diff.con commit diff: add --word-diff option that generalizes --color-words (882749a)
   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
  18#ifdef NO_FAST_WORKING_DIRECTORY
  19#define FAST_WORKING_DIRECTORY 0
  20#else
  21#define FAST_WORKING_DIRECTORY 1
  22#endif
  23
  24static int diff_detect_rename_default;
  25static int diff_rename_limit_default = 200;
  26static int diff_suppress_blank_empty;
  27int diff_use_color_default = -1;
  28static const char *diff_word_regex_cfg;
  29static const char *external_diff_cmd_cfg;
  30int diff_auto_refresh_index = 1;
  31static int diff_mnemonic_prefix;
  32
  33static char diff_colors[][COLOR_MAXLEN] = {
  34        GIT_COLOR_RESET,
  35        GIT_COLOR_NORMAL,       /* PLAIN */
  36        GIT_COLOR_BOLD,         /* METAINFO */
  37        GIT_COLOR_CYAN,         /* FRAGINFO */
  38        GIT_COLOR_RED,          /* OLD */
  39        GIT_COLOR_GREEN,        /* NEW */
  40        GIT_COLOR_YELLOW,       /* COMMIT */
  41        GIT_COLOR_BG_RED,       /* WHITESPACE */
  42        GIT_COLOR_NORMAL,       /* FUNCINFO */
  43};
  44
  45static void diff_filespec_load_driver(struct diff_filespec *one);
  46static char *run_textconv(const char *, struct diff_filespec *, size_t *);
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.external"))
 103                return git_config_string(&external_diff_cmd_cfg, var, value);
 104        if (!strcmp(var, "diff.wordregex"))
 105                return git_config_string(&diff_word_regex_cfg, var, value);
 106
 107        return git_diff_basic_config(var, value, cb);
 108}
 109
 110int git_diff_basic_config(const char *var, const char *value, void *cb)
 111{
 112        if (!strcmp(var, "diff.renamelimit")) {
 113                diff_rename_limit_default = git_config_int(var, value);
 114                return 0;
 115        }
 116
 117        switch (userdiff_config(var, value)) {
 118                case 0: break;
 119                case -1: return -1;
 120                default: return 0;
 121        }
 122
 123        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 124                int slot = parse_diff_color_slot(var, 11);
 125                if (slot < 0)
 126                        return 0;
 127                if (!value)
 128                        return config_error_nonbool(var);
 129                color_parse(value, var, diff_colors[slot]);
 130                return 0;
 131        }
 132
 133        /* like GNU diff's --suppress-blank-empty option  */
 134        if (!strcmp(var, "diff.suppressblankempty") ||
 135                        /* for backwards compatibility */
 136                        !strcmp(var, "diff.suppress-blank-empty")) {
 137                diff_suppress_blank_empty = git_config_bool(var, value);
 138                return 0;
 139        }
 140
 141        return git_color_default_config(var, value, cb);
 142}
 143
 144static char *quote_two(const char *one, const char *two)
 145{
 146        int need_one = quote_c_style(one, NULL, NULL, 1);
 147        int need_two = quote_c_style(two, NULL, NULL, 1);
 148        struct strbuf res = STRBUF_INIT;
 149
 150        if (need_one + need_two) {
 151                strbuf_addch(&res, '"');
 152                quote_c_style(one, &res, NULL, 1);
 153                quote_c_style(two, &res, NULL, 1);
 154                strbuf_addch(&res, '"');
 155        } else {
 156                strbuf_addstr(&res, one);
 157                strbuf_addstr(&res, two);
 158        }
 159        return strbuf_detach(&res, NULL);
 160}
 161
 162static const char *external_diff(void)
 163{
 164        static const char *external_diff_cmd = NULL;
 165        static int done_preparing = 0;
 166
 167        if (done_preparing)
 168                return external_diff_cmd;
 169        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 170        if (!external_diff_cmd)
 171                external_diff_cmd = external_diff_cmd_cfg;
 172        done_preparing = 1;
 173        return external_diff_cmd;
 174}
 175
 176static struct diff_tempfile {
 177        const char *name; /* filename external diff should read from */
 178        char hex[41];
 179        char mode[10];
 180        char tmp_path[PATH_MAX];
 181} diff_temp[2];
 182
 183typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 184
 185struct emit_callback {
 186        int color_diff;
 187        unsigned ws_rule;
 188        int blank_at_eof_in_preimage;
 189        int blank_at_eof_in_postimage;
 190        int lno_in_preimage;
 191        int lno_in_postimage;
 192        sane_truncate_fn truncate;
 193        const char **label_path;
 194        struct diff_words_data *diff_words;
 195        int *found_changesp;
 196        FILE *file;
 197        struct strbuf *header;
 198};
 199
 200static int count_lines(const char *data, int size)
 201{
 202        int count, ch, completely_empty = 1, nl_just_seen = 0;
 203        count = 0;
 204        while (0 < size--) {
 205                ch = *data++;
 206                if (ch == '\n') {
 207                        count++;
 208                        nl_just_seen = 1;
 209                        completely_empty = 0;
 210                }
 211                else {
 212                        nl_just_seen = 0;
 213                        completely_empty = 0;
 214                }
 215        }
 216        if (completely_empty)
 217                return 0;
 218        if (!nl_just_seen)
 219                count++; /* no trailing newline */
 220        return count;
 221}
 222
 223static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 224{
 225        if (!DIFF_FILE_VALID(one)) {
 226                mf->ptr = (char *)""; /* does not matter */
 227                mf->size = 0;
 228                return 0;
 229        }
 230        else if (diff_populate_filespec(one, 0))
 231                return -1;
 232
 233        mf->ptr = one->data;
 234        mf->size = one->size;
 235        return 0;
 236}
 237
 238static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 239{
 240        char *ptr = mf->ptr;
 241        long size = mf->size;
 242        int cnt = 0;
 243
 244        if (!size)
 245                return cnt;
 246        ptr += size - 1; /* pointing at the very end */
 247        if (*ptr != '\n')
 248                ; /* incomplete line */
 249        else
 250                ptr--; /* skip the last LF */
 251        while (mf->ptr < ptr) {
 252                char *prev_eol;
 253                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 254                        if (*prev_eol == '\n')
 255                                break;
 256                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 257                        break;
 258                cnt++;
 259                ptr = prev_eol - 1;
 260        }
 261        return cnt;
 262}
 263
 264static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 265                               struct emit_callback *ecbdata)
 266{
 267        int l1, l2, at;
 268        unsigned ws_rule = ecbdata->ws_rule;
 269        l1 = count_trailing_blank(mf1, ws_rule);
 270        l2 = count_trailing_blank(mf2, ws_rule);
 271        if (l2 <= l1) {
 272                ecbdata->blank_at_eof_in_preimage = 0;
 273                ecbdata->blank_at_eof_in_postimage = 0;
 274                return;
 275        }
 276        at = count_lines(mf1->ptr, mf1->size);
 277        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 278
 279        at = count_lines(mf2->ptr, mf2->size);
 280        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 281}
 282
 283static void emit_line_0(FILE *file, const char *set, const char *reset,
 284                        int first, const char *line, int len)
 285{
 286        int has_trailing_newline, has_trailing_carriage_return;
 287        int nofirst;
 288
 289        if (len == 0) {
 290                has_trailing_newline = (first == '\n');
 291                has_trailing_carriage_return = (!has_trailing_newline &&
 292                                                (first == '\r'));
 293                nofirst = has_trailing_newline || has_trailing_carriage_return;
 294        } else {
 295                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 296                if (has_trailing_newline)
 297                        len--;
 298                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 299                if (has_trailing_carriage_return)
 300                        len--;
 301                nofirst = 0;
 302        }
 303
 304        if (len || !nofirst) {
 305                fputs(set, file);
 306                if (!nofirst)
 307                        fputc(first, file);
 308                fwrite(line, len, 1, file);
 309                fputs(reset, file);
 310        }
 311        if (has_trailing_carriage_return)
 312                fputc('\r', file);
 313        if (has_trailing_newline)
 314                fputc('\n', file);
 315}
 316
 317static void emit_line(FILE *file, const char *set, const char *reset,
 318                      const char *line, int len)
 319{
 320        emit_line_0(file, set, reset, line[0], line+1, len-1);
 321}
 322
 323static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 324{
 325        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 326              ecbdata->blank_at_eof_in_preimage &&
 327              ecbdata->blank_at_eof_in_postimage &&
 328              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 329              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 330                return 0;
 331        return ws_blank_line(line, len, ecbdata->ws_rule);
 332}
 333
 334static void emit_add_line(const char *reset,
 335                          struct emit_callback *ecbdata,
 336                          const char *line, int len)
 337{
 338        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 339        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 340
 341        if (!*ws)
 342                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 343        else if (new_blank_line_at_eof(ecbdata, line, len))
 344                /* Blank line at EOF - paint '+' as well */
 345                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 346        else {
 347                /* Emit just the prefix, then the rest. */
 348                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 349                ws_check_emit(line, len, ecbdata->ws_rule,
 350                              ecbdata->file, set, reset, ws);
 351        }
 352}
 353
 354static void emit_hunk_header(struct emit_callback *ecbdata,
 355                             const char *line, int len)
 356{
 357        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 358        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 359        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 360        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 361        static const char atat[2] = { '@', '@' };
 362        const char *cp, *ep;
 363
 364        /*
 365         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 366         * it always is at least 10 bytes long.
 367         */
 368        if (len < 10 ||
 369            memcmp(line, atat, 2) ||
 370            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 371                emit_line(ecbdata->file, plain, reset, line, len);
 372                return;
 373        }
 374        ep += 2; /* skip over @@ */
 375
 376        /* The hunk header in fraginfo color */
 377        emit_line(ecbdata->file, frag, reset, line, ep - line);
 378
 379        /* blank before the func header */
 380        for (cp = ep; ep - line < len; ep++)
 381                if (*ep != ' ' && *ep != '\t')
 382                        break;
 383        if (ep != cp)
 384                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 385
 386        if (ep < line + len)
 387                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 388}
 389
 390static struct diff_tempfile *claim_diff_tempfile(void) {
 391        int i;
 392        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 393                if (!diff_temp[i].name)
 394                        return diff_temp + i;
 395        die("BUG: diff is failing to clean up its tempfiles");
 396}
 397
 398static int remove_tempfile_installed;
 399
 400static void remove_tempfile(void)
 401{
 402        int i;
 403        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 404                if (diff_temp[i].name == diff_temp[i].tmp_path)
 405                        unlink_or_warn(diff_temp[i].name);
 406                diff_temp[i].name = NULL;
 407        }
 408}
 409
 410static void remove_tempfile_on_signal(int signo)
 411{
 412        remove_tempfile();
 413        sigchain_pop(signo);
 414        raise(signo);
 415}
 416
 417static void print_line_count(FILE *file, int count)
 418{
 419        switch (count) {
 420        case 0:
 421                fprintf(file, "0,0");
 422                break;
 423        case 1:
 424                fprintf(file, "1");
 425                break;
 426        default:
 427                fprintf(file, "1,%d", count);
 428                break;
 429        }
 430}
 431
 432static void emit_rewrite_lines(struct emit_callback *ecb,
 433                               int prefix, const char *data, int size)
 434{
 435        const char *endp = NULL;
 436        static const char *nneof = " No newline at end of file\n";
 437        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 438        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 439
 440        while (0 < size) {
 441                int len;
 442
 443                endp = memchr(data, '\n', size);
 444                len = endp ? (endp - data + 1) : size;
 445                if (prefix != '+') {
 446                        ecb->lno_in_preimage++;
 447                        emit_line_0(ecb->file, old, reset, '-',
 448                                    data, len);
 449                } else {
 450                        ecb->lno_in_postimage++;
 451                        emit_add_line(reset, ecb, data, len);
 452                }
 453                size -= len;
 454                data += len;
 455        }
 456        if (!endp) {
 457                const char *plain = diff_get_color(ecb->color_diff,
 458                                                   DIFF_PLAIN);
 459                emit_line_0(ecb->file, plain, reset, '\\',
 460                            nneof, strlen(nneof));
 461        }
 462}
 463
 464static void emit_rewrite_diff(const char *name_a,
 465                              const char *name_b,
 466                              struct diff_filespec *one,
 467                              struct diff_filespec *two,
 468                              const char *textconv_one,
 469                              const char *textconv_two,
 470                              struct diff_options *o)
 471{
 472        int lc_a, lc_b;
 473        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 474        const char *name_a_tab, *name_b_tab;
 475        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 476        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 477        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 478        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 479        const char *a_prefix, *b_prefix;
 480        const char *data_one, *data_two;
 481        size_t size_one, size_two;
 482        struct emit_callback ecbdata;
 483
 484        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 485                a_prefix = o->b_prefix;
 486                b_prefix = o->a_prefix;
 487        } else {
 488                a_prefix = o->a_prefix;
 489                b_prefix = o->b_prefix;
 490        }
 491
 492        name_a += (*name_a == '/');
 493        name_b += (*name_b == '/');
 494        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 495        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 496
 497        strbuf_reset(&a_name);
 498        strbuf_reset(&b_name);
 499        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 500        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 501
 502        diff_populate_filespec(one, 0);
 503        diff_populate_filespec(two, 0);
 504        if (textconv_one) {
 505                data_one = run_textconv(textconv_one, one, &size_one);
 506                if (!data_one)
 507                        die("unable to read files to diff");
 508        }
 509        else {
 510                data_one = one->data;
 511                size_one = one->size;
 512        }
 513        if (textconv_two) {
 514                data_two = run_textconv(textconv_two, two, &size_two);
 515                if (!data_two)
 516                        die("unable to read files to diff");
 517        }
 518        else {
 519                data_two = two->data;
 520                size_two = two->size;
 521        }
 522
 523        memset(&ecbdata, 0, sizeof(ecbdata));
 524        ecbdata.color_diff = color_diff;
 525        ecbdata.found_changesp = &o->found_changes;
 526        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 527        ecbdata.file = o->file;
 528        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 529                mmfile_t mf1, mf2;
 530                mf1.ptr = (char *)data_one;
 531                mf2.ptr = (char *)data_two;
 532                mf1.size = size_one;
 533                mf2.size = size_two;
 534                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 535        }
 536        ecbdata.lno_in_preimage = 1;
 537        ecbdata.lno_in_postimage = 1;
 538
 539        lc_a = count_lines(data_one, size_one);
 540        lc_b = count_lines(data_two, size_two);
 541        fprintf(o->file,
 542                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 543                metainfo, a_name.buf, name_a_tab, reset,
 544                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 545        print_line_count(o->file, lc_a);
 546        fprintf(o->file, " +");
 547        print_line_count(o->file, lc_b);
 548        fprintf(o->file, " @@%s\n", reset);
 549        if (lc_a)
 550                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 551        if (lc_b)
 552                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 553}
 554
 555struct diff_words_buffer {
 556        mmfile_t text;
 557        long alloc;
 558        struct diff_words_orig {
 559                const char *begin, *end;
 560        } *orig;
 561        int orig_nr, orig_alloc;
 562};
 563
 564static void diff_words_append(char *line, unsigned long len,
 565                struct diff_words_buffer *buffer)
 566{
 567        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 568        line++;
 569        len--;
 570        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 571        buffer->text.size += len;
 572        buffer->text.ptr[buffer->text.size] = '\0';
 573}
 574
 575struct diff_words_style_elem
 576{
 577        const char *prefix;
 578        const char *suffix;
 579        const char *color; /* NULL; filled in by the setup code if
 580                            * color is enabled */
 581};
 582
 583struct diff_words_style
 584{
 585        enum diff_words_type type;
 586        struct diff_words_style_elem new, old, ctx;
 587        const char *newline;
 588};
 589
 590struct diff_words_style diff_words_styles[] = {
 591        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 592        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 593        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 594};
 595
 596struct diff_words_data {
 597        struct diff_words_buffer minus, plus;
 598        const char *current_plus;
 599        FILE *file;
 600        regex_t *word_regex;
 601        enum diff_words_type type;
 602        struct diff_words_style *style;
 603};
 604
 605static int fn_out_diff_words_write_helper(FILE *fp,
 606                                          struct diff_words_style_elem *st_el,
 607                                          const char *newline,
 608                                          size_t count, const char *buf)
 609{
 610        while (count) {
 611                char *p = memchr(buf, '\n', count);
 612                if (p != buf) {
 613                        if (st_el->color && fputs(st_el->color, fp) < 0)
 614                                return -1;
 615                        if (fputs(st_el->prefix, fp) < 0 ||
 616                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 617                            fputs(st_el->suffix, fp) < 0)
 618                                return -1;
 619                        if (st_el->color && *st_el->color
 620                            && fputs(GIT_COLOR_RESET, fp) < 0)
 621                                return -1;
 622                }
 623                if (!p)
 624                        return 0;
 625                if (fputs(newline, fp) < 0)
 626                        return -1;
 627                count -= p + 1 - buf;
 628                buf = p + 1;
 629        }
 630        return 0;
 631}
 632
 633static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 634{
 635        struct diff_words_data *diff_words = priv;
 636        struct diff_words_style *style = diff_words->style;
 637        int minus_first, minus_len, plus_first, plus_len;
 638        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 639
 640        if (line[0] != '@' || parse_hunk_header(line, len,
 641                        &minus_first, &minus_len, &plus_first, &plus_len))
 642                return;
 643
 644        /* POSIX requires that first be decremented by one if len == 0... */
 645        if (minus_len) {
 646                minus_begin = diff_words->minus.orig[minus_first].begin;
 647                minus_end =
 648                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 649        } else
 650                minus_begin = minus_end =
 651                        diff_words->minus.orig[minus_first].end;
 652
 653        if (plus_len) {
 654                plus_begin = diff_words->plus.orig[plus_first].begin;
 655                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 656        } else
 657                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 658
 659        if (diff_words->current_plus != plus_begin)
 660                fn_out_diff_words_write_helper(diff_words->file,
 661                                &style->ctx, style->newline,
 662                                plus_begin - diff_words->current_plus,
 663                                diff_words->current_plus);
 664        if (minus_begin != minus_end)
 665                fn_out_diff_words_write_helper(diff_words->file,
 666                                &style->old, style->newline,
 667                                minus_end - minus_begin, minus_begin);
 668        if (plus_begin != plus_end)
 669                fn_out_diff_words_write_helper(diff_words->file,
 670                                &style->new, style->newline,
 671                                plus_end - plus_begin, plus_begin);
 672
 673        diff_words->current_plus = plus_end;
 674}
 675
 676/* This function starts looking at *begin, and returns 0 iff a word was found. */
 677static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 678                int *begin, int *end)
 679{
 680        if (word_regex && *begin < buffer->size) {
 681                regmatch_t match[1];
 682                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 683                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 684                                        '\n', match[0].rm_eo - match[0].rm_so);
 685                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 686                        *begin += match[0].rm_so;
 687                        return *begin >= *end;
 688                }
 689                return -1;
 690        }
 691
 692        /* find the next word */
 693        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 694                (*begin)++;
 695        if (*begin >= buffer->size)
 696                return -1;
 697
 698        /* find the end of the word */
 699        *end = *begin + 1;
 700        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 701                (*end)++;
 702
 703        return 0;
 704}
 705
 706/*
 707 * This function splits the words in buffer->text, stores the list with
 708 * newline separator into out, and saves the offsets of the original words
 709 * in buffer->orig.
