37c886a81588c556c105665d9926f25da377d3e5
   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
  16#ifdef NO_FAST_WORKING_DIRECTORY
  17#define FAST_WORKING_DIRECTORY 0
  18#else
  19#define FAST_WORKING_DIRECTORY 1
  20#endif
  21
  22static int diff_detect_rename_default;
  23static int diff_rename_limit_default = 200;
  24static int diff_suppress_blank_empty;
  25int diff_use_color_default = -1;
  26static const char *external_diff_cmd_cfg;
  27int diff_auto_refresh_index = 1;
  28static int diff_mnemonic_prefix;
  29
  30static char diff_colors[][COLOR_MAXLEN] = {
  31        "\033[m",       /* reset */
  32        "",             /* PLAIN (normal) */
  33        "\033[1m",      /* METAINFO (bold) */
  34        "\033[36m",     /* FRAGINFO (cyan) */
  35        "\033[31m",     /* OLD (red) */
  36        "\033[32m",     /* NEW (green) */
  37        "\033[33m",     /* COMMIT (yellow) */
  38        "\033[41m",     /* WHITESPACE (red background) */
  39};
  40
  41static void diff_filespec_load_driver(struct diff_filespec *one);
  42static char *run_textconv(const char *, struct diff_filespec *, size_t *);
  43
  44static int parse_diff_color_slot(const char *var, int ofs)
  45{
  46        if (!strcasecmp(var+ofs, "plain"))
  47                return DIFF_PLAIN;
  48        if (!strcasecmp(var+ofs, "meta"))
  49                return DIFF_METAINFO;
  50        if (!strcasecmp(var+ofs, "frag"))
  51                return DIFF_FRAGINFO;
  52        if (!strcasecmp(var+ofs, "old"))
  53                return DIFF_FILE_OLD;
  54        if (!strcasecmp(var+ofs, "new"))
  55                return DIFF_FILE_NEW;
  56        if (!strcasecmp(var+ofs, "commit"))
  57                return DIFF_COMMIT;
  58        if (!strcasecmp(var+ofs, "whitespace"))
  59                return DIFF_WHITESPACE;
  60        die("bad config variable '%s'", var);
  61}
  62
  63/*
  64 * These are to give UI layer defaults.
  65 * The core-level commands such as git-diff-files should
  66 * never be affected by the setting of diff.renames
  67 * the user happens to have in the configuration file.
  68 */
  69int git_diff_ui_config(const char *var, const char *value, void *cb)
  70{
  71        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  72                diff_use_color_default = git_config_colorbool(var, value, -1);
  73                return 0;
  74        }
  75        if (!strcmp(var, "diff.renames")) {
  76                if (!value)
  77                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  78                else if (!strcasecmp(value, "copies") ||
  79                         !strcasecmp(value, "copy"))
  80                        diff_detect_rename_default = DIFF_DETECT_COPY;
  81                else if (git_config_bool(var,value))
  82                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  83                return 0;
  84        }
  85        if (!strcmp(var, "diff.autorefreshindex")) {
  86                diff_auto_refresh_index = git_config_bool(var, value);
  87                return 0;
  88        }
  89        if (!strcmp(var, "diff.mnemonicprefix")) {
  90                diff_mnemonic_prefix = git_config_bool(var, value);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.external"))
  94                return git_config_string(&external_diff_cmd_cfg, var, value);
  95
  96        return git_diff_basic_config(var, value, cb);
  97}
  98
  99int git_diff_basic_config(const char *var, const char *value, void *cb)
 100{
 101        if (!strcmp(var, "diff.renamelimit")) {
 102                diff_rename_limit_default = git_config_int(var, value);
 103                return 0;
 104        }
 105
 106        switch (userdiff_config(var, value)) {
 107                case 0: break;
 108                case -1: return -1;
 109                default: return 0;
 110        }
 111
 112        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 113                int slot = parse_diff_color_slot(var, 11);
 114                if (!value)
 115                        return config_error_nonbool(var);
 116                color_parse(value, var, diff_colors[slot]);
 117                return 0;
 118        }
 119
 120        /* like GNU diff's --suppress-blank-empty option  */
 121        if (!strcmp(var, "diff.suppress-blank-empty")) {
 122                diff_suppress_blank_empty = git_config_bool(var, value);
 123                return 0;
 124        }
 125
 126        return git_color_default_config(var, value, cb);
 127}
 128
 129static char *quote_two(const char *one, const char *two)
 130{
 131        int need_one = quote_c_style(one, NULL, NULL, 1);
 132        int need_two = quote_c_style(two, NULL, NULL, 1);
 133        struct strbuf res = STRBUF_INIT;
 134
 135        if (need_one + need_two) {
 136                strbuf_addch(&res, '"');
 137                quote_c_style(one, &res, NULL, 1);
 138                quote_c_style(two, &res, NULL, 1);
 139                strbuf_addch(&res, '"');
 140        } else {
 141                strbuf_addstr(&res, one);
 142                strbuf_addstr(&res, two);
 143        }
 144        return strbuf_detach(&res, NULL);
 145}
 146
 147static const char *external_diff(void)
 148{
 149        static const char *external_diff_cmd = NULL;
 150        static int done_preparing = 0;
 151
 152        if (done_preparing)
 153                return external_diff_cmd;
 154        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 155        if (!external_diff_cmd)
 156                external_diff_cmd = external_diff_cmd_cfg;
 157        done_preparing = 1;
 158        return external_diff_cmd;
 159}
 160
 161static struct diff_tempfile {
 162        const char *name; /* filename external diff should read from */
 163        char hex[41];
 164        char mode[10];
 165        char tmp_path[PATH_MAX];
 166} diff_temp[2];
 167
 168static int count_lines(const char *data, int size)
 169{
 170        int count, ch, completely_empty = 1, nl_just_seen = 0;
 171        count = 0;
 172        while (0 < size--) {
 173                ch = *data++;
 174                if (ch == '\n') {
 175                        count++;
 176                        nl_just_seen = 1;
 177                        completely_empty = 0;
 178                }
 179                else {
 180                        nl_just_seen = 0;
 181                        completely_empty = 0;
 182                }
 183        }
 184        if (completely_empty)
 185                return 0;
 186        if (!nl_just_seen)
 187                count++; /* no trailing newline */
 188        return count;
 189}
 190
 191static void print_line_count(FILE *file, int count)
 192{
 193        switch (count) {
 194        case 0:
 195                fprintf(file, "0,0");
 196                break;
 197        case 1:
 198                fprintf(file, "1");
 199                break;
 200        default:
 201                fprintf(file, "1,%d", count);
 202                break;
 203        }
 204}
 205
 206static void copy_file_with_prefix(FILE *file,
 207                                  int prefix, const char *data, int size,
 208                                  const char *set, const char *reset)
 209{
 210        int ch, nl_just_seen = 1;
 211        while (0 < size--) {
 212                ch = *data++;
 213                if (nl_just_seen) {
 214                        fputs(set, file);
 215                        putc(prefix, file);
 216                }
 217                if (ch == '\n') {
 218                        nl_just_seen = 1;
 219                        fputs(reset, file);
 220                } else
 221                        nl_just_seen = 0;
 222                putc(ch, file);
 223        }
 224        if (!nl_just_seen)
 225                fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 226}
 227
 228static void emit_rewrite_diff(const char *name_a,
 229                              const char *name_b,
 230                              struct diff_filespec *one,
 231                              struct diff_filespec *two,
 232                              const char *textconv_one,
 233                              const char *textconv_two,
 234                              struct diff_options *o)
 235{
 236        int lc_a, lc_b;
 237        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 238        const char *name_a_tab, *name_b_tab;
 239        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 240        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 241        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 242        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 243        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 244        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 245        const char *a_prefix, *b_prefix;
 246        const char *data_one, *data_two;
 247        size_t size_one, size_two;
 248
 249        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 250                a_prefix = o->b_prefix;
 251                b_prefix = o->a_prefix;
 252        } else {
 253                a_prefix = o->a_prefix;
 254                b_prefix = o->b_prefix;
 255        }
 256
 257        name_a += (*name_a == '/');
 258        name_b += (*name_b == '/');
 259        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 260        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 261
 262        strbuf_reset(&a_name);
 263        strbuf_reset(&b_name);
 264        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 265        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 266
 267        diff_populate_filespec(one, 0);
 268        diff_populate_filespec(two, 0);
 269        if (textconv_one) {
 270                data_one = run_textconv(textconv_one, one, &size_one);
 271                if (!data_one)
 272                        die("unable to read files to diff");
 273        }
 274        else {
 275                data_one = one->data;
 276                size_one = one->size;
 277        }
 278        if (textconv_two) {
 279                data_two = run_textconv(textconv_two, two, &size_two);
 280                if (!data_two)
 281                        die("unable to read files to diff");
 282        }
 283        else {
 284                data_two = two->data;
 285                size_two = two->size;
 286        }
 287
 288        lc_a = count_lines(data_one, size_one);
 289        lc_b = count_lines(data_two, size_two);
 290        fprintf(o->file,
 291                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 292                metainfo, a_name.buf, name_a_tab, reset,
 293                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 294        print_line_count(o->file, lc_a);
 295        fprintf(o->file, " +");
 296        print_line_count(o->file, lc_b);
 297        fprintf(o->file, " @@%s\n", reset);
 298        if (lc_a)
 299                copy_file_with_prefix(o->file, '-', data_one, size_one, old, reset);
 300        if (lc_b)
 301                copy_file_with_prefix(o->file, '+', data_two, size_two, new, reset);
 302}
 303
 304static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 305{
 306        if (!DIFF_FILE_VALID(one)) {
 307                mf->ptr = (char *)""; /* does not matter */
 308                mf->size = 0;
 309                return 0;
 310        }
 311        else if (diff_populate_filespec(one, 0))
 312                return -1;
 313
 314        mf->ptr = one->data;
 315        mf->size = one->size;
 316        return 0;
 317}
 318
 319struct diff_words_buffer {
 320        mmfile_t text;
 321        long alloc;
 322        struct diff_words_orig {
 323                const char *begin, *end;
 324        } *orig;
 325        int orig_nr, orig_alloc;
 326};
 327
 328static void diff_words_append(char *line, unsigned long len,
 329                struct diff_words_buffer *buffer)
 330{
 331        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 332        line++;
 333        len--;
 334        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 335        buffer->text.size += len;
 336}
 337
 338struct diff_words_data {
 339        struct diff_words_buffer minus, plus;
 340        const char *current_plus;
 341        FILE *file;
 342};
 343
 344static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 345{
 346        struct diff_words_data *diff_words = priv;
 347        int minus_first, minus_len, plus_first, plus_len;
 348        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 349
 350        if (line[0] != '@' || parse_hunk_header(line, len,
 351                        &minus_first, &minus_len, &plus_first, &plus_len))
 352                return;
 353
 354        /* POSIX requires that first be decremented by one if len == 0... */
 355        if (minus_len) {
 356                minus_begin = diff_words->minus.orig[minus_first].begin;
 357                minus_end =
 358                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 359        } else
 360                minus_begin = minus_end =
 361                        diff_words->minus.orig[minus_first].end;
 362
 363        if (plus_len) {
 364                plus_begin = diff_words->plus.orig[plus_first].begin;
 365                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 366        } else
 367                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 368
 369        if (diff_words->current_plus != plus_begin)
 370                fwrite(diff_words->current_plus,
 371                                plus_begin - diff_words->current_plus, 1,
 372                                diff_words->file);
 373        if (minus_begin != minus_end)
 374                color_fwrite_lines(diff_words->file,
 375                                diff_get_color(1, DIFF_FILE_OLD),
 376                                minus_end - minus_begin, minus_begin);
 377        if (plus_begin != plus_end)
 378                color_fwrite_lines(diff_words->file,
 379                                diff_get_color(1, DIFF_FILE_NEW),
 380                                plus_end - plus_begin, plus_begin);
 381
 382        diff_words->current_plus = plus_end;
 383}
 384
 385/*
 386 * This function splits the words in buffer->text, stores the list with
 387 * newline separator into out, and saves the offsets of the original words
 388 * in buffer->orig.
