size; cnt++)
1389                if (line[cnt] != firstchar)
1390                        return 0;
1391        /* line[1] thru line[marker_size-1] are same as firstchar */
1392        if (len < marker_size + 1 || !isspace(line[marker_size]))
1393                return 0;
1394        return 1;
1395}
1396
1397static void checkdiff_consume(void *priv, char *line, unsigned long len)
1398{
1399        struct checkdiff_t *data = priv;
1400        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1401        int marker_size = data->conflict_marker_size;
1402        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1403        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1404        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1405        char *err;
1406
1407        if (line[0] == '+') {
1408                unsigned bad;
1409                data->lineno++;
1410                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1411                        data->status |= 1;
1412                        fprintf(data->o->file,
1413                                "%s:%d: leftover conflict marker\n",
1414                                data->filename, data->lineno);
1415                }
1416                bad = ws_check(line + 1, len - 1, data->ws_rule);
1417                if (!bad)
1418                        return;
1419                data->status |= bad;
1420                err = whitespace_error_string(bad);
1421                fprintf(data->o->file, "%s:%d: %s.\n",
1422                        data->filename, data->lineno, err);
1423                free(err);
1424                emit_line(data->o->file, set, reset, line, 1);
1425                ws_check_emit(line + 1, len - 1, data->ws_rule,
1426                              data->o->file, set, reset, ws);
1427        } else if (line[0] == ' ') {
1428                data->lineno++;
1429        } else if (line[0] == '@') {
1430                char *plus = strchr(line, '+');
1431                if (plus)
1432                        data->lineno = strtol(plus, NULL, 10) - 1;
1433                else
1434                        die("invalid diff");
1435        }
1436}
1437
1438static unsigned char *deflate_it(char *data,
1439                                 unsigned long size,
1440                                 unsigned long *result_size)
1441{
1442        int bound;
1443        unsigned char *deflated;
1444        z_stream stream;
1445
1446        memset(&stream, 0, sizeof(stream));
1447        deflateInit(&stream, zlib_compression_level);
1448        bound = deflateBound(&stream, size);
1449        deflated = xmalloc(bound);
1450        stream.next_out = deflated;
1451        stream.avail_out = bound;
1452
1453        stream.next_in = (unsigned char *)data;
1454        stream.avail_in = size;
1455        while (deflate(&stream, Z_FINISH) == Z_OK)
1456                ; /* nothing */
1457        deflateEnd(&stream);
1458        *result_size = stream.total_out;
1459        return deflated;
1460}
1461
1462static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1463{
1464        void *cp;
1465        void *delta;
1466        void *deflated;
1467        void *data;
1468        unsigned long orig_size;
1469        unsigned long delta_size;
1470        unsigned long deflate_size;
1471        unsigned long data_size;
1472
1473        /* We could do deflated delta, or we could do just deflated two,
1474         * whichever is smaller.
1475         */
1476        delta = NULL;
1477        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1478        if (one->size && two->size) {
1479                delta = diff_delta(one->ptr, one->size,
1480                                   two->ptr, two->size,
1481                                   &delta_size, deflate_size);
1482                if (delta) {
1483                        void *to_free = delta;
1484                        orig_size = delta_size;
1485                        delta = deflate_it(delta, delta_size, &delta_size);
1486                        free(to_free);
1487                }
1488        }
1489
1490        if (delta && delta_size < deflate_size) {
1491                fprintf(file, "delta %lu\n", orig_size);
1492                free(deflated);
1493                data = delta;
1494                data_size = delta_size;
1495        }
1496        else {
1497                fprintf(file, "literal %lu\n", two->size);
1498                free(delta);
1499                data = deflated;
1500                data_size = deflate_size;
1501        }
1502
1503        /* emit data encoded in base85 */
1504        cp = data;
1505        while (data_size) {
1506                int bytes = (52 < data_size) ? 52 : data_size;
1507                char line[70];
1508                data_size -= bytes;
1509                if (bytes <= 26)
1510                        line[0] = bytes + 'A' - 1;
1511                else
1512                        line[0] = bytes - 26 + 'a' - 1;
1513                encode_85(line + 1, cp, bytes);
1514                cp = (char *) cp + bytes;
1515                fputs(line, file);
1516                fputc('\n', file);
1517        }
1518        fprintf(file, "\n");
1519        free(data);
1520}
1521
1522static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1523{
1524        fprintf(file, "GIT binary patch\n");
1525        emit_binary_diff_body(file, one, two);
1526        emit_binary_diff_body(file, two, one);
1527}
1528
1529static void diff_filespec_load_driver(struct diff_filespec *one)
1530{
1531        if (!one->driver)
1532                one->driver = userdiff_find_by_path(one->path);
1533        if (!one->driver)
1534                one->driver = userdiff_find_by_name("default");
1535}
1536
1537int diff_filespec_is_binary(struct diff_filespec *one)
1538{
1539        if (one->is_binary == -1) {
1540                diff_filespec_load_driver(one);
1541                if (one->driver->binary != -1)
1542                        one->is_binary = one->driver->binary;
1543                else {
1544                        if (!one->data && DIFF_FILE_VALID(one))
1545                                diff_populate_filespec(one, 0);
1546                        if (one->data)
1547                                one->is_binary = buffer_is_binary(one->data,
1548                                                one->size);
1549                        if (one->is_binary == -1)
1550                                one->is_binary = 0;
1551                }
1552        }
1553        return one->is_binary;
1554}
1555
1556static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1557{
1558        diff_filespec_load_driver(one);
1559        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1560}
1561
1562static const char *userdiff_word_regex(struct diff_filespec *one)
1563{
1564        diff_filespec_load_driver(one);
1565        return one->driver->word_regex;
1566}
1567
1568void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1569{
1570        if (!options->a_prefix)
1571                options->a_prefix = a;
1572        if (!options->b_prefix)
1573                options->b_prefix = b;
1574}
1575
1576static struct userdiff_driver *get_textconv(struct diff_filespec *one)
1577{
1578        if (!DIFF_FILE_VALID(one))
1579                return NULL;
1580        if (!S_ISREG(one->mode))
1581                return NULL;
1582        diff_filespec_load_driver(one);
1583        if (!one->driver->textconv)
1584                return NULL;
1585
1586        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1587                struct notes_cache *c = xmalloc(sizeof(*c));
1588                struct strbuf name = STRBUF_INIT;
1589
1590                strbuf_addf(&name, "textconv/%s", one->driver->name);
1591                notes_cache_init(c, name.buf, one->driver->textconv);
1592                one->driver->textconv_cache = c;
1593        }
1594
1595        return one->driver;
1596}
1597
1598static void builtin_diff(const char *name_a,
1599                         const char *name_b,
1600                         struct diff_filespec *one,
1601                         struct diff_filespec *two,
1602                         const char *xfrm_msg,
1603                         struct diff_options *o,
1604                         int complete_rewrite)
1605{
1606        mmfile_t mf1, mf2;
1607        const char *lbl[2];
1608        char *a_one, *b_two;
1609        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1610        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1611        const char *a_prefix, *b_prefix;
1612        struct userdiff_driver *textconv_one = NULL;
1613        struct userdiff_driver *textconv_two = NULL;
1614        struct strbuf header = STRBUF_INIT;
1615
1616        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1617                        (!one->mode || S_ISGITLINK(one->mode)) &&
1618                        (!two->mode || S_ISGITLINK(two->mode))) {
1619                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1620                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1621                show_submodule_summary(o->file, one ? one->path : two->path,
1622                                one->sha1, two->sha1, two->dirty_submodule,
1623                                del, add, reset);
1624                return;
1625        }
1626
1627        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1628                textconv_one = get_textconv(one);
1629                textconv_two = get_textconv(two);
1630        }
1631
1632        diff_set_mnemonic_prefix(o, "a/", "b/");
1633        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1634                a_prefix = o->b_prefix;
1635                b_prefix = o->a_prefix;
1636        } else {
1637                a_prefix = o->a_prefix;
1638                b_prefix = o->b_prefix;
1639        }
1640
1641        /* Never use a non-valid filename anywhere if at all possible */
1642        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1643        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1644
1645        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1646        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1647        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1648        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1649        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1650        if (lbl[0][0] == '/') {
1651                /* /dev/null */
1652                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1653                if (xfrm_msg && xfrm_msg[0])
1654                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1655        }
1656        else if (lbl[1][0] == '/') {
1657                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1658                if (xfrm_msg && xfrm_msg[0])
1659                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1660        }
1661        else {
1662                if (one->mode != two->mode) {
1663                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1664                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1665                }
1666                if (xfrm_msg && xfrm_msg[0])
1667                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1668
1669                /*
1670                 * we do not run diff between different kind
1671                 * of objects.