 710 */
 711static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 712                regex_t *word_regex)
 713{
 714        int i, j;
 715        long alloc = 0;
 716
 717        out->size = 0;
 718        out->ptr = NULL;
 719
 720        /* fake an empty "0th" word */
 721        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 722        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 723        buffer->orig_nr = 1;
 724
 725        for (i = 0; i < buffer->text.size; i++) {
 726                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 727                        return;
 728
 729                /* store original boundaries */
 730                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 731                                buffer->orig_alloc);
 732                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 733                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 734                buffer->orig_nr++;
 735
 736                /* store one word */
 737                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 738                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 739                out->ptr[out->size + j - i] = '\n';
 740                out->size += j - i + 1;
 741
 742                i = j - 1;
 743        }
 744}
 745
 746/* this executes the word diff on the accumulated buffers */
 747static void diff_words_show(struct diff_words_data *diff_words)
 748{
 749        xpparam_t xpp;
 750        xdemitconf_t xecfg;
 751        xdemitcb_t ecb;
 752        mmfile_t minus, plus;
 753        struct diff_words_style *style = diff_words->style;
 754
 755        /* special case: only removal */
 756        if (!diff_words->plus.text.size) {
 757                fn_out_diff_words_write_helper(diff_words->file,
 758                        &style->old, style->newline,
 759                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 760                diff_words->minus.text.size = 0;
 761                return;
 762        }
 763
 764        diff_words->current_plus = diff_words->plus.text.ptr;
 765
 766        memset(&xpp, 0, sizeof(xpp));
 767        memset(&xecfg, 0, sizeof(xecfg));
 768        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 769        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 770        xpp.flags = XDF_NEED_MINIMAL;
 771        /* as only the hunk header will be parsed, we need a 0-context */
 772        xecfg.ctxlen = 0;
 773        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 774                      &xpp, &xecfg, &ecb);
 775        free(minus.ptr);
 776        free(plus.ptr);
 777        if (diff_words->current_plus != diff_words->plus.text.ptr +
 778                        diff_words->plus.text.size)
 779                fn_out_diff_words_write_helper(diff_words->file,
 780                        &style->ctx, style->newline,
 781                        diff_words->plus.text.ptr + diff_words->plus.text.size
 782                        - diff_words->current_plus, diff_words->current_plus);
 783        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 784}
 785
 786/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 787static void diff_words_flush(struct emit_callback *ecbdata)
 788{
 789        if (ecbdata->diff_words->minus.text.size ||
 790            ecbdata->diff_words->plus.text.size)
 791                diff_words_show(ecbdata->diff_words);
 792}
 793
 794static void free_diff_words_data(struct emit_callback *ecbdata)
 795{
 796        if (ecbdata->diff_words) {
 797                diff_words_flush(ecbdata);
 798                free (ecbdata->diff_words->minus.text.ptr);
 799                free (ecbdata->diff_words->minus.orig);
 800                free (ecbdata->diff_words->plus.text.ptr);
 801                free (ecbdata->diff_words->plus.orig);
 802                free(ecbdata->diff_words->word_regex);
 803                free(ecbdata->diff_words);
 804                ecbdata->diff_words = NULL;
 805        }
 806}
 807
 808const char *diff_get_color(int diff_use_color, enum color_diff ix)
 809{
 810        if (diff_use_color)
 811                return diff_colors[ix];
 812        return "";
 813}
 814
 815static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 816{
 817        const char *cp;
 818        unsigned long allot;
 819        size_t l = len;
 820
 821        if (ecb->truncate)
 822                return ecb->truncate(line, len);
 823        cp = line;
 824        allot = l;
 825        while (0 < l) {
 826                (void) utf8_width(&cp, &l);
 827                if (!cp)
 828                        break; /* truncated in the middle? */
 829        }
 830        return allot - l;
 831}
 832
 833static void find_lno(const char *line, struct emit_callback *ecbdata)
 834{
 835        const char *p;
 836        ecbdata->lno_in_preimage = 0;
 837        ecbdata->lno_in_postimage = 0;
 838        p = strchr(line, '-');
 839        if (!p)
 840                return; /* cannot happen */
 841        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 842        p = strchr(p, '+');
 843        if (!p)
 844                return; /* cannot happen */
 845        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 846}
 847
 848static void fn_out_consume(void *priv, char *line, unsigned long len)
 849{
 850        struct emit_callback *ecbdata = priv;
 851        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 852        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 853        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 854
 855        if (ecbdata->header) {
 856                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 857                strbuf_reset(ecbdata->header);
 858                ecbdata->header = NULL;
 859        }
 860        *(ecbdata->found_changesp) = 1;
 861
 862        if (ecbdata->label_path[0]) {
 863                const char *name_a_tab, *name_b_tab;
 864
 865                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 866                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 867
 868                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 869                        meta, ecbdata->label_path[0], reset, name_a_tab);
 870                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 871                        meta, ecbdata->label_path[1], reset, name_b_tab);
 872                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 873        }
 874
 875        if (diff_suppress_blank_empty
 876            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 877                line[0] = '\n';
 878                len = 1;
 879        }
 880
 881        if (line[0] == '@') {
 882                if (ecbdata->diff_words)
 883                        diff_words_flush(ecbdata);
 884                len = sane_truncate_line(ecbdata, line, len);
 885                find_lno(line, ecbdata);
 886                emit_hunk_header(ecbdata, line, len);
 887                if (line[len-1] != '\n')
 888                        putc('\n', ecbdata->file);
 889                return;
 890        }
 891
 892        if (len < 1) {
 893                emit_line(ecbdata->file, reset, reset, line, len);
 894                if (ecbdata->diff_words
 895                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
 896                        fputs("~\n", ecbdata->file);
 897                return;
 898        }
 899
 900        if (ecbdata->diff_words) {
 901                if (line[0] == '-') {
 902                        diff_words_append(line, len,
 903                                          &ecbdata->diff_words->minus);
 904                        return;
 905                } else if (line[0] == '+') {
 906                        diff_words_append(line, len,
 907                                          &ecbdata->diff_words->plus);
 908                        return;
 909                }
 910                diff_words_flush(ecbdata);
 911                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
 912                        emit_line(ecbdata->file, plain, reset, line, len);
 913                        fputs("~\n", ecbdata->file);
 914                } else {
 915                        /* don't print the prefix character */
 916                        emit_line(ecbdata->file, plain, reset, line+1, len-1);
 917                }
 918                return;
 919        }
 920
 921        if (line[0] != '+') {
 922                const char *color =
 923                        diff_get_color(ecbdata->color_diff,
 924                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 925                ecbdata->lno_in_preimage++;
 926                if (line[0] == ' ')
 927                        ecbdata->lno_in_postimage++;
 928                emit_line(ecbdata->file, color, reset, line, len);
 929        } else {
 930                ecbdata->lno_in_postimage++;
 931                emit_add_line(reset, ecbdata, line + 1, len - 1);
 932        }
 933}
 934
 935static char *pprint_rename(const char *a, const char *b)
 936{
 937        const char *old = a;
 938        const char *new = b;
 939        struct strbuf name = STRBUF_INIT;
 940        int pfx_length, sfx_length;
 941        int len_a = strlen(a);
 942        int len_b = strlen(b);
 943        int a_midlen, b_midlen;
 944        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 945        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 946
 947        if (qlen_a || qlen_b) {
 948                quote_c_style(a, &name, NULL, 0);
 949                strbuf_addstr(&name, " => ");
 950                quote_c_style(b, &name, NULL, 0);
 951                return strbuf_detach(&name, NULL);
 952        }
 953
 954        /* Find common prefix */
 955        pfx_length = 0;
 956        while (*old && *new && *old == *new) {
 957                if (*old == '/')
 958                        pfx_length = old - a + 1;
 959                old++;
 960                new++;
 961        }
 962
 963        /* Find common suffix */
 964        old = a + len_a;
 965        new = b + len_b;
 966        sfx_length = 0;
 967        while (a <= old && b <= new && *old == *new) {
 968                if (*old == '/')
 969                        sfx_length = len_a - (old - a);
 970                old--;
 971                new--;
 972        }
 973
 974        /*
 975         * pfx{mid-a => mid-b}sfx
 976         * {pfx-a => pfx-b}sfx
 977         * pfx{sfx-a => sfx-b}
 978         * name-a => name-b
 979         */
 980        a_midlen = len_a - pfx_length - sfx_length;
 981        b_midlen = len_b - pfx_length - sfx_length;
 982        if (a_midlen < 0)
 983                a_midlen = 0;
 984        if (b_midlen < 0)
 985                b_midlen = 0;
 986
 987        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 988        if (pfx_length + sfx_length) {
 989                strbuf_add(&name, a, pfx_length);
 990                strbuf_addch(&name, '{');
 991        }
 992        strbuf_add(&name, a + pfx_length, a_midlen);
 993        strbuf_addstr(&name, " => ");
 994        strbuf_add(&name, b + pfx_length, b_midlen);
 995        if (pfx_length + sfx_length) {
 996                strbuf_addch(&name, '}');
 997                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 998        }
 999        return strbuf_detach(&name, NULL);
1000}
1001
1002struct diffstat_t {
1003        int nr;
1004        int alloc;
1005        struct diffstat_file {
1006                char *from_name;
1007                char *name;
1008                char *print_name;
1009                unsigned is_unmerged:1;
1010                unsigned is_binary:1;
1011                unsigned is_renamed:1;
1012                unsigned int added, deleted;
1013        } **files;
1014};
1015
1016static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1017                                          const char *name_a,
1018                                          const char *name_b)
1019{
1020        struct diffstat_file *x;
1021        x = xcalloc(sizeof (*x), 1);
1022        if (diffstat->nr == diffstat->alloc) {
1023                diffstat->alloc = alloc_nr(diffstat->alloc);
1024                diffstat->files = xrealloc(diffstat->files,
1025                                diffstat->alloc * sizeof(x));
1026        }
1027        diffstat->files[diffstat->nr++] = x;
1028        if (name_b) {
1029                x->from_name = xstrdup(name_a);
1030                x->name = xstrdup(name_b);
1031                x->is_renamed = 1;
1032        }
1033        else {
1034                x->from_name = NULL;
1035                x->name = xstrdup(name_a);
1036        }
1037        return x;
1038}
1039
1040static void diffstat_consume(void *priv, char *line, unsigned long len)
1041{
1042        struct diffstat_t *diffstat = priv;
1043        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1044
1045        if (line[0] == '+')
1046                x->added++;
1047        else if (line[0] == '-')
1048                x->deleted++;
1049}
1050
1051const char mime_boundary_leader[] = "------------";
1052
1053static int scale_linear(int it, int width, int max_change)
1054{
1055        /*
1056         * make sure that at least one '-' is printed if there were deletions,
1057         * and likewise for '+'.
1058         */
1059        if (max_change < 2)
1060                return it;
1061        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1062}
1063
1064static void show_name(FILE *file,
1065                      const char *prefix, const char *name, int len)
1066{
1067        fprintf(file, " %s%-*s |", prefix, len, name);
1068}
1069
1070static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1071{
1072        if (cnt <= 0)
1073                return;
1074        fprintf(file, "%s", set);
1075        while (cnt--)
1076                putc(ch, file);
1077        fprintf(file, "%s", reset);
1078}
1079
1080static void fill_print_name(struct diffstat_file *file)
1081{
1082        char *pname;
1083
1084        if (file->print_name)
1085                return;
1086
1087        if (!file->is_renamed) {
1088                struct strbuf buf = STRBUF_INIT;
1089                if (quote_c_style(file->name, &buf, NULL, 0)) {
1090                        pname = strbuf_detach(&buf, NULL);
1091                } else {
1092                        pname = file->name;
1093                        strbuf_release(&buf);
1094                }
1095        } else {
1096                pname = pprint_rename(file->from_name, file->name);
1097        }
1098        file->print_name = pname;
1099}
1100
1101static void show_stats(struct diffstat_t *data, struct diff_options *options)
1102{
1103        int i, len, add, del, adds = 0, dels = 0;
1104        int max_change = 0, max_len = 0;
1105        int total_files = data->nr;
1106        int width, name_width;
1107        const char *reset, *set, *add_c, *del_c;
1108
1109        if (data->nr == 0)
1110                return;
1111
1112        width = options->stat_width ? options->stat_width : 80;
1113        name_width = options->stat_name_width ? options->stat_name_width : 50;
1114
1115        /* Sanity: give at least 5 columns to the graph,
1116         * but leave at least 10 columns for the name.