 389 */
 390static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out)
 391{
 392        int i, j;
 393
 394        out->size = 0;
 395        out->ptr = xmalloc(buffer->text.size);
 396
 397        /* fake an empty "0th" word */
 398        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 399        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 400        buffer->orig_nr = 1;
 401
 402        for (i = 0; i < buffer->text.size; i++) {
 403                if (isspace(buffer->text.ptr[i]))
 404                        continue;
 405                for (j = i + 1; j < buffer->text.size &&
 406                                !isspace(buffer->text.ptr[j]); j++)
 407                        ; /* find the end of the word */
 408
 409                /* store original boundaries */
 410                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 411                                buffer->orig_alloc);
 412                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 413                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 414                buffer->orig_nr++;
 415
 416                /* store one word */
 417                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 418                out->ptr[out->size + j - i] = '\n';
 419                out->size += j - i + 1;
 420
 421                i = j - 1;
 422        }
 423}
 424
 425/* this executes the word diff on the accumulated buffers */
 426static void diff_words_show(struct diff_words_data *diff_words)
 427{
 428        xpparam_t xpp;
 429        xdemitconf_t xecfg;
 430        xdemitcb_t ecb;
 431        mmfile_t minus, plus;
 432
 433        /* special case: only removal */
 434        if (!diff_words->plus.text.size) {
 435                color_fwrite_lines(diff_words->file,
 436                        diff_get_color(1, DIFF_FILE_OLD),
 437                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 438                diff_words->minus.text.size = 0;
 439                return;
 440        }
 441
 442        diff_words->current_plus = diff_words->plus.text.ptr;
 443
 444        memset(&xpp, 0, sizeof(xpp));
 445        memset(&xecfg, 0, sizeof(xecfg));
 446        diff_words_fill(&diff_words->minus, &minus);
 447        diff_words_fill(&diff_words->plus, &plus);
 448        xpp.flags = XDF_NEED_MINIMAL;
 449        xecfg.ctxlen = 0;
 450        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 451                      &xpp, &xecfg, &ecb);
 452        free(minus.ptr);
 453        free(plus.ptr);
 454        if (diff_words->current_plus != diff_words->plus.text.ptr +
 455                        diff_words->plus.text.size)
 456                fwrite(diff_words->current_plus,
 457                        diff_words->plus.text.ptr + diff_words->plus.text.size
 458                        - diff_words->current_plus, 1,
 459                        diff_words->file);
 460        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 461}
 462
 463typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 464
 465struct emit_callback {
 466        int nparents, color_diff;
 467        unsigned ws_rule;
 468        sane_truncate_fn truncate;
 469        const char **label_path;
 470        struct diff_words_data *diff_words;
 471        int *found_changesp;
 472        FILE *file;
 473};
 474
 475static void free_diff_words_data(struct emit_callback *ecbdata)
 476{
 477        if (ecbdata->diff_words) {
 478                /* flush buffers */
 479                if (ecbdata->diff_words->minus.text.size ||
 480                                ecbdata->diff_words->plus.text.size)
 481                        diff_words_show(ecbdata->diff_words);
 482
 483                free (ecbdata->diff_words->minus.text.ptr);
 484                free (ecbdata->diff_words->minus.orig);
 485                free (ecbdata->diff_words->plus.text.ptr);
 486                free (ecbdata->diff_words->plus.orig);
 487                free(ecbdata->diff_words);
 488                ecbdata->diff_words = NULL;
 489        }
 490}
 491
 492const char *diff_get_color(int diff_use_color, enum color_diff ix)
 493{
 494        if (diff_use_color)
 495                return diff_colors[ix];
 496        return "";
 497}
 498
 499static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 500{
 501        int has_trailing_newline, has_trailing_carriage_return;
 502
 503        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 504        if (has_trailing_newline)
 505                len--;
 506        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 507        if (has_trailing_carriage_return)
 508                len--;
 509
 510        fputs(set, file);
 511        fwrite(line, len, 1, file);
 512        fputs(reset, file);
 513        if (has_trailing_carriage_return)
 514                fputc('\r', file);
 515        if (has_trailing_newline)
 516                fputc('\n', file);
 517}
 518
 519static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 520{
 521        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 522        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 523
 524        if (!*ws)
 525                emit_line(ecbdata->file, set, reset, line, len);
 526        else {
 527                /* Emit just the prefix, then the rest. */
 528                emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 529                ws_check_emit(line + ecbdata->nparents,
 530                              len - ecbdata->nparents, ecbdata->ws_rule,
 531                              ecbdata->file, set, reset, ws);
 532        }
 533}
 534
 535static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 536{
 537        const char *cp;
 538        unsigned long allot;
 539        size_t l = len;
 540
 541        if (ecb->truncate)
 542                return ecb->truncate(line, len);
 543        cp = line;
 544        allot = l;
 545        while (0 < l) {
 546                (void) utf8_width(&cp, &l);
 547                if (!cp)
 548                        break; /* truncated in the middle? */
 549        }
 550        return allot - l;
 551}
 552
 553static void fn_out_consume(void *priv, char *line, unsigned long len)
 554{
 555        int i;
 556        int color;
 557        struct emit_callback *ecbdata = priv;
 558        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 559        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 560        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 561
 562        *(ecbdata->found_changesp) = 1;
 563
 564        if (ecbdata->label_path[0]) {
 565                const char *name_a_tab, *name_b_tab;
 566
 567                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 568                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 569
 570                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 571                        meta, ecbdata->label_path[0], reset, name_a_tab);
 572                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 573                        meta, ecbdata->label_path[1], reset, name_b_tab);
 574                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 575        }
 576
 577        if (diff_suppress_blank_empty
 578            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 579                line[0] = '\n';
 580                len = 1;
 581        }
 582
 583        /* This is not really necessary for now because
 584         * this codepath only deals with two-way diffs.
 585         */
 586        for (i = 0; i < len && line[i] == '@'; i++)
 587                ;
 588        if (2 <= i && i < len && line[i] == ' ') {
 589                ecbdata->nparents = i - 1;
 590                len = sane_truncate_line(ecbdata, line, len);
 591                emit_line(ecbdata->file,
 592                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 593                          reset, line, len);
 594                if (line[len-1] != '\n')
 595                        putc('\n', ecbdata->file);
 596                return;
 597        }
 598
 599        if (len < ecbdata->nparents) {
 600                emit_line(ecbdata->file, reset, reset, line, len);
 601                return;
 602        }
 603
 604        color = DIFF_PLAIN;
 605        if (ecbdata->diff_words && ecbdata->nparents != 1)
 606                /* fall back to normal diff */
 607                free_diff_words_data(ecbdata);
 608        if (ecbdata->diff_words) {
 609                if (line[0] == '-') {
 610                        diff_words_append(line, len,
 611                                          &ecbdata->diff_words->minus);
 612                        return;
 613                } else if (line[0] == '+') {
 614                        diff_words_append(line, len,
 615                                          &ecbdata->diff_words->plus);
 616                        return;
 617                }
 618                if (ecbdata->diff_words->minus.text.size ||
 619                    ecbdata->diff_words->plus.text.size)
 620                        diff_words_show(ecbdata->diff_words);
 621                line++;
 622                len--;
 623                emit_line(ecbdata->file, plain, reset, line, len);
 624                return;
 625        }
 626        for (i = 0; i < ecbdata->nparents && len; i++) {
 627                if (line[i] == '-')
 628                        color = DIFF_FILE_OLD;
 629                else if (line[i] == '+')
 630                        color = DIFF_FILE_NEW;
 631        }
 632
 633        if (color != DIFF_FILE_NEW) {
 634                emit_line(ecbdata->file,
 635                          diff_get_color(ecbdata->color_diff, color),
 636                          reset, line, len);
 637                return;
 638        }
 639        emit_add_line(reset, ecbdata, line, len);
 640}
 641
 642static char *pprint_rename(const char *a, const char *b)
 643{
 644        const char *old = a;
 645        const char *new = b;
 646        struct strbuf name = STRBUF_INIT;
 647        int pfx_length, sfx_length;
 648        int len_a = strlen(a);
 649        int len_b = strlen(b);
 650        int a_midlen, b_midlen;
 651        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 652        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 653
 654        if (qlen_a || qlen_b) {
 655                quote_c_style(a, &name, NULL, 0);
 656                strbuf_addstr(&name, " => ");
 657                quote_c_style(b, &name, NULL, 0);
 658                return strbuf_detach(&name, NULL);
 659        }
 660
 661        /* Find common prefix */
 662        pfx_length = 0;
 663        while (*old && *new && *old == *new) {
 664                if (*old == '/')
 665                        pfx_length = old - a + 1;
 666                old++;
 667                new++;
 668        }
 669
 670        /* Find common suffix */
 671        old = a + len_a;
 672        new = b + len_b;
 673        sfx_length = 0;
 674        while (a <= old && b <= new && *old == *new) {
 675                if (*old == '/')
 676                        sfx_length = len_a - (old - a);
 677                old--;
 678                new--;
 679        }
 680
 681        /*
 682         * pfx{mid-a => mid-b}sfx
 683         * {pfx-a => pfx-b}sfx
 684         * pfx{sfx-a => sfx-b}
 685         * name-a => name-b
 686         */
 687        a_midlen = len_a - pfx_length - sfx_length;
 688        b_midlen = len_b - pfx_length - sfx_length;
 689        if (a_midlen < 0)
 690                a_midlen = 0;
 691        if (b_midlen < 0)
 692                b_midlen = 0;
 693
 694        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 695        if (pfx_length + sfx_length) {
 696                strbuf_add(&name, a, pfx_length);
 697                strbuf_addch(&name, '{');
 698        }
 699        strbuf_add(&name, a + pfx_length, a_midlen);
 700        strbuf_addstr(&name, " => ");
 701        strbuf_add(&name, b + pfx_length, b_midlen);
 702        if (pfx_length + sfx_length) {
 703                strbuf_addch(&name, '}');
 704                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 705        }
 706        return strbuf_detach(&name, NULL);
 707}
 708
 709struct diffstat_t {
 710        int nr;
 711        int alloc;
 712        struct diffstat_file {
 713                char *from_name;
 714                char *name;
 715                char *print_name;
 716                unsigned is_unmerged:1;
 717                unsigned is_binary:1;
 718                unsigned is_renamed:1;
 719                unsigned int added, deleted;
 720        } **files;
 721};
 722
 723static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 724                                          const char *name_a,
 725                                          const char *name_b)
 726{
 727        struct diffstat_file *x;
 728        x = xcalloc(sizeof (*x), 1);
 729        if (diffstat->nr == diffstat->alloc) {
 730                diffstat->alloc = alloc_nr(diffstat->alloc);
 731                diffstat->files = xrealloc(diffstat->files,
 732                                diffstat->alloc * sizeof(x));
 733        }
 734        diffstat->files[diffstat->nr++] = x;
 735        if (name_b) {
 736                x->from_name = xstrdup(name_a);
 737                x->name = xstrdup(name_b);
 738                x->is_renamed = 1;
 739        }
 740        else {
 741                x->from_name = NULL;
 742                x->name = xstrdup(name_a);
 743        }
 744        return x;
 745}
 746
 747static void diffstat_consume(void *priv, char *line, unsigned long len)
 748{
 749        struct diffstat_t *diffstat = priv;
 750        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 751
 752        if (line[0] == '+')
 753                x->added++;
 754        else if (line[0] == '-')
 755                x->deleted++;
 756}
 757
 758const char mime_boundary_leader[] = "------------";
 759
 760static int scale_linear(int it, int width, int max_change)
 761{
 762        /*
 763         * make sure that at least one '-' is printed if there were deletions,
 764         * and likewise for '+'.
 765         */
 766        if (max_change < 2)
 767                return it;
 768        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 769}
 770
 771static void show_name(FILE *file,
 772                      const char *prefix, const char *name, int len,
 773                      const char *reset, const char *set)
 774{
 775        fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 776}
 777
 778static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 779{
 780        if (cnt <= 0)
 781                return;
 782        fprintf(file, "%s", set);
 783        while (cnt--)
 784                putc(ch, file);
 785        fprintf(file, "%s", reset);
 786}
 787
 788static void fill_print_name(struct diffstat_file *file)
 789{
 790        char *pname;
 791
 792        if (file->print_name)
 793                return;
 794
 795        if (!file->is_renamed) {
 796                struct strbuf buf = STRBUF_INIT;
 797                if (quote_c_style(file->name, &buf, NULL, 0)) {
 798                        pname = strbuf_detach(&buf, NULL);
 799                } else {
 800                        pname = file->name;
 801                        strbuf_release(&buf);
 802                }
 803        } else {
 804                pname = pprint_rename(file->from_name, file->name);
 805        }
 806        file->print_name = pname;
 807}
 808
 809static void show_stats(struct diffstat_t* data, struct diff_options *options)
 810{
 811        int i, len, add, del, total, adds = 0, dels = 0;
 812        int max_change = 0, max_len = 0;
 813        int total_files = data->nr;
 814        int width, name_width;
 815        const char *reset, *set, *add_c, *del_c;
 816
 817        if (data->nr == 0)
 818                return;
 819
 820        width = options->stat_width ? options->stat_width : 80;
 821        name_width = options->stat_name_width ? options->stat_name_width : 50;
 822
 823        /* Sanity: give at least 5 columns to the graph,
 824         * but leave at least 10 columns for the name.
 825         */
 826        if (width < 25)
 827                width = 25;
 828        if (name_width < 10)
 829                name_width = 10;
 830        else if (width < name_width + 15)
 831                name_width = width - 15;
 832
 833        /* Find the longest filename and max number of changes */
 834        reset = diff_get_color_opt(options, DIFF_RESET);
 835        set   = diff_get_color_opt(options, DIFF_PLAIN);
 836        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 837        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 838
 839        for (i = 0; i < data->nr; i++) {
 840                struct diffstat_file *file = data->files[i];
 841                int change = file->added + file->deleted;
 842                fill_print_name(file);
 843                len = strlen(file->print_name);
 844                if (max_len < len)
 845                        max_len = len;
 846
 847                if (file->is_binary || file->is_unmerged)
 848                        continue;
 849                if (max_change < change)
 850                        max_change = change;
 851        }
 852
 853        /* Compute the width of the graph part;
 854         * 10 is for one blank at the beginning of the line plus
 855         * " | count " between the name and the graph.
 856         *
 857         * From here on, name_width is the width of the name area,
 858         * and width is the width of the graph area.