1672                 */
1673                if ((one->mode ^ two->mode) & S_IFMT)
1674                        goto free_ab_and_return;
1675                if (complete_rewrite &&
1676                    (textconv_one || !diff_filespec_is_binary(one)) &&
1677                    (textconv_two || !diff_filespec_is_binary(two))) {
1678                        fprintf(o->file, "%s", header.buf);
1679                        strbuf_reset(&header);
1680                        emit_rewrite_diff(name_a, name_b, one, two,
1681                                                textconv_one, textconv_two, o);
1682                        o->found_changes = 1;
1683                        goto free_ab_and_return;
1684                }
1685        }
1686
1687        if (!DIFF_OPT_TST(o, TEXT) &&
1688            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1689              (!textconv_two && diff_filespec_is_binary(two)) )) {
1690                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1691                        die("unable to read files to diff");
1692                /* Quite common confusing case */
1693                if (mf1.size == mf2.size &&
1694                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1695                        goto free_ab_and_return;
1696                fprintf(o->file, "%s", header.buf);
1697                strbuf_reset(&header);
1698                if (DIFF_OPT_TST(o, BINARY))
1699                        emit_binary_diff(o->file, &mf1, &mf2);
1700                else
1701                        fprintf(o->file, "Binary files %s and %s differ\n",
1702                                lbl[0], lbl[1]);
1703                o->found_changes = 1;
1704        }
1705        else {
1706                /* Crazy xdl interfaces.. */
1707                const char *diffopts = getenv("GIT_DIFF_OPTS");
1708                xpparam_t xpp;
1709                xdemitconf_t xecfg;
1710                struct emit_callback ecbdata;
1711                const struct userdiff_funcname *pe;
1712
1713                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1714                        fprintf(o->file, "%s", header.buf);
1715                        strbuf_reset(&header);
1716                }
1717
1718                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1719                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1720
1721                pe = diff_funcname_pattern(one);
1722                if (!pe)
1723                        pe = diff_funcname_pattern(two);
1724
1725                memset(&xpp, 0, sizeof(xpp));
1726                memset(&xecfg, 0, sizeof(xecfg));
1727                memset(&ecbdata, 0, sizeof(ecbdata));
1728                ecbdata.label_path = lbl;
1729                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1730                ecbdata.found_changesp = &o->found_changes;
1731                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1732                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1733                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1734                ecbdata.file = o->file;
1735                ecbdata.header = header.len ? &header : NULL;
1736                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1737                xecfg.ctxlen = o->context;
1738                xecfg.interhunkctxlen = o->interhunkcontext;
1739                xecfg.flags = XDL_EMIT_FUNCNAMES;
1740                if (pe)
1741                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1742                if (!diffopts)
1743                        ;
1744                else if (!prefixcmp(diffopts, "--unified="))
1745                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1746                else if (!prefixcmp(diffopts, "-u"))
1747                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1748                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1749                        ecbdata.diff_words =
1750                                xcalloc(1, sizeof(struct diff_words_data));
1751                        ecbdata.diff_words->file = o->file;
1752                        if (!o->word_regex)
1753                                o->word_regex = userdiff_word_regex(one);
1754                        if (!o->word_regex)
1755                                o->word_regex = userdiff_word_regex(two);
1756                        if (!o->word_regex)
1757                                o->word_regex = diff_word_regex_cfg;
1758                        if (o->word_regex) {
1759                                ecbdata.diff_words->word_regex = (regex_t *)
1760                                        xmalloc(sizeof(regex_t));
1761                                if (regcomp(ecbdata.diff_words->word_regex,
1762                                                o->word_regex,
1763                                                REG_EXTENDED | REG_NEWLINE))
1764                                        die ("Invalid regular expression: %s",
1765                                                        o->word_regex);
1766                        }
1767                }
1768                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1769                              &xpp, &xecfg);
1770                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1771                        free_diff_words_data(&ecbdata);
1772                if (textconv_one)
1773                        free(mf1.ptr);
1774                if (textconv_two)
1775                        free(mf2.ptr);
1776                xdiff_clear_find_func(&xecfg);
1777        }
1778
1779 free_ab_and_return:
1780        strbuf_release(&header);
1781        diff_free_filespec_data(one);
1782        diff_free_filespec_data(two);
1783        free(a_one);
1784        free(b_two);
1785        return;
1786}
1787
1788static void builtin_diffstat(const char *name_a, const char *name_b,
1789                             struct diff_filespec *one,
1790                             struct diff_filespec *two,
1791                             struct diffstat_t *diffstat,
1792                             struct diff_options *o,
1793                             int complete_rewrite)
1794{
1795        mmfile_t mf1, mf2;
1796        struct diffstat_file *data;
1797
1798        data = diffstat_add(diffstat, name_a, name_b);
1799
1800        if (!one || !two) {
1801                data->is_unmerged = 1;
1802                return;
1803        }
1804        if (complete_rewrite) {
1805                diff_populate_filespec(one, 0);
1806                diff_populate_filespec(two, 0);
1807                data->deleted = count_lines(one->data, one->size);
1808                data->added = count_lines(two->data, two->size);
1809                goto free_and_return;
1810        }
1811        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1812                die("unable to read files to diff");
1813
1814        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1815                data->is_binary = 1;
1816                data->added = mf2.size;
1817                data->deleted = mf1.size;
1818        } else {
1819                /* Crazy xdl interfaces.. */
1820                xpparam_t xpp;
1821                xdemitconf_t xecfg;
1822
1823                memset(&xpp, 0, sizeof(xpp));
1824                memset(&xecfg, 0, sizeof(xecfg));
1825                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1826                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1827                              &xpp, &xecfg);
1828        }
1829
1830 free_and_return:
1831        diff_free_filespec_data(one);
1832        diff_free_filespec_data(two);
1833}
1834
1835static void builtin_checkdiff(const char *name_a, const char *name_b,
1836                              const char *attr_path,
1837                              struct diff_filespec *one,
1838                              struct diff_filespec *two,
1839                              struct diff_options *o)
1840{
1841        mmfile_t mf1, mf2;
1842        struct checkdiff_t data;
1843
1844        if (!two)
1845                return;
1846
1847        memset(&data, 0, sizeof(data));
1848        data.filename = name_b ? name_b : name_a;
1849        data.lineno = 0;
1850        data.o = o;
1851        data.ws_rule = whitespace_rule(attr_path);
1852        data.conflict_marker_size = ll_merge_marker_size(attr_path);
1853
1854        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1855                die("unable to read files to diff");
1856
1857        /*
1858         * All the other codepaths check both sides, but not checking
1859         * the "old" side here is deliberate.  We are checking the newly
1860         * introduced changes, and as long as the "new" side is text, we
1861         * can and should check what it introduces.
1862         */
1863        if (diff_filespec_is_binary(two))
1864                goto free_and_return;
1865        else {
1866                /* Crazy xdl interfaces.. */
1867                xpparam_t xpp;
1868                xdemitconf_t xecfg;
1869
1870                memset(&xpp, 0, sizeof(xpp));
1871                memset(&xecfg, 0, sizeof(xecfg));
1872                xecfg.ctxlen = 1; /* at least one context line */
1873                xpp.flags = XDF_NEED_MINIMAL;
1874                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1875                              &xpp, &xecfg);
1876
1877                if (data.ws_rule & WS_BLANK_AT_EOF) {
1878                        struct emit_callback ecbdata;
1879                        int blank_at_eof;
1880
1881                        ecbdata.ws_rule = data.ws_rule;
1882                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1883                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1884
1885                        if (blank_at_eof) {
1886                                static char *err;
1887                                if (!err)
1888                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1889                                fprintf(o->file, "%s:%d: %s.\n",
1890                                        data.filename, blank_at_eof, err);
1891                                data.status = 1; /* report errors */
1892                        }
1893                }
1894        }
1895 free_and_return:
1896        diff_free_filespec_data(one);
1897        diff_free_filespec_data(two);
1898        if (data.status)
1899                DIFF_OPT_SET(o, CHECK_FAILED);
1900}
1901
1902struct diff_filespec *alloc_filespec(const char *path)
1903{
1904        int namelen = strlen(path);
1905        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1906
1907        memset(spec, 0, sizeof(*spec));
1908        spec->path = (char *)(spec + 1);
1909        memcpy(spec->path, path, namelen+1);
1910        spec->count = 1;
1911        spec->is_binary = -1;
1912        return spec;
1913}
1914
1915void free_filespec(struct diff_filespec *spec)
1916{
1917        if (!--spec->count) {
1918                diff_free_filespec_data(spec);
1919                free(spec);
1920        }
1921}
1922
1923void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1924                   unsigned short mode)
1925{
1926        if (mode) {
1927                spec->mode = canon_mode(mode);
1928                hashcpy(spec->sha1, sha1);
1929                spec->sha1_valid = !is_null_sha1(sha1);
1930        }
1931}
1932
1933/*
1934 * Given a name and sha1 pair, if the index tells us the file in
1935 * the work tree has that object contents, return true, so that
1936 * prepare_temp_file() does not have to inflate and extract.
1937 */
1938static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1939{
1940        struct cache_entry *ce;
1941        struct stat st;
1942        int pos, len;
1943
1944        /*
1945         * We do not read the cache ourselves here, because the
1946         * benchmark with my previous version that always reads cache
1947         * shows that it makes things worse for diff-tree comparing
1948         * two linux-2.6 kernel trees in an already checked out work
1949         * tree.  This is because most diff-tree comparisons deal with
1950         * only a small number of files, while reading the cache is
1951         * expensive for a large project, and its cost outweighs the
1952         * savings we get by not inflating the object to a temporary
1953         * file.  Practically, this code only helps when we are used
1954         * by diff-cache --cached, which does read the cache before
1955         * calling us.
1956         */
1957        if (!active_cache)
1958                return 0;
1959
1960        /* We want to avoid the working directory if our caller
1961         * doesn't need the data in a normal file, this system
1962         * is rather slow with its stat/open/mmap/close syscalls,
1963         * and the object is contained in a pack file.  The pack
1964         * is probably already open and will be faster to obtain
1965         * the data through than the working directory.  Loose
1966         * objects however would tend to be slower as they need
1967         * to be individually opened and inflated.
1968         */
1969        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1970                return 0;
1971
1972        len = strlen(name);
1973        pos = cache_name_pos(name, len);
1974        if (pos < 0)
1975                return 0;
1976        ce = active_cache[pos];
1977
1978        /*
1979         * This is not the sha1 we are looking for, or
1980         * unreusable because it is not a regular file.
1981         */
1982        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1983                return 0;
1984
1985        /*
1986         * If ce is marked as "assume unchanged", there is no
1987         * guarantee that work tree matches what we are looking for.
1988         */
1989        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1990                return 0;
1991
1992        /*
1993         * If ce matches the file in the work tree, we can reuse it.
1994         */
1995        if (ce_uptodate(ce) ||
1996            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1997                return 1;
1998
1999        return 0;
2000}
2001
2002static int populate_from_stdin(struct diff_filespec *s)
2003{
2004        struct strbuf buf = STRBUF_INIT;
2005        size_t size = 0;
2006
2007        if (strbuf_read(&buf, 0, 0) < 0)
2008                return error("error while reading from stdin %s",
2009                                     strerror(errno));
2010
2011        s->should_munmap = 0;
2012        s->data = strbuf_detach(&buf, &size);
2013        s->size = size;
2014        s->should_free = 1;
2015        return 0;
2016}
2017
2018static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2019{
2020        int len;
2021        char *data = xmalloc(100), *dirty = "";
2022
2023        /* Are we looking at the work tree? */
2024        if (s->dirty_submodule)
2025                dirty = "-dirty";
2026
2027        len = snprintf(data, 100,
2028                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2029        s->data = data;
2030        s->size = len;
2031        s->should_free = 1;
2032        if (size_only) {
2033                s->data = NULL;
2034                free(data);
2035        }
2036        return 0;
2037}
2038
2039/*
2040 * While doing rename detection and pickaxe operation, we may need to
2041 * grab the data for the blob (or file) for our own in-core comparison.