1117         */
1118        if (width < 25)
1119                width = 25;
1120        if (name_width < 10)
1121                name_width = 10;
1122        else if (width < name_width + 15)
1123                name_width = width - 15;
1124
1125        /* Find the longest filename and max number of changes */
1126        reset = diff_get_color_opt(options, DIFF_RESET);
1127        set   = diff_get_color_opt(options, DIFF_PLAIN);
1128        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1129        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1130
1131        for (i = 0; i < data->nr; i++) {
1132                struct diffstat_file *file = data->files[i];
1133                int change = file->added + file->deleted;
1134                fill_print_name(file);
1135                len = strlen(file->print_name);
1136                if (max_len < len)
1137                        max_len = len;
1138
1139                if (file->is_binary || file->is_unmerged)
1140                        continue;
1141                if (max_change < change)
1142                        max_change = change;
1143        }
1144
1145        /* Compute the width of the graph part;
1146         * 10 is for one blank at the beginning of the line plus
1147         * " | count " between the name and the graph.
1148         *
1149         * From here on, name_width is the width of the name area,
1150         * and width is the width of the graph area.
1151         */
1152        name_width = (name_width < max_len) ? name_width : max_len;
1153        if (width < (name_width + 10) + max_change)
1154                width = width - (name_width + 10);
1155        else
1156                width = max_change;
1157
1158        for (i = 0; i < data->nr; i++) {
1159                const char *prefix = "";
1160                char *name = data->files[i]->print_name;
1161                int added = data->files[i]->added;
1162                int deleted = data->files[i]->deleted;
1163                int name_len;
1164
1165                /*
1166                 * "scale" the filename
1167                 */
1168                len = name_width;
1169                name_len = strlen(name);
1170                if (name_width < name_len) {
1171                        char *slash;
1172                        prefix = "...";
1173                        len -= 3;
1174                        name += name_len - len;
1175                        slash = strchr(name, '/');
1176                        if (slash)
1177                                name = slash;
1178                }
1179
1180                if (data->files[i]->is_binary) {
1181                        show_name(options->file, prefix, name, len);
1182                        fprintf(options->file, "  Bin ");
1183                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
1184                        fprintf(options->file, " -> ");
1185                        fprintf(options->file, "%s%d%s", add_c, added, reset);
1186                        fprintf(options->file, " bytes");
1187                        fprintf(options->file, "\n");
1188                        continue;
1189                }
1190                else if (data->files[i]->is_unmerged) {
1191                        show_name(options->file, prefix, name, len);
1192                        fprintf(options->file, "  Unmerged\n");
1193                        continue;
1194                }
1195                else if (!data->files[i]->is_renamed &&
1196                         (added + deleted == 0)) {
1197                        total_files--;
1198                        continue;
1199                }
1200
1201                /*
1202                 * scale the add/delete
1203                 */
1204                add = added;
1205                del = deleted;
1206                adds += add;
1207                dels += del;
1208
1209                if (width <= max_change) {
1210                        add = scale_linear(add, width, max_change);
1211                        del = scale_linear(del, width, max_change);
1212                }
1213                show_name(options->file, prefix, name, len);
1214                fprintf(options->file, "%5d%s", added + deleted,
1215                                added + deleted ? " " : "");
1216                show_graph(options->file, '+', add, add_c, reset);
1217                show_graph(options->file, '-', del, del_c, reset);
1218                fprintf(options->file, "\n");
1219        }
1220        fprintf(options->file,
1221               " %d files changed, %d insertions(+), %d deletions(-)\n",
1222               total_files, adds, dels);
1223}
1224
1225static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1226{
1227        int i, adds = 0, dels = 0, total_files = data->nr;
1228
1229        if (data->nr == 0)
1230                return;
1231
1232        for (i = 0; i < data->nr; i++) {
1233                if (!data->files[i]->is_binary &&
1234                    !data->files[i]->is_unmerged) {
1235                        int added = data->files[i]->added;
1236                        int deleted= data->files[i]->deleted;
1237                        if (!data->files[i]->is_renamed &&
1238                            (added + deleted == 0)) {
1239                                total_files--;
1240                        } else {
1241                                adds += added;
1242                                dels += deleted;
1243                        }
1244                }
1245        }
1246        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1247               total_files, adds, dels);
1248}
1249
1250static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1251{
1252        int i;
1253
1254        if (data->nr == 0)
1255                return;
1256
1257        for (i = 0; i < data->nr; i++) {
1258                struct diffstat_file *file = data->files[i];
1259
1260                if (file->is_binary)
1261                        fprintf(options->file, "-\t-\t");
1262                else
1263                        fprintf(options->file,
1264                                "%d\t%d\t", file->added, file->deleted);
1265                if (options->line_termination) {
1266                        fill_print_name(file);
1267                        if (!file->is_renamed)
1268                                write_name_quoted(file->name, options->file,
1269                                                  options->line_termination);
1270                        else {
1271                                fputs(file->print_name, options->file);
1272                                putc(options->line_termination, options->file);
1273                        }
1274                } else {
1275                        if (file->is_renamed) {
1276                                putc('\0', options->file);
1277                                write_name_quoted(file->from_name, options->file, '\0');
1278                        }
1279                        write_name_quoted(file->name, options->file, '\0');
1280                }
1281        }
1282}
1283
1284struct dirstat_file {
1285        const char *name;
1286        unsigned long changed;
1287};
1288
1289struct dirstat_dir {
1290        struct dirstat_file *files;
1291        int alloc, nr, percent, cumulative;
1292};
1293
1294static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1295{
1296        unsigned long this_dir = 0;
1297        unsigned int sources = 0;
1298
1299        while (dir->nr) {
1300                struct dirstat_file *f = dir->files;
1301                int namelen = strlen(f->name);
1302                unsigned long this;
1303                char *slash;
1304
1305                if (namelen < baselen)
1306                        break;
1307                if (memcmp(f->name, base, baselen))
1308                        break;
1309                slash = strchr(f->name + baselen, '/');
1310                if (slash) {
1311                        int newbaselen = slash + 1 - f->name;
1312                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1313                        sources++;
1314                } else {
1315                        this = f->changed;
1316                        dir->files++;
1317                        dir->nr--;
1318                        sources += 2;
1319                }
1320                this_dir += this;
1321        }
1322
1323        /*
1324         * We don't report dirstat's for
1325         *  - the top level
1326         *  - or cases where everything came from a single directory
1327         *    under this directory (sources == 1).
1328         */
1329        if (baselen && sources != 1) {
1330                int permille = this_dir * 1000 / changed;
1331                if (permille) {
1332                        int percent = permille / 10;
1333                        if (percent >= dir->percent) {
1334                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1335                                if (!dir->cumulative)
1336                                        return 0;
1337                        }
1338                }
1339        }
1340        return this_dir;
1341}
1342
1343static int dirstat_compare(const void *_a, const void *_b)
1344{
1345        const struct dirstat_file *a = _a;
1346        const struct dirstat_file *b = _b;
1347        return strcmp(a->name, b->name);
1348}
1349
1350static void show_dirstat(struct diff_options *options)
1351{
1352        int i;
1353        unsigned long changed;
1354        struct dirstat_dir dir;
1355        struct diff_queue_struct *q = &diff_queued_diff;
1356
1357        dir.files = NULL;
1358        dir.alloc = 0;
1359        dir.nr = 0;
1360        dir.percent = options->dirstat_percent;
1361        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1362
1363        changed = 0;
1364        for (i = 0; i < q->nr; i++) {
1365                struct diff_filepair *p = q->queue[i];
1366                const char *name;
1367                unsigned long copied, added, damage;
1368
1369                name = p->one->path ? p->one->path : p->two->path;
1370
1371                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1372                        diff_populate_filespec(p->one, 0);
1373                        diff_populate_filespec(p->two, 0);
1374                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1375                                               &copied, &added);
1376                        diff_free_filespec_data(p->one);
1377                        diff_free_filespec_data(p->two);
1378                } else if (DIFF_FILE_VALID(p->one)) {
1379                        diff_populate_filespec(p->one, 1);
1380                        copied = added = 0;
1381                        diff_free_filespec_data(p->one);
1382                } else if (DIFF_FILE_VALID(p->two)) {
1383                        diff_populate_filespec(p->two, 1);
1384                        copied = 0;
1385                        added = p->two->size;
1386                        diff_free_filespec_data(p->two);
1387                } else
1388                        continue;
1389
1390                /*
1391                 * Original minus copied is the removed material,
1392                 * added is the new material.  They are both damages
1393                 * made to the preimage. In --dirstat-by-file mode, count
1394                 * damaged files, not damaged lines. This is done by
1395                 * counting only a single damaged line per file.
1396                 */
1397                damage = (p->one->size - copied) + added;
1398                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1399                        damage = 1;
1400
1401                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1402                dir.files[dir.nr].name = name;
1403                dir.files[dir.nr].changed = damage;
1404                changed += damage;
1405                dir.nr++;
1406        }
1407
1408        /* This can happen even with many files, if everything was renames */
1409        if (!changed)
1410                return;
1411
1412        /* Show all directories with more than x% of the changes */
1413        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1414        gather_dirstat(options->file, &dir, changed, "", 0);
1415}
1416
1417static void free_diffstat_info(struct diffstat_t *diffstat)
1418{
1419        int i;
1420        for (i = 0; i < diffstat->nr; i++) {
1421                struct diffstat_file *f = diffstat->files[i];
1422                if (f->name != f->print_name)
1423                        free(f->print_name);
1424                free(f->name);
1425                free(f->from_name);
1426                free(f);
1427        }
1428        free(diffstat->files);
1429}
1430
1431struct checkdiff_t {
1432        const char *filename;
1433        int lineno;
1434        struct diff_options *o;
1435        unsigned ws_rule;
1436        unsigned status;
1437};
1438
1439static int is_conflict_marker(const char *line, unsigned long len)
1440{
1441        char firstchar;
1442        int cnt;
1443
1444        if (len < 8)
1445                return 0;
1446        firstchar = line[0];
1447        switch (firstchar) {
1448        case '=': case '>': case '<':
1449                break;
1450        default:
1451                return 0;
1452        }
1453        for (cnt = 1; cnt < 7; cnt++)
1454                if (line[cnt] != firstchar)
1455                        return 0;
1456        /* line[0] thru line[6] are same as firstchar */
1457        if (firstchar == '=') {
1458                /* divider between ours and theirs? */
1459                if (len != 8 || line[7] != '\n')
1460                        return 0;
1461        } else if (len < 8 || !isspace(line[7])) {
1462                /* not divider before ours nor after theirs */
1463                return 0;
1464        }
1465        return 1;
1466}
1467
1468static void checkdiff_consume(void *priv, char *line, unsigned long len)
1469{
1470        struct checkdiff_t *data = priv;
1471        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1472        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1473        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1474        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1475        char *err;
1476
1477        if (line[0] == '+') {
1478                unsigned bad;
1479                data->lineno++;
1480                if (is_conflict_marker(line + 1, len - 1)) {
1481                        data->status |= 1;
1482                        fprintf(data->o->file,
1483                                "%s:%d: leftover conflict marker\n",
1484                                data->filename, data->lineno);
1485                }
1486                bad = ws_check(line + 1, len - 1, data->ws_rule);
1487                if (!bad)
1488                        return;
1489                data->status |= bad;
1490                err = whitespace_error_string(bad);
1491                fprintf(data->o->file, "%s:%d: %s.\n",
1492                        data->filename, data->lineno, err);
1493                free(err);
1494                emit_line(data->o->file, set, reset, line, 1);
1495                ws_check_emit(line + 1, len - 1, data->ws_rule,
1496                              data->o->file, set, reset, ws);
1497        } else if (line[0] == ' ') {
1498                data->lineno++;
1499        } else if (line[0] == '@') {
1500                char *plus = strchr(line, '+');
1501                if (plus)
1502                        data->lineno = strtol(plus, NULL, 10) - 1;
1503                else
1504                        die("invalid diff");
1505        }
1506}
1507
1508static unsigned char *deflate_it(char *data,
1509                                 unsigned long size,
1510                                 unsigned long *result_size)
1511{
1512        int bound;
1513        unsigned char *deflated;
1514        z_stream stream;
1515
1516        memset(&stream, 0, sizeof(stream));
1517        deflateInit(&stream, zlib_compression_level);
1518        bound = deflateBound(&stream, size);
1519        deflated = xmalloc(bound);
1520        stream.next_out = deflated;
1521        stream.avail_out = bound;
1522
1523        stream.next_in = (unsigned char *)data;
1524        stream.avail_in = size;
1525        while (deflate(&stream, Z_FINISH) == Z_OK)
1526                ; /* nothing */
1527        deflateEnd(&stream);
1528        *result_size = stream.total_out;
1529        return deflated;
1530}
1531
1532static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1533{
1534        void *cp;
1535        void *delta;
1536        void *deflated;
1537        void *data;
1538        unsigned long orig_size;
1539        unsigned long delta_size;
1540        unsigned long deflate_size;
1541        unsigned long data_size;
1542
1543        /* We could do deflated delta, or we could do just deflated two,
1544         * whichever is smaller.