 859         */
 860        name_width = (name_width < max_len) ? name_width : max_len;
 861        if (width < (name_width + 10) + max_change)
 862                width = width - (name_width + 10);
 863        else
 864                width = max_change;
 865
 866        for (i = 0; i < data->nr; i++) {
 867                const char *prefix = "";
 868                char *name = data->files[i]->print_name;
 869                int added = data->files[i]->added;
 870                int deleted = data->files[i]->deleted;
 871                int name_len;
 872
 873                /*
 874                 * "scale" the filename
 875                 */
 876                len = name_width;
 877                name_len = strlen(name);
 878                if (name_width < name_len) {
 879                        char *slash;
 880                        prefix = "...";
 881                        len -= 3;
 882                        name += name_len - len;
 883                        slash = strchr(name, '/');
 884                        if (slash)
 885                                name = slash;
 886                }
 887
 888                if (data->files[i]->is_binary) {
 889                        show_name(options->file, prefix, name, len, reset, set);
 890                        fprintf(options->file, "  Bin ");
 891                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 892                        fprintf(options->file, " -> ");
 893                        fprintf(options->file, "%s%d%s", add_c, added, reset);
 894                        fprintf(options->file, " bytes");
 895                        fprintf(options->file, "\n");
 896                        continue;
 897                }
 898                else if (data->files[i]->is_unmerged) {
 899                        show_name(options->file, prefix, name, len, reset, set);
 900                        fprintf(options->file, "  Unmerged\n");
 901                        continue;
 902                }
 903                else if (!data->files[i]->is_renamed &&
 904                         (added + deleted == 0)) {
 905                        total_files--;
 906                        continue;
 907                }
 908
 909                /*
 910                 * scale the add/delete
 911                 */
 912                add = added;
 913                del = deleted;
 914                total = add + del;
 915                adds += add;
 916                dels += del;
 917
 918                if (width <= max_change) {
 919                        add = scale_linear(add, width, max_change);
 920                        del = scale_linear(del, width, max_change);
 921                        total = add + del;
 922                }
 923                show_name(options->file, prefix, name, len, reset, set);
 924                fprintf(options->file, "%5d%s", added + deleted,
 925                                added + deleted ? " " : "");
 926                show_graph(options->file, '+', add, add_c, reset);
 927                show_graph(options->file, '-', del, del_c, reset);
 928                fprintf(options->file, "\n");
 929        }
 930        fprintf(options->file,
 931               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 932               set, total_files, adds, dels, reset);
 933}
 934
 935static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 936{
 937        int i, adds = 0, dels = 0, total_files = data->nr;
 938
 939        if (data->nr == 0)
 940                return;
 941
 942        for (i = 0; i < data->nr; i++) {
 943                if (!data->files[i]->is_binary &&
 944                    !data->files[i]->is_unmerged) {
 945                        int added = data->files[i]->added;
 946                        int deleted= data->files[i]->deleted;
 947                        if (!data->files[i]->is_renamed &&
 948                            (added + deleted == 0)) {
 949                                total_files--;
 950                        } else {
 951                                adds += added;
 952                                dels += deleted;
 953                        }
 954                }
 955        }
 956        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 957               total_files, adds, dels);
 958}
 959
 960static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 961{
 962        int i;
 963
 964        if (data->nr == 0)
 965                return;
 966
 967        for (i = 0; i < data->nr; i++) {
 968                struct diffstat_file *file = data->files[i];
 969
 970                if (file->is_binary)
 971                        fprintf(options->file, "-\t-\t");
 972                else
 973                        fprintf(options->file,
 974                                "%d\t%d\t", file->added, file->deleted);
 975                if (options->line_termination) {
 976                        fill_print_name(file);
 977                        if (!file->is_renamed)
 978                                write_name_quoted(file->name, options->file,
 979                                                  options->line_termination);
 980                        else {
 981                                fputs(file->print_name, options->file);
 982                                putc(options->line_termination, options->file);
 983                        }
 984                } else {
 985                        if (file->is_renamed) {
 986                                putc('\0', options->file);
 987                                write_name_quoted(file->from_name, options->file, '\0');
 988                        }
 989                        write_name_quoted(file->name, options->file, '\0');
 990                }
 991        }
 992}
 993
 994struct dirstat_file {
 995        const char *name;
 996        unsigned long changed;
 997};
 998
 999struct dirstat_dir {
1000        struct dirstat_file *files;
1001        int alloc, nr, percent, cumulative;
1002};
1003
1004static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1005{
1006        unsigned long this_dir = 0;
1007        unsigned int sources = 0;
1008
1009        while (dir->nr) {
1010                struct dirstat_file *f = dir->files;
1011                int namelen = strlen(f->name);
1012                unsigned long this;
1013                char *slash;
1014
1015                if (namelen < baselen)
1016                        break;
1017                if (memcmp(f->name, base, baselen))
1018                        break;
1019                slash = strchr(f->name + baselen, '/');
1020                if (slash) {
1021                        int newbaselen = slash + 1 - f->name;
1022                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1023                        sources++;
1024                } else {
1025                        this = f->changed;
1026                        dir->files++;
1027                        dir->nr--;
1028                        sources += 2;
1029                }
1030                this_dir += this;
1031        }
1032
1033        /*
1034         * We don't report dirstat's for
1035         *  - the top level
1036         *  - or cases where everything came from a single directory
1037         *    under this directory (sources == 1).
1038         */
1039        if (baselen && sources != 1) {
1040                int permille = this_dir * 1000 / changed;
1041                if (permille) {
1042                        int percent = permille / 10;
1043                        if (percent >= dir->percent) {
1044                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1045                                if (!dir->cumulative)
1046                                        return 0;
1047                        }
1048                }
1049        }
1050        return this_dir;
1051}
1052
1053static int dirstat_compare(const void *_a, const void *_b)
1054{
1055        const struct dirstat_file *a = _a;
1056        const struct dirstat_file *b = _b;
1057        return strcmp(a->name, b->name);
1058}
1059
1060static void show_dirstat(struct diff_options *options)
1061{
1062        int i;
1063        unsigned long changed;
1064        struct dirstat_dir dir;
1065        struct diff_queue_struct *q = &diff_queued_diff;
1066
1067        dir.files = NULL;
1068        dir.alloc = 0;
1069        dir.nr = 0;
1070        dir.percent = options->dirstat_percent;
1071        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1072
1073        changed = 0;
1074        for (i = 0; i < q->nr; i++) {
1075                struct diff_filepair *p = q->queue[i];
1076                const char *name;
1077                unsigned long copied, added, damage;
1078
1079                name = p->one->path ? p->one->path : p->two->path;
1080
1081                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1082                        diff_populate_filespec(p->one, 0);
1083                        diff_populate_filespec(p->two, 0);
1084                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1085                                               &copied, &added);
1086                        diff_free_filespec_data(p->one);
1087                        diff_free_filespec_data(p->two);
1088                } else if (DIFF_FILE_VALID(p->one)) {
1089                        diff_populate_filespec(p->one, 1);
1090                        copied = added = 0;
1091                        diff_free_filespec_data(p->one);
1092                } else if (DIFF_FILE_VALID(p->two)) {
1093                        diff_populate_filespec(p->two, 1);
1094                        copied = 0;
1095                        added = p->two->size;
1096                        diff_free_filespec_data(p->two);
1097                } else
1098                        continue;
1099
1100                /*
1101                 * Original minus copied is the removed material,
1102                 * added is the new material.  They are both damages
1103                 * made to the preimage. In --dirstat-by-file mode, count
1104                 * damaged files, not damaged lines. This is done by
1105                 * counting only a single damaged line per file.
1106                 */
1107                damage = (p->one->size - copied) + added;
1108                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1109                        damage = 1;
1110
1111                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1112                dir.files[dir.nr].name = name;
1113                dir.files[dir.nr].changed = damage;
1114                changed += damage;
1115                dir.nr++;
1116        }
1117
1118        /* This can happen even with many files, if everything was renames */
1119        if (!changed)
1120                return;
1121
1122        /* Show all directories with more than x% of the changes */
1123        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1124        gather_dirstat(options->file, &dir, changed, "", 0);
1125}
1126
1127static void free_diffstat_info(struct diffstat_t *diffstat)
1128{
1129        int i;
1130        for (i = 0; i < diffstat->nr; i++) {
1131                struct diffstat_file *f = diffstat->files[i];
1132                if (f->name != f->print_name)
1133                        free(f->print_name);
1134                free(f->name);
1135                free(f->from_name);
1136                free(f);
1137        }
1138        free(diffstat->files);
1139}
1140
1141struct checkdiff_t {
1142        const char *filename;
1143        int lineno;
1144        struct diff_options *o;
1145        unsigned ws_rule;
1146        unsigned status;
1147        int trailing_blanks_start;
1148};
1149
1150static int is_conflict_marker(const char *line, unsigned long len)
1151{
1152        char firstchar;
1153        int cnt;
1154
1155        if (len < 8)
1156                return 0;
1157        firstchar = line[0];
1158        switch (firstchar) {
1159        case '=': case '>': case '<':
1160                break;
1161        default:
1162                return 0;
1163        }
1164        for (cnt = 1; cnt < 7; cnt++)
1165                if (line[cnt] != firstchar)
1166                        return 0;
1167        /* line[0] thru line[6] are same as firstchar */
1168        if (firstchar == '=') {
1169                /* divider between ours and theirs? */
1170                if (len != 8 || line[7] != '\n')
1171                        return 0;
1172        } else if (len < 8 || !isspace(line[7])) {
1173                /* not divider before ours nor after theirs */
1174                return 0;
1175        }
1176        return 1;
1177}
1178
1179static void checkdiff_consume(void *priv, char *line, unsigned long len)
1180{
1181        struct checkdiff_t *data = priv;
1182        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1183        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1184        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1185        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1186        char *err;
1187
1188        if (line[0] == '+') {
1189                unsigned bad;
1190                data->lineno++;
1191                if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1192                        data->trailing_blanks_start = 0;
1193                else if (!data->trailing_blanks_start)
1194                        data->trailing_blanks_start = data->lineno;
1195                if (is_conflict_marker(line + 1, len - 1)) {
1196                        data->status |= 1;
1197                        fprintf(data->o->file,
1198                                "%s:%d: leftover conflict marker\n",
1199                                data->filename, data->lineno);
1200                }
1201                bad = ws_check(line + 1, len - 1, data->ws_rule);
1202                if (!bad)
1203                        return;
1204                data->status |= bad;
1205                err = whitespace_error_string(bad);
1206                fprintf(data->o->file, "%s:%d: %s.\n",
1207                        data->filename, data->lineno, err);
1208                free(err);
1209                emit_line(data->o->file, set, reset, line, 1);
1210                ws_check_emit(line + 1, len - 1, data->ws_rule,
1211                              data->o->file, set, reset, ws);
1212        } else if (line[0] == ' ') {
1213                data->lineno++;
1214                data->trailing_blanks_start = 0;
1215        } else if (line[0] == '@') {
1216                char *plus = strchr(line, '+');
1217                if (plus)
1218                        data->lineno = strtol(plus, NULL, 10) - 1;
1219                else
1220                        die("invalid diff");
1221                data->trailing_blanks_start = 0;
1222        }
1223}
1224
1225static unsigned char *deflate_it(char *data,
1226                                 unsigned long size,
1227                                 unsigned long *result_size)
1228{
1229        int bound;
1230        unsigned char *deflated;
1231        z_stream stream;
1232
1233        memset(&stream, 0, sizeof(stream));
1234        deflateInit(&stream, zlib_compression_level);
1235        bound = deflateBound(&stream, size);
1236        deflated = xmalloc(bound);
1237        stream.next_out = deflated;
1238        stream.avail_out = bound;
1239
1240        stream.next_in = (unsigned char *)data;
1241        stream.avail_in = size;
1242        while (deflate(&stream, Z_FINISH) == Z_OK)
1243                ; /* nothing */
1244        deflateEnd(&stream);
1245        *result_size = stream.total_out;
1246        return deflated;
1247}
1248
1249static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1250{
1251        void *cp;
1252        void *delta;
1253        void *deflated;
1254        void *data;
1255        unsigned long orig_size;
1256        unsigned long delta_size;
1257        unsigned long deflate_size;
1258        unsigned long data_size;
1259
1260        /* We could do deflated delta, or we could do just deflated two,
1261         * whichever is smaller.
1262         */
1263        delta = NULL;
1264        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1265        if (one->size && two->size) {
1266                delta = diff_delta(one->ptr, one->size,
1267                                   two->ptr, two->size,
1268                                   &delta_size, deflate_size);
1269                if (delta) {
1270                        void *to_free = delta;
1271                        orig_size = delta_size;
1272                        delta = deflate_it(delta, delta_size, &delta_size);
1273                        free(to_free);
1274                }
1275        }
1276
1277        if (delta && delta_size < deflate_size) {
1278                fprintf(file, "delta %lu\n", orig_size);
1279                free(deflated);
1280                data = delta;
1281                data_size = delta_size;
1282        }
1283        else {
1284                fprintf(file, "literal %lu\n", two->size);
1285                free(delta);
1286                data = deflated;
1287                data_size = deflate_size;
1288        }
1289
1290        /* emit data encoded in base85 */
1291        cp = data;
1292        while (data_size) {
1293                int bytes = (52 < data_size) ? 52 : data_size;
1294                char line[70];
1295                data_size -= bytes;
1296                if (bytes <= 26)
1297                        line[0] = bytes + 'A' - 1;
1298                else
1299                        line[0] = bytes - 26 + 'a' - 1;
1300                encode_85(line + 1, cp, bytes);
1301                cp = (char *) cp + bytes;
1302                fputs(line, file);
1303                fputc('\n', file);
1304        }
1305        fprintf(file, "\n");
1306        free(data);
1307}
1308
1309static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1310{
1311        fprintf(file, "GIT binary patch\n");
1312        emit_binary_diff_body(file, one, two);
1313        emit_binary_diff_body(file, two, one);
1314}
1315
1316static void diff_filespec_load_driver(struct diff_filespec *one)
1317{
1318        if (!one->driver)
1319                one->driver = userdiff_find_by_path(one->path);
1320        if (!one->driver)
1321                one->driver = userdiff_find_by_name("default");
1322}
1323
1324int diff_filespec_is_binary(struct diff_filespec *one)
1325{
1326        if (one->is_binary == -1) {
1327                diff_filespec_load_driver(one);
1328                if (one->driver->binary != -1)
1329                        one->is_binary = one->driver->binary;
1330                else {
1331                        if (!one->data && DIFF_FILE_VALID(one))
1332                                diff_populate_filespec(one, 0);
1333                        if (one->data)
1334                                one->is_binary = buffer_is_binary(one->data,
1335                                                one->size);
1336                        if (one->is_binary == -1)
1337                                one->is_binary = 0;
1338                }
1339        }
1340        return one->is_binary;
1341}
1342
1343static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1344{
1345        diff_filespec_load_driver(one);
1346        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1347}
1348
1349void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1350{
1351        if (!options->a_prefix)
1352                options->a_prefix = a;
1353        if (!options->b_prefix)
1354                options->b_prefix = b;
1355}
1356
1357static const char *get_textconv(struct diff_filespec *one)
1358{
1359        if (!DIFF_FILE_VALID(one))
1360                return NULL;
1361        if (!S_ISREG(one->mode))
1362                return NULL;
1363        diff_filespec_load_driver(one);
1364        return one->driver->textconv;
1365}
1366
1367static void builtin_diff(const char *name_a,
1368                         const char *name_b,
1369                         struct diff_filespec *one,
1370                         struct diff_filespec *two,
1371                         const char *xfrm_msg,
1372                         struct diff_options *o,
1373                         int complete_rewrite)
1374{
1375        mmfile_t mf1, mf2;
1376        const char *lbl[2];
1377        char *a_one, *b_two;
1378        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1379        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1380        const char *a_prefix, *b_prefix;
1381        const char *textconv_one = NULL, *textconv_two = NULL;
1382
1383        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1384                textconv_one = get_textconv(one);
1385                textconv_two = get_textconv(two);
1386        }
1387
1388        diff_set_mnemonic_prefix(o, "a/", "b/");
1389        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1390                a_prefix = o->b_prefix;
1391                b_prefix = o->a_prefix;
1392        } else {
1393                a_prefix = o->a_prefix;
1394                b_prefix = o->b_prefix;
1395        }
1396
1397        /* Never use a non-valid filename anywhere if at all possible */
1398        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1399        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1400
1401        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1402        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1403        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1404        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1405        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1406        if (lbl[0][0] == '/') {
1407                /* /dev/null */
1408                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1409                if (xfrm_msg && xfrm_msg[0])
1410                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1411        }
1412        else if (lbl[1][0] == '/') {
1413                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1414                if (xfrm_msg && xfrm_msg[0])
1415                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1416        }
1417        else {
1418                if (one->mode != two->mode) {
1419                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1420                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1421                }
1422                if (xfrm_msg && xfrm_msg[0])
1423                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1424                /*
1425                 * we do not run diff between different kind
1426                 * of objects.