2042 * diff_filespec has data and size fields for this purpose.
2043 */
2044int diff_populate_filespec(struct diff_filespec *s, int size_only)
2045{
2046        int err = 0;
2047        if (!DIFF_FILE_VALID(s))
2048                die("internal error: asking to populate invalid file.");
2049        if (S_ISDIR(s->mode))
2050                return -1;
2051
2052        if (s->data)
2053                return 0;
2054
2055        if (size_only && 0 < s->size)
2056                return 0;
2057
2058        if (S_ISGITLINK(s->mode))
2059                return diff_populate_gitlink(s, size_only);
2060
2061        if (!s->sha1_valid ||
2062            reuse_worktree_file(s->path, s->sha1, 0)) {
2063                struct strbuf buf = STRBUF_INIT;
2064                struct stat st;
2065                int fd;
2066
2067                if (!strcmp(s->path, "-"))
2068                        return populate_from_stdin(s);
2069
2070                if (lstat(s->path, &st) < 0) {
2071                        if (errno == ENOENT) {
2072                        err_empty:
2073                                err = -1;
2074                        empty:
2075                                s->data = (char *)"";
2076                                s->size = 0;
2077                                return err;
2078                        }
2079                }
2080                s->size = xsize_t(st.st_size);
2081                if (!s->size)
2082                        goto empty;
2083                if (S_ISLNK(st.st_mode)) {
2084                        struct strbuf sb = STRBUF_INIT;
2085
2086                        if (strbuf_readlink(&sb, s->path, s->size))
2087                                goto err_empty;
2088                        s->size = sb.len;
2089                        s->data = strbuf_detach(&sb, NULL);
2090                        s->should_free = 1;
2091                        return 0;
2092                }
2093                if (size_only)
2094                        return 0;
2095                fd = open(s->path, O_RDONLY);
2096                if (fd < 0)
2097                        goto err_empty;
2098                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2099                close(fd);
2100                s->should_munmap = 1;
2101
2102                /*
2103                 * Convert from working tree format to canonical git format
2104                 */
2105                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2106                        size_t size = 0;
2107                        munmap(s->data, s->size);
2108                        s->should_munmap = 0;
2109                        s->data = strbuf_detach(&buf, &size);
2110                        s->size = size;
2111                        s->should_free = 1;
2112                }
2113        }
2114        else {
2115                enum object_type type;
2116                if (size_only)
2117                        type = sha1_object_info(s->sha1, &s->size);
2118                else {
2119                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2120                        s->should_free = 1;
2121                }
2122        }
2123        return 0;
2124}
2125
2126void diff_free_filespec_blob(struct diff_filespec *s)
2127{
2128        if (s->should_free)
2129                free(s->data);
2130        else if (s->should_munmap)
2131                munmap(s->data, s->size);
2132
2133        if (s->should_free || s->should_munmap) {
2134                s->should_free = s->should_munmap = 0;
2135                s->data = NULL;
2136        }
2137}
2138
2139void diff_free_filespec_data(struct diff_filespec *s)
2140{
2141        diff_free_filespec_blob(s);
2142        free(s->cnt_data);
2143        s->cnt_data = NULL;
2144}
2145
2146static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2147                           void *blob,
2148                           unsigned long size,
2149                           const unsigned char *sha1,
2150                           int mode)
2151{
2152        int fd;
2153        struct strbuf buf = STRBUF_INIT;
2154        struct strbuf template = STRBUF_INIT;
2155        char *path_dup = xstrdup(path);
2156        const char *base = basename(path_dup);
2157
2158        /* Generate "XXXXXX_basename.ext" */
2159        strbuf_addstr(&template, "XXXXXX_");
2160        strbuf_addstr(&template, base);
2161
2162        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2163                        strlen(base) + 1);
2164        if (fd < 0)
2165                die_errno("unable to create temp-file");
2166        if (convert_to_working_tree(path,
2167                        (const char *)blob, (size_t)size, &buf)) {
2168                blob = buf.buf;
2169                size = buf.len;
2170        }
2171        if (write_in_full(fd, blob, size) != size)
2172                die_errno("unable to write temp-file");
2173        close(fd);
2174        temp->name = temp->tmp_path;
2175        strcpy(temp->hex, sha1_to_hex(sha1));
2176        temp->hex[40] = 0;
2177        sprintf(temp->mode, "%06o", mode);
2178        strbuf_release(&buf);
2179        strbuf_release(&template);
2180        free(path_dup);
2181}
2182
2183static struct diff_tempfile *prepare_temp_file(const char *name,
2184                struct diff_filespec *one)
2185{
2186        struct diff_tempfile *temp = claim_diff_tempfile();
2187
2188        if (!DIFF_FILE_VALID(one)) {
2189        not_a_valid_file:
2190                /* A '-' entry produces this for file-2, and
2191                 * a '+' entry produces this for file-1.
2192                 */
2193                temp->name = "/dev/null";
2194                strcpy(temp->hex, ".");
2195                strcpy(temp->mode, ".");
2196                return temp;
2197        }
2198
2199        if (!remove_tempfile_installed) {
2200                atexit(remove_tempfile);
2201                sigchain_push_common(remove_tempfile_on_signal);
2202                remove_tempfile_installed = 1;
2203        }
2204
2205        if (!one->sha1_valid ||
2206            reuse_worktree_file(name, one->sha1, 1)) {
2207                struct stat st;
2208                if (lstat(name, &st) < 0) {
2209                        if (errno == ENOENT)
2210                                goto not_a_valid_file;
2211                        die_errno("stat(%s)", name);
2212                }
2213                if (S_ISLNK(st.st_mode)) {
2214                        struct strbuf sb = STRBUF_INIT;
2215                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2216                                die_errno("readlink(%s)", name);
2217                        prep_temp_blob(name, temp, sb.buf, sb.len,
2218                                       (one->sha1_valid ?
2219                                        one->sha1 : null_sha1),
2220                                       (one->sha1_valid ?
2221                                        one->mode : S_IFLNK));
2222                        strbuf_release(&sb);
2223                }
2224                else {
2225                        /* we can borrow from the file in the work tree */
2226                        temp->name = name;
2227                        if (!one->sha1_valid)
2228                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2229                        else
2230                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2231                        /* Even though we may sometimes borrow the
2232                         * contents from the work tree, we always want
2233                         * one->mode.  mode is trustworthy even when
2234                         * !(one->sha1_valid), as long as
2235                         * DIFF_FILE_VALID(one).
2236                         */
2237                        sprintf(temp->mode, "%06o", one->mode);
2238                }
2239                return temp;
2240        }
2241        else {
2242                if (diff_populate_filespec(one, 0))
2243                        die("cannot read data blob for %s", one->path);
2244                prep_temp_blob(name, temp, one->data, one->size,
2245                               one->sha1, one->mode);
2246        }
2247        return temp;
2248}
2249
2250/* An external diff command takes:
2251 *
2252 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2253 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2254 *
2255 */
2256static void run_external_diff(const char *pgm,
2257                              const char *name,
2258                              const char *other,
2259                              struct diff_filespec *one,
2260                              struct diff_filespec *two,
2261                              const char *xfrm_msg,
2262                              int complete_rewrite)
2263{
2264        const char *spawn_arg[10];
2265        int retval;
2266        const char **arg = &spawn_arg[0];
2267
2268        if (one && two) {
2269                struct diff_tempfile *temp_one, *temp_two;
2270                const char *othername = (other ? other : name);
2271                temp_one = prepare_temp_file(name, one);
2272                temp_two = prepare_temp_file(othername, two);
2273                *arg++ = pgm;
2274                *arg++ = name;
2275                *arg++ = temp_one->name;
2276                *arg++ = temp_one->hex;
2277                *arg++ = temp_one->mode;
2278                *arg++ = temp_two->name;
2279                *arg++ = temp_two->hex;
2280                *arg++ = temp_two->mode;
2281                if (other) {
2282                        *arg++ = other;
2283                        *arg++ = xfrm_msg;
2284                }
2285        } else {
2286                *arg++ = pgm;
2287                *arg++ = name;
2288        }
2289        *arg = NULL;
2290        fflush(NULL);
2291        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2292        remove_tempfile();
2293        if (retval) {
2294                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2295                exit(1);
2296        }
2297}
2298
2299static int similarity_index(struct diff_filepair *p)
2300{
2301        return p->score * 100 / MAX_SCORE;
2302}
2303
2304static void fill_metainfo(struct strbuf *msg,
2305                          const char *name,
2306                          const char *other,
2307                          struct diff_filespec *one,
2308                          struct diff_filespec *two,
2309                          struct diff_options *o,
2310                          struct diff_filepair *p)
2311{
2312        strbuf_init(msg, PATH_MAX * 2 + 300);
2313        switch (p->status) {
2314        case DIFF_STATUS_COPIED:
2315                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2316                strbuf_addstr(msg, "\ncopy from ");
2317                quote_c_style(name, msg, NULL, 0);
2318                strbuf_addstr(msg, "\ncopy to ");
2319                quote_c_style(other, msg, NULL, 0);
2320                strbuf_addch(msg, '\n');
2321                break;
2322        case DIFF_STATUS_RENAMED:
2323                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2324                strbuf_addstr(msg, "\nrename from ");
2325                quote_c_style(name, msg, NULL, 0);
2326                strbuf_addstr(msg, "\nrename to ");
2327                quote_c_style(other, msg, NULL, 0);
2328                strbuf_addch(msg, '\n');
2329                break;
2330        case DIFF_STATUS_MODIFIED:
2331                if (p->score) {
2332                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2333                                    similarity_index(p));
2334                        break;
2335                }
2336                /* fallthru */
2337        default:
2338                /* nothing */
2339                ;
2340        }
2341        if (one && two && hashcmp(one->sha1, two->sha1)) {
2342                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2343
2344                if (DIFF_OPT_TST(o, BINARY)) {
2345                        mmfile_t mf;