1545         */
1546        delta = NULL;
1547        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1548        if (one->size && two->size) {
1549                delta = diff_delta(one->ptr, one->size,
1550                                   two->ptr, two->size,
1551                                   &delta_size, deflate_size);
1552                if (delta) {
1553                        void *to_free = delta;
1554                        orig_size = delta_size;
1555                        delta = deflate_it(delta, delta_size, &delta_size);
1556                        free(to_free);
1557                }
1558        }
1559
1560        if (delta && delta_size < deflate_size) {
1561                fprintf(file, "delta %lu\n", orig_size);
1562                free(deflated);
1563                data = delta;
1564                data_size = delta_size;
1565        }
1566        else {
1567                fprintf(file, "literal %lu\n", two->size);
1568                free(delta);
1569                data = deflated;
1570                data_size = deflate_size;
1571        }
1572
1573        /* emit data encoded in base85 */
1574        cp = data;
1575        while (data_size) {
1576                int bytes = (52 < data_size) ? 52 : data_size;
1577                char line[70];
1578                data_size -= bytes;
1579                if (bytes <= 26)
1580                        line[0] = bytes + 'A' - 1;
1581                else
1582                        line[0] = bytes - 26 + 'a' - 1;
1583                encode_85(line + 1, cp, bytes);
1584                cp = (char *) cp + bytes;
1585                fputs(line, file);
1586                fputc('\n', file);
1587        }
1588        fprintf(file, "\n");
1589        free(data);
1590}
1591
1592static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1593{
1594        fprintf(file, "GIT binary patch\n");
1595        emit_binary_diff_body(file, one, two);
1596        emit_binary_diff_body(file, two, one);
1597}
1598
1599static void diff_filespec_load_driver(struct diff_filespec *one)
1600{
1601        if (!one->driver)
1602                one->driver = userdiff_find_by_path(one->path);
1603        if (!one->driver)
1604                one->driver = userdiff_find_by_name("default");
1605}
1606
1607int diff_filespec_is_binary(struct diff_filespec *one)
1608{
1609        if (one->is_binary == -1) {
1610                diff_filespec_load_driver(one);
1611                if (one->driver->binary != -1)
1612                        one->is_binary = one->driver->binary;
1613                else {
1614                        if (!one->data && DIFF_FILE_VALID(one))
1615                                diff_populate_filespec(one, 0);
1616                        if (one->data)
1617                                one->is_binary = buffer_is_binary(one->data,
1618                                                one->size);
1619                        if (one->is_binary == -1)
1620                                one->is_binary = 0;
1621                }
1622        }
1623        return one->is_binary;
1624}
1625
1626static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1627{
1628        diff_filespec_load_driver(one);
1629        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1630}
1631
1632static const char *userdiff_word_regex(struct diff_filespec *one)
1633{
1634        diff_filespec_load_driver(one);
1635        return one->driver->word_regex;
1636}
1637
1638void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1639{
1640        if (!options->a_prefix)
1641                options->a_prefix = a;
1642        if (!options->b_prefix)
1643                options->b_prefix = b;
1644}
1645
1646static const char *get_textconv(struct diff_filespec *one)
1647{
1648        if (!DIFF_FILE_VALID(one))
1649                return NULL;
1650        if (!S_ISREG(one->mode))
1651                return NULL;
1652        diff_filespec_load_driver(one);
1653        return one->driver->textconv;
1654}
1655
1656static void builtin_diff(const char *name_a,
1657                         const char *name_b,
1658                         struct diff_filespec *one,
1659                         struct diff_filespec *two,
1660                         const char *xfrm_msg,
1661                         struct diff_options *o,
1662                         int complete_rewrite)
1663{
1664        mmfile_t mf1, mf2;
1665        const char *lbl[2];
1666        char *a_one, *b_two;
1667        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1668        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1669        const char *a_prefix, *b_prefix;
1670        const char *textconv_one = NULL, *textconv_two = NULL;
1671        struct strbuf header = STRBUF_INIT;
1672
1673        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1674                        (!one->mode || S_ISGITLINK(one->mode)) &&
1675                        (!two->mode || S_ISGITLINK(two->mode))) {
1676                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1677                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1678                show_submodule_summary(o->file, one ? one->path : two->path,
1679                                one->sha1, two->sha1, two->dirty_submodule,
1680                                del, add, reset);
1681                return;
1682        }
1683
1684        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1685                textconv_one = get_textconv(one);
1686                textconv_two = get_textconv(two);
1687        }
1688
1689        diff_set_mnemonic_prefix(o, "a/", "b/");
1690        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1691                a_prefix = o->b_prefix;
1692                b_prefix = o->a_prefix;
1693        } else {
1694                a_prefix = o->a_prefix;
1695                b_prefix = o->b_prefix;
1696        }
1697
1698        /* Never use a non-valid filename anywhere if at all possible */
1699        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1700        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1701
1702        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1703        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1704        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1705        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1706        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1707        if (lbl[0][0] == '/') {
1708                /* /dev/null */
1709                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1710                if (xfrm_msg && xfrm_msg[0])
1711                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1712        }
1713        else if (lbl[1][0] == '/') {
1714                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1715                if (xfrm_msg && xfrm_msg[0])
1716                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1717        }
1718        else {
1719                if (one->mode != two->mode) {
1720                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1721                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1722                }
1723                if (xfrm_msg && xfrm_msg[0])
1724                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1725
1726                /*
1727                 * we do not run diff between different kind
1728                 * of objects.
1729                 */
1730                if ((one->mode ^ two->mode) & S_IFMT)
1731                        goto free_ab_and_return;
1732                if (complete_rewrite &&
1733                    (textconv_one || !diff_filespec_is_binary(one)) &&
1734                    (textconv_two || !diff_filespec_is_binary(two))) {
1735                        fprintf(o->file, "%s", header.buf);
1736                        strbuf_reset(&header);
1737                        emit_rewrite_diff(name_a, name_b, one, two,
1738                                                textconv_one, textconv_two, o);
1739                        o->found_changes = 1;
1740                        goto free_ab_and_return;
1741                }
1742        }
1743
1744        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1745                die("unable to read files to diff");
1746
1747        if (!DIFF_OPT_TST(o, TEXT) &&
1748            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1749              (diff_filespec_is_binary(two) && !textconv_two) )) {
1750                /* Quite common confusing case */
1751                if (mf1.size == mf2.size &&
1752                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1753                        goto free_ab_and_return;
1754                fprintf(o->file, "%s", header.buf);
1755                strbuf_reset(&header);
1756                if (DIFF_OPT_TST(o, BINARY))
1757                        emit_binary_diff(o->file, &mf1, &mf2);
1758                else
1759                        fprintf(o->file, "Binary files %s and %s differ\n",
1760                                lbl[0], lbl[1]);
1761                o->found_changes = 1;
1762        }
1763        else {
1764                /* Crazy xdl interfaces.. */
1765                const char *diffopts = getenv("GIT_DIFF_OPTS");
1766                xpparam_t xpp;
1767                xdemitconf_t xecfg;
1768                xdemitcb_t ecb;
1769                struct emit_callback ecbdata;
1770                const struct userdiff_funcname *pe;
1771
1772                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1773                        fprintf(o->file, "%s", header.buf);
1774                        strbuf_reset(&header);
1775                }
1776
1777                if (textconv_one) {
1778                        size_t size;
1779                        mf1.ptr = run_textconv(textconv_one, one, &size);
1780                        if (!mf1.ptr)
1781                                die("unable to read files to diff");
1782                        mf1.size = size;
1783                }
1784                if (textconv_two) {
1785                        size_t size;
1786                        mf2.ptr = run_textconv(textconv_two, two, &size);
1787                        if (!mf2.ptr)
1788                                die("unable to read files to diff");
1789                        mf2.size = size;
1790                }
1791
1792                pe = diff_funcname_pattern(one);
1793                if (!pe)
1794                        pe = diff_funcname_pattern(two);
1795
1796                memset(&xpp, 0, sizeof(xpp));
1797                memset(&xecfg, 0, sizeof(xecfg));
1798                memset(&ecbdata, 0, sizeof(ecbdata));
1799                ecbdata.label_path = lbl;
1800                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1801                ecbdata.found_changesp = &o->found_changes;
1802                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1803                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1804                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1805                ecbdata.file = o->file;
1806                ecbdata.header = header.len ? &header : NULL;
1807                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1808                xecfg.ctxlen = o->context;
1809                xecfg.interhunkctxlen = o->interhunkcontext;
1810                xecfg.flags = XDL_EMIT_FUNCNAMES;
1811                if (pe)
1812                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1813                if (!diffopts)
1814                        ;
1815                else if (!prefixcmp(diffopts, "--unified="))
1816                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1817                else if (!prefixcmp(diffopts, "-u"))
1818                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1819                if (o->word_diff) {
1820                        int i;
1821
1822                        ecbdata.diff_words =
1823                                xcalloc(1, sizeof(struct diff_words_data));
1824                        ecbdata.diff_words->file = o->file;
1825                        ecbdata.diff_words->type = o->word_diff;
1826                        if (!o->word_regex)
1827                                o->word_regex = userdiff_word_regex(one);
1828                        if (!o->word_regex)
1829                                o->word_regex = userdiff_word_regex(two);
1830                        if (!o->word_regex)
1831                                o->word_regex = diff_word_regex_cfg;
1832                        if (o->word_regex) {
1833                                ecbdata.diff_words->word_regex = (regex_t *)
1834                                        xmalloc(sizeof(regex_t));
1835                                if (regcomp(ecbdata.diff_words->word_regex,
1836                                                o->word_regex,
1837                                                REG_EXTENDED | REG_NEWLINE))
1838                                        die ("Invalid regular expression: %s",
1839                                                        o->word_regex);
1840                        }
1841                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1842                                if (o->word_diff == diff_words_styles[i].type) {
1843                                        ecbdata.diff_words->style =
1844                                                &diff_words_styles[i];
1845                                        break;
1846                                }
1847                        }
1848                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1849                                struct diff_words_style *st = ecbdata.diff_words->style;
1850                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1851                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1852                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1853                        }
1854                }
1855                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1856                              &xpp, &xecfg, &ecb);
1857                if (o->word_diff)
1858                        free_diff_words_data(&ecbdata);
1859                if (textconv_one)
1860                        free(mf1.ptr);
1861                if (textconv_two)
1862                        free(mf2.ptr);
1863                xdiff_clear_find_func(&xecfg);
1864        }
1865
1866 free_ab_and_return:
1867        strbuf_release(&header);
1868        diff_free_filespec_data(one);
1869        diff_free_filespec_data(two);
1870        free(a_one);
1871        free(b_two);
1872        return;
1873}
1874
1875static void builtin_diffstat(const char *name_a, const char *name_b,
1876                             struct diff_filespec *one,
1877                             struct diff_filespec *two,
1878                             struct diffstat_t *diffstat,
1879                             struct diff_options *o,
1880                             int complete_rewrite)
1881{
1882        mmfile_t mf1, mf2;
1883        struct diffstat_file *data;
1884
1885        data = diffstat_add(diffstat, name_a, name_b);
1886
1887        if (!one || !two) {
1888                data->is_unmerged = 1;
1889                return;
1890        }
1891        if (complete_rewrite) {
1892                diff_populate_filespec(one, 0);
1893                diff_populate_filespec(two, 0);
1894                data->deleted = count_lines(one->data, one->size);
1895                data->added = count_lines(two->data, two->size);
1896                goto free_and_return;
1897        }
1898        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1899                die("unable to read files to diff");
1900
1901        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1902                data->is_binary = 1;
1903                data->added = mf2.size;
1904                data->deleted = mf1.size;
1905        } else {
1906                /* Crazy xdl interfaces.. */
1907                xpparam_t xpp;
1908                xdemitconf_t xecfg;
1909                xdemitcb_t ecb;
1910
1911                memset(&xpp, 0, sizeof(xpp));
1912                memset(&xecfg, 0, sizeof(xecfg));
1913                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1914                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1915                              &xpp, &xecfg, &ecb);
1916        }
1917
1918 free_and_return:
1919        diff_free_filespec_data(one);
1920        diff_free_filespec_data(two);
1921}
1922
1923static void builtin_checkdiff(const char *name_a, const char *name_b,
1924                              const char *attr_path,
1925                              struct diff_filespec *one,
1926                              struct diff_filespec *two,
1927                              struct diff_options *o)
1928{
1929        mmfile_t mf1, mf2;
1930        struct checkdiff_t data;
1931
1932        if (!two)
1933                return;
1934
1935        memset(&data, 0, sizeof(data));
1936        data.filename = name_b ? name_b : name_a;
1937        data.lineno = 0;
1938        data.o = o;
1939        data.ws_rule = whitespace_rule(attr_path);
1940
1941        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1942                die("unable to read files to diff");
1943
1944        /*
1945         * All the other codepaths check both sides, but not checking
1946         * the "old" side here is deliberate.  We are checking the newly
1947         * introduced changes, and as long as the "new" side is text, we
1948         * can and should check what it introduces.
1949         */
1950        if (diff_filespec_is_binary(two))
1951                goto free_and_return;
1952        else {
1953                /* Crazy xdl interfaces.. */
1954                xpparam_t xpp;
1955                xdemitconf_t xecfg;
1956                xdemitcb_t ecb;
1957
1958                memset(&xpp, 0, sizeof(xpp));
1959                memset(&xecfg, 0, sizeof(xecfg));
1960                xecfg.ctxlen = 1; /* at least one context line */
1961                xpp.flags = XDF_NEED_MINIMAL;
1962                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1963                              &xpp, &xecfg, &ecb);
1964
1965                if (data.ws_rule & WS_BLANK_AT_EOF) {
1966                        struct emit_callback ecbdata;
1967                        int blank_at_eof;
1968
1969                        ecbdata.ws_rule = data.ws_rule;
1970                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1971                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1972
1973                        if (blank_at_eof) {
1974                                static char *err;
1975                                if (!err)
1976                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1977                                fprintf(o->file, "%s:%d: %s.\n",
1978                                        data.filename, blank_at_eof, err);
1979                                data.status = 1; /* report errors */
1980                        }
1981                }
1982        }
1983 free_and_return:
1984        diff_free_filespec_data(one);
1985        diff_free_filespec_data(two);
1986        if (data.status)
1987                DIFF_OPT_SET(o, CHECK_FAILED);
1988}
1989
1990struct diff_filespec *alloc_filespec(const char *path)
1991{
1992        int namelen = strlen(path);
1993        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1994
1995        memset(spec, 0, sizeof(*spec));
1996        spec->path = (char *)(spec + 1);
1997        memcpy(spec->path, path, namelen+1);
1998        spec->count = 1;
1999        spec->is_binary = -1;
2000        return spec;
2001}
2002
2003void free_filespec(struct diff_filespec *spec)
2004{
2005        if (!--spec->count) {
2006                diff_free_filespec_data(spec);
2007                free(spec);
2008        }
2009}
2010
2011void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2012                   unsigned short mode)
2013{
2014        if (mode) {
2015                spec->mode = canon_mode(mode);
2016                hashcpy(spec->sha1, sha1);
2017                spec->sha1_valid = !is_null_sha1(sha1);
2018        }
2019}
2020
2021/*
2022 * Given a name and sha1 pair, if the index tells us the file in
2023 * the work tree has that object contents, return true, so that
2024 * prepare_temp_file() does not have to inflate and extract.
2025 */
2026static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2027{
2028        struct cache_entry *ce;
2029        struct stat st;
2030        int pos, len;
2031
2032        /*
2033         * We do not read the cache ourselves here, because the
2034         * benchmark with my previous version that always reads cache
2035         * shows that it makes things worse for diff-tree comparing
2036         * two linux-2.6 kernel trees in an already checked out work
2037         * tree.  This is because most diff-tree comparisons deal with
2038         * only a small number of files, while reading the cache is
2039         * expensive for a large project, and its cost outweighs the
2040         * savings we get by not inflating the object to a temporary
2041         * file.  Practically, this code only helps when we are used
2042         * by diff-cache --cached, which does read the cache before
2043         * calling us.
2044         */
2045        if (!active_cache)
2046                return 0;
2047
2048        /* We want to avoid the working directory if our caller
2049         * doesn't need the data in a normal file, this system
2050         * is rather slow with its stat/open/mmap/close syscalls,
2051         * and the object is contained in a pack file.  The pack
2052         * is probably already open and will be faster to obtain
2053         * the data through than the working directory.  Loose
2054         * objects however would tend to be slower as they need
2055         * to be individually opened and inflated.
2056         */
2057        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2058                return 0;
2059
2060        len = strlen(name);
2061        pos = cache_name_pos(name, len);
2062        if (pos < 0)
2063                return 0;
2064        ce = active_cache[pos];
2065
2066        /*
2067         * This is not the sha1 we are looking for, or
2068         * unreusable because it is not a regular file.
2069         */
2070        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2071                return 0;
2072
2073        /*
2074         * If ce is marked as "assume unchanged", there is no
2075         * guarantee that work tree matches what we are looking for.
2076         */
2077        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2078                return 0;
2079
2080        /*
2081         * If ce matches the file in the work tree, we can reuse it.