1427                 */
1428                if ((one->mode ^ two->mode) & S_IFMT)
1429                        goto free_ab_and_return;
1430                if (complete_rewrite &&
1431                    (textconv_one || !diff_filespec_is_binary(one)) &&
1432                    (textconv_two || !diff_filespec_is_binary(two))) {
1433                        emit_rewrite_diff(name_a, name_b, one, two,
1434                                                textconv_one, textconv_two, o);
1435                        o->found_changes = 1;
1436                        goto free_ab_and_return;
1437                }
1438        }
1439
1440        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1441                die("unable to read files to diff");
1442
1443        if (!DIFF_OPT_TST(o, TEXT) &&
1444            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1445              (diff_filespec_is_binary(two) && !textconv_two) )) {
1446                /* Quite common confusing case */
1447                if (mf1.size == mf2.size &&
1448                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1449                        goto free_ab_and_return;
1450                if (DIFF_OPT_TST(o, BINARY))
1451                        emit_binary_diff(o->file, &mf1, &mf2);
1452                else
1453                        fprintf(o->file, "Binary files %s and %s differ\n",
1454                                lbl[0], lbl[1]);
1455                o->found_changes = 1;
1456        }
1457        else {
1458                /* Crazy xdl interfaces.. */
1459                const char *diffopts = getenv("GIT_DIFF_OPTS");
1460                xpparam_t xpp;
1461                xdemitconf_t xecfg;
1462                xdemitcb_t ecb;
1463                struct emit_callback ecbdata;
1464                const struct userdiff_funcname *pe;
1465
1466                if (textconv_one) {
1467                        size_t size;
1468                        mf1.ptr = run_textconv(textconv_one, one, &size);
1469                        if (!mf1.ptr)
1470                                die("unable to read files to diff");
1471                        mf1.size = size;
1472                }
1473                if (textconv_two) {
1474                        size_t size;
1475                        mf2.ptr = run_textconv(textconv_two, two, &size);
1476                        if (!mf2.ptr)
1477                                die("unable to read files to diff");
1478                        mf2.size = size;
1479                }
1480
1481                pe = diff_funcname_pattern(one);
1482                if (!pe)
1483                        pe = diff_funcname_pattern(two);
1484
1485                memset(&xpp, 0, sizeof(xpp));
1486                memset(&xecfg, 0, sizeof(xecfg));
1487                memset(&ecbdata, 0, sizeof(ecbdata));
1488                ecbdata.label_path = lbl;
1489                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1490                ecbdata.found_changesp = &o->found_changes;
1491                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1492                ecbdata.file = o->file;
1493                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1494                xecfg.ctxlen = o->context;
1495                xecfg.interhunkctxlen = o->interhunkcontext;
1496                xecfg.flags = XDL_EMIT_FUNCNAMES;
1497                if (pe)
1498                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1499                if (!diffopts)
1500                        ;
1501                else if (!prefixcmp(diffopts, "--unified="))
1502                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1503                else if (!prefixcmp(diffopts, "-u"))
1504                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1505                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1506                        ecbdata.diff_words =
1507                                xcalloc(1, sizeof(struct diff_words_data));
1508                        ecbdata.diff_words->file = o->file;
1509                }
1510                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1511                              &xpp, &xecfg, &ecb);
1512                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1513                        free_diff_words_data(&ecbdata);
1514                if (textconv_one)
1515                        free(mf1.ptr);
1516                if (textconv_two)
1517                        free(mf2.ptr);
1518        }
1519
1520 free_ab_and_return:
1521        diff_free_filespec_data(one);
1522        diff_free_filespec_data(two);
1523        free(a_one);
1524        free(b_two);
1525        return;
1526}
1527
1528static void builtin_diffstat(const char *name_a, const char *name_b,
1529                             struct diff_filespec *one,
1530                             struct diff_filespec *two,
1531                             struct diffstat_t *diffstat,
1532                             struct diff_options *o,
1533                             int complete_rewrite)
1534{
1535        mmfile_t mf1, mf2;
1536        struct diffstat_file *data;
1537
1538        data = diffstat_add(diffstat, name_a, name_b);
1539
1540        if (!one || !two) {
1541                data->is_unmerged = 1;
1542                return;
1543        }
1544        if (complete_rewrite) {
1545                diff_populate_filespec(one, 0);
1546                diff_populate_filespec(two, 0);
1547                data->deleted = count_lines(one->data, one->size);
1548                data->added = count_lines(two->data, two->size);
1549                goto free_and_return;
1550        }
1551        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1552                die("unable to read files to diff");
1553
1554        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1555                data->is_binary = 1;
1556                data->added = mf2.size;
1557                data->deleted = mf1.size;
1558        } else {
1559                /* Crazy xdl interfaces.. */
1560                xpparam_t xpp;
1561                xdemitconf_t xecfg;
1562                xdemitcb_t ecb;
1563
1564                memset(&xpp, 0, sizeof(xpp));
1565                memset(&xecfg, 0, sizeof(xecfg));
1566                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1567                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1568                              &xpp, &xecfg, &ecb);
1569        }
1570
1571 free_and_return:
1572        diff_free_filespec_data(one);
1573        diff_free_filespec_data(two);
1574}
1575
1576static void builtin_checkdiff(const char *name_a, const char *name_b,
1577                              const char *attr_path,
1578                              struct diff_filespec *one,
1579                              struct diff_filespec *two,
1580                              struct diff_options *o)
1581{
1582        mmfile_t mf1, mf2;
1583        struct checkdiff_t data;
1584
1585        if (!two)
1586                return;
1587
1588        memset(&data, 0, sizeof(data));
1589        data.filename = name_b ? name_b : name_a;
1590        data.lineno = 0;
1591        data.o = o;
1592        data.ws_rule = whitespace_rule(attr_path);
1593
1594        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1595                die("unable to read files to diff");
1596
1597        /*
1598         * All the other codepaths check both sides, but not checking
1599         * the "old" side here is deliberate.  We are checking the newly
1600         * introduced changes, and as long as the "new" side is text, we
1601         * can and should check what it introduces.
1602         */
1603        if (diff_filespec_is_binary(two))
1604                goto free_and_return;
1605        else {
1606                /* Crazy xdl interfaces.. */
1607                xpparam_t xpp;
1608                xdemitconf_t xecfg;
1609                xdemitcb_t ecb;
1610
1611                memset(&xpp, 0, sizeof(xpp));
1612                memset(&xecfg, 0, sizeof(xecfg));
1613                xecfg.ctxlen = 1; /* at least one context line */
1614                xpp.flags = XDF_NEED_MINIMAL;
1615                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1616                              &xpp, &xecfg, &ecb);
1617
1618                if ((data.ws_rule & WS_TRAILING_SPACE) &&
1619                    data.trailing_blanks_start) {
1620                        fprintf(o->file, "%s:%d: ends with blank lines.\n",
1621                                data.filename, data.trailing_blanks_start);
1622                        data.status = 1; /* report errors */
1623                }
1624        }
1625 free_and_return:
1626        diff_free_filespec_data(one);
1627        diff_free_filespec_data(two);
1628        if (data.status)
1629                DIFF_OPT_SET(o, CHECK_FAILED);
1630}
1631
1632struct diff_filespec *alloc_filespec(const char *path)
1633{
1634        int namelen = strlen(path);
1635        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1636
1637        memset(spec, 0, sizeof(*spec));
1638        spec->path = (char *)(spec + 1);
1639        memcpy(spec->path, path, namelen+1);
1640        spec->count = 1;
1641        spec->is_binary = -1;
1642        return spec;
1643}
1644
1645void free_filespec(struct diff_filespec *spec)
1646{
1647        if (!--spec->count) {
1648                diff_free_filespec_data(spec);
1649                free(spec);
1650        }
1651}
1652
1653void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1654                   unsigned short mode)
1655{
1656        if (mode) {
1657                spec->mode = canon_mode(mode);
1658                hashcpy(spec->sha1, sha1);
1659                spec->sha1_valid = !is_null_sha1(sha1);
1660        }
1661}
1662
1663/*
1664 * Given a name and sha1 pair, if the index tells us the file in
1665 * the work tree has that object contents, return true, so that
1666 * prepare_temp_file() does not have to inflate and extract.
1667 */
1668static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1669{
1670        struct cache_entry *ce;
1671        struct stat st;
1672        int pos, len;
1673
1674        /* We do not read the cache ourselves here, because the
1675         * benchmark with my previous version that always reads cache
1676         * shows that it makes things worse for diff-tree comparing
1677         * two linux-2.6 kernel trees in an already checked out work
1678         * tree.  This is because most diff-tree comparisons deal with
1679         * only a small number of files, while reading the cache is
1680         * expensive for a large project, and its cost outweighs the
1681         * savings we get by not inflating the object to a temporary
1682         * file.  Practically, this code only helps when we are used
1683         * by diff-cache --cached, which does read the cache before
1684         * calling us.
1685         */
1686        if (!active_cache)
1687                return 0;
1688
1689        /* We want to avoid the working directory if our caller
1690         * doesn't need the data in a normal file, this system
1691         * is rather slow with its stat/open/mmap/close syscalls,
1692         * and the object is contained in a pack file.  The pack
1693         * is probably already open and will be faster to obtain
1694         * the data through than the working directory.  Loose
1695         * objects however would tend to be slower as they need
1696         * to be individually opened and inflated.
1697         */
1698        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1699                return 0;
1700
1701        len = strlen(name);
1702        pos = cache_name_pos(name, len);
1703        if (pos < 0)
1704                return 0;
1705        ce = active_cache[pos];
1706
1707        /*
1708         * This is not the sha1 we are looking for, or
1709         * unreusable because it is not a regular file.
1710         */
1711        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1712                return 0;
1713
1714        /*
1715         * If ce matches the file in the work tree, we can reuse it.
1716         */
1717        if (ce_uptodate(ce) ||
1718            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1719                return 1;
1720
1721        return 0;
1722}
1723
1724static int populate_from_stdin(struct diff_filespec *s)
1725{
1726        struct strbuf buf = STRBUF_INIT;
1727        size_t size = 0;
1728
1729        if (strbuf_read(&buf, 0, 0) < 0)
1730                return error("error while reading from stdin %s",
1731                                     strerror(errno));
1732
1733        s->should_munmap = 0;
1734        s->data = strbuf_detach(&buf, &size);
1735        s->size = size;
1736        s->should_free = 1;
1737        return 0;
1738}
1739
1740static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1741{
1742        int len;
1743        char *data = xmalloc(100);
1744        len = snprintf(data, 100,
1745                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1746        s->data = data;
1747        s->size = len;
1748        s->should_free = 1;
1749        if (size_only) {
1750                s->data = NULL;
1751                free(data);
1752        }
1753        return 0;
1754}
1755
1756/*
1757 * While doing rename detection and pickaxe operation, we may need to
1758 * grab the data for the blob (or file) for our own in-core comparison.
1759 * diff_filespec has data and size fields for this purpose.