2346                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2347                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2348                                abbrev = 40;
2349                }
2350                strbuf_addf(msg, "index %.*s..%.*s",
2351                            abbrev, sha1_to_hex(one->sha1),
2352                            abbrev, sha1_to_hex(two->sha1));
2353                if (one->mode == two->mode)
2354                        strbuf_addf(msg, " %06o", one->mode);
2355                strbuf_addch(msg, '\n');
2356        }
2357        if (msg->len)
2358                strbuf_setlen(msg, msg->len - 1);
2359}
2360
2361static void run_diff_cmd(const char *pgm,
2362                         const char *name,
2363                         const char *other,
2364                         const char *attr_path,
2365                         struct diff_filespec *one,
2366                         struct diff_filespec *two,
2367                         struct strbuf *msg,
2368                         struct diff_options *o,
2369                         struct diff_filepair *p)
2370{
2371        const char *xfrm_msg = NULL;
2372        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2373
2374        if (msg) {
2375                fill_metainfo(msg, name, other, one, two, o, p);
2376                xfrm_msg = msg->len ? msg->buf : NULL;
2377        }
2378
2379        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2380                pgm = NULL;
2381        else {
2382                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2383                if (drv && drv->external)
2384                        pgm = drv->external;
2385        }
2386
2387        if (pgm) {
2388                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2389                                  complete_rewrite);
2390                return;
2391        }
2392        if (one && two)
2393                builtin_diff(name, other ? other : name,
2394                             one, two, xfrm_msg, o, complete_rewrite);
2395        else
2396                fprintf(o->file, "* Unmerged path %s\n", name);
2397}
2398
2399static void diff_fill_sha1_info(struct diff_filespec *one)
2400{
2401        if (DIFF_FILE_VALID(one)) {
2402                if (!one->sha1_valid) {
2403                        struct stat st;
2404                        if (!strcmp(one->path, "-")) {
2405                                hashcpy(one->sha1, null_sha1);
2406                                return;
2407                        }
2408                        if (lstat(one->path, &st) < 0)
2409                                die_errno("stat '%s'", one->path);
2410                        if (index_path(one->sha1, one->path, &st, 0))
2411                                die("cannot hash %s", one->path);
2412                }
2413        }
2414        else
2415                hashclr(one->sha1);
2416}
2417
2418static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2419{
2420        /* Strip the prefix but do not molest /dev/null and absolute paths */
2421        if (*namep && **namep != '/')
2422                *namep += prefix_length;
2423        if (*otherp && **otherp != '/')
2424                *otherp += prefix_length;
2425}
2426
2427static void run_diff(struct diff_filepair *p, struct diff_options *o)
2428{
2429        const char *pgm = external_diff();
2430        struct strbuf msg;
2431        struct diff_filespec *one = p->one;
2432        struct diff_filespec *two = p->two;
2433        const char *name;
2434        const char *other;
2435        const char *attr_path;
2436
2437        name  = p->one->path;
2438        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2439        attr_path = name;
2440        if (o->prefix_length)
2441                strip_prefix(o->prefix_length, &name, &other);
2442
2443        if (DIFF_PAIR_UNMERGED(p)) {
2444                run_diff_cmd(pgm, name, NULL, attr_path,
2445                             NULL, NULL, NULL, o, p);
2446                return;
2447        }
2448
2449        diff_fill_sha1_info(one);
2450        diff_fill_sha1_info(two);
2451
2452        if (!pgm &&
2453            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2454            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2455                /*
2456                 * a filepair that changes between file and symlink
2457                 * needs to be split into deletion and creation.
2458                 */
2459                struct diff_filespec *null = alloc_filespec(two->path);
2460                run_diff_cmd(NULL, name, other, attr_path,
2461                             one, null, &msg, o, p);
2462                free(null);
2463                strbuf_release(&msg);
2464
2465                null = alloc_filespec(one->path);
2466                run_diff_cmd(NULL, name, other, attr_path,
2467                             null, two, &msg, o, p);
2468                free(null);
2469        }
2470        else
2471                run_diff_cmd(pgm, name, other, attr_path,
2472                             one, two, &msg, o, p);
2473
2474        strbuf_release(&msg);
2475}
2476
2477static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2478                         struct diffstat_t *diffstat)
2479{
2480        const char *name;
2481        const char *other;
2482        int complete_rewrite = 0;
2483
2484        if (DIFF_PAIR_UNMERGED(p)) {
2485                /* unmerged */
2486                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2487                return;
2488        }
2489
2490        name = p->one->path;
2491        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2492
2493        if (o->prefix_length)
2494                strip_prefix(o->prefix_length, &name, &other);
2495
2496        diff_fill_sha1_info(p->one);
2497        diff_fill_sha1_info(p->two);
2498
2499        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2500                complete_rewrite = 1;
2501        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2502}
2503
2504static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2505{
2506        const char *name;
2507        const char *other;
2508        const char *attr_path;
2509
2510        if (DIFF_PAIR_UNMERGED(p)) {
2511                /* unmerged */
2512                return;
2513        }
2514
2515        name = p->one->path;
2516        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2517        attr_path = other ? other : name;
2518
2519        if (o->prefix_length)
2520                strip_prefix(o->prefix_length, &name, &other);
2521
2522        diff_fill_sha1_info(p->one);
2523        diff_fill_sha1_info(p->two);
2524
2525        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2526}
2527
2528void diff_setup(struct diff_options *options)
2529{
2530        memset(options, 0, sizeof(*options));
2531
2532        options->file = stdout;
2533
2534        options->line_termination = '\n';
2535        options->break_opt = -1;
2536        options->rename_limit = -1;
2537        options->dirstat_percent = 3;
2538        options->context = 3;
2539
2540        options->change = diff_change;
2541        options->add_remove = diff_addremove;
2542        if (diff_use_color_default > 0)
2543                DIFF_OPT_SET(options, COLOR_DIFF);
2544        options->detect_rename = diff_detect_rename_default;
2545
2546        if (diff_no_prefix) {
2547                options->a_prefix = options->b_prefix = "";
2548        } else if (!diff_mnemonic_prefix) {
2549                options->a_prefix = "a/";
2550                options->b_prefix = "b/";
2551        }
2552}
2553
2554int diff_setup_done(struct diff_options *options)
2555{
2556        int count = 0;
2557
2558        if (options->output_format & DIFF_FORMAT_NAME)
2559                count++;
2560        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2561                count++;
2562        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2563                count++;
2564        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2565                count++;
2566        if (count > 1)
2567                die("--name-only, --name-status, --check and -s are mutually exclusive");
2568
2569        /*
2570         * Most of the time we can say "there are changes"
2571         * only by checking if there are changed paths, but
2572         * --ignore-whitespace* options force us to look
2573         * inside contents.
2574         */
2575
2576        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2577            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2578            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2579                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2580        else
2581                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2582
2583        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2584                options->detect_rename = DIFF_DETECT_COPY;
2585
2586        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2587                options->prefix = NULL;
2588        if (options->prefix)
2589                options->prefix_length = strlen(options->prefix);
2590        else
2591                options->prefix_length = 0;
2592
2593        if (options->output_format & (DIFF_FORMAT_NAME |
2594                                      DIFF_FORMAT_NAME_STATUS |
2595                                      DIFF_FORMAT_CHECKDIFF |
2596                                      DIFF_FORMAT_NO_OUTPUT))
2597                options->output_format &= ~(DIFF_FORMAT_RAW |
2598                                            DIFF_FORMAT_NUMSTAT |
2599                                            DIFF_FORMAT_DIFFSTAT |
2600                                            DIFF_FORMAT_SHORTSTAT |
2601                                            DIFF_FORMAT_DIRSTAT |
2602                                            DIFF_FORMAT_SUMMARY |
2603                                            DIFF_FORMAT_PATCH);
2604
2605        /*
2606         * These cases always need recursive; we do not drop caller-supplied
2607         * recursive bits for other formats here.
2608         */
2609        if (options->output_format & (DIFF_FORMAT_PATCH |
2610                                      DIFF_FORMAT_NUMSTAT |
2611                                      DIFF_FORMAT_DIFFSTAT |
2612                                      DIFF_FORMAT_SHORTSTAT |
2613                                      DIFF_FORMAT_DIRSTAT |
2614                                      DIFF_FORMAT_SUMMARY |
2615                                      DIFF_FORMAT_CHECKDIFF))
2616                DIFF_OPT_SET(options, RECURSIVE);
2617        /*
2618         * Also pickaxe would not work very well if you do not say recursive
2619         */
2620        if (options->pickaxe)
2621                DIFF_OPT_SET(options, RECURSIVE);
2622        /*
2623         * When patches are generated, submodules diffed against the work tree
2624         * must be checked for dirtiness too so it can be shown in the output
2625         */
2626        if (options->output_format & DIFF_FORMAT_PATCH)
2627                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2628
2629        if (options->detect_rename && options->rename_limit < 0)
2630                options->rename_limit = diff_rename_limit_default;
2631        if (options->setup & DIFF_SETUP_USE_CACHE) {
2632                if (!active_cache)
2633                        /* read-cache does not die even when it fails
2634                         * so it is safe for us to do this here.  Also
2635                         * it does not smudge active_cache or active_nr
2636                         * when it fails, so we do not have to worry about
2637                         * cleaning it up ourselves either.
2638                         */
2639                        read_cache();
2640        }
2641        if (options->abbrev <= 0 || 40 < options->abbrev)
2642                options->abbrev = 40; /* full */
2643
2644        /*
2645         * It does not make sense to show the first hit we happened
2646         * to have found.  It does not make sense not to return with
2647         * exit code in such a case either.