2082         */
2083        if (ce_uptodate(ce) ||
2084            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2085                return 1;
2086
2087        return 0;
2088}
2089
2090static int populate_from_stdin(struct diff_filespec *s)
2091{
2092        struct strbuf buf = STRBUF_INIT;
2093        size_t size = 0;
2094
2095        if (strbuf_read(&buf, 0, 0) < 0)
2096                return error("error while reading from stdin %s",
2097                                     strerror(errno));
2098
2099        s->should_munmap = 0;
2100        s->data = strbuf_detach(&buf, &size);
2101        s->size = size;
2102        s->should_free = 1;
2103        return 0;
2104}
2105
2106static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2107{
2108        int len;
2109        char *data = xmalloc(100), *dirty = "";
2110
2111        /* Are we looking at the work tree? */
2112        if (s->dirty_submodule)
2113                dirty = "-dirty";
2114
2115        len = snprintf(data, 100,
2116                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2117        s->data = data;
2118        s->size = len;
2119        s->should_free = 1;
2120        if (size_only) {
2121                s->data = NULL;
2122                free(data);
2123        }
2124        return 0;
2125}
2126
2127/*
2128 * While doing rename detection and pickaxe operation, we may need to
2129 * grab the data for the blob (or file) for our own in-core comparison.
2130 * diff_filespec has data and size fields for this purpose.
2131 */
2132int diff_populate_filespec(struct diff_filespec *s, int size_only)
2133{
2134        int err = 0;
2135        if (!DIFF_FILE_VALID(s))
2136                die("internal error: asking to populate invalid file.");
2137        if (S_ISDIR(s->mode))
2138                return -1;
2139
2140        if (s->data)
2141                return 0;
2142
2143        if (size_only && 0 < s->size)
2144                return 0;
2145
2146        if (S_ISGITLINK(s->mode))
2147                return diff_populate_gitlink(s, size_only);
2148
2149        if (!s->sha1_valid ||
2150            reuse_worktree_file(s->path, s->sha1, 0)) {
2151                struct strbuf buf = STRBUF_INIT;
2152                struct stat st;
2153                int fd;
2154
2155                if (!strcmp(s->path, "-"))
2156                        return populate_from_stdin(s);
2157
2158                if (lstat(s->path, &st) < 0) {
2159                        if (errno == ENOENT) {
2160                        err_empty:
2161                                err = -1;
2162                        empty:
2163                                s->data = (char *)"";
2164                                s->size = 0;
2165                                return err;
2166                        }
2167                }
2168                s->size = xsize_t(st.st_size);
2169                if (!s->size)
2170                        goto empty;
2171                if (S_ISLNK(st.st_mode)) {
2172                        struct strbuf sb = STRBUF_INIT;
2173
2174                        if (strbuf_readlink(&sb, s->path, s->size))
2175                                goto err_empty;
2176                        s->size = sb.len;
2177                        s->data = strbuf_detach(&sb, NULL);
2178                        s->should_free = 1;
2179                        return 0;
2180                }
2181                if (size_only)
2182                        return 0;
2183                fd = open(s->path, O_RDONLY);
2184                if (fd < 0)
2185                        goto err_empty;
2186                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2187                close(fd);
2188                s->should_munmap = 1;
2189
2190                /*
2191                 * Convert from working tree format to canonical git format
2192                 */
2193                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2194                        size_t size = 0;
2195                        munmap(s->data, s->size);
2196                        s->should_munmap = 0;
2197                        s->data = strbuf_detach(&buf, &size);
2198                        s->size = size;
2199                        s->should_free = 1;
2200                }
2201        }
2202        else {
2203                enum object_type type;
2204                if (size_only)
2205                        type = sha1_object_info(s->sha1, &s->size);
2206                else {
2207                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2208                        s->should_free = 1;
2209                }
2210        }
2211        return 0;
2212}
2213
2214void diff_free_filespec_blob(struct diff_filespec *s)
2215{
2216        if (s->should_free)
2217                free(s->data);
2218        else if (s->should_munmap)
2219                munmap(s->data, s->size);
2220
2221        if (s->should_free || s->should_munmap) {
2222                s->should_free = s->should_munmap = 0;
2223                s->data = NULL;
2224        }
2225}
2226
2227void diff_free_filespec_data(struct diff_filespec *s)
2228{
2229        diff_free_filespec_blob(s);
2230        free(s->cnt_data);
2231        s->cnt_data = NULL;
2232}
2233
2234static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2235                           void *blob,
2236                           unsigned long size,
2237                           const unsigned char *sha1,
2238                           int mode)
2239{
2240        int fd;
2241        struct strbuf buf = STRBUF_INIT;
2242        struct strbuf template = STRBUF_INIT;
2243        char *path_dup = xstrdup(path);
2244        const char *base = basename(path_dup);
2245
2246        /* Generate "XXXXXX_basename.ext" */
2247        strbuf_addstr(&template, "XXXXXX_");
2248        strbuf_addstr(&template, base);
2249
2250        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2251                        strlen(base) + 1);
2252        if (fd < 0)
2253                die_errno("unable to create temp-file");
2254        if (convert_to_working_tree(path,
2255                        (const char *)blob, (size_t)size, &buf)) {
2256                blob = buf.buf;
2257                size = buf.len;
2258        }
2259        if (write_in_full(fd, blob, size) != size)
2260                die_errno("unable to write temp-file");
2261        close(fd);
2262        temp->name = temp->tmp_path;
2263        strcpy(temp->hex, sha1_to_hex(sha1));
2264        temp->hex[40] = 0;
2265        sprintf(temp->mode, "%06o", mode);
2266        strbuf_release(&buf);
2267        strbuf_release(&template);
2268        free(path_dup);
2269}
2270
2271static struct diff_tempfile *prepare_temp_file(const char *name,
2272                struct diff_filespec *one)
2273{
2274        struct diff_tempfile *temp = claim_diff_tempfile();
2275
2276        if (!DIFF_FILE_VALID(one)) {
2277        not_a_valid_file:
2278                /* A '-' entry produces this for file-2, and
2279                 * a '+' entry produces this for file-1.
2280                 */
2281                temp->name = "/dev/null";
2282                strcpy(temp->hex, ".");
2283                strcpy(temp->mode, ".");
2284                return temp;
2285        }
2286
2287        if (!remove_tempfile_installed) {
2288                atexit(remove_tempfile);
2289                sigchain_push_common(remove_tempfile_on_signal);
2290                remove_tempfile_installed = 1;
2291        }
2292
2293        if (!one->sha1_valid ||
2294            reuse_worktree_file(name, one->sha1, 1)) {
2295                struct stat st;
2296                if (lstat(name, &st) < 0) {
2297                        if (errno == ENOENT)
2298                                goto not_a_valid_file;
2299                        die_errno("stat(%s)", name);
2300                }
2301                if (S_ISLNK(st.st_mode)) {
2302                        struct strbuf sb = STRBUF_INIT;
2303                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2304                                die_errno("readlink(%s)", name);
2305                        prep_temp_blob(name, temp, sb.buf, sb.len,
2306                                       (one->sha1_valid ?
2307                                        one->sha1 : null_sha1),
2308                                       (one->sha1_valid ?
2309                                        one->mode : S_IFLNK));
2310                        strbuf_release(&sb);
2311                }
2312                else {
2313                        /* we can borrow from the file in the work tree */
2314                        temp->name = name;
2315                        if (!one->sha1_valid)
2316                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2317                        else
2318                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2319                        /* Even though we may sometimes borrow the
2320                         * contents from the work tree, we always want
2321                         * one->mode.  mode is trustworthy even when
2322                         * !(one->sha1_valid), as long as
2323                         * DIFF_FILE_VALID(one).
2324                         */
2325                        sprintf(temp->mode, "%06o", one->mode);
2326                }
2327                return temp;
2328        }
2329        else {
2330                if (diff_populate_filespec(one, 0))
2331                        die("cannot read data blob for %s", one->path);
2332                prep_temp_blob(name, temp, one->data, one->size,
2333                               one->sha1, one->mode);
2334        }
2335        return temp;
2336}
2337
2338/* An external diff command takes:
2339 *
2340 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2341 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2342 *
2343 */
2344static void run_external_diff(const char *pgm,
2345                              const char *name,
2346                              const char *other,
2347                              struct diff_filespec *one,
2348                              struct diff_filespec *two,
2349                              const char *xfrm_msg,
2350                              int complete_rewrite)
2351{
2352        const char *spawn_arg[10];
2353        int retval;
2354        const char **arg = &spawn_arg[0];
2355
2356        if (one && two) {
2357                struct diff_tempfile *temp_one, *temp_two;
2358                const char *othername = (other ? other : name);
2359                temp_one = prepare_temp_file(name, one);
2360                temp_two = prepare_temp_file(othername, two);
2361                *arg++ = pgm;
2362                *arg++ = name;
2363                *arg++ = temp_one->name;
2364                *arg++ = temp_one->hex;
2365                *arg++ = temp_one->mode;
2366                *arg++ = temp_two->name;
2367                *arg++ = temp_two->hex;
2368                *arg++ = temp_two->mode;
2369                if (other) {
2370                        *arg++ = other;
2371                        *arg++ = xfrm_msg;
2372                }
2373        } else {
2374                *arg++ = pgm;
2375                *arg++ = name;
2376        }
2377        *arg = NULL;
2378        fflush(NULL);
2379        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2380        remove_tempfile();
2381        if (retval) {
2382                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2383                exit(1);
2384        }
2385}
2386
2387static int similarity_index(struct diff_filepair *p)
2388{
2389        return p->score * 100 / MAX_SCORE;
2390}
2391
2392static void fill_metainfo(struct strbuf *msg,
2393                          const char *name,
2394                          const char *other,
2395                          struct diff_filespec *one,
2396                          struct diff_filespec *two,
2397                          struct diff_options *o,
2398                          struct diff_filepair *p)
2399{
2400        strbuf_init(msg, PATH_MAX * 2 + 300);
2401        switch (p->status) {
2402        case DIFF_STATUS_COPIED:
2403                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2404                strbuf_addstr(msg, "\ncopy from ");
2405                quote_c_style(name, msg, NULL, 0);
2406                strbuf_addstr(msg, "\ncopy to ");
2407                quote_c_style(other, msg, NULL, 0);
2408                strbuf_addch(msg, '\n');
2409                break;
2410        case DIFF_STATUS_RENAMED:
2411                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2412                strbuf_addstr(msg, "\nrename from ");
2413                quote_c_style(name, msg, NULL, 0);
2414                strbuf_addstr(msg, "\nrename to ");
2415                quote_c_style(other, msg, NULL, 0);
2416                strbuf_addch(msg, '\n');
2417                break;
2418        case DIFF_STATUS_MODIFIED:
2419                if (p->score) {
2420                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2421                                    similarity_index(p));
2422                        break;
2423                }
2424                /* fallthru */
2425        default:
2426                /* nothing */
2427                ;
2428        }
2429        if (one && two && hashcmp(one->sha1, two->sha1)) {
2430                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2431
2432                if (DIFF_OPT_TST(o, BINARY)) {
2433                        mmfile_t mf;
2434                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2435                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2436                                abbrev = 40;
2437                }
2438                strbuf_addf(msg, "index %.*s..%.*s",
2439                            abbrev, sha1_to_hex(one->sha1),
2440                            abbrev, sha1_to_hex(two->sha1));
2441                if (one->mode == two->mode)
2442                        strbuf_addf(msg, " %06o", one->mode);
2443                strbuf_addch(msg, '\n');
2444        }
2445        if (msg->len)
2446                strbuf_setlen(msg, msg->len - 1);
2447}
2448
2449static void run_diff_cmd(const char *pgm,
2450                         const char *name,
2451                         const char *other,
2452                         const char *attr_path,
2453                         struct diff_filespec *one,
2454                         struct diff_filespec *two,
2455                         struct strbuf *msg,
2456                         struct diff_options *o,
2457                         struct diff_filepair *p)
2458{
2459        const char *xfrm_msg = NULL;
2460        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2461
2462        if (msg) {
2463                fill_metainfo(msg, name, other, one, two, o, p);
2464                xfrm_msg = msg->len ? msg->buf : NULL;
2465        }
2466
2467        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2468                pgm = NULL;
2469        else {
2470                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2471                if (drv && drv->external)
2472                        pgm = drv->external;
2473        }
2474
2475        if (pgm) {
2476                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2477                                  complete_rewrite);
2478                return;
2479        }
2480        if (one && two)
2481                builtin_diff(name, other ? other : name,
2482                             one, two, xfrm_msg, o, complete_rewrite);
2483        else
2484                fprintf(o->file, "* Unmerged path %s\n", name);
2485}
2486
2487static void diff_fill_sha1_info(struct diff_filespec *one)
2488{
2489        if (DIFF_FILE_VALID(one)) {
2490                if (!one->sha1_valid) {
2491                        struct stat st;
2492                        if (!strcmp(one->path, "-")) {
2493                                hashcpy(one->sha1, null_sha1);
2494                                return;
2495                        }
2496                        if (lstat(one->path, &st) < 0)
2497                                die_errno("stat '%s'", one->path);
2498                        if (index_path(one->sha1, one->path, &st, 0))
2499                                die("cannot hash %s", one->path);
2500                }
2501        }
2502        else
2503                hashclr(one->sha1);
2504}
2505
2506static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2507{
2508        /* Strip the prefix but do not molest /dev/null and absolute paths */
2509        if (*namep && **namep != '/')
2510                *namep += prefix_length;
2511        if (*otherp && **otherp != '/')
2512                *otherp += prefix_length;
2513}
2514
2515static void run_diff(struct diff_filepair *p, struct diff_options *o)
2516{
2517        const char *pgm = external_diff();
2518        struct strbuf msg;
2519        struct diff_filespec *one = p->one;
2520        struct diff_filespec *two = p->two;
2521        const char *name;
2522        const char *other;
2523        const char *attr_path;
2524
2525        name  = p->one->path;
2526        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2527        attr_path = name;
2528        if (o->prefix_length)
2529                strip_prefix(o->prefix_length, &name, &other);
2530
2531        if (DIFF_PAIR_UNMERGED(p)) {
2532                run_diff_cmd(pgm, name, NULL, attr_path,
2533                             NULL, NULL, NULL, o, p);
2534                return;
2535        }
2536
2537        diff_fill_sha1_info(one);
2538        diff_fill_sha1_info(two);
2539
2540        if (!pgm &&
2541            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2542            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2543                /*
2544                 * a filepair that changes between file and symlink
2545                 * needs to be split into deletion and creation.