1760 */
1761int diff_populate_filespec(struct diff_filespec *s, int size_only)
1762{
1763        int err = 0;
1764        if (!DIFF_FILE_VALID(s))
1765                die("internal error: asking to populate invalid file.");
1766        if (S_ISDIR(s->mode))
1767                return -1;
1768
1769        if (s->data)
1770                return 0;
1771
1772        if (size_only && 0 < s->size)
1773                return 0;
1774
1775        if (S_ISGITLINK(s->mode))
1776                return diff_populate_gitlink(s, size_only);
1777
1778        if (!s->sha1_valid ||
1779            reuse_worktree_file(s->path, s->sha1, 0)) {
1780                struct strbuf buf = STRBUF_INIT;
1781                struct stat st;
1782                int fd;
1783
1784                if (!strcmp(s->path, "-"))
1785                        return populate_from_stdin(s);
1786
1787                if (lstat(s->path, &st) < 0) {
1788                        if (errno == ENOENT) {
1789                        err_empty:
1790                                err = -1;
1791                        empty:
1792                                s->data = (char *)"";
1793                                s->size = 0;
1794                                return err;
1795                        }
1796                }
1797                s->size = xsize_t(st.st_size);
1798                if (!s->size)
1799                        goto empty;
1800                if (S_ISLNK(st.st_mode)) {
1801                        struct strbuf sb = STRBUF_INIT;
1802
1803                        if (strbuf_readlink(&sb, s->path, s->size))
1804                                goto err_empty;
1805                        s->size = sb.len;
1806                        s->data = strbuf_detach(&sb, NULL);
1807                        s->should_free = 1;
1808                        return 0;
1809                }
1810                if (size_only)
1811                        return 0;
1812                fd = open(s->path, O_RDONLY);
1813                if (fd < 0)
1814                        goto err_empty;
1815                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1816                close(fd);
1817                s->should_munmap = 1;
1818
1819                /*
1820                 * Convert from working tree format to canonical git format
1821                 */
1822                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1823                        size_t size = 0;
1824                        munmap(s->data, s->size);
1825                        s->should_munmap = 0;
1826                        s->data = strbuf_detach(&buf, &size);
1827                        s->size = size;
1828                        s->should_free = 1;
1829                }
1830        }
1831        else {
1832                enum object_type type;
1833                if (size_only)
1834                        type = sha1_object_info(s->sha1, &s->size);
1835                else {
1836                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1837                        s->should_free = 1;
1838                }
1839        }
1840        return 0;
1841}
1842
1843void diff_free_filespec_blob(struct diff_filespec *s)
1844{
1845        if (s->should_free)
1846                free(s->data);
1847        else if (s->should_munmap)
1848                munmap(s->data, s->size);
1849
1850        if (s->should_free || s->should_munmap) {
1851                s->should_free = s->should_munmap = 0;
1852                s->data = NULL;
1853        }
1854}
1855
1856void diff_free_filespec_data(struct diff_filespec *s)
1857{
1858        diff_free_filespec_blob(s);
1859        free(s->cnt_data);
1860        s->cnt_data = NULL;
1861}
1862
1863static void prep_temp_blob(struct diff_tempfile *temp,
1864                           void *blob,
1865                           unsigned long size,
1866                           const unsigned char *sha1,
1867                           int mode)
1868{
1869        int fd;
1870
1871        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1872        if (fd < 0)
1873                die("unable to create temp-file: %s", strerror(errno));
1874        if (write_in_full(fd, blob, size) != size)
1875                die("unable to write temp-file");
1876        close(fd);
1877        temp->name = temp->tmp_path;
1878        strcpy(temp->hex, sha1_to_hex(sha1));
1879        temp->hex[40] = 0;
1880        sprintf(temp->mode, "%06o", mode);
1881}
1882
1883static void prepare_temp_file(const char *name,
1884                              struct diff_tempfile *temp,
1885                              struct diff_filespec *one)
1886{
1887        if (!DIFF_FILE_VALID(one)) {
1888        not_a_valid_file:
1889                /* A '-' entry produces this for file-2, and
1890                 * a '+' entry produces this for file-1.
1891                 */
1892                temp->name = "/dev/null";
1893                strcpy(temp->hex, ".");
1894                strcpy(temp->mode, ".");
1895                return;
1896        }
1897
1898        if (!one->sha1_valid ||
1899            reuse_worktree_file(name, one->sha1, 1)) {
1900                struct stat st;
1901                if (lstat(name, &st) < 0) {
1902                        if (errno == ENOENT)
1903                                goto not_a_valid_file;
1904                        die("stat(%s): %s", name, strerror(errno));
1905                }
1906                if (S_ISLNK(st.st_mode)) {
1907                        int ret;
1908                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1909                        ret = readlink(name, buf, sizeof(buf));
1910                        if (ret < 0)
1911                                die("readlink(%s)", name);
1912                        if (ret == sizeof(buf))
1913                                die("symlink too long: %s", name);
1914                        prep_temp_blob(temp, buf, ret,
1915                                       (one->sha1_valid ?
1916                                        one->sha1 : null_sha1),
1917                                       (one->sha1_valid ?
1918                                        one->mode : S_IFLNK));
1919                }
1920                else {
1921                        /* we can borrow from the file in the work tree */
1922                        temp->name = name;
1923                        if (!one->sha1_valid)
1924                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1925                        else
1926                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1927                        /* Even though we may sometimes borrow the
1928                         * contents from the work tree, we always want
1929                         * one->mode.  mode is trustworthy even when
1930                         * !(one->sha1_valid), as long as
1931                         * DIFF_FILE_VALID(one).
1932                         */
1933                        sprintf(temp->mode, "%06o", one->mode);
1934                }
1935                return;
1936        }
1937        else {
1938                if (diff_populate_filespec(one, 0))
1939                        die("cannot read data blob for %s", one->path);
1940                prep_temp_blob(temp, one->data, one->size,
1941                               one->sha1, one->mode);
1942        }
1943}
1944
1945static void remove_tempfile(void)
1946{
1947        int i;
1948
1949        for (i = 0; i < 2; i++)
1950                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1951                        unlink(diff_temp[i].name);
1952                        diff_temp[i].name = NULL;
1953                }
1954}
1955
1956static void remove_tempfile_on_signal(int signo)
1957{
1958        remove_tempfile();
1959        signal(SIGINT, SIG_DFL);
1960        raise(signo);
1961}
1962
1963/* An external diff command takes:
1964 *
1965 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1966 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1967 *
1968 */
1969static void run_external_diff(const char *pgm,
1970                              const char *name,
1971                              const char *other,
1972                              struct diff_filespec *one,
1973                              struct diff_filespec *two,
1974                              const char *xfrm_msg,
1975                              int complete_rewrite)
1976{
1977        const char *spawn_arg[10];
1978        struct diff_tempfile *temp = diff_temp;
1979        int retval;
1980        static int atexit_asked = 0;
1981        const char *othername;
1982        const char **arg = &spawn_arg[0];
1983
1984        othername = (other? other : name);
1985        if (one && two) {
1986                prepare_temp_file(name, &temp[0], one);
1987                prepare_temp_file(othername, &temp[1], two);
1988                if (! atexit_asked &&
1989                    (temp[0].name == temp[0].tmp_path ||
1990                     temp[1].name == temp[1].tmp_path)) {
1991                        atexit_asked = 1;
1992                        atexit(remove_tempfile);
1993                }
1994                signal(SIGINT, remove_tempfile_on_signal);
1995        }
1996
1997        if (one && two) {
1998                *arg++ = pgm;
1999                *arg++ = name;
2000                *arg++ = temp[0].name;
2001                *arg++ = temp[0].hex;
2002                *arg++ = temp[0].mode;
2003                *arg++ = temp[1].name;
2004                *arg++ = temp[1].hex;
2005                *arg++ = temp[1].mode;
2006                if (other) {
2007                        *arg++ = other;
2008                        *arg++ = xfrm_msg;
2009                }
2010        } else {
2011                *arg++ = pgm;
2012                *arg++ = name;
2013        }
2014        *arg = NULL;
2015        fflush(NULL);
2016        retval = run_command_v_opt(spawn_arg, 0);
2017        remove_tempfile();
2018        if (retval) {
2019                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2020                exit(1);
2021        }
2022}
2023
2024static void run_diff_cmd(const char *pgm,
2025                         const char *name,
2026                         const char *other,
2027                         const char *attr_path,
2028                         struct diff_filespec *one,
2029                         struct diff_filespec *two,
2030                         const char *xfrm_msg,
2031                         struct diff_options *o,
2032                         int complete_rewrite)
2033{
2034        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2035                pgm = NULL;
2036        else {
2037                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2038                if (drv && drv->external)
2039                        pgm = drv->external;
2040        }
2041
2042        if (pgm) {
2043                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2044                                  complete_rewrite);
2045                return;
2046        }
2047        if (one && two)
2048                builtin_diff(name, other ? other : name,
2049                             one, two, xfrm_msg, o, complete_rewrite);
2050        else
2051                fprintf(o->file, "* Unmerged path %s\n", name);
2052}
2053
2054static void diff_fill_sha1_info(struct diff_filespec *one)
2055{
2056        if (DIFF_FILE_VALID(one)) {
2057                if (!one->sha1_valid) {
2058                        struct stat st;
2059                        if (!strcmp(one->path, "-")) {
2060                                hashcpy(one->sha1, null_sha1);
2061                                return;
2062                        }
2063                        if (lstat(one->path, &st) < 0)
2064                                die("stat %s", one->path);
2065                        if (index_path(one->sha1, one->path, &st, 0))
2066                                die("cannot hash %s", one->path);
2067                }
2068        }
2069        else
2070                hashclr(one->sha1);
2071}
2072
2073static int similarity_index(struct diff_filepair *p)
2074{
2075        return p->score * 100 / MAX_SCORE;
2076}
2077
2078static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2079{
2080        /* Strip the prefix but do not molest /dev/null and absolute paths */
2081        if (*namep && **namep != '/')
2082                *namep += prefix_length;
2083        if (*otherp && **otherp != '/')
2084                *otherp += prefix_length;
2085}
2086
2087static void run_diff(struct diff_filepair *p, struct diff_options *o)
2088{
2089        const char *pgm = external_diff();
2090        struct strbuf msg;
2091        char *xfrm_msg;
2092        struct diff_filespec *one = p->one;
2093        struct diff_filespec *two = p->two;
2094        const char *name;
2095        const char *other;
2096        const char *attr_path;
2097        int complete_rewrite = 0;
2098
2099        name  = p->one->path;
2100        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2101        attr_path = name;
2102        if (o->prefix_length)
2103                strip_prefix(o->prefix_length, &name, &other);
2104
2105        if (DIFF_PAIR_UNMERGED(p)) {
2106                run_diff_cmd(pgm, name, NULL, attr_path,
2107                             NULL, NULL, NULL, o, 0);
2108                return;
2109        }
2110
2111        diff_fill_sha1_info(one);
2112        diff_fill_sha1_info(two);
2113
2114        strbuf_init(&msg, PATH_MAX * 2 + 300);
2115        switch (p->status) {
2116        case DIFF_STATUS_COPIED:
2117                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2118                strbuf_addstr(&msg, "\ncopy from ");
2119                quote_c_style(name, &msg, NULL, 0);
2120                strbuf_addstr(&msg, "\ncopy to ");
2121                quote_c_style(other, &msg, NULL, 0);
2122                strbuf_addch(&msg, '\n');
2123                break;
2124        case DIFF_STATUS_RENAMED:
2125                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2126                strbuf_addstr(&msg, "\nrename from ");
2127                quote_c_style(name, &msg, NULL, 0);
2128                strbuf_addstr(&msg, "\nrename to ");
2129                quote_c_style(other, &msg, NULL, 0);
2130                strbuf_addch(&msg, '\n');
2131                break;
2132        case DIFF_STATUS_MODIFIED:
2133                if (p->score) {
2134                        strbuf_addf(&msg, "dissimilarity index %d%%\n",
2135                                        similarity_index(p));
2136                        complete_rewrite = 1;
2137                        break;
2138                }
2139                /* fallthru */
2140        default:
2141                /* nothing */
2142                ;
2143        }
2144
2145        if (hashcmp(one->sha1, two->sha1)) {
2146                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2147
2148                if (DIFF_OPT_TST(o, BINARY)) {
2149                        mmfile_t mf;
2150                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2151                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2152                                abbrev = 40;
2153                }
2154                strbuf_addf(&msg, "index %.*s..%.*s",
2155                                abbrev, sha1_to_hex(one->sha1),
2156                                abbrev, sha1_to_hex(two->sha1));
2157                if (one->mode == two->mode)
2158                        strbuf_addf(&msg, " %06o", one->mode);
2159                strbuf_addch(&msg, '\n');
2160        }
2161
2162        if (msg.len)
2163                strbuf_setlen(&msg, msg.len - 1);
2164        xfrm_msg = msg.len ? msg.buf : NULL;
2165
2166        if (!pgm &&
2167            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2168            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2169                /* a filepair that changes between file and symlink
2170                 * needs to be split into deletion and creation.