2648         */
2649        if (DIFF_OPT_TST(options, QUICK)) {
2650                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2651                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2652        }
2653
2654        return 0;
2655}
2656
2657static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2658{
2659        char c, *eq;
2660        int len;
2661
2662        if (*arg != '-')
2663                return 0;
2664        c = *++arg;
2665        if (!c)
2666                return 0;
2667        if (c == arg_short) {
2668                c = *++arg;
2669                if (!c)
2670                        return 1;
2671                if (val && isdigit(c)) {
2672                        char *end;
2673                        int n = strtoul(arg, &end, 10);
2674                        if (*end)
2675                                return 0;
2676                        *val = n;
2677                        return 1;
2678                }
2679                return 0;
2680        }
2681        if (c != '-')
2682                return 0;
2683        arg++;
2684        eq = strchr(arg, '=');
2685        if (eq)
2686                len = eq - arg;
2687        else
2688                len = strlen(arg);
2689        if (!len || strncmp(arg, arg_long, len))
2690                return 0;
2691        if (eq) {
2692                int n;
2693                char *end;
2694                if (!isdigit(*++eq))
2695                        return 0;
2696                n = strtoul(eq, &end, 10);
2697                if (*end)
2698                        return 0;
2699                *val = n;
2700        }
2701        return 1;
2702}
2703
2704static int diff_scoreopt_parse(const char *opt);
2705
2706int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2707{
2708        const char *arg = av[0];
2709
2710        /* Output format options */
2711        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2712                options->output_format |= DIFF_FORMAT_PATCH;
2713        else if (opt_arg(arg, 'U', "unified", &options->context))
2714                options->output_format |= DIFF_FORMAT_PATCH;
2715        else if (!strcmp(arg, "--raw"))
2716                options->output_format |= DIFF_FORMAT_RAW;
2717        else if (!strcmp(arg, "--patch-with-raw"))
2718                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2719        else if (!strcmp(arg, "--numstat"))
2720                options->output_format |= DIFF_FORMAT_NUMSTAT;
2721        else if (!strcmp(arg, "--shortstat"))
2722                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2723        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2724                options->output_format |= DIFF_FORMAT_DIRSTAT;
2725        else if (!strcmp(arg, "--cumulative")) {
2726                options->output_format |= DIFF_FORMAT_DIRSTAT;
2727                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2728        } else if (opt_arg(arg, 0, "dirstat-by-file",
2729                           &options->dirstat_percent)) {
2730                options->output_format |= DIFF_FORMAT_DIRSTAT;
2731                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2732        }
2733        else if (!strcmp(arg, "--check"))
2734                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2735        else if (!strcmp(arg, "--summary"))
2736                options->output_format |= DIFF_FORMAT_SUMMARY;
2737        else if (!strcmp(arg, "--patch-with-stat"))
2738                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2739        else if (!strcmp(arg, "--name-only"))
2740                options->output_format |= DIFF_FORMAT_NAME;
2741        else if (!strcmp(arg, "--name-status"))
2742                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2743        else if (!strcmp(arg, "-s"))
2744                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2745        else if (!prefixcmp(arg, "--stat")) {
2746                char *end;
2747                int width = options->stat_width;
2748                int name_width = options->stat_name_width;
2749                arg += 6;
2750                end = (char *)arg;
2751
2752                switch (*arg) {
2753                case '-':
2754                        if (!prefixcmp(arg, "-width="))
2755                                width = strtoul(arg + 7, &end, 10);
2756                        else if (!prefixcmp(arg, "-name-width="))
2757                                name_width = strtoul(arg + 12, &end, 10);
2758                        break;
2759                case '=':
2760                        width = strtoul(arg+1, &end, 10);
2761                        if (*end == ',')
2762                                name_width = strtoul(end+1, &end, 10);
2763                }
2764
2765                /* Important! This checks all the error cases! */
2766                if (*end)
2767                        return 0;
2768                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2769                options->stat_name_width = name_width;
2770                options->stat_width = width;
2771        }
2772
2773        /* renames options */
2774        else if (!prefixcmp(arg, "-B")) {
2775                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2776                        return -1;
2777        }
2778        else if (!prefixcmp(arg, "-M")) {
2779                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2780                        return -1;
2781                options->detect_rename = DIFF_DETECT_RENAME;
2782        }
2783        else if (!prefixcmp(arg, "-C")) {
2784                if (options->detect_rename == DIFF_DETECT_COPY)
2785                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2786                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2787                        return -1;
2788                options->detect_rename = DIFF_DETECT_COPY;
2789        }
2790        else if (!strcmp(arg, "--no-renames"))
2791                options->detect_rename = 0;
2792        else if (!strcmp(arg, "--relative"))
2793                DIFF_OPT_SET(options, RELATIVE_NAME);
2794        else if (!prefixcmp(arg, "--relative=")) {
2795                DIFF_OPT_SET(options, RELATIVE_NAME);
2796                options->prefix = arg + 11;
2797        }
2798
2799        /* xdiff options */
2800        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2801                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2802        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2803                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2804        else if (!strcmp(arg, "--ignore-space-at-eol"))
2805                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2806        else if (!strcmp(arg, "--patience"))
2807                DIFF_XDL_SET(options, PATIENCE_DIFF);
2808
2809        /* flags options */
2810        else if (!strcmp(arg, "--binary")) {
2811                options->output_format |= DIFF_FORMAT_PATCH;
2812                DIFF_OPT_SET(options, BINARY);
2813        }
2814        else if (!strcmp(arg, "--full-index"))
2815                DIFF_OPT_SET(options, FULL_INDEX);
2816        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2817                DIFF_OPT_SET(options, TEXT);
2818        else if (!strcmp(arg, "-R"))
2819                DIFF_OPT_SET(options, REVERSE_DIFF);
2820        else if (!strcmp(arg, "--find-copies-harder"))
2821                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2822        else if (!strcmp(arg, "--follow"))
2823                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2824        else if (!strcmp(arg, "--color"))
2825                DIFF_OPT_SET(options, COLOR_DIFF);
2826        else if (!prefixcmp(arg, "--color=")) {
2827                int value = git_config_colorbool(NULL, arg+8, -1);
2828                if (value == 0)
2829                        DIFF_OPT_CLR(options, COLOR_DIFF);
2830                else if (value > 0)
2831                        DIFF_OPT_SET(options, COLOR_DIFF);
2832                else
2833                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2834        }
2835        else if (!strcmp(arg, "--no-color"))
2836                DIFF_OPT_CLR(options, COLOR_DIFF);
2837        else if (!strcmp(arg, "--color-words")) {
2838                DIFF_OPT_SET(options, COLOR_DIFF);
2839                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2840        }
2841        else if (!prefixcmp(arg, "--color-words=")) {
2842                DIFF_OPT_SET(options, COLOR_DIFF);
2843                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2844                options->word_regex = arg + 14;
2845        }
2846        else if (!strcmp(arg, "--exit-code"))
2847                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2848        else if (!strcmp(arg, "--quiet"))
2849                DIFF_OPT_SET(options, QUICK);
2850        else if (!strcmp(arg, "--ext-diff"))
2851                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2852        else if (!strcmp(arg, "--no-ext-diff"))
2853                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2854        else if (!strcmp(arg, "--textconv"))
2855                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2856        else if (!strcmp(arg, "--no-textconv"))
2857                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2858        else if (!strcmp(arg, "--ignore-submodules"))
2859                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2860        else if (!strcmp(arg, "--submodule"))
2861                DIFF_OPT_SET(options, SUBMODULE_LOG);
2862        else if (!prefixcmp(arg, "--submodule=")) {
2863                if (!strcmp(arg + 12, "log"))
2864                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2865        }
2866
2867        /* misc options */
2868        else if (!strcmp(arg, "-z"))
2869                options->line_termination = 0;
2870        else if (!prefixcmp(arg, "-l"))
2871                options->rename_limit = strtoul(arg+2, NULL, 10);
2872        else if (!prefixcmp(arg, "-S"))
2873                options->pickaxe = arg + 2;
2874        else if (!strcmp(arg, "--pickaxe-all"))
2875                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2876        else if (!strcmp(arg, "--pickaxe-regex"))
2877                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2878        else if (!prefixcmp(arg, "-O"))
2879                options->orderfile = arg + 2;
2880        else if (!prefixcmp(arg, "--diff-filter="))
2881                options->filter = arg + 14;
2882        else if (!strcmp(arg, "--abbrev"))
2883                options->abbrev = DEFAULT_ABBREV;
2884        else if (!prefixcmp(arg, "--abbrev=")) {
2885                options->abbrev = strtoul(arg + 9, NULL, 10);
2886                if (options->abbrev < MINIMUM_ABBREV)
2887                        options->abbrev = MINIMUM_ABBREV;
2888                else if (40 < options->abbrev)
2889                        options->abbrev = 40;
2890        }
2891        else if (!prefixcmp(arg, "--src-prefix="))
2892                options->a_prefix = arg + 13;
2893        else if (!prefixcmp(arg, "--dst-prefix="))
2894                options->b_prefix = arg + 13;
2895        else if (!strcmp(arg, "--no-prefix"))
2896                options->a_prefix = options->b_prefix = "";
2897        else if (opt_arg(arg, '\0', "inter-hunk-context",
2898                         &options->interhunkcontext))
2899                ;
2900        else if (!prefixcmp(arg, "--output=")) {
2901                options->file = fopen(arg + strlen("--output="), "w");
2902                if (!options->file)
2903                        die_errno("Could not open '%s'", arg + strlen("--output="));
2904                options->close_file = 1;
2905        } else
2906                return 0;
2907        return 1;
2908}
2909
2910static int parse_num(const char **cp_p)
2911{
2912        unsigned long num, scale;
2913        int ch, dot;
2914        const char *cp = *cp_p;
2915
2916        num = 0;
2917        scale = 1;
2918        dot = 0;
2919        for (;;) {
2920                ch = *cp;
2921                if ( !dot && ch == '.' ) {
2922                        scale = 1;
2923                        dot = 1;
2924                } else if ( ch == '%' ) {
2925                        scale = dot ? scale*100 : 100;
2926                        cp++;   /* % is always at the end */
2927                        break;
2928                } else if ( ch >= '0' && ch <= '9' ) {
2929                        if ( scale < 100000 ) {
2930                                scale *= 10;
2931                                num = (num*10) + (ch-'0');
2932                        }
2933                } else {
2934                        break;
2935                }
2936                cp++;
2937        }
2938        *cp_p = cp;
2939
2940        /* user says num divided by scale and we say internally that
2941         * is MAX_SCORE * num / scale.
2942         */
2943        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2944}
2945
2946static int diff_scoreopt_parse(const char *opt)
2947{
2948        int opt1, opt2, cmd;
2949
2950        if (*opt++ != '-')
2951                return -1;
2952        cmd = *opt++;
2953        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2954                return -1; /* that is not a -M, -C nor -B option */
2955
2956        opt1 = parse_num(&opt);
2957        if (cmd != 'B')
2958                opt2 = 0;
2959        else {
2960                if (*opt == 0)
2961                        opt2 = 0;
2962                else if (*opt != '/')
2963                        return -1; /* we expect -B80/99 or -B80 */
2964                else {
2965                        opt++;
2966                        opt2 = parse_num(&opt);
2967                }
2968        }
2969        if (*opt != 0)
2970                return -1;
2971        return opt1 | (opt2 << 16);
2972}
2973
2974struct diff_queue_struct diff_queued_diff;
2975
2976void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2977{
2978        if (queue->alloc <= queue->nr) {
2979                queue->alloc = alloc_nr(queue->alloc);
2980                queue->queue = xrealloc(queue->queue,
2981                                        sizeof(dp) * queue->alloc);
2982        }
2983        queue->queue[queue->nr++] = dp;
2984}
2985
2986struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2987                                 struct diff_filespec *one,
2988                                 struct diff_filespec *two)
2989{
2990        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2991        dp->one = one;
2992        dp->two = two;
2993        if (queue)
2994                diff_q(queue, dp);
2995        return dp;
2996}
2997
2998void diff_free_filepair(struct diff_filepair *p)
2999{
3000        free_filespec(p->one);
3001        free_filespec(p->two);
3002        free(p);
3003}
3004
3005/* This is different from find_unique_abbrev() in that
3006 * it stuffs the result with dots for alignment.