2546                 */
2547                struct diff_filespec *null = alloc_filespec(two->path);
2548                run_diff_cmd(NULL, name, other, attr_path,
2549                             one, null, &msg, o, p);
2550                free(null);
2551                strbuf_release(&msg);
2552
2553                null = alloc_filespec(one->path);
2554                run_diff_cmd(NULL, name, other, attr_path,
2555                             null, two, &msg, o, p);
2556                free(null);
2557        }
2558        else
2559                run_diff_cmd(pgm, name, other, attr_path,
2560                             one, two, &msg, o, p);
2561
2562        strbuf_release(&msg);
2563}
2564
2565static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2566                         struct diffstat_t *diffstat)
2567{
2568        const char *name;
2569        const char *other;
2570        int complete_rewrite = 0;
2571
2572        if (DIFF_PAIR_UNMERGED(p)) {
2573                /* unmerged */
2574                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2575                return;
2576        }
2577
2578        name = p->one->path;
2579        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2580
2581        if (o->prefix_length)
2582                strip_prefix(o->prefix_length, &name, &other);
2583
2584        diff_fill_sha1_info(p->one);
2585        diff_fill_sha1_info(p->two);
2586
2587        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2588                complete_rewrite = 1;
2589        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2590}
2591
2592static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2593{
2594        const char *name;
2595        const char *other;
2596        const char *attr_path;
2597
2598        if (DIFF_PAIR_UNMERGED(p)) {
2599                /* unmerged */
2600                return;
2601        }
2602
2603        name = p->one->path;
2604        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2605        attr_path = other ? other : name;
2606
2607        if (o->prefix_length)
2608                strip_prefix(o->prefix_length, &name, &other);
2609
2610        diff_fill_sha1_info(p->one);
2611        diff_fill_sha1_info(p->two);
2612
2613        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2614}
2615
2616void diff_setup(struct diff_options *options)
2617{
2618        memset(options, 0, sizeof(*options));
2619
2620        options->file = stdout;
2621
2622        options->line_termination = '\n';
2623        options->break_opt = -1;
2624        options->rename_limit = -1;
2625        options->dirstat_percent = 3;
2626        options->context = 3;
2627
2628        options->change = diff_change;
2629        options->add_remove = diff_addremove;
2630        if (diff_use_color_default > 0)
2631                DIFF_OPT_SET(options, COLOR_DIFF);
2632        options->detect_rename = diff_detect_rename_default;
2633
2634        if (!diff_mnemonic_prefix) {
2635                options->a_prefix = "a/";
2636                options->b_prefix = "b/";
2637        }
2638}
2639
2640int diff_setup_done(struct diff_options *options)
2641{
2642        int count = 0;
2643
2644        if (options->output_format & DIFF_FORMAT_NAME)
2645                count++;
2646        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2647                count++;
2648        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2649                count++;
2650        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2651                count++;
2652        if (count > 1)
2653                die("--name-only, --name-status, --check and -s are mutually exclusive");
2654
2655        /*
2656         * Most of the time we can say "there are changes"
2657         * only by checking if there are changed paths, but
2658         * --ignore-whitespace* options force us to look
2659         * inside contents.
2660         */
2661
2662        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2663            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2664            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2665                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2666        else
2667                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2668
2669        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2670                options->detect_rename = DIFF_DETECT_COPY;
2671
2672        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2673                options->prefix = NULL;
2674        if (options->prefix)
2675                options->prefix_length = strlen(options->prefix);
2676        else
2677                options->prefix_length = 0;
2678
2679        if (options->output_format & (DIFF_FORMAT_NAME |
2680                                      DIFF_FORMAT_NAME_STATUS |
2681                                      DIFF_FORMAT_CHECKDIFF |
2682                                      DIFF_FORMAT_NO_OUTPUT))
2683                options->output_format &= ~(DIFF_FORMAT_RAW |
2684                                            DIFF_FORMAT_NUMSTAT |
2685                                            DIFF_FORMAT_DIFFSTAT |
2686                                            DIFF_FORMAT_SHORTSTAT |
2687                                            DIFF_FORMAT_DIRSTAT |
2688                                            DIFF_FORMAT_SUMMARY |
2689                                            DIFF_FORMAT_PATCH);
2690
2691        /*
2692         * These cases always need recursive; we do not drop caller-supplied
2693         * recursive bits for other formats here.
2694         */
2695        if (options->output_format & (DIFF_FORMAT_PATCH |
2696                                      DIFF_FORMAT_NUMSTAT |
2697                                      DIFF_FORMAT_DIFFSTAT |
2698                                      DIFF_FORMAT_SHORTSTAT |
2699                                      DIFF_FORMAT_DIRSTAT |
2700                                      DIFF_FORMAT_SUMMARY |
2701                                      DIFF_FORMAT_CHECKDIFF))
2702                DIFF_OPT_SET(options, RECURSIVE);
2703        /*
2704         * Also pickaxe would not work very well if you do not say recursive
2705         */
2706        if (options->pickaxe)
2707                DIFF_OPT_SET(options, RECURSIVE);
2708        /*
2709         * When patches are generated, submodules diffed against the work tree
2710         * must be checked for dirtiness too so it can be shown in the output
2711         */
2712        if (options->output_format & DIFF_FORMAT_PATCH)
2713                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2714
2715        if (options->detect_rename && options->rename_limit < 0)
2716                options->rename_limit = diff_rename_limit_default;
2717        if (options->setup & DIFF_SETUP_USE_CACHE) {
2718                if (!active_cache)
2719                        /* read-cache does not die even when it fails
2720                         * so it is safe for us to do this here.  Also
2721                         * it does not smudge active_cache or active_nr
2722                         * when it fails, so we do not have to worry about
2723                         * cleaning it up ourselves either.
2724                         */
2725                        read_cache();
2726        }
2727        if (options->abbrev <= 0 || 40 < options->abbrev)
2728                options->abbrev = 40; /* full */
2729
2730        /*
2731         * It does not make sense to show the first hit we happened
2732         * to have found.  It does not make sense not to return with
2733         * exit code in such a case either.
2734         */
2735        if (DIFF_OPT_TST(options, QUICK)) {
2736                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2737                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2738        }
2739
2740        return 0;
2741}
2742
2743static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2744{
2745        char c, *eq;
2746        int len;
2747
2748        if (*arg != '-')
2749                return 0;
2750        c = *++arg;
2751        if (!c)
2752                return 0;
2753        if (c == arg_short) {
2754                c = *++arg;
2755                if (!c)
2756                        return 1;
2757                if (val && isdigit(c)) {
2758                        char *end;
2759                        int n = strtoul(arg, &end, 10);
2760                        if (*end)
2761                                return 0;
2762                        *val = n;
2763                        return 1;
2764                }
2765                return 0;
2766        }
2767        if (c != '-')
2768                return 0;
2769        arg++;
2770        eq = strchr(arg, '=');
2771        if (eq)
2772                len = eq - arg;
2773        else
2774                len = strlen(arg);
2775        if (!len || strncmp(arg, arg_long, len))
2776                return 0;
2777        if (eq) {
2778                int n;
2779                char *end;
2780                if (!isdigit(*++eq))
2781                        return 0;
2782                n = strtoul(eq, &end, 10);
2783                if (*end)
2784                        return 0;
2785                *val = n;
2786        }
2787        return 1;
2788}
2789
2790static int diff_scoreopt_parse(const char *opt);
2791
2792int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2793{
2794        const char *arg = av[0];
2795
2796        /* Output format options */
2797        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2798                options->output_format |= DIFF_FORMAT_PATCH;
2799        else if (opt_arg(arg, 'U', "unified", &options->context))
2800                options->output_format |= DIFF_FORMAT_PATCH;
2801        else if (!strcmp(arg, "--raw"))
2802                options->output_format |= DIFF_FORMAT_RAW;
2803        else if (!strcmp(arg, "--patch-with-raw"))
2804                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2805        else if (!strcmp(arg, "--numstat"))
2806                options->output_format |= DIFF_FORMAT_NUMSTAT;
2807        else if (!strcmp(arg, "--shortstat"))
2808                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2809        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2810                options->output_format |= DIFF_FORMAT_DIRSTAT;
2811        else if (!strcmp(arg, "--cumulative")) {
2812                options->output_format |= DIFF_FORMAT_DIRSTAT;
2813                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2814        } else if (opt_arg(arg, 0, "dirstat-by-file",
2815                           &options->dirstat_percent)) {
2816                options->output_format |= DIFF_FORMAT_DIRSTAT;
2817                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2818        }
2819        else if (!strcmp(arg, "--check"))
2820                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2821        else if (!strcmp(arg, "--summary"))
2822                options->output_format |= DIFF_FORMAT_SUMMARY;
2823        else if (!strcmp(arg, "--patch-with-stat"))
2824                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2825        else if (!strcmp(arg, "--name-only"))
2826                options->output_format |= DIFF_FORMAT_NAME;
2827        else if (!strcmp(arg, "--name-status"))
2828                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2829        else if (!strcmp(arg, "-s"))
2830                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2831        else if (!prefixcmp(arg, "--stat")) {
2832                char *end;
2833                int width = options->stat_width;
2834                int name_width = options->stat_name_width;
2835                arg += 6;
2836                end = (char *)arg;
2837
2838                switch (*arg) {
2839                case '-':
2840                        if (!prefixcmp(arg, "-width="))
2841                                width = strtoul(arg + 7, &end, 10);
2842                        else if (!prefixcmp(arg, "-name-width="))
2843                                name_width = strtoul(arg + 12, &end, 10);
2844                        break;
2845                case '=':
2846                        width = strtoul(arg+1, &end, 10);
2847                        if (*end == ',')
2848                                name_width = strtoul(end+1, &end, 10);
2849                }
2850
2851                /* Important! This checks all the error cases! */
2852                if (*end)
2853                        return 0;
2854                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2855                options->stat_name_width = name_width;
2856                options->stat_width = width;
2857        }
2858
2859        /* renames options */
2860        else if (!prefixcmp(arg, "-B")) {
2861                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2862                        return -1;
2863        }
2864        else if (!prefixcmp(arg, "-M")) {
2865                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2866                        return -1;
2867                options->detect_rename = DIFF_DETECT_RENAME;
2868        }
2869        else if (!prefixcmp(arg, "-C")) {
2870                if (options->detect_rename == DIFF_DETECT_COPY)
2871                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2872                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2873                        return -1;
2874                options->detect_rename = DIFF_DETECT_COPY;
2875        }
2876        else if (!strcmp(arg, "--no-renames"))
2877                options->detect_rename = 0;
2878        else if (!strcmp(arg, "--relative"))
2879                DIFF_OPT_SET(options, RELATIVE_NAME);
2880        else if (!prefixcmp(arg, "--relative=")) {
2881                DIFF_OPT_SET(options, RELATIVE_NAME);
2882                options->prefix = arg + 11;
2883        }
2884
2885        /* xdiff options */
2886        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2887                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2888        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2889                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2890        else if (!strcmp(arg, "--ignore-space-at-eol"))
2891                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2892        else if (!strcmp(arg, "--patience"))
2893                DIFF_XDL_SET(options, PATIENCE_DIFF);
2894
2895        /* flags options */
2896        else if (!strcmp(arg, "--binary")) {
2897                options->output_format |= DIFF_FORMAT_PATCH;
2898                DIFF_OPT_SET(options, BINARY);
2899        }
2900        else if (!strcmp(arg, "--full-index"))
2901                DIFF_OPT_SET(options, FULL_INDEX);
2902        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2903                DIFF_OPT_SET(options, TEXT);
2904        else if (!strcmp(arg, "-R"))
2905                DIFF_OPT_SET(options, REVERSE_DIFF);
2906        else if (!strcmp(arg, "--find-copies-harder"))
2907                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2908        else if (!strcmp(arg, "--follow"))
2909                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2910        else if (!strcmp(arg, "--color"))
2911                DIFF_OPT_SET(options, COLOR_DIFF);
2912        else if (!prefixcmp(arg, "--color=")) {
2913                int value = git_config_colorbool(NULL, arg+8, -1);
2914                if (value == 0)
2915                        DIFF_OPT_CLR(options, COLOR_DIFF);
2916                else if (value > 0)
2917                        DIFF_OPT_SET(options, COLOR_DIFF);
2918                else
2919                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2920        }
2921        else if (!strcmp(arg, "--no-color"))
2922                DIFF_OPT_CLR(options, COLOR_DIFF);
2923        else if (!strcmp(arg, "--color-words")) {
2924                DIFF_OPT_SET(options, COLOR_DIFF);
2925                options->word_diff = DIFF_WORDS_COLOR;
2926        }
2927        else if (!prefixcmp(arg, "--color-words=")) {
2928                DIFF_OPT_SET(options, COLOR_DIFF);
2929                options->word_diff = DIFF_WORDS_COLOR;
2930                options->word_regex = arg + 14;
2931        }
2932        else if (!strcmp(arg, "--word-diff")) {
2933                if (options->word_diff == DIFF_WORDS_NONE)
2934                        options->word_diff = DIFF_WORDS_PLAIN;
2935        }
2936        else if (!prefixcmp(arg, "--word-diff=")) {
2937                const char *type = arg + 12;
2938                if (!strcmp(type, "plain"))
2939                        options->word_diff = DIFF_WORDS_PLAIN;
2940                else if (!strcmp(type, "color")) {
2941                        DIFF_OPT_SET(options, COLOR_DIFF);
2942                        options->word_diff = DIFF_WORDS_COLOR;
2943                }
2944                else if (!strcmp(type, "porcelain"))
2945                        options->word_diff = DIFF_WORDS_PORCELAIN;
2946                else if (!strcmp(type, "none"))
2947                        options->word_diff = DIFF_WORDS_NONE;
2948                else
2949                        die("bad --word-diff argument: %s", type);
2950        }
2951        else if (!prefixcmp(arg, "--word-diff-regex=")) {
2952                if (options->word_diff == DIFF_WORDS_NONE)
2953                        options->word_diff = DIFF_WORDS_PLAIN;
2954                options->word_regex = arg + 18;
2955        }
2956        else if (!strcmp(arg, "--exit-code"))
2957                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2958        else if (!strcmp(arg, "--quiet"))
2959                DIFF_OPT_SET(options, QUICK);
2960        else if (!strcmp(arg, "--ext-diff"))
2961                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2962        else if (!strcmp(arg, "--no-ext-diff"))
2963                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2964        else if (!strcmp(arg, "--textconv"))
2965                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2966        else if (!strcmp(arg, "--no-textconv"))
2967                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2968        else if (!strcmp(arg, "--ignore-submodules"))
2969                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2970        else if (!strcmp(arg, "--submodule"))
2971                DIFF_OPT_SET(options, SUBMODULE_LOG);
2972        else if (!prefixcmp(arg, "--submodule=")) {
2973                if (!strcmp(arg + 12, "log"))
2974                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2975        }
2976
2977        /* misc options */
2978        else if (!strcmp(arg, "-z"))
2979                options->line_termination = 0;
2980        else if (!prefixcmp(arg, "-l"))
2981                options->rename_limit = strtoul(arg+2, NULL, 10);
2982        else if (!prefixcmp(arg, "-S"))
2983                options->pickaxe = arg + 2;
2984        else if (!strcmp(arg, "--pickaxe-all"))
2985                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2986        else if (!strcmp(arg, "--pickaxe-regex"))
2987                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2988        else if (!prefixcmp(arg, "-O"))
2989                options->orderfile = arg + 2;
2990        else if (!prefixcmp(arg, "--diff-filter="))
2991                options->filter = arg + 14;
2992        else if (!strcmp(arg, "--abbrev"))
2993                options->abbrev = DEFAULT_ABBREV;
2994        else if (!prefixcmp(arg, "--abbrev=")) {
2995                options->abbrev = strtoul(arg + 9, NULL, 10);
2996                if (options->abbrev < MINIMUM_ABBREV)
2997                        options->abbrev = MINIMUM_ABBREV;
2998                else if (40 < options->abbrev)
2999                        options->abbrev = 40;
3000        }
3001        else if (!prefixcmp(arg, "--src-prefix="))
3002                options->a_prefix = arg + 13;
3003        else if (!prefixcmp(arg, "--dst-prefix="))
3004                options->b_prefix = arg + 13;
3005        else if (!strcmp(arg, "--no-prefix"))
3006                options->a_prefix = options->b_prefix = "";
3007        else if (opt_arg(arg, '\0', "inter-hunk-context",
3008                         &options->interhunkcontext))
3009                ;
3010        else if (!prefixcmp(arg, "--output=")) {
3011                options->file = fopen(arg + strlen("--output="), "w");
3012                if (!options->file)
3013                        die_errno("Could not open '%s'", arg + strlen("--output="));
3014                options->close_file = 1;
3015        } else
3016                return 0;
3017        return 1;
3018}
3019
3020static int parse_num(const char **cp_p)
3021{
3022        unsigned long num, scale;
3023        int ch, dot;
3024        const char *cp = *cp_p;
3025
3026        num = 0;
3027        scale = 1;
3028        dot = 0;
3029        for (;;) {
3030                ch = *cp;
3031                if ( !dot && ch == '.' ) {
3032                        scale = 1;
3033                        dot = 1;
3034                } else if ( ch == '%' ) {
3035                        scale = dot ? scale*100 : 100;
3036                        cp++;   /* % is always at the end */
3037                        break;
3038                } else if ( ch >= '0' && ch <= '9' ) {
3039                        if ( scale < 100000 ) {
3040                                scale *= 10;
3041                                num = (num*10) + (ch-'0');
3042                        }
3043                } else {
3044                        break;
3045                }
3046                cp++;
3047        }
3048        *cp_p = cp;
3049
3050        /* user says num divided by scale and we say internally that
3051         * is MAX_SCORE * num / scale.