2171                 */
2172                struct diff_filespec *null = alloc_filespec(two->path);
2173                run_diff_cmd(NULL, name, other, attr_path,
2174                             one, null, xfrm_msg, o, 0);
2175                free(null);
2176                null = alloc_filespec(one->path);
2177                run_diff_cmd(NULL, name, other, attr_path,
2178                             null, two, xfrm_msg, o, 0);
2179                free(null);
2180        }
2181        else
2182                run_diff_cmd(pgm, name, other, attr_path,
2183                             one, two, xfrm_msg, o, complete_rewrite);
2184
2185        strbuf_release(&msg);
2186}
2187
2188static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2189                         struct diffstat_t *diffstat)
2190{
2191        const char *name;
2192        const char *other;
2193        int complete_rewrite = 0;
2194
2195        if (DIFF_PAIR_UNMERGED(p)) {
2196                /* unmerged */
2197                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2198                return;
2199        }
2200
2201        name = p->one->path;
2202        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2203
2204        if (o->prefix_length)
2205                strip_prefix(o->prefix_length, &name, &other);
2206
2207        diff_fill_sha1_info(p->one);
2208        diff_fill_sha1_info(p->two);
2209
2210        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2211                complete_rewrite = 1;
2212        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2213}
2214
2215static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2216{
2217        const char *name;
2218        const char *other;
2219        const char *attr_path;
2220
2221        if (DIFF_PAIR_UNMERGED(p)) {
2222                /* unmerged */
2223                return;
2224        }
2225
2226        name = p->one->path;
2227        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2228        attr_path = other ? other : name;
2229
2230        if (o->prefix_length)
2231                strip_prefix(o->prefix_length, &name, &other);
2232
2233        diff_fill_sha1_info(p->one);
2234        diff_fill_sha1_info(p->two);
2235
2236        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2237}
2238
2239void diff_setup(struct diff_options *options)
2240{
2241        memset(options, 0, sizeof(*options));
2242
2243        options->file = stdout;
2244
2245        options->line_termination = '\n';
2246        options->break_opt = -1;
2247        options->rename_limit = -1;
2248        options->dirstat_percent = 3;
2249        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
2250        options->context = 3;
2251
2252        options->change = diff_change;
2253        options->add_remove = diff_addremove;
2254        if (diff_use_color_default > 0)
2255                DIFF_OPT_SET(options, COLOR_DIFF);
2256        else
2257                DIFF_OPT_CLR(options, COLOR_DIFF);
2258        options->detect_rename = diff_detect_rename_default;
2259
2260        if (!diff_mnemonic_prefix) {
2261                options->a_prefix = "a/";
2262                options->b_prefix = "b/";
2263        }
2264}
2265
2266int diff_setup_done(struct diff_options *options)
2267{
2268        int count = 0;
2269
2270        if (options->output_format & DIFF_FORMAT_NAME)
2271                count++;
2272        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2273                count++;
2274        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2275                count++;
2276        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2277                count++;
2278        if (count > 1)
2279                die("--name-only, --name-status, --check and -s are mutually exclusive");
2280
2281        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2282                options->detect_rename = DIFF_DETECT_COPY;
2283
2284        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2285                options->prefix = NULL;
2286        if (options->prefix)
2287                options->prefix_length = strlen(options->prefix);
2288        else
2289                options->prefix_length = 0;
2290
2291        if (options->output_format & (DIFF_FORMAT_NAME |
2292                                      DIFF_FORMAT_NAME_STATUS |
2293                                      DIFF_FORMAT_CHECKDIFF |
2294                                      DIFF_FORMAT_NO_OUTPUT))
2295                options->output_format &= ~(DIFF_FORMAT_RAW |
2296                                            DIFF_FORMAT_NUMSTAT |
2297                                            DIFF_FORMAT_DIFFSTAT |
2298                                            DIFF_FORMAT_SHORTSTAT |
2299                                            DIFF_FORMAT_DIRSTAT |
2300                                            DIFF_FORMAT_SUMMARY |
2301                                            DIFF_FORMAT_PATCH);
2302
2303        /*
2304         * These cases always need recursive; we do not drop caller-supplied
2305         * recursive bits for other formats here.
2306         */
2307        if (options->output_format & (DIFF_FORMAT_PATCH |
2308                                      DIFF_FORMAT_NUMSTAT |
2309                                      DIFF_FORMAT_DIFFSTAT |
2310                                      DIFF_FORMAT_SHORTSTAT |
2311                                      DIFF_FORMAT_DIRSTAT |
2312                                      DIFF_FORMAT_SUMMARY |
2313                                      DIFF_FORMAT_CHECKDIFF))
2314                DIFF_OPT_SET(options, RECURSIVE);
2315        /*
2316         * Also pickaxe would not work very well if you do not say recursive
2317         */
2318        if (options->pickaxe)
2319                DIFF_OPT_SET(options, RECURSIVE);
2320
2321        if (options->detect_rename && options->rename_limit < 0)
2322                options->rename_limit = diff_rename_limit_default;
2323        if (options->setup & DIFF_SETUP_USE_CACHE) {
2324                if (!active_cache)
2325                        /* read-cache does not die even when it fails
2326                         * so it is safe for us to do this here.  Also
2327                         * it does not smudge active_cache or active_nr
2328                         * when it fails, so we do not have to worry about
2329                         * cleaning it up ourselves either.
2330                         */
2331                        read_cache();
2332        }
2333        if (options->abbrev <= 0 || 40 < options->abbrev)
2334                options->abbrev = 40; /* full */
2335
2336        /*
2337         * It does not make sense to show the first hit we happened
2338         * to have found.  It does not make sense not to return with
2339         * exit code in such a case either.
2340         */
2341        if (DIFF_OPT_TST(options, QUIET)) {
2342                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2343                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2344        }
2345
2346        return 0;
2347}
2348
2349static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2350{
2351        char c, *eq;
2352        int len;
2353
2354        if (*arg != '-')
2355                return 0;
2356        c = *++arg;
2357        if (!c)
2358                return 0;
2359        if (c == arg_short) {
2360                c = *++arg;
2361                if (!c)
2362                        return 1;
2363                if (val && isdigit(c)) {
2364                        char *end;
2365                        int n = strtoul(arg, &end, 10);
2366                        if (*end)
2367                                return 0;
2368                        *val = n;
2369                        return 1;
2370                }
2371                return 0;
2372        }
2373        if (c != '-')
2374                return 0;
2375        arg++;
2376        eq = strchr(arg, '=');
2377        if (eq)
2378                len = eq - arg;
2379        else
2380                len = strlen(arg);
2381        if (!len || strncmp(arg, arg_long, len))
2382                return 0;
2383        if (eq) {
2384                int n;
2385                char *end;
2386                if (!isdigit(*++eq))
2387                        return 0;
2388                n = strtoul(eq, &end, 10);
2389                if (*end)
2390                        return 0;
2391                *val = n;
2392        }
2393        return 1;
2394}
2395
2396static int diff_scoreopt_parse(const char *opt);
2397
2398int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2399{
2400        const char *arg = av[0];
2401
2402        /* Output format options */
2403        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2404                options->output_format |= DIFF_FORMAT_PATCH;
2405        else if (opt_arg(arg, 'U', "unified", &options->context))
2406                options->output_format |= DIFF_FORMAT_PATCH;
2407        else if (!strcmp(arg, "--raw"))
2408                options->output_format |= DIFF_FORMAT_RAW;
2409        else if (!strcmp(arg, "--patch-with-raw"))
2410                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2411        else if (!strcmp(arg, "--numstat"))
2412                options->output_format |= DIFF_FORMAT_NUMSTAT;
2413        else if (!strcmp(arg, "--shortstat"))
2414                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2415        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2416                options->output_format |= DIFF_FORMAT_DIRSTAT;
2417        else if (!strcmp(arg, "--cumulative")) {
2418                options->output_format |= DIFF_FORMAT_DIRSTAT;
2419                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2420        } else if (opt_arg(arg, 0, "dirstat-by-file",
2421                           &options->dirstat_percent)) {
2422                options->output_format |= DIFF_FORMAT_DIRSTAT;
2423                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2424        }
2425        else if (!strcmp(arg, "--check"))
2426                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2427        else if (!strcmp(arg, "--summary"))
2428                options->output_format |= DIFF_FORMAT_SUMMARY;
2429        else if (!strcmp(arg, "--patch-with-stat"))
2430                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2431        else if (!strcmp(arg, "--name-only"))
2432                options->output_format |= DIFF_FORMAT_NAME;
2433        else if (!strcmp(arg, "--name-status"))
2434                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2435        else if (!strcmp(arg, "-s"))
2436                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2437        else if (!prefixcmp(arg, "--stat")) {
2438                char *end;
2439                int width = options->stat_width;
2440                int name_width = options->stat_name_width;
2441                arg += 6;
2442                end = (char *)arg;
2443
2444                switch (*arg) {
2445                case '-':
2446                        if (!prefixcmp(arg, "-width="))
2447                                width = strtoul(arg + 7, &end, 10);
2448                        else if (!prefixcmp(arg, "-name-width="))
2449                                name_width = strtoul(arg + 12, &end, 10);
2450                        break;
2451                case '=':
2452                        width = strtoul(arg+1, &end, 10);
2453                        if (*end == ',')
2454                                name_width = strtoul(end+1, &end, 10);
2455                }
2456
2457                /* Important! This checks all the error cases! */
2458                if (*end)
2459                        return 0;
2460                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2461                options->stat_name_width = name_width;
2462                options->stat_width = width;
2463        }
2464
2465        /* renames options */
2466        else if (!prefixcmp(arg, "-B")) {
2467                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2468                        return -1;
2469        }
2470        else if (!prefixcmp(arg, "-M")) {
2471                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2472                        return -1;
2473                options->detect_rename = DIFF_DETECT_RENAME;
2474        }
2475        else if (!prefixcmp(arg, "-C")) {
2476                if (options->detect_rename == DIFF_DETECT_COPY)
2477                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2478                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2479                        return -1;
2480                options->detect_rename = DIFF_DETECT_COPY;
2481        }
2482        else if (!strcmp(arg, "--no-renames"))
2483                options->detect_rename = 0;
2484        else if (!strcmp(arg, "--relative"))
2485                DIFF_OPT_SET(options, RELATIVE_NAME);
2486        else if (!prefixcmp(arg, "--relative=")) {
2487                DIFF_OPT_SET(options, RELATIVE_NAME);
2488                options->prefix = arg + 11;
2489        }
2490
2491        /* xdiff options */
2492        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2493                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2494        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2495                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2496        else if (!strcmp(arg, "--ignore-space-at-eol"))
2497                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2498
2499        /* flags options */
2500        else if (!strcmp(arg, "--binary")) {
2501                options->output_format |= DIFF_FORMAT_PATCH;
2502                DIFF_OPT_SET(options, BINARY);
2503        }
2504        else if (!strcmp(arg, "--full-index"))
2505                DIFF_OPT_SET(options, FULL_INDEX);
2506        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2507                DIFF_OPT_SET(options, TEXT);
2508        else if (!strcmp(arg, "-R"))
2509                DIFF_OPT_SET(options, REVERSE_DIFF);
2510        else if (!strcmp(arg, "--find-copies-harder"))
2511                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2512        else if (!strcmp(arg, "--follow"))
2513                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2514        else if (!strcmp(arg, "--color"))
2515                DIFF_OPT_SET(options, COLOR_DIFF);
2516        else if (!strcmp(arg, "--no-color"))
2517                DIFF_OPT_CLR(options, COLOR_DIFF);
2518        else if (!strcmp(arg, "--color-words"))
2519                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2520        else if (!strcmp(arg, "--exit-code"))
2521                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2522        else if (!strcmp(arg, "--quiet"))
2523                DIFF_OPT_SET(options, QUIET);
2524        else if (!strcmp(arg, "--ext-diff"))
2525                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2526        else if (!strcmp(arg, "--no-ext-diff"))
2527                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2528        else if (!strcmp(arg, "--textconv"))
2529                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2530        else if (!strcmp(arg, "--no-textconv"))
2531                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2532        else if (!strcmp(arg, "--ignore-submodules"))
2533                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2534
2535        /* misc options */
2536        else if (!strcmp(arg, "-z"))
2537                options->line_termination = 0;
2538        else if (!prefixcmp(arg, "-l"))
2539                options->rename_limit = strtoul(arg+2, NULL, 10);
2540        else if (!prefixcmp(arg, "-S"))
2541                options->pickaxe = arg + 2;
2542        else if (!strcmp(arg, "--pickaxe-all"))
2543                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2544        else if (!strcmp(arg, "--pickaxe-regex"))
2545                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2546        else if (!prefixcmp(arg, "-O"))
2547                options->orderfile = arg + 2;
2548        else if (!prefixcmp(arg, "--diff-filter="))
2549                options->filter = arg + 14;
2550        else if (!strcmp(arg, "--abbrev"))
2551                options->abbrev = DEFAULT_ABBREV;
2552        else if (!prefixcmp(arg, "--abbrev=")) {
2553                options->abbrev = strtoul(arg + 9, NULL, 10);
2554                if (options->abbrev < MINIMUM_ABBREV)
2555                        options->abbrev = MINIMUM_ABBREV;
2556                else if (40 < options->abbrev)
2557                        options->abbrev = 40;
2558        }
2559        else if (!prefixcmp(arg, "--src-prefix="))
2560                options->a_prefix = arg + 13;
2561        else if (!prefixcmp(arg, "--dst-prefix="))
2562                options->b_prefix = arg + 13;
2563        else if (!strcmp(arg, "--no-prefix"))
2564                options->a_prefix = options->b_prefix = "";
2565        else if (opt_arg(arg, '\0', "inter-hunk-context",
2566                         &options->interhunkcontext))
2567                ;
2568        else if (!prefixcmp(arg, "--output=")) {
2569                options->file = fopen(arg + strlen("--output="), "w");
2570                options->close_file = 1;
2571        } else
2572                return 0;
2573        return 1;
2574}
2575
2576static int parse_num(const char **cp_p)
2577{
2578        unsigned long num, scale;
2579        int ch, dot;
2580        const char *cp = *cp_p;
2581
2582        num = 0;
2583        scale = 1;
2584        dot = 0;
2585        for(;;) {
2586                ch = *cp;
2587                if ( !dot && ch == '.' ) {
2588                        scale = 1;
2589                        dot = 1;
2590                } else if ( ch == '%' ) {
2591                        scale = dot ? scale*100 : 100;
2592                        cp++;   /* % is always at the end */
2593                        break;
2594                } else if ( ch >= '0' && ch <= '9' ) {
2595                        if ( scale < 100000 ) {
2596                                scale *= 10;
2597                                num = (num*10) + (ch-'0');
2598                        }
2599                } else {
2600                        break;
2601                }
2602                cp++;
2603        }
2604        *cp_p = cp;
2605
2606        /* user says num divided by scale and we say internally that
2607         * is MAX_SCORE * num / scale.