3007 */
3008const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3009{
3010        int abblen;
3011        const char *abbrev;
3012        if (len == 40)
3013                return sha1_to_hex(sha1);
3014
3015        abbrev = find_unique_abbrev(sha1, len);
3016        abblen = strlen(abbrev);
3017        if (abblen < 37) {
3018                static char hex[41];
3019                if (len < abblen && abblen <= len + 2)
3020                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3021                else
3022                        sprintf(hex, "%s...", abbrev);
3023                return hex;
3024        }
3025        return sha1_to_hex(sha1);
3026}
3027
3028static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3029{
3030        int line_termination = opt->line_termination;
3031        int inter_name_termination = line_termination ? '\t' : '\0';
3032
3033        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3034                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3035                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3036                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3037        }
3038        if (p->score) {
3039                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3040                        inter_name_termination);
3041        } else {
3042                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3043        }
3044
3045        if (p->status == DIFF_STATUS_COPIED ||
3046            p->status == DIFF_STATUS_RENAMED) {
3047                const char *name_a, *name_b;
3048                name_a = p->one->path;
3049                name_b = p->two->path;
3050                strip_prefix(opt->prefix_length, &name_a, &name_b);
3051                write_name_quoted(name_a, opt->file, inter_name_termination);
3052                write_name_quoted(name_b, opt->file, line_termination);
3053        } else {
3054                const char *name_a, *name_b;
3055                name_a = p->one->mode ? p->one->path : p->two->path;
3056                name_b = NULL;
3057                strip_prefix(opt->prefix_length, &name_a, &name_b);
3058                write_name_quoted(name_a, opt->file, line_termination);
3059        }
3060}
3061
3062int diff_unmodified_pair(struct diff_filepair *p)
3063{
3064        /* This function is written stricter than necessary to support
3065         * the currently implemented transformers, but the idea is to
3066         * let transformers to produce diff_filepairs any way they want,
3067         * and filter and clean them up here before producing the output.
3068         */
3069        struct diff_filespec *one = p->one, *two = p->two;
3070
3071        if (DIFF_PAIR_UNMERGED(p))
3072                return 0; /* unmerged is interesting */
3073
3074        /* deletion, addition, mode or type change
3075         * and rename are all interesting.
3076         */
3077        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3078            DIFF_PAIR_MODE_CHANGED(p) ||
3079            strcmp(one->path, two->path))
3080                return 0;
3081
3082        /* both are valid and point at the same path.  that is, we are
3083         * dealing with a change.
3084         */
3085        if (one->sha1_valid && two->sha1_valid &&
3086            !hashcmp(one->sha1, two->sha1) &&
3087            !one->dirty_submodule && !two->dirty_submodule)
3088                return 1; /* no change */
3089        if (!one->sha1_valid && !two->sha1_valid)
3090                return 1; /* both look at the same file on the filesystem. */
3091        return 0;
3092}
3093
3094static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3095{
3096        if (diff_unmodified_pair(p))
3097                return;
3098
3099        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3100            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3101                return; /* no tree diffs in patch format */
3102
3103        run_diff(p, o);
3104}
3105
3106static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3107                            struct diffstat_t *diffstat)
3108{
3109        if (diff_unmodified_pair(p))
3110                return;
3111
3112        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3113            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3114                return; /* no tree diffs in patch format */
3115
3116        run_diffstat(p, o, diffstat);
3117}
3118
3119static void diff_flush_checkdiff(struct diff_filepair *p,
3120                struct diff_options *o)
3121{
3122        if (diff_unmodified_pair(p))
3123                return;
3124
3125        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3126            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3127                return; /* no tree diffs in patch format */
3128
3129        run_checkdiff(p, o);
3130}
3131
3132int diff_queue_is_empty(void)
3133{
3134        struct diff_queue_struct *q = &diff_queued_diff;
3135        int i;
3136        for (i = 0; i < q->nr; i++)
3137                if (!diff_unmodified_pair(q->queue[i]))
3138                        return 0;
3139        return 1;
3140}
3141
3142#if DIFF_DEBUG
3143void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3144{
3145        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3146                x, one ? one : "",
3147                s->path,
3148                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3149                s->mode,
3150                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3151        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3152                x, one ? one : "",
3153                s->size, s->xfrm_flags);
3154}
3155
3156void diff_debug_filepair(const struct diff_filepair *p, int i)
3157{
3158        diff_debug_filespec(p->one, i, "one");
3159        diff_debug_filespec(p->two, i, "two");
3160        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3161                p->score, p->status ? p->status : '?',
3162                p->one->rename_used, p->broken_pair);
3163}
3164
3165void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3166{
3167        int i;
3168        if (msg)
3169                fprintf(stderr, "%s\n", msg);
3170        fprintf(stderr, "q->nr = %d\n", q->nr);
3171        for (i = 0; i < q->nr; i++) {
3172                struct diff_filepair *p = q->queue[i];
3173                diff_debug_filepair(p, i);
3174        }
3175}
3176#endif
3177
3178static void diff_resolve_rename_copy(void)
3179{
3180        int i;
3181        struct diff_filepair *p;
3182        struct diff_queue_struct *q = &diff_queued_diff;
3183
3184        diff_debug_queue("resolve-rename-copy", q);
3185
3186        for (i = 0; i < q->nr; i++) {
3187                p = q->queue[i];
3188                p->status = 0; /* undecided */
3189                if (DIFF_PAIR_UNMERGED(p))
3190                        p->status = DIFF_STATUS_UNMERGED;
3191                else if (!DIFF_FILE_VALID(p->one))
3192                        p->status = DIFF_STATUS_ADDED;
3193                else if (!DIFF_FILE_VALID(p->two))
3194                        p->status = DIFF_STATUS_DELETED;
3195                else if (DIFF_PAIR_TYPE_CHANGED(p))
3196                        p->status = DIFF_STATUS_TYPE_CHANGED;
3197
3198                /* from this point on, we are dealing with a pair
3199                 * whose both sides are valid and of the same type, i.e.
3200                 * either in-place edit or rename/copy edit.
3201                 */
3202                else if (DIFF_PAIR_RENAME(p)) {
3203                        /*
3204                         * A rename might have re-connected a broken
3205                         * pair up, causing the pathnames to be the
3206                         * same again. If so, that's not a rename at
3207                         * all, just a modification..
3208                         *
3209                         * Otherwise, see if this source was used for
3210                         * multiple renames, in which case we decrement
3211                         * the count, and call it a copy.
3212                         */
3213                        if (!strcmp(p->one->path, p->two->path))
3214                                p->status = DIFF_STATUS_MODIFIED;
3215                        else if (--p->one->rename_used > 0)
3216                                p->status = DIFF_STATUS_COPIED;
3217                        else
3218                                p->status = DIFF_STATUS_RENAMED;
3219                }
3220                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3221                         p->one->mode != p->two->mode ||
3222                         p->one->dirty_submodule ||
3223                         p->two->dirty_submodule ||
3224                         is_null_sha1(p->one->sha1))
3225                        p->status = DIFF_STATUS_MODIFIED;
3226                else {
3227                        /* This is a "no-change" entry and should not
3228                         * happen anymore, but prepare for broken callers.