3052         */
3053        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3054}
3055
3056static int diff_scoreopt_parse(const char *opt)
3057{
3058        int opt1, opt2, cmd;
3059
3060        if (*opt++ != '-')
3061                return -1;
3062        cmd = *opt++;
3063        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3064                return -1; /* that is not a -M, -C nor -B option */
3065
3066        opt1 = parse_num(&opt);
3067        if (cmd != 'B')
3068                opt2 = 0;
3069        else {
3070                if (*opt == 0)
3071                        opt2 = 0;
3072                else if (*opt != '/')
3073                        return -1; /* we expect -B80/99 or -B80 */
3074                else {
3075                        opt++;
3076                        opt2 = parse_num(&opt);
3077                }
3078        }
3079        if (*opt != 0)
3080                return -1;
3081        return opt1 | (opt2 << 16);
3082}
3083
3084struct diff_queue_struct diff_queued_diff;
3085
3086void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3087{
3088        if (queue->alloc <= queue->nr) {
3089                queue->alloc = alloc_nr(queue->alloc);
3090                queue->queue = xrealloc(queue->queue,
3091                                        sizeof(dp) * queue->alloc);
3092        }
3093        queue->queue[queue->nr++] = dp;
3094}
3095
3096struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3097                                 struct diff_filespec *one,
3098                                 struct diff_filespec *two)
3099{
3100        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3101        dp->one = one;
3102        dp->two = two;
3103        if (queue)
3104                diff_q(queue, dp);
3105        return dp;
3106}
3107
3108void diff_free_filepair(struct diff_filepair *p)
3109{
3110        free_filespec(p->one);
3111        free_filespec(p->two);
3112        free(p);
3113}
3114
3115/* This is different from find_unique_abbrev() in that
3116 * it stuffs the result with dots for alignment.
3117 */
3118const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3119{
3120        int abblen;
3121        const char *abbrev;
3122        if (len == 40)
3123                return sha1_to_hex(sha1);
3124
3125        abbrev = find_unique_abbrev(sha1, len);
3126        abblen = strlen(abbrev);
3127        if (abblen < 37) {
3128                static char hex[41];
3129                if (len < abblen && abblen <= len + 2)
3130                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3131                else
3132                        sprintf(hex, "%s...", abbrev);
3133                return hex;
3134        }
3135        return sha1_to_hex(sha1);
3136}
3137
3138static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3139{
3140        int line_termination = opt->line_termination;
3141        int inter_name_termination = line_termination ? '\t' : '\0';
3142
3143        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3144                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3145                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3146                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3147        }
3148        if (p->score) {
3149                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3150                        inter_name_termination);
3151        } else {
3152                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3153        }
3154
3155        if (p->status == DIFF_STATUS_COPIED ||
3156            p->status == DIFF_STATUS_RENAMED) {
3157                const char *name_a, *name_b;
3158                name_a = p->one->path;
3159                name_b = p->two->path;
3160                strip_prefix(opt->prefix_length, &name_a, &name_b);
3161                write_name_quoted(name_a, opt->file, inter_name_termination);
3162                write_name_quoted(name_b, opt->file, line_termination);
3163        } else {
3164                const char *name_a, *name_b;
3165                name_a = p->one->mode ? p->one->path : p->two->path;
3166                name_b = NULL;
3167                strip_prefix(opt->prefix_length, &name_a, &name_b);
3168                write_name_quoted(name_a, opt->file, line_termination);
3169        }
3170}
3171
3172int diff_unmodified_pair(struct diff_filepair *p)
3173{
3174        /* This function is written stricter than necessary to support
3175         * the currently implemented transformers, but the idea is to
3176         * let transformers to produce diff_filepairs any way they want,
3177         * and filter and clean them up here before producing the output.
3178         */
3179        struct diff_filespec *one = p->one, *two = p->two;
3180
3181        if (DIFF_PAIR_UNMERGED(p))
3182                return 0; /* unmerged is interesting */
3183
3184        /* deletion, addition, mode or type change
3185         * and rename are all interesting.
3186         */
3187        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3188            DIFF_PAIR_MODE_CHANGED(p) ||
3189            strcmp(one->path, two->path))
3190                return 0;
3191
3192        /* both are valid and point at the same path.  that is, we are
3193         * dealing with a change.
3194         */
3195        if (one->sha1_valid && two->sha1_valid &&
3196            !hashcmp(one->sha1, two->sha1) &&
3197            !one->dirty_submodule && !two->dirty_submodule)
3198                return 1; /* no change */
3199        if (!one->sha1_valid && !two->sha1_valid)
3200                return 1; /* both look at the same file on the filesystem. */
3201        return 0;
3202}
3203
3204static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3205{
3206        if (diff_unmodified_pair(p))
3207                return;
3208
3209        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3210            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3211                return; /* no tree diffs in patch format */
3212
3213        run_diff(p, o);
3214}
3215
3216static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3217                            struct diffstat_t *diffstat)
3218{
3219        if (diff_unmodified_pair(p))
3220                return;
3221
3222        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3223            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3224                return; /* no tree diffs in patch format */
3225
3226        run_diffstat(p, o, diffstat);
3227}
3228
3229static void diff_flush_checkdiff(struct diff_filepair *p,
3230                struct diff_options *o)
3231{
3232        if (diff_unmodified_pair(p))
3233                return;
3234
3235        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3236            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3237                return; /* no tree diffs in patch format */
3238
3239        run_checkdiff(p, o);
3240}
3241
3242int diff_queue_is_empty(void)
3243{
3244        struct diff_queue_struct *q = &diff_queued_diff;
3245        int i;
3246        for (i = 0; i < q->nr; i++)
3247                if (!diff_unmodified_pair(q->queue[i]))
3248                        return 0;
3249        return 1;
3250}
3251
3252#if DIFF_DEBUG
3253void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3254{
3255        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3256                x, one ? one : "",
3257                s->path,
3258                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3259                s->mode,
3260                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3261        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3262                x, one ? one : "",
3263                s->size, s->xfrm_flags);
3264}
3265
3266void diff_debug_filepair(const struct diff_filepair *p, int i)
3267{
3268        diff_debug_filespec(p->one, i, "one");
3269        diff_debug_filespec(p->two, i, "two");
3270        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3271                p->score, p->status ? p->status : '?',
3272                p->one->rename_used, p->broken_pair);
3273}
3274
3275void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3276{
3277        int i;
3278        if (msg)
3279                fprintf(stderr, "%s\n", msg);
3280        fprintf(stderr, "q->nr = %d\n", q->nr);
3281        for (i = 0; i < q->nr; i++) {
3282                struct diff_filepair *p = q->queue[i];
3283                diff_debug_filepair(p, i);
3284        }
3285}
3286#endif
3287
3288static void diff_resolve_rename_copy(void)
3289{
3290        int i;
3291        struct diff_filepair *p;
3292        struct diff_queue_struct *q = &diff_queued_diff;
3293
3294        diff_debug_queue("resolve-rename-copy", q);
3295
3296        for (i = 0; i < q->nr; i++) {
3297                p = q->queue[i];
3298                p->status = 0; /* undecided */
3299                if (DIFF_PAIR_UNMERGED(p))
3300                        p->status = DIFF_STATUS_UNMERGED;
3301                else if (!DIFF_FILE_VALID(p->one))
3302                        p->status = DIFF_STATUS_ADDED;
3303                else if (!DIFF_FILE_VALID(p->two))
3304                        p->status = DIFF_STATUS_DELETED;
3305                else if (DIFF_PAIR_TYPE_CHANGED(p))
3306                        p->status = DIFF_STATUS_TYPE_CHANGED;
3307
3308                /* from this point on, we are dealing with a pair
3309                 * whose both sides are valid and of the same type, i.e.
3310                 * either in-place edit or rename/copy edit.
3311                 */
3312                else if (DIFF_PAIR_RENAME(p)) {
3313                        /*
3314                         * A rename might have re-connected a broken
3315                         * pair up, causing the pathnames to be the
3316                         * same again. If so, that's not a rename at
3317                         * all, just a modification..
3318                         *
3319                         * Otherwise, see if this source was used for
3320                         * multiple renames, in which case we decrement
3321                         * the count, and call it a copy.
3322                         */
3323                        if (!strcmp(p->one->path, p->two->path))
3324                                p->status = DIFF_STATUS_MODIFIED;
3325                        else if (--p->one->rename_used > 0)
3326                                p->status = DIFF_STATUS_COPIED;
3327                        else
3328                                p->status = DIFF_STATUS_RENAMED;
3329                }
3330                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3331                         p->one->mode != p->two->mode ||
3332                         p->one->dirty_submodule ||
3333                         p->two->dirty_submodule ||
3334                         is_null_sha1(p->one->sha1))
3335                        p->status = DIFF_STATUS_MODIFIED;
3336                else {
3337                        /* This is a "no-change" entry and should not
3338                         * happen anymore, but prepare for broken callers.
3339                         */
3340                        error("feeding unmodified %s to diffcore",
3341                              p->one->path);
3342                        p->status = DIFF_STATUS_UNKNOWN;
3343                }
3344        }
3345        diff_debug_queue("resolve-rename-copy done", q);
3346}
3347
3348static int check_pair_status(struct diff_filepair *p)
3349{
3350        switch (p->status) {
3351        case DIFF_STATUS_UNKNOWN:
3352                return 0;
3353        case 0:
3354                die("internal error in diff-resolve-rename-copy");
3355        default:
3356                return 1;
3357        }
3358}
3359
3360static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3361{
3362        int fmt = opt->output_format;
3363
3364        if (fmt & DIFF_FORMAT_CHECKDIFF)
3365                diff_flush_checkdiff(p, opt);
3366        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3367                diff_flush_raw(p, opt);
3368        else if (fmt & DIFF_FORMAT_NAME) {
3369                const char *name_a, *name_b;
3370                name_a = p->two->path;
3371                name_b = NULL;
3372                strip_prefix(opt->prefix_length, &name_a, &name_b);
3373                write_name_quoted(name_a, opt->file, opt->line_termination);
3374        }
3375}
3376
3377static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3378{
3379        if (fs->mode)
3380                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3381        else
3382                fprintf(file, " %s ", newdelete);
3383        write_name_quoted(fs->path, file, '\n');
3384}
3385
3386
3387static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3388{
3389        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3390                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3391                        show_name ? ' ' : '\n');
3392                if (show_name) {
3393                        write_name_quoted(p->two->path, file, '\n');
3394                }
3395        }
3396}
3397
3398static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3399{
3400        char *names = pprint_rename(p->one->path, p->two->path);
3401
3402        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3403        free(names);
3404        show_mode_change(file, p, 0);
3405}
3406
3407static void diff_summary(FILE *file, struct diff_filepair *p)
3408{
3409        switch(p->status) {
3410        case DIFF_STATUS_DELETED:
3411                show_file_mode_name(file, "delete", p->one);
3412                break;
3413        case DIFF_STATUS_ADDED:
3414                show_file_mode_name(file, "create", p->two);
3415                break;
3416        case DIFF_STATUS_COPIED:
3417                show_rename_copy(file, "copy", p);
3418                break;
3419        case DIFF_STATUS_RENAMED:
3420                show_rename_copy(file, "rename", p);
3421                break;
3422        default:
3423                if (p->score) {
3424                        fputs(" rewrite ", file);
3425                        write_name_quoted(p->two->path, file, ' ');
3426                        fprintf(file, "(%d%%)\n", similarity_index(p));
3427                }
3428                show_mode_change(file, p, !p->score);
3429                break;
3430        }
3431}
3432
3433struct patch_id_t {
3434        git_SHA_CTX *ctx;
3435        int patchlen;
3436};
3437
3438static int remove_space(char *line, int len)
3439{
3440        int i;
3441        char *dst = line;
3442        unsigned char c;
3443
3444        for (i = 0; i < len; i++)
3445                if (!isspace((c = line[i])))
3446                        *dst++ = c;
3447
3448        return dst - line;
3449}
3450
3451static void patch_id_consume(void *priv, char *line, unsigned long len)
3452{
3453        struct patch_id_t *data = priv;
3454        int new_len;
3455
3456        /* Ignore line numbers when computing the SHA1 of the patch */
3457        if (!prefixcmp(line, "@@ -"))
3458                return;
3459
3460        new_len = remove_space(line, len);
3461
3462        git_SHA1_Update(data->ctx, line, new_len);
3463        data->patchlen += new_len;
3464}
3465
3466/* returns 0 upon success, and writes result into sha1 */
3467static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3468{
3469        struct diff_queue_struct *q = &diff_queued_diff;
3470        int i;
3471        git_SHA_CTX ctx;
3472        struct patch_id_t data;
3473        char buffer[PATH_MAX * 4 + 20];
3474
3475        git_SHA1_Init(&ctx);
3476        memset(&data, 0, sizeof(struct patch_id_t));
3477        data.ctx = &ctx;
3478
3479        for (i = 0; i < q->nr; i++) {
3480                xpparam_t xpp;
3481                xdemitconf_t xecfg;
3482                xdemitcb_t ecb;
3483                mmfile_t mf1, mf2;
3484                struct diff_filepair *p = q->queue[i];
3485                int len1, len2;
3486
3487                memset(&xpp, 0, sizeof(xpp));
3488                memset(&xecfg, 0, sizeof(xecfg));
3489                if (p->status == 0)
3490                        return error("internal diff status error");
3491                if (p->status == DIFF_STATUS_UNKNOWN)
3492                        continue;
3493                if (diff_unmodified_pair(p))
3494                        continue;
3495                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3496                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3497                        continue;
3498                if (DIFF_PAIR_UNMERGED(p))
3499                        continue;
3500
3501                diff_fill_sha1_info(p->one);
3502                diff_fill_sha1_info(p->two);
3503                if (fill_mmfile(&mf1, p->one) < 0 ||
3504                                fill_mmfile(&mf2, p->two) < 0)
3505                        return error("unable to read files to diff");
3506
3507                len1 = remove_space(p->one->path, strlen(p->one->path));
3508                len2 = remove_space(p->two->path, strlen(p->two->path));
3509                if (p->one->mode == 0)
3510                        len1 = snprintf(buffer, sizeof(buffer),
3511                                        "diff--gita/%.*sb/%.*s"
3512                                        "newfilemode%06o"
3513                                        "---/dev/null"
3514                                        "+++b/%.*s",
3515                                        len1, p->one->path,
3516                                        len2, p->two->path,
3517                                        p->two->mode,
3518                                        len2, p->two->path);
3519                else if (p->two->mode == 0)
3520                        len1 = snprintf(buffer, sizeof(buffer),
3521                                        "diff--gita/%.*sb/%.*s"
3522                                        "deletedfilemode%06o"
3523                                        "---a/%.*s"
3524                                        "+++/dev/null",
3525                                        len1, p->one->path,
3526                                        len2, p->two->path,
3527                                        p->one->mode,
3528                                        len1, p->one->path);
3529                else
3530                        len1 = snprintf(buffer, sizeof(buffer),
3531                                        "diff--gita/%.*sb/%.*s"
3532                                        "---a/%.*s"
3533                                        "+++b/%.*s",
3534                                        len1, p->one->path,
3535                                        len2, p->two->path,
3536                                        len1, p->one->path,
3537                                        len2, p->two->path);
3538                git_SHA1_Update(&ctx, buffer, len1);
3539
3540                xpp.flags = XDF_NEED_MINIMAL;
3541                xecfg.ctxlen = 3;
3542                xecfg.flags = XDL_EMIT_FUNCNAMES;
3543                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3544                              &xpp, &xecfg, &ecb);
3545        }
3546
3547        git_SHA1_Final(sha1, &ctx);
3548        return 0;
3549}
3550
3551int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3552{
3553        struct diff_queue_struct *q = &diff_queued_diff;
3554        int i;
3555        int result = diff_get_patch_id(options, sha1);
3556
3557        for (i = 0; i < q->nr; i++)
3558                diff_free_filepair(q->queue[i]);
3559
3560        free(q->queue);
3561        q->queue = NULL;
3562        q->nr = q->alloc = 0;
3563
3564        return result;
3565}
3566
3567static int is_summary_empty(const struct diff_queue_struct *q)
3568{
3569        int i;
3570
3571        for (i = 0; i < q->nr; i++) {
3572                const struct diff_filepair *p = q->queue[i];
3573
3574                switch (p->status) {
3575                case DIFF_STATUS_DELETED:
3576                case DIFF_STATUS_ADDED:
3577                case DIFF_STATUS_COPIED:
3578                case DIFF_STATUS_RENAMED:
3579                        return 0;
3580                default:
3581                        if (p->score)
3582                                return 0;
3583                        if (p->one->mode && p->two->mode &&
3584                            p->one->mode != p->two->mode)
3585                                return 0;
3586                        break;
3587                }
3588        }
3589        return 1;
3590}
3591
3592void diff_flush(struct diff_options *options)
3593{
3594        struct diff_queue_struct *q = &diff_queued_diff;
3595        int i, output_format = options->output_format;
3596        int separator = 0;
3597
3598        /*
3599         * Order: raw, stat, summary, patch
3600         * or:    name/name-status/checkdiff (other bits clear)
3601         */
3602        if (!q->nr)
3603                goto free_queue;
3604
3605        if (output_format & (DIFF_FORMAT_RAW |
3606                             DIFF_FORMAT_NAME |
3607                             DIFF_FORMAT_NAME_STATUS |
3608                             DIFF_FORMAT_CHECKDIFF)) {
3609                for (i = 0; i < q->nr; i++) {
3610                        struct diff_filepair *p = q->queue[i];
3611                        if (check_pair_status(p))
3612                                flush_one_pair(p, options);
3613                }
3614                separator++;
3615        }
3616
3617        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3618                struct diffstat_t diffstat;
3619
3620                memset(&diffstat, 0, sizeof(struct diffstat_t));
3621                for (i = 0; i < q->nr; i++) {
3622                        struct diff_filepair *p = q->queue[i];
3623                        if (check_pair_status(p))
3624                                diff_flush_stat(p, options, &diffstat);
3625                }
3626                if (output_format & DIFF_FORMAT_NUMSTAT)
3627                        show_numstat(&diffstat, options);
3628                if (output_format & DIFF_FORMAT_DIFFSTAT)
3629                        show_stats(&diffstat, options);
3630                if (output_format & DIFF_FORMAT_SHORTSTAT)
3631                        show_shortstats(&diffstat, options);
3632                free_diffstat_info(&diffstat);
3633                separator++;
3634        }
3635        if (output_format & DIFF_FORMAT_DIRSTAT)
3636                show_dirstat(options);
3637
3638        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3639                for (i = 0; i < q->nr; i++)
3640                        diff_summary(options->file, q->queue[i]);
3641                separator++;
3642        }
3643
3644        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3645            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3646            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3647                /*
3648                 * run diff_flush_patch for the exit status. setting
3649                 * options->file to /dev/null should be safe, becaue we
3650                 * aren't supposed to produce any output anyway.