2608         */
2609        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2610}
2611
2612static int diff_scoreopt_parse(const char *opt)
2613{
2614        int opt1, opt2, cmd;
2615
2616        if (*opt++ != '-')
2617                return -1;
2618        cmd = *opt++;
2619        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2620                return -1; /* that is not a -M, -C nor -B option */
2621
2622        opt1 = parse_num(&opt);
2623        if (cmd != 'B')
2624                opt2 = 0;
2625        else {
2626                if (*opt == 0)
2627                        opt2 = 0;
2628                else if (*opt != '/')
2629                        return -1; /* we expect -B80/99 or -B80 */
2630                else {
2631                        opt++;
2632                        opt2 = parse_num(&opt);
2633                }
2634        }
2635        if (*opt != 0)
2636                return -1;
2637        return opt1 | (opt2 << 16);
2638}
2639
2640struct diff_queue_struct diff_queued_diff;
2641
2642void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2643{
2644        if (queue->alloc <= queue->nr) {
2645                queue->alloc = alloc_nr(queue->alloc);
2646                queue->queue = xrealloc(queue->queue,
2647                                        sizeof(dp) * queue->alloc);
2648        }
2649        queue->queue[queue->nr++] = dp;
2650}
2651
2652struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2653                                 struct diff_filespec *one,
2654                                 struct diff_filespec *two)
2655{
2656        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2657        dp->one = one;
2658        dp->two = two;
2659        if (queue)
2660                diff_q(queue, dp);
2661        return dp;
2662}
2663
2664void diff_free_filepair(struct diff_filepair *p)
2665{
2666        free_filespec(p->one);
2667        free_filespec(p->two);
2668        free(p);
2669}
2670
2671/* This is different from find_unique_abbrev() in that
2672 * it stuffs the result with dots for alignment.
2673 */
2674const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2675{
2676        int abblen;
2677        const char *abbrev;
2678        if (len == 40)
2679                return sha1_to_hex(sha1);
2680
2681        abbrev = find_unique_abbrev(sha1, len);
2682        abblen = strlen(abbrev);
2683        if (abblen < 37) {
2684                static char hex[41];
2685                if (len < abblen && abblen <= len + 2)
2686                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2687                else
2688                        sprintf(hex, "%s...", abbrev);
2689                return hex;
2690        }
2691        return sha1_to_hex(sha1);
2692}
2693
2694static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2695{
2696        int line_termination = opt->line_termination;
2697        int inter_name_termination = line_termination ? '\t' : '\0';
2698
2699        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2700                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2701                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2702                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2703        }
2704        if (p->score) {
2705                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2706                        inter_name_termination);
2707        } else {
2708                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2709        }
2710
2711        if (p->status == DIFF_STATUS_COPIED ||
2712            p->status == DIFF_STATUS_RENAMED) {
2713                const char *name_a, *name_b;
2714                name_a = p->one->path;
2715                name_b = p->two->path;
2716                strip_prefix(opt->prefix_length, &name_a, &name_b);
2717                write_name_quoted(name_a, opt->file, inter_name_termination);
2718                write_name_quoted(name_b, opt->file, line_termination);
2719        } else {
2720                const char *name_a, *name_b;
2721                name_a = p->one->mode ? p->one->path : p->two->path;
2722                name_b = NULL;
2723                strip_prefix(opt->prefix_length, &name_a, &name_b);
2724                write_name_quoted(name_a, opt->file, line_termination);
2725        }
2726}
2727
2728int diff_unmodified_pair(struct diff_filepair *p)
2729{
2730        /* This function is written stricter than necessary to support
2731         * the currently implemented transformers, but the idea is to
2732         * let transformers to produce diff_filepairs any way they want,
2733         * and filter and clean them up here before producing the output.
2734         */
2735        struct diff_filespec *one = p->one, *two = p->two;
2736
2737        if (DIFF_PAIR_UNMERGED(p))
2738                return 0; /* unmerged is interesting */
2739
2740        /* deletion, addition, mode or type change
2741         * and rename are all interesting.
2742         */
2743        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2744            DIFF_PAIR_MODE_CHANGED(p) ||
2745            strcmp(one->path, two->path))
2746                return 0;
2747
2748        /* both are valid and point at the same path.  that is, we are
2749         * dealing with a change.
2750         */
2751        if (one->sha1_valid && two->sha1_valid &&
2752            !hashcmp(one->sha1, two->sha1))
2753                return 1; /* no change */
2754        if (!one->sha1_valid && !two->sha1_valid)
2755                return 1; /* both look at the same file on the filesystem. */
2756        return 0;
2757}
2758
2759static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2760{
2761        if (diff_unmodified_pair(p))
2762                return;
2763
2764        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2765            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2766                return; /* no tree diffs in patch format */
2767
2768        run_diff(p, o);
2769}
2770
2771static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2772                            struct diffstat_t *diffstat)
2773{
2774        if (diff_unmodified_pair(p))
2775                return;
2776
2777        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2778            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2779                return; /* no tree diffs in patch format */
2780
2781        run_diffstat(p, o, diffstat);
2782}
2783
2784static void diff_flush_checkdiff(struct diff_filepair *p,
2785                struct diff_options *o)
2786{
2787        if (diff_unmodified_pair(p))
2788                return;
2789
2790        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2791            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2792                return; /* no tree diffs in patch format */
2793
2794        run_checkdiff(p, o);
2795}
2796
2797int diff_queue_is_empty(void)
2798{
2799        struct diff_queue_struct *q = &diff_queued_diff;
2800        int i;
2801        for (i = 0; i < q->nr; i++)
2802                if (!diff_unmodified_pair(q->queue[i]))
2803                        return 0;
2804        return 1;
2805}
2806
2807#if DIFF_DEBUG
2808void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2809{
2810        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2811                x, one ? one : "",
2812                s->path,
2813                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2814                s->mode,
2815                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2816        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2817                x, one ? one : "",
2818                s->size, s->xfrm_flags);
2819}
2820
2821void diff_debug_filepair(const struct diff_filepair *p, int i)
2822{
2823        diff_debug_filespec(p->one, i, "one");
2824        diff_debug_filespec(p->two, i, "two");
2825        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2826                p->score, p->status ? p->status : '?',
2827                p->one->rename_used, p->broken_pair);
2828}
2829
2830void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2831{
2832        int i;
2833        if (msg)
2834                fprintf(stderr, "%s\n", msg);
2835        fprintf(stderr, "q->nr = %d\n", q->nr);
2836        for (i = 0; i < q->nr; i++) {
2837                struct diff_filepair *p = q->queue[i];
2838                diff_debug_filepair(p, i);
2839        }
2840}
2841#endif
2842
2843static void diff_resolve_rename_copy(void)
2844{
2845        int i;
2846        struct diff_filepair *p;
2847        struct diff_queue_struct *q = &diff_queued_diff;
2848
2849        diff_debug_queue("resolve-rename-copy", q);
2850
2851        for (i = 0; i < q->nr; i++) {
2852                p = q->queue[i];
2853                p->status = 0; /* undecided */
2854                if (DIFF_PAIR_UNMERGED(p))
2855                        p->status = DIFF_STATUS_UNMERGED;
2856                else if (!DIFF_FILE_VALID(p->one))
2857                        p->status = DIFF_STATUS_ADDED;
2858                else if (!DIFF_FILE_VALID(p->two))
2859                        p->status = DIFF_STATUS_DELETED;
2860                else if (DIFF_PAIR_TYPE_CHANGED(p))
2861                        p->status = DIFF_STATUS_TYPE_CHANGED;
2862
2863                /* from this point on, we are dealing with a pair
2864                 * whose both sides are valid and of the same type, i.e.
2865                 * either in-place edit or rename/copy edit.
2866                 */
2867                else if (DIFF_PAIR_RENAME(p)) {
2868                        /*
2869                         * A rename might have re-connected a broken
2870                         * pair up, causing the pathnames to be the
2871                         * same again. If so, that's not a rename at
2872                         * all, just a modification..
2873                         *
2874                         * Otherwise, see if this source was used for
2875                         * multiple renames, in which case we decrement
2876                         * the count, and call it a copy.
2877                         */
2878                        if (!strcmp(p->one->path, p->two->path))
2879                                p->status = DIFF_STATUS_MODIFIED;
2880                        else if (--p->one->rename_used > 0)
2881                                p->status = DIFF_STATUS_COPIED;
2882                        else
2883                                p->status = DIFF_STATUS_RENAMED;
2884                }
2885                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2886                         p->one->mode != p->two->mode ||
2887                         is_null_sha1(p->one->sha1))
2888                        p->status = DIFF_STATUS_MODIFIED;
2889                else {
2890                        /* This is a "no-change" entry and should not
2891                         * happen anymore, but prepare for broken callers.
2892                         */
2893                        error("feeding unmodified %s to diffcore",
2894                              p->one->path);
2895                        p->status = DIFF_STATUS_UNKNOWN;
2896                }
2897        }
2898        diff_debug_queue("resolve-rename-copy done", q);
2899}
2900
2901static int check_pair_status(struct diff_filepair *p)
2902{
2903        switch (p->status) {
2904        case DIFF_STATUS_UNKNOWN:
2905                return 0;
2906        case 0:
2907                die("internal error in diff-resolve-rename-copy");
2908        default:
2909                return 1;
2910        }
2911}
2912
2913static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2914{
2915        int fmt = opt->output_format;
2916
2917        if (fmt & DIFF_FORMAT_CHECKDIFF)
2918                diff_flush_checkdiff(p, opt);
2919        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2920                diff_flush_raw(p, opt);
2921        else if (fmt & DIFF_FORMAT_NAME) {
2922                const char *name_a, *name_b;
2923                name_a = p->two->path;
2924                name_b = NULL;
2925                strip_prefix(opt->prefix_length, &name_a, &name_b);
2926                write_name_quoted(name_a, opt->file, opt->line_termination);
2927        }
2928}
2929
2930static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2931{
2932        if (fs->mode)
2933                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2934        else
2935                fprintf(file, " %s ", newdelete);
2936        write_name_quoted(fs->path, file, '\n');
2937}
2938
2939
2940static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2941{
2942        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2943                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2944                        show_name ? ' ' : '\n');
2945                if (show_name) {
2946                        write_name_quoted(p->two->path, file, '\n');
2947                }
2948        }
2949}
2950
2951static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2952{
2953        char *names = pprint_rename(p->one->path, p->two->path);
2954
2955        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2956        free(names);
2957        show_mode_change(file, p, 0);
2958}
2959
2960static void diff_summary(FILE *file, struct diff_filepair *p)
2961{
2962        switch(p->status) {
2963        case DIFF_STATUS_DELETED:
2964                show_file_mode_name(file, "delete", p->one);
2965                break;
2966        case DIFF_STATUS_ADDED:
2967                show_file_mode_name(file, "create", p->two);
2968                break;
2969        case DIFF_STATUS_COPIED:
2970                show_rename_copy(file, "copy", p);
2971                break;
2972        case DIFF_STATUS_RENAMED:
2973                show_rename_copy(file, "rename", p);
2974                break;
2975        default:
2976                if (p->score) {
2977                        fputs(" rewrite ", file);
2978                        write_name_quoted(p->two->path, file, ' ');
2979                        fprintf(file, "(%d%%)\n", similarity_index(p));
2980                }
2981                show_mode_change(file, p, !p->score);
2982                break;
2983        }
2984}
2985
2986struct patch_id_t {
2987        git_SHA_CTX *ctx;
2988        int patchlen;
2989};
2990
2991static int remove_space(char *line, int len)
2992{
2993        int i;
2994        char *dst = line;
2995        unsigned char c;
2996
2997        for (i = 0; i < len; i++)
2998                if (!isspace((c = line[i])))
2999                        *dst++ = c;
3000
3001        return dst - line;
3002}
3003
3004static void patch_id_consume(void *priv, char *line, unsigned long len)
3005{
3006        struct patch_id_t *data = priv;
3007        int new_len;
3008
3009        /* Ignore line numbers when computing the SHA1 of the patch */
3010        if (!prefixcmp(line, "@@ -"))
3011                return;
3012
3013        new_len = remove_space(line, len);
3014
3015        git_SHA1_Update(data->ctx, line, new_len);
3016        data->patchlen += new_len;
3017}
3018
3019/* returns 0 upon success, and writes result into sha1 */
3020static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3021{
3022        struct diff_queue_struct *q = &diff_queued_diff;
3023        int i;
3024        git_SHA_CTX ctx;
3025        struct patch_id_t data;
3026        char buffer[PATH_MAX * 4 + 20];
3027
3028        git_SHA1_Init(&ctx);
3029        memset(&data, 0, sizeof(struct patch_id_t));
3030        data.ctx = &ctx;
3031
3032        for (i = 0; i < q->nr; i++) {
3033                xpparam_t xpp;
3034                xdemitconf_t xecfg;
3035                xdemitcb_t ecb;
3036                mmfile_t mf1, mf2;
3037                struct diff_filepair *p = q->queue[i];
3038                int len1, len2;
3039
3040                memset(&xpp, 0, sizeof(xpp));
3041                memset(&xecfg, 0, sizeof(xecfg));
3042                if (p->status == 0)
3043                        return error("internal diff status error");
3044                if (p->status == DIFF_STATUS_UNKNOWN)
3045                        continue;
3046                if (diff_unmodified_pair(p))
3047                        continue;
3048                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3049                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3050                        continue;
3051                if (DIFF_PAIR_UNMERGED(p))
3052                        continue;
3053
3054                diff_fill_sha1_info(p->one);
3055                diff_fill_sha1_info(p->two);
3056                if (fill_mmfile(&mf1, p->one) < 0 ||
3057                                fill_mmfile(&mf2, p->two) < 0)
3058                        return error("unable to read files to diff");
3059
3060                len1 = remove_space(p->one->path, strlen(p->one->path));
3061                len2 = remove_space(p->two->path, strlen(p->two->path));
3062                if (p->one->mode == 0)
3063                        len1 = snprintf(buffer, sizeof(buffer),
3064                                        "diff--gita/%.*sb/%.*s"
3065                                        "newfilemode%06o"
3066                                        "---/dev/null"
3067                                        "+++b/%.*s",
3068                                        len1, p->one->path,
3069                                        len2, p->two->path,