3229                         */
3230                        error("feeding unmodified %s to diffcore",
3231                              p->one->path);
3232                        p->status = DIFF_STATUS_UNKNOWN;
3233                }
3234        }
3235        diff_debug_queue("resolve-rename-copy done", q);
3236}
3237
3238static int check_pair_status(struct diff_filepair *p)
3239{
3240        switch (p->status) {
3241        case DIFF_STATUS_UNKNOWN:
3242                return 0;
3243        case 0:
3244                die("internal error in diff-resolve-rename-copy");
3245        default:
3246                return 1;
3247        }
3248}
3249
3250static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3251{
3252        int fmt = opt->output_format;
3253
3254        if (fmt & DIFF_FORMAT_CHECKDIFF)
3255                diff_flush_checkdiff(p, opt);
3256        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3257                diff_flush_raw(p, opt);
3258        else if (fmt & DIFF_FORMAT_NAME) {
3259                const char *name_a, *name_b;
3260                name_a = p->two->path;
3261                name_b = NULL;
3262                strip_prefix(opt->prefix_length, &name_a, &name_b);
3263                write_name_quoted(name_a, opt->file, opt->line_termination);
3264        }
3265}
3266
3267static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3268{
3269        if (fs->mode)
3270                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3271        else
3272                fprintf(file, " %s ", newdelete);
3273        write_name_quoted(fs->path, file, '\n');
3274}
3275
3276
3277static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3278{
3279        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3280                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3281                        show_name ? ' ' : '\n');
3282                if (show_name) {
3283                        write_name_quoted(p->two->path, file, '\n');
3284                }
3285        }
3286}
3287
3288static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3289{
3290        char *names = pprint_rename(p->one->path, p->two->path);
3291
3292        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3293        free(names);
3294        show_mode_change(file, p, 0);
3295}
3296
3297static void diff_summary(FILE *file, struct diff_filepair *p)
3298{
3299        switch(p->status) {
3300        case DIFF_STATUS_DELETED:
3301                show_file_mode_name(file, "delete", p->one);
3302                break;
3303        case DIFF_STATUS_ADDED:
3304                show_file_mode_name(file, "create", p->two);
3305                break;
3306        case DIFF_STATUS_COPIED:
3307                show_rename_copy(file, "copy", p);
3308                break;
3309        case DIFF_STATUS_RENAMED:
3310                show_rename_copy(file, "rename", p);
3311                break;
3312        default:
3313                if (p->score) {
3314                        fputs(" rewrite ", file);
3315                        write_name_quoted(p->two->path, file, ' ');
3316                        fprintf(file, "(%d%%)\n", similarity_index(p));
3317                }
3318                show_mode_change(file, p, !p->score);
3319                break;
3320        }
3321}
3322
3323struct patch_id_t {
3324        git_SHA_CTX *ctx;
3325        int patchlen;
3326};
3327
3328static int remove_space(char *line, int len)
3329{
3330        int i;
3331        char *dst = line;
3332        unsigned char c;
3333
3334        for (i = 0; i < len; i++)
3335                if (!isspace((c = line[i])))
3336                        *dst++ = c;
3337
3338        return dst - line;
3339}
3340
3341static void patch_id_consume(void *priv, char *line, unsigned long len)
3342{
3343        struct patch_id_t *data = priv;
3344        int new_len;
3345
3346        /* Ignore line numbers when computing the SHA1 of the patch */
3347        if (!prefixcmp(line, "@@ -"))
3348                return;
3349
3350        new_len = remove_space(line, len);
3351
3352        git_SHA1_Update(data->ctx, line, new_len);
3353        data->patchlen += new_len;
3354}
3355
3356/* returns 0 upon success, and writes result into sha1 */
3357static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3358{
3359        struct diff_queue_struct *q = &diff_queued_diff;
3360        int i;
3361        git_SHA_CTX ctx;
3362        struct patch_id_t data;
3363        char buffer[PATH_MAX * 4 + 20];
3364
3365        git_SHA1_Init(&ctx);
3366        memset(&data, 0, sizeof(struct patch_id_t));
3367        data.ctx = &ctx;
3368
3369        for (i = 0; i < q->nr; i++) {
3370                xpparam_t xpp;
3371                xdemitconf_t xecfg;
3372                mmfile_t mf1, mf2;
3373                struct diff_filepair *p = q->queue[i];
3374                int len1, len2;
3375
3376                memset(&xpp, 0, sizeof(xpp));
3377                memset(&xecfg, 0, sizeof(xecfg));
3378                if (p->status == 0)
3379                        return error("internal diff status error");
3380                if (p->status == DIFF_STATUS_UNKNOWN)
3381                        continue;
3382                if (diff_unmodified_pair(p))
3383                        continue;
3384                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3385                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3386                        continue;
3387                if (DIFF_PAIR_UNMERGED(p))
3388                        continue;
3389
3390                diff_fill_sha1_info(p->one);
3391                diff_fill_sha1_info(p->two);
3392                if (fill_mmfile(&mf1, p->one) < 0 ||
3393                                fill_mmfile(&mf2, p->two) < 0)
3394                        return error("unable to read files to diff");
3395
3396                len1 = remove_space(p->one->path, strlen(p->one->path));
3397                len2 = remove_space(p->two->path, strlen(p->two->path));
3398                if (p->one->mode == 0)
3399                        len1 = snprintf(buffer, sizeof(buffer),
3400                                        "diff--gita/%.*sb/%.*s"
3401                                        "newfilemode%06o"
3402                                        "---/dev/null"
3403                                        "+++b/%.*s",
3404                                        len1, p->one->path,
3405                                        len2, p->two->path,
3406                                        p->two->mode,
3407                                        len2, p->two->path);
3408                else if (p->two->mode == 0)
3409                        len1 = snprintf(buffer, sizeof(buffer),
3410                                        "diff--gita/%.*sb/%.*s"
3411                                        "deletedfilemode%06o"
3412                                        "---a/%.*s"
3413                                        "+++/dev/null",
3414                                        len1, p->one->path,
3415                                        len2, p->two->path,
3416                                        p->one->mode,
3417                                        len1, p->one->path);
3418                else
3419                        len1 = snprintf(buffer, sizeof(buffer),
3420                                        "diff--gita/%.*sb/%.*s"
3421                                        "---a/%.*s"
3422                                        "+++b/%.*s",
3423                                        len1, p->one->path,
3424                                        len2, p->two->path,
3425                                        len1, p->one->path,
3426                                        len2, p->two->path);
3427                git_SHA1_Update(&ctx, buffer, len1);
3428
3429                xpp.flags = XDF_NEED_MINIMAL;
3430                xecfg.ctxlen = 3;
3431                xecfg.flags = XDL_EMIT_FUNCNAMES;
3432                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3433                              &xpp, &xecfg);
3434        }
3435
3436        git_SHA1_Final(sha1, &ctx);
3437        return 0;
3438}
3439
3440int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3441{
3442        struct diff_queue_struct *q = &diff_queued_diff;
3443        int i;
3444        int result = diff_get_patch_id(options, sha1);
3445
3446        for (i = 0; i < q->nr; i++)
3447                diff_free_filepair(q->queue[i]);
3448
3449        free(q->queue);
3450        q->queue = NULL;
3451        q->nr = q->alloc = 0;
3452
3453        return result;
3454}
3455
3456static int is_summary_empty(const struct diff_queue_struct *q)
3457{
3458        int i;
3459
3460        for (i = 0; i < q->nr; i++) {
3461                const struct diff_filepair *p = q->queue[i];
3462
3463                switch (p->status) {
3464                case DIFF_STATUS_DELETED:
3465                case DIFF_STATUS_ADDED:
3466                case DIFF_STATUS_COPIED:
3467                case DIFF_STATUS_RENAMED:
3468                        return 0;
3469                default:
3470                        if (p->score)
3471                                return 0;
3472                        if (p->one->mode && p->two->mode &&
3473                            p->one->mode != p->two->mode)
3474                                return 0;
3475                        break;
3476                }
3477        }
3478        return 1;
3479}
3480
3481void diff_flush(struct diff_options *options)
3482{
3483        struct diff_queue_struct *q = &diff_queued_diff;
3484        int i, output_format = options->output_format;
3485        int separator = 0;
3486
3487        /*
3488         * Order: raw, stat, summary, patch
3489         * or:    name/name-status/checkdiff (other bits clear)
3490         */
3491        if (!q->nr)
3492                goto free_queue;
3493
3494        if (output_format & (DIFF_FORMAT_RAW |
3495                             DIFF_FORMAT_NAME |
3496                             DIFF_FORMAT_NAME_STATUS |
3497                             DIFF_FORMAT_CHECKDIFF)) {
3498                for (i = 0; i < q->nr; i++) {
3499                        struct diff_filepair *p = q->queue[i];
3500                        if (check_pair_status(p))
3501                                flush_one_pair(p, options);
3502                }
3503                separator++;
3504        }
3505
3506        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3507                struct diffstat_t diffstat;
3508
3509                memset(&diffstat, 0, sizeof(struct diffstat_t));
3510                for (i = 0; i < q->nr; i++) {
3511                        struct diff_filepair *p = q->queue[i];
3512                        if (check_pair_status(p))
3513                                diff_flush_stat(p, options, &diffstat);
3514                }
3515                if (output_format & DIFF_FORMAT_NUMSTAT)
3516                        show_numstat(&diffstat, options);
3517                if (output_format & DIFF_FORMAT_DIFFSTAT)
3518                        show_stats(&diffstat, options);
3519                if (output_format & DIFF_FORMAT_SHORTSTAT)
3520                        show_shortstats(&diffstat, options);
3521                free_diffstat_info(&diffstat);
3522                separator++;
3523        }
3524        if (output_format & DIFF_FORMAT_DIRSTAT)
3525                show_dirstat(options);
3526
3527        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3528                for (i = 0; i < q->nr; i++)
3529                        diff_summary(options->file, q->queue[i]);
3530                separator++;
3531        }
3532
3533        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3534            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3535            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3536                /*
3537                 * run diff_flush_patch for the exit status. setting
3538                 * options->file to /dev/null should be safe, becaue we
3539                 * aren't supposed to produce any output anyway.
3540                 */
3541                if (options->close_file)
3542                        fclose(options->file);
3543                options->file = fopen("/dev/null", "w");
3544                if (!options->file)
3545                        die_errno("Could not open /dev/null");
3546                options->close_file = 1;
3547                for (i = 0; i < q->nr; i++) {
3548                        struct diff_filepair *p = q->queue[i];
3549                        if (check_pair_status(p))
3550                                diff_flush_patch(p, options);
3551                        if (options->found_changes)
3552                                break;
3553                }
3554        }
3555
3556        if (output_format & DIFF_FORMAT_PATCH) {
3557                if (separator) {
3558                        putc(options->line_termination, options->file);
3559                        if (options->stat_sep) {
3560                                /* attach patch instead of inline */
3561                                fputs(options->stat_sep, options->file);
3562                        }
3563                }
3564
3565                for (i = 0; i < q->nr; i++) {
3566                        struct diff_filepair *p = q->queue[i];
3567                        if (check_pair_status(p))
3568                                diff_flush_patch(p, options);
3569                }
3570        }
3571
3572        if (output_format & DIFF_FORMAT_CALLBACK)
3573                options->format_callback(q, options, options->format_callback_data);
3574
3575        for (i = 0; i < q->nr; i++)
3576                diff_free_filepair(q->queue[i]);
3577free_queue:
3578        free(q->queue);
3579        q->queue = NULL;
3580        q->nr = q->alloc = 0;
3581        if (options->close_file)
3582                fclose(options->file);
3583
3584        /*
3585         * Report the content-level differences with HAS_CHANGES;
3586         * diff_addremove/diff_change does not set the bit when
3587         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3588         */
3589        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3590                if (options->found_changes)
3591                        DIFF_OPT_SET(options, HAS_CHANGES);
3592                else
3593                        DIFF_OPT_CLR(options, HAS_CHANGES);
3594        }
3595}
3596
3597static void diffcore_apply_filter(const char *filter)
3598{
3599        int i;
3600        struct diff_queue_struct *q = &diff_queued_diff;
3601        struct diff_queue_struct outq;
3602        outq.queue = NULL;
3603        outq.nr = outq.alloc = 0;
3604
3605        if (!filter)
3606                return;
3607
3608        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3609                int found;
3610                for (i = found = 0; !found && i < q->nr; i++) {
3611                        struct diff_filepair *p = q->queue[i];
3612                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3613                             ((p->score &&
3614                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3615                              (!p->score &&
3616                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3617                            ((p->status != DIFF_STATUS_MODIFIED) &&
3618                             strchr(filter, p->status)))
3619                                found++;
3620                }
3621                if (found)
3622                        return;
3623
3624                /* otherwise we will clear the whole queue
3625                 * by copying the empty outq at the end of this
3626                 * function, but first clear the current entries
3627                 * in the queue.