3651                 */
3652                if (options->close_file)
3653                        fclose(options->file);
3654                options->file = fopen("/dev/null", "w");
3655                if (!options->file)
3656                        die_errno("Could not open /dev/null");
3657                options->close_file = 1;
3658                for (i = 0; i < q->nr; i++) {
3659                        struct diff_filepair *p = q->queue[i];
3660                        if (check_pair_status(p))
3661                                diff_flush_patch(p, options);
3662                        if (options->found_changes)
3663                                break;
3664                }
3665        }
3666
3667        if (output_format & DIFF_FORMAT_PATCH) {
3668                if (separator) {
3669                        putc(options->line_termination, options->file);
3670                        if (options->stat_sep) {
3671                                /* attach patch instead of inline */
3672                                fputs(options->stat_sep, options->file);
3673                        }
3674                }
3675
3676                for (i = 0; i < q->nr; i++) {
3677                        struct diff_filepair *p = q->queue[i];
3678                        if (check_pair_status(p))
3679                                diff_flush_patch(p, options);
3680                }
3681        }
3682
3683        if (output_format & DIFF_FORMAT_CALLBACK)
3684                options->format_callback(q, options, options->format_callback_data);
3685
3686        for (i = 0; i < q->nr; i++)
3687                diff_free_filepair(q->queue[i]);
3688free_queue:
3689        free(q->queue);
3690        q->queue = NULL;
3691        q->nr = q->alloc = 0;
3692        if (options->close_file)
3693                fclose(options->file);
3694
3695        /*
3696         * Report the content-level differences with HAS_CHANGES;
3697         * diff_addremove/diff_change does not set the bit when
3698         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3699         */
3700        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3701                if (options->found_changes)
3702                        DIFF_OPT_SET(options, HAS_CHANGES);
3703                else
3704                        DIFF_OPT_CLR(options, HAS_CHANGES);
3705        }
3706}
3707
3708static void diffcore_apply_filter(const char *filter)
3709{
3710        int i;
3711        struct diff_queue_struct *q = &diff_queued_diff;
3712        struct diff_queue_struct outq;
3713        outq.queue = NULL;
3714        outq.nr = outq.alloc = 0;
3715
3716        if (!filter)
3717                return;
3718
3719        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3720                int found;
3721                for (i = found = 0; !found && i < q->nr; i++) {
3722                        struct diff_filepair *p = q->queue[i];
3723                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3724                             ((p->score &&
3725                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3726                              (!p->score &&
3727                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3728                            ((p->status != DIFF_STATUS_MODIFIED) &&
3729                             strchr(filter, p->status)))
3730                                found++;
3731                }
3732                if (found)
3733                        return;
3734
3735                /* otherwise we will clear the whole queue
3736                 * by copying the empty outq at the end of this
3737                 * function, but first clear the current entries
3738                 * in the queue.
3739                 */
3740                for (i = 0; i < q->nr; i++)
3741                        diff_free_filepair(q->queue[i]);
3742        }
3743        else {
3744                /* Only the matching ones */
3745                for (i = 0; i < q->nr; i++) {
3746                        struct diff_filepair *p = q->queue[i];
3747
3748                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3749                             ((p->score &&
3750                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3751                              (!p->score &&
3752                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3753                            ((p->status != DIFF_STATUS_MODIFIED) &&
3754                             strchr(filter, p->status)))
3755                                diff_q(&outq, p);
3756                        else
3757                                diff_free_filepair(p);
3758                }
3759        }
3760        free(q->queue);
3761        *q = outq;
3762}
3763
3764/* Check whether two filespecs with the same mode and size are identical */
3765static int diff_filespec_is_identical(struct diff_filespec *one,
3766                                      struct diff_filespec *two)
3767{
3768        if (S_ISGITLINK(one->mode))
3769                return 0;
3770        if (diff_populate_filespec(one, 0))
3771                return 0;
3772        if (diff_populate_filespec(two, 0))
3773                return 0;
3774        return !memcmp(one->data, two->data, one->size);
3775}
3776
3777static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3778{
3779        int i;
3780        struct diff_queue_struct *q = &diff_queued_diff;
3781        struct diff_queue_struct outq;
3782        outq.queue = NULL;
3783        outq.nr = outq.alloc = 0;
3784
3785        for (i = 0; i < q->nr; i++) {
3786                struct diff_filepair *p = q->queue[i];
3787
3788                /*
3789                 * 1. Entries that come from stat info dirtiness
3790                 *    always have both sides (iow, not create/delete),
3791                 *    one side of the object name is unknown, with
3792                 *    the same mode and size.  Keep the ones that
3793                 *    do not match these criteria.  They have real
3794                 *    differences.
3795                 *
3796                 * 2. At this point, the file is known to be modified,
3797                 *    with the same mode and size, and the object
3798                 *    name of one side is unknown.  Need to inspect
3799                 *    the identical contents.
3800                 */
3801                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3802                    !DIFF_FILE_VALID(p->two) ||
3803                    (p->one->sha1_valid && p->two->sha1_valid) ||
3804                    (p->one->mode != p->two->mode) ||
3805                    diff_populate_filespec(p->one, 1) ||
3806                    diff_populate_filespec(p->two, 1) ||
3807                    (p->one->size != p->two->size) ||
3808                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3809                        diff_q(&outq, p);
3810                else {
3811                        /*
3812                         * The caller can subtract 1 from skip_stat_unmatch
3813                         * to determine how many paths were dirty only
3814                         * due to stat info mismatch.
3815                         */
3816                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3817                                diffopt->skip_stat_unmatch++;
3818                        diff_free_filepair(p);
3819                }
3820        }
3821        free(q->queue);
3822        *q = outq;
3823}
3824
3825static int diffnamecmp(const void *a_, const void *b_)
3826{
3827        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3828        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3829        const char *name_a, *name_b;
3830
3831        name_a = a->one ? a->one->path : a->two->path;
3832        name_b = b->one ? b->one->path : b->two->path;
3833        return strcmp(name_a, name_b);
3834}
3835
3836void diffcore_fix_diff_index(struct diff_options *options)
3837{
3838        struct diff_queue_struct *q = &diff_queued_diff;
3839        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3840}
3841
3842void diffcore_std(struct diff_options *options)
3843{
3844        if (options->skip_stat_unmatch)
3845                diffcore_skip_stat_unmatch(options);
3846        if (options->break_opt != -1)
3847                diffcore_break(options->break_opt);
3848        if (options->detect_rename)
3849                diffcore_rename(options);
3850        if (options->break_opt != -1)
3851                diffcore_merge_broken();
3852        if (options->pickaxe)
3853                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3854        if (options->orderfile)
3855                diffcore_order(options->orderfile);
3856        diff_resolve_rename_copy();
3857        diffcore_apply_filter(options->filter);
3858
3859        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3860                DIFF_OPT_SET(options, HAS_CHANGES);
3861        else
3862                DIFF_OPT_CLR(options, HAS_CHANGES);
3863}
3864
3865int diff_result_code(struct diff_options *opt, int status)
3866{
3867        int result = 0;
3868        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3869            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3870                return status;
3871        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3872            DIFF_OPT_TST(opt, HAS_CHANGES))
3873                result |= 01;
3874        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3875            DIFF_OPT_TST(opt, CHECK_FAILED))
3876                result |= 02;
3877        return result;
3878}
3879
3880void diff_addremove(struct diff_options *options,
3881                    int addremove, unsigned mode,
3882                    const unsigned char *sha1,
3883                    const char *concatpath, unsigned dirty_submodule)
3884{
3885        struct diff_filespec *one, *two;
3886
3887        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3888                return;
3889
3890        /* This may look odd, but it is a preparation for
3891         * feeding "there are unchanged files which should
3892         * not produce diffs, but when you are doing copy
3893         * detection you would need them, so here they are"
3894         * entries to the diff-core.  They will be prefixed
3895         * with something like '=' or '*' (I haven't decided
3896         * which but should not make any difference).
3897         * Feeding the same new and old to diff_change()
3898         * also has the same effect.
3899         * Before the final output happens, they are pruned after
3900         * merged into rename/copy pairs as appropriate.
3901         */
3902        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3903                addremove = (addremove == '+' ? '-' :
3904                             addremove == '-' ? '+' : addremove);
3905
3906        if (options->prefix &&
3907            strncmp(concatpath, options->prefix, options->prefix_length))
3908                return;
3909
3910        one = alloc_filespec(concatpath);
3911        two = alloc_filespec(concatpath);
3912
3913        if (addremove != '+')
3914                fill_filespec(one, sha1, mode);
3915        if (addremove != '-') {
3916                fill_filespec(two, sha1, mode);
3917                two->dirty_submodule = dirty_submodule;
3918        }
3919
3920        diff_queue(&diff_queued_diff, one, two);
3921        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3922                DIFF_OPT_SET(options, HAS_CHANGES);
3923}
3924
3925void diff_change(struct diff_options *options,
3926                 unsigned old_mode, unsigned new_mode,
3927                 const unsigned char *old_sha1,
3928                 const unsigned char *new_sha1,
3929                 const char *concatpath,
3930                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3931{
3932        struct diff_filespec *one, *two;
3933
3934        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3935                        && S_ISGITLINK(new_mode))
3936                return;
3937
3938        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3939                unsigned tmp;
3940                const unsigned char *tmp_c;
3941                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3942                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3943                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3944                        new_dirty_submodule = tmp;
3945        }
3946
3947        if (options->prefix &&
3948            strncmp(concatpath, options->prefix, options->prefix_length))
3949                return;
3950
3951        one = alloc_filespec(concatpath);
3952        two = alloc_filespec(concatpath);
3953        fill_filespec(one, old_sha1, old_mode);
3954        fill_filespec(two, new_sha1, new_mode);
3955        one->dirty_submodule = old_dirty_submodule;
3956        two->dirty_submodule = new_dirty_submodule;
3957
3958        diff_queue(&diff_queued_diff, one, two);
3959        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3960                DIFF_OPT_SET(options, HAS_CHANGES);
3961}
3962
3963void diff_unmerge(struct diff_options *options,
3964                  const char *path,
3965                  unsigned mode, const unsigned char *sha1)
3966{
3967        struct diff_filespec *one, *two;
3968
3969        if (options->prefix &&
3970            strncmp(path, options->prefix, options->prefix_length))
3971                return;
3972
3973        one = alloc_filespec(path);
3974        two = alloc_filespec(path);
3975        fill_filespec(one, sha1, mode);
3976        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3977}
3978
3979static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3980                size_t *outsize)
3981{
3982        struct diff_tempfile *temp;
3983        const char *argv[3];
3984        const char **arg = argv;
3985        struct child_process child;
3986        struct strbuf buf = STRBUF_INIT;
3987        int err = 0;
3988
3989        temp = prepare_temp_file(spec->path, spec);
3990        *arg++ = pgm;
3991        *arg++ = temp->name;
3992        *arg = NULL;
3993
3994        memset(&child, 0, sizeof(child));
3995        child.use_shell = 1;
3996        child.argv = argv;
3997        child.out = -1;
3998        if (start_command(&child)) {
3999                remove_tempfile();
4000                return NULL;
4001        }
4002
4003        if (strbuf_read(&buf, child.out, 0) < 0)
4004                err = error("error reading from textconv command '%s'", pgm);
4005        close(child.out);
4006
4007        if (finish_command(&child) || err) {
4008                strbuf_release(&buf);
4009                remove_tempfile();
4010                return NULL;
4011        }
4012        remove_tempfile();
4013
4014        return strbuf_detach(&buf, outsize);
4015}