3070                                        p->two->mode,
3071                                        len2, p->two->path);
3072                else if (p->two->mode == 0)
3073                        len1 = snprintf(buffer, sizeof(buffer),
3074                                        "diff--gita/%.*sb/%.*s"
3075                                        "deletedfilemode%06o"
3076                                        "---a/%.*s"
3077                                        "+++/dev/null",
3078                                        len1, p->one->path,
3079                                        len2, p->two->path,
3080                                        p->one->mode,
3081                                        len1, p->one->path);
3082                else
3083                        len1 = snprintf(buffer, sizeof(buffer),
3084                                        "diff--gita/%.*sb/%.*s"
3085                                        "---a/%.*s"
3086                                        "+++b/%.*s",
3087                                        len1, p->one->path,
3088                                        len2, p->two->path,
3089                                        len1, p->one->path,
3090                                        len2, p->two->path);
3091                git_SHA1_Update(&ctx, buffer, len1);
3092
3093                xpp.flags = XDF_NEED_MINIMAL;
3094                xecfg.ctxlen = 3;
3095                xecfg.flags = XDL_EMIT_FUNCNAMES;
3096                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3097                              &xpp, &xecfg, &ecb);
3098        }
3099
3100        git_SHA1_Final(sha1, &ctx);
3101        return 0;
3102}
3103
3104int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3105{
3106        struct diff_queue_struct *q = &diff_queued_diff;
3107        int i;
3108        int result = diff_get_patch_id(options, sha1);
3109
3110        for (i = 0; i < q->nr; i++)
3111                diff_free_filepair(q->queue[i]);
3112
3113        free(q->queue);
3114        q->queue = NULL;
3115        q->nr = q->alloc = 0;
3116
3117        return result;
3118}
3119
3120static int is_summary_empty(const struct diff_queue_struct *q)
3121{
3122        int i;
3123
3124        for (i = 0; i < q->nr; i++) {
3125                const struct diff_filepair *p = q->queue[i];
3126
3127                switch (p->status) {
3128                case DIFF_STATUS_DELETED:
3129                case DIFF_STATUS_ADDED:
3130                case DIFF_STATUS_COPIED:
3131                case DIFF_STATUS_RENAMED:
3132                        return 0;
3133                default:
3134                        if (p->score)
3135                                return 0;
3136                        if (p->one->mode && p->two->mode &&
3137                            p->one->mode != p->two->mode)
3138                                return 0;
3139                        break;
3140                }
3141        }
3142        return 1;
3143}
3144
3145void diff_flush(struct diff_options *options)
3146{
3147        struct diff_queue_struct *q = &diff_queued_diff;
3148        int i, output_format = options->output_format;
3149        int separator = 0;
3150
3151        /*
3152         * Order: raw, stat, summary, patch
3153         * or:    name/name-status/checkdiff (other bits clear)
3154         */
3155        if (!q->nr)
3156                goto free_queue;
3157
3158        if (output_format & (DIFF_FORMAT_RAW |
3159                             DIFF_FORMAT_NAME |
3160                             DIFF_FORMAT_NAME_STATUS |
3161                             DIFF_FORMAT_CHECKDIFF)) {
3162                for (i = 0; i < q->nr; i++) {
3163                        struct diff_filepair *p = q->queue[i];
3164                        if (check_pair_status(p))
3165                                flush_one_pair(p, options);
3166                }
3167                separator++;
3168        }
3169
3170        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3171                struct diffstat_t diffstat;
3172
3173                memset(&diffstat, 0, sizeof(struct diffstat_t));
3174                for (i = 0; i < q->nr; i++) {
3175                        struct diff_filepair *p = q->queue[i];
3176                        if (check_pair_status(p))
3177                                diff_flush_stat(p, options, &diffstat);
3178                }
3179                if (output_format & DIFF_FORMAT_NUMSTAT)
3180                        show_numstat(&diffstat, options);
3181                if (output_format & DIFF_FORMAT_DIFFSTAT)
3182                        show_stats(&diffstat, options);
3183                if (output_format & DIFF_FORMAT_SHORTSTAT)
3184                        show_shortstats(&diffstat, options);
3185                free_diffstat_info(&diffstat);
3186                separator++;
3187        }
3188        if (output_format & DIFF_FORMAT_DIRSTAT)
3189                show_dirstat(options);
3190
3191        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3192                for (i = 0; i < q->nr; i++)
3193                        diff_summary(options->file, q->queue[i]);
3194                separator++;
3195        }
3196
3197        if (output_format & DIFF_FORMAT_PATCH) {
3198                if (separator) {
3199                        putc(options->line_termination, options->file);
3200                        if (options->stat_sep) {
3201                                /* attach patch instead of inline */
3202                                fputs(options->stat_sep, options->file);
3203                        }
3204                }
3205
3206                for (i = 0; i < q->nr; i++) {
3207                        struct diff_filepair *p = q->queue[i];
3208                        if (check_pair_status(p))
3209                                diff_flush_patch(p, options);
3210                }
3211        }
3212
3213        if (output_format & DIFF_FORMAT_CALLBACK)
3214                options->format_callback(q, options, options->format_callback_data);
3215
3216        for (i = 0; i < q->nr; i++)
3217                diff_free_filepair(q->queue[i]);
3218free_queue:
3219        free(q->queue);
3220        q->queue = NULL;
3221        q->nr = q->alloc = 0;
3222        if (options->close_file)
3223                fclose(options->file);
3224}
3225
3226static void diffcore_apply_filter(const char *filter)
3227{
3228        int i;
3229        struct diff_queue_struct *q = &diff_queued_diff;
3230        struct diff_queue_struct outq;
3231        outq.queue = NULL;
3232        outq.nr = outq.alloc = 0;
3233
3234        if (!filter)
3235                return;
3236
3237        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3238                int found;
3239                for (i = found = 0; !found && i < q->nr; i++) {
3240                        struct diff_filepair *p = q->queue[i];
3241                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3242                             ((p->score &&
3243                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3244                              (!p->score &&
3245                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3246                            ((p->status != DIFF_STATUS_MODIFIED) &&
3247                             strchr(filter, p->status)))
3248                                found++;
3249                }
3250                if (found)
3251                        return;
3252
3253                /* otherwise we will clear the whole queue
3254                 * by copying the empty outq at the end of this
3255                 * function, but first clear the current entries
3256                 * in the queue.
3257                 */
3258                for (i = 0; i < q->nr; i++)
3259                        diff_free_filepair(q->queue[i]);
3260        }
3261        else {
3262                /* Only the matching ones */
3263                for (i = 0; i < q->nr; i++) {
3264                        struct diff_filepair *p = q->queue[i];
3265
3266                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3267                             ((p->score &&
3268                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3269                              (!p->score &&
3270                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3271                            ((p->status != DIFF_STATUS_MODIFIED) &&
3272                             strchr(filter, p->status)))
3273                                diff_q(&outq, p);
3274                        else
3275                                diff_free_filepair(p);
3276                }
3277        }
3278        free(q->queue);
3279        *q = outq;
3280}
3281
3282/* Check whether two filespecs with the same mode and size are identical */
3283static int diff_filespec_is_identical(struct diff_filespec *one,
3284                                      struct diff_filespec *two)
3285{
3286        if (S_ISGITLINK(one->mode))
3287                return 0;
3288        if (diff_populate_filespec(one, 0))
3289                return 0;
3290        if (diff_populate_filespec(two, 0))
3291                return 0;
3292        return !memcmp(one->data, two->data, one->size);
3293}
3294
3295static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3296{
3297        int i;
3298        struct diff_queue_struct *q = &diff_queued_diff;
3299        struct diff_queue_struct outq;
3300        outq.queue = NULL;
3301        outq.nr = outq.alloc = 0;
3302
3303        for (i = 0; i < q->nr; i++) {
3304                struct diff_filepair *p = q->queue[i];
3305
3306                /*
3307                 * 1. Entries that come from stat info dirtyness
3308                 *    always have both sides (iow, not create/delete),
3309                 *    one side of the object name is unknown, with
3310                 *    the same mode and size.  Keep the ones that
3311                 *    do not match these criteria.  They have real
3312                 *    differences.
3313                 *
3314                 * 2. At this point, the file is known to be modified,
3315                 *    with the same mode and size, and the object
3316                 *    name of one side is unknown.  Need to inspect
3317                 *    the identical contents.
3318                 */
3319                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3320                    !DIFF_FILE_VALID(p->two) ||
3321                    (p->one->sha1_valid && p->two->sha1_valid) ||
3322                    (p->one->mode != p->two->mode) ||
3323                    diff_populate_filespec(p->one, 1) ||
3324                    diff_populate_filespec(p->two, 1) ||
3325                    (p->one->size != p->two->size) ||
3326                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3327                        diff_q(&outq, p);
3328                else {
3329                        /*
3330                         * The caller can subtract 1 from skip_stat_unmatch
3331                         * to determine how many paths were dirty only
3332                         * due to stat info mismatch.
3333                         */
3334                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3335                                diffopt->skip_stat_unmatch++;
3336                        diff_free_filepair(p);
3337                }
3338        }
3339        free(q->queue);
3340        *q = outq;
3341}
3342
3343void diffcore_std(struct diff_options *options)
3344{
3345        if (options->skip_stat_unmatch)
3346                diffcore_skip_stat_unmatch(options);
3347        if (options->break_opt != -1)
3348                diffcore_break(options->break_opt);
3349        if (options->detect_rename)
3350                diffcore_rename(options);
3351        if (options->break_opt != -1)
3352                diffcore_merge_broken();
3353        if (options->pickaxe)
3354                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3355        if (options->orderfile)
3356                diffcore_order(options->orderfile);
3357        diff_resolve_rename_copy();
3358        diffcore_apply_filter(options->filter);
3359
3360        if (diff_queued_diff.nr)
3361                DIFF_OPT_SET(options, HAS_CHANGES);
3362        else
3363                DIFF_OPT_CLR(options, HAS_CHANGES);
3364}
3365
3366int diff_result_code(struct diff_options *opt, int status)
3367{
3368        int result = 0;
3369        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3370            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3371                return status;
3372        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3373            DIFF_OPT_TST(opt, HAS_CHANGES))
3374                result |= 01;
3375        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3376            DIFF_OPT_TST(opt, CHECK_FAILED))
3377                result |= 02;
3378        return result;
3379}
3380
3381void diff_addremove(struct diff_options *options,
3382                    int addremove, unsigned mode,
3383                    const unsigned char *sha1,
3384                    const char *concatpath)
3385{
3386        struct diff_filespec *one, *two;
3387
3388        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3389                return;
3390
3391        /* This may look odd, but it is a preparation for
3392         * feeding "there are unchanged files which should
3393         * not produce diffs, but when you are doing copy
3394         * detection you would need them, so here they are"
3395         * entries to the diff-core.  They will be prefixed
3396         * with something like '=' or '*' (I haven't decided
3397         * which but should not make any difference).
3398         * Feeding the same new and old to diff_change()
3399         * also has the same effect.
3400         * Before the final output happens, they are pruned after
3401         * merged into rename/copy pairs as appropriate.
3402         */
3403        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3404                addremove = (addremove == '+' ? '-' :
3405                             addremove == '-' ? '+' : addremove);
3406
3407        if (options->prefix &&
3408            strncmp(concatpath, options->prefix, options->prefix_length))
3409                return;
3410
3411        one = alloc_filespec(concatpath);
3412        two = alloc_filespec(concatpath);
3413
3414        if (addremove != '+')
3415                fill_filespec(one, sha1, mode);
3416        if (addremove != '-')
3417                fill_filespec(two, sha1, mode);
3418
3419        diff_queue(&diff_queued_diff, one, two);
3420        DIFF_OPT_SET(options, HAS_CHANGES);
3421}
3422
3423void diff_change(struct diff_options *options,
3424                 unsigned old_mode, unsigned new_mode,
3425                 const unsigned char *old_sha1,
3426                 const unsigned char *new_sha1,
3427                 const char *concatpath)
3428{
3429        struct diff_filespec *one, *two;
3430
3431        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3432                        && S_ISGITLINK(new_mode))
3433                return;
3434
3435        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3436                unsigned tmp;
3437                const unsigned char *tmp_c;
3438                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3439                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3440        }
3441
3442        if (options->prefix &&
3443            strncmp(concatpath, options->prefix, options->prefix_length))
3444                return;
3445
3446        one = alloc_filespec(concatpath);
3447        two = alloc_filespec(concatpath);
3448        fill_filespec(one, old_sha1, old_mode);
3449        fill_filespec(two, new_sha1, new_mode);
3450
3451        diff_queue(&diff_queued_diff, one, two);
3452        DIFF_OPT_SET(options, HAS_CHANGES);
3453}
3454
3455void diff_unmerge(struct diff_options *options,
3456                  const char *path,
3457                  unsigned mode, const unsigned char *sha1)
3458{
3459        struct diff_filespec *one, *two;
3460
3461        if (options->prefix &&
3462            strncmp(path, options->prefix, options->prefix_length))
3463                return;
3464
3465        one = alloc_filespec(path);
3466        two = alloc_filespec(path);
3467        fill_filespec(one, sha1, mode);
3468        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3469}
3470
3471static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3472                size_t *outsize)
3473{
3474        struct diff_tempfile temp;
3475        const char *argv[3];
3476        const char **arg = argv;
3477        struct child_process child;
3478        struct strbuf buf = STRBUF_INIT;
3479
3480        prepare_temp_file(spec->path, &temp, spec);
3481        *arg++ = pgm;
3482        *arg++ = temp.name;
3483        *arg = NULL;
3484
3485        memset(&child, 0, sizeof(child));
3486        child.argv = argv;
3487        child.out = -1;
3488        if (start_command(&child) != 0 ||
3489            strbuf_read(&buf, child.out, 0) < 0 ||
3490            finish_command(&child) != 0) {
3491                if (temp.name == temp.tmp_path)
3492                        unlink(temp.name);
3493                error("error running textconv command '%s'", pgm);
3494                return NULL;
3495        }
3496        if (temp.name == temp.tmp_path)
3497                unlink(temp.name);
3498
3499        return strbuf_detach(&buf, outsize);
3500}