3628                 */
3629                for (i = 0; i < q->nr; i++)
3630                        diff_free_filepair(q->queue[i]);
3631        }
3632        else {
3633                /* Only the matching ones */
3634                for (i = 0; i < q->nr; i++) {
3635                        struct diff_filepair *p = q->queue[i];
3636
3637                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3638                             ((p->score &&
3639                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3640                              (!p->score &&
3641                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3642                            ((p->status != DIFF_STATUS_MODIFIED) &&
3643                             strchr(filter, p->status)))
3644                                diff_q(&outq, p);
3645                        else
3646                                diff_free_filepair(p);
3647                }
3648        }
3649        free(q->queue);
3650        *q = outq;
3651}
3652
3653/* Check whether two filespecs with the same mode and size are identical */
3654static int diff_filespec_is_identical(struct diff_filespec *one,
3655                                      struct diff_filespec *two)
3656{
3657        if (S_ISGITLINK(one->mode))
3658                return 0;
3659        if (diff_populate_filespec(one, 0))
3660                return 0;
3661        if (diff_populate_filespec(two, 0))
3662                return 0;
3663        return !memcmp(one->data, two->data, one->size);
3664}
3665
3666static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3667{
3668        int i;
3669        struct diff_queue_struct *q = &diff_queued_diff;
3670        struct diff_queue_struct outq;
3671        outq.queue = NULL;
3672        outq.nr = outq.alloc = 0;
3673
3674        for (i = 0; i < q->nr; i++) {
3675                struct diff_filepair *p = q->queue[i];
3676
3677                /*
3678                 * 1. Entries that come from stat info dirtiness
3679                 *    always have both sides (iow, not create/delete),
3680                 *    one side of the object name is unknown, with
3681                 *    the same mode and size.  Keep the ones that
3682                 *    do not match these criteria.  They have real
3683                 *    differences.
3684                 *
3685                 * 2. At this point, the file is known to be modified,
3686                 *    with the same mode and size, and the object
3687                 *    name of one side is unknown.  Need to inspect
3688                 *    the identical contents.
3689                 */
3690                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3691                    !DIFF_FILE_VALID(p->two) ||
3692                    (p->one->sha1_valid && p->two->sha1_valid) ||
3693                    (p->one->mode != p->two->mode) ||
3694                    diff_populate_filespec(p->one, 1) ||
3695                    diff_populate_filespec(p->two, 1) ||
3696                    (p->one->size != p->two->size) ||
3697                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3698                        diff_q(&outq, p);
3699                else {
3700                        /*
3701                         * The caller can subtract 1 from skip_stat_unmatch
3702                         * to determine how many paths were dirty only
3703                         * due to stat info mismatch.
3704                         */
3705                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3706                                diffopt->skip_stat_unmatch++;
3707                        diff_free_filepair(p);
3708                }
3709        }
3710        free(q->queue);
3711        *q = outq;
3712}
3713
3714static int diffnamecmp(const void *a_, const void *b_)
3715{
3716        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3717        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3718        const char *name_a, *name_b;
3719
3720        name_a = a->one ? a->one->path : a->two->path;
3721        name_b = b->one ? b->one->path : b->two->path;
3722        return strcmp(name_a, name_b);
3723}
3724
3725void diffcore_fix_diff_index(struct diff_options *options)
3726{
3727        struct diff_queue_struct *q = &diff_queued_diff;
3728        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3729}
3730
3731void diffcore_std(struct diff_options *options)
3732{
3733        if (options->skip_stat_unmatch)
3734                diffcore_skip_stat_unmatch(options);
3735        if (options->break_opt != -1)
3736                diffcore_break(options->break_opt);
3737        if (options->detect_rename)
3738                diffcore_rename(options);
3739        if (options->break_opt != -1)
3740                diffcore_merge_broken();
3741        if (options->pickaxe)
3742                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3743        if (options->orderfile)
3744                diffcore_order(options->orderfile);
3745        diff_resolve_rename_copy();
3746        diffcore_apply_filter(options->filter);
3747
3748        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3749                DIFF_OPT_SET(options, HAS_CHANGES);
3750        else
3751                DIFF_OPT_CLR(options, HAS_CHANGES);
3752}
3753
3754int diff_result_code(struct diff_options *opt, int status)
3755{
3756        int result = 0;
3757        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3758            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3759                return status;
3760        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3761            DIFF_OPT_TST(opt, HAS_CHANGES))
3762                result |= 01;
3763        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3764            DIFF_OPT_TST(opt, CHECK_FAILED))
3765                result |= 02;
3766        return result;
3767}
3768
3769void diff_addremove(struct diff_options *options,
3770                    int addremove, unsigned mode,
3771                    const unsigned char *sha1,
3772                    const char *concatpath, unsigned dirty_submodule)
3773{
3774        struct diff_filespec *one, *two;
3775
3776        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3777                return;
3778
3779        /* This may look odd, but it is a preparation for
3780         * feeding "there are unchanged files which should
3781         * not produce diffs, but when you are doing copy
3782         * detection you would need them, so here they are"
3783         * entries to the diff-core.  They will be prefixed
3784         * with something like '=' or '*' (I haven't decided
3785         * which but should not make any difference).
3786         * Feeding the same new and old to diff_change()
3787         * also has the same effect.
3788         * Before the final output happens, they are pruned after
3789         * merged into rename/copy pairs as appropriate.
3790         */
3791        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3792                addremove = (addremove == '+' ? '-' :
3793                             addremove == '-' ? '+' : addremove);
3794
3795        if (options->prefix &&
3796            strncmp(concatpath, options->prefix, options->prefix_length))
3797                return;
3798
3799        one = alloc_filespec(concatpath);
3800        two = alloc_filespec(concatpath);
3801
3802        if (addremove != '+')
3803                fill_filespec(one, sha1, mode);
3804        if (addremove != '-') {
3805                fill_filespec(two, sha1, mode);
3806                two->dirty_submodule = dirty_submodule;
3807        }
3808
3809        diff_queue(&diff_queued_diff, one, two);
3810        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3811                DIFF_OPT_SET(options, HAS_CHANGES);
3812}
3813
3814void diff_change(struct diff_options *options,
3815                 unsigned old_mode, unsigned new_mode,
3816                 const unsigned char *old_sha1,
3817                 const unsigned char *new_sha1,
3818                 const char *concatpath,
3819                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3820{
3821        struct diff_filespec *one, *two;
3822
3823        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3824                        && S_ISGITLINK(new_mode))
3825                return;
3826
3827        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3828                unsigned tmp;
3829                const unsigned char *tmp_c;
3830                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3831                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3832                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3833                        new_dirty_submodule = tmp;
3834        }
3835
3836        if (options->prefix &&
3837            strncmp(concatpath, options->prefix, options->prefix_length))
3838                return;
3839
3840        one = alloc_filespec(concatpath);
3841        two = alloc_filespec(concatpath);
3842        fill_filespec(one, old_sha1, old_mode);
3843        fill_filespec(two, new_sha1, new_mode);
3844        one->dirty_submodule = old_dirty_submodule;
3845        two->dirty_submodule = new_dirty_submodule;
3846
3847        diff_queue(&diff_queued_diff, one, two);
3848        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3849                DIFF_OPT_SET(options, HAS_CHANGES);
3850}
3851
3852void diff_unmerge(struct diff_options *options,
3853                  const char *path,
3854                  unsigned mode, const unsigned char *sha1)
3855{
3856        struct diff_filespec *one, *two;
3857
3858        if (options->prefix &&
3859            strncmp(path, options->prefix, options->prefix_length))
3860                return;
3861
3862        one = alloc_filespec(path);
3863        two = alloc_filespec(path);
3864        fill_filespec(one, sha1, mode);
3865        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3866}
3867
3868static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3869                size_t *outsize)
3870{
3871        struct diff_tempfile *temp;
3872        const char *argv[3];
3873        const char **arg = argv;
3874        struct child_process child;
3875        struct strbuf buf = STRBUF_INIT;
3876        int err = 0;
3877
3878        temp = prepare_temp_file(spec->path, spec);
3879        *arg++ = pgm;
3880        *arg++ = temp->name;
3881        *arg = NULL;
3882
3883        memset(&child, 0, sizeof(child));
3884        child.use_shell = 1;
3885        child.argv = argv;
3886        child.out = -1;
3887        if (start_command(&child)) {
3888                remove_tempfile();
3889                return NULL;
3890        }
3891
3892        if (strbuf_read(&buf, child.out, 0) < 0)
3893                err = error("error reading from textconv command '%s'", pgm);
3894        close(child.out);
3895
3896        if (finish_command(&child) || err) {
3897                strbuf_release(&buf);
3898                remove_tempfile();
3899                return NULL;
3900        }
3901        remove_tempfile();
3902
3903        return strbuf_detach(&buf, outsize);
3904}
3905
3906static size_t fill_textconv(struct userdiff_driver *driver,
3907                            struct diff_filespec *df,
3908                            char **outbuf)
3909{
3910        size_t size;
3911
3912        if (!driver || !driver->textconv) {
3913                if (!DIFF_FILE_VALID(df)) {
3914                        *outbuf = "";
3915                        return 0;
3916                }
3917                if (diff_populate_filespec(df, 0))
3918                        die("unable to read files to diff");
3919                *outbuf = df->data;
3920                return df->size;
3921        }
3922
3923        if (driver->textconv_cache) {
3924                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
3925                                          &size);
3926                if (*outbuf)
3927                        return size;
3928        }
3929
3930        *outbuf = run_textconv(driver->textconv, df, &size);
3931        if (!*outbuf)
3932                die("unable to read files to diff");
3933
3934        if (driver->textconv_cache) {
3935                /* ignore errors, as we might be in a readonly repository */
3936                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
3937                                size);
3938                /*
3939                 * we could save up changes and flush them all at the end,
3940                 * but we would need an extra call after all diffing is done.
3941                 * Since generating a cache entry is the slow path anyway,
3942                 * this extra overhead probably isn't a big deal.
3943                 */
3944                notes_cache_write(driver->textconv_cache);
3945        }
3946
3947        return size;
3948}