git.oblomov.eu Git - git/blob - diff.c

   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
  15 #ifdef NO_FAST_WORKING_DIRECTORY
  16 #define FAST_WORKING_DIRECTORY 0
  17 #else
  18 #define FAST_WORKING_DIRECTORY 1
  19 #endif
  20
  21 static int diff_detect_rename_default;
  22 static int diff_rename_limit_default = 200;
  23 int diff_use_color_default = -1;
  24 static const char *external_diff_cmd_cfg;
  25 int diff_auto_refresh_index = 1;
  26
  27 static char diff_colors[][COLOR_MAXLEN] = {
  28         "\033[m",       /* reset */
  29         "",             /* PLAIN (normal) */
  30         "\033[1m",      /* METAINFO (bold) */
  31         "\033[36m",     /* FRAGINFO (cyan) */
  32         "\033[31m",     /* OLD (red) */
  33         "\033[32m",     /* NEW (green) */
  34         "\033[33m",     /* COMMIT (yellow) */
  35         "\033[41m",     /* WHITESPACE (red background) */
  36 };
  37
  38 static int parse_diff_color_slot(const char *var, int ofs)
  39 {
  40         if (!strcasecmp(var+ofs, "plain"))
  41                 return DIFF_PLAIN;
  42         if (!strcasecmp(var+ofs, "meta"))
  43                 return DIFF_METAINFO;
  44         if (!strcasecmp(var+ofs, "frag"))
  45                 return DIFF_FRAGINFO;
  46         if (!strcasecmp(var+ofs, "old"))
  47                 return DIFF_FILE_OLD;
  48         if (!strcasecmp(var+ofs, "new"))
  49                 return DIFF_FILE_NEW;
  50         if (!strcasecmp(var+ofs, "commit"))
  51                 return DIFF_COMMIT;
  52         if (!strcasecmp(var+ofs, "whitespace"))
  53                 return DIFF_WHITESPACE;
  54         die("bad config variable '%s'", var);
  55 }
  56
  57 static struct ll_diff_driver {
  58         const char *name;
  59         struct ll_diff_driver *next;
  60         const char *cmd;
  61 } *user_diff, **user_diff_tail;
  62
  63 /*
  64  * Currently there is only "diff.<drivername>.command" variable;
  65  * because there are "diff.color.<slot>" variables, we are parsing
  66  * this in a bit convoluted way to allow low level diff driver
  67  * called "color".
  68  */
  69 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
  70 {
  71         const char *name;
  72         int namelen;
  73         struct ll_diff_driver *drv;
  74
  75         name = var + 5;
  76         namelen = ep - name;
  77         for (drv = user_diff; drv; drv = drv->next)
  78                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
  79                         break;
  80         if (!drv) {
  81                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
  82                 drv->name = xmemdupz(name, namelen);
  83                 if (!user_diff_tail)
  84                         user_diff_tail = &user_diff;
  85                 *user_diff_tail = drv;
  86                 user_diff_tail = &(drv->next);
  87         }
  88
  89         return git_config_string(&(drv->cmd), var, value);
  90 }
  91
  92 /*
  93  * 'diff.<what>.funcname' attribute can be specified in the configuration
  94  * to define a customized regexp to find the beginning of a function to
  95  * be used for hunk header lines of "diff -p" style output.
  96  */
  97 static struct funcname_pattern {
  98         char *name;
  99         char *pattern;
 100         struct funcname_pattern *next;
 101 } *funcname_pattern_list;
 102
 103 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
 104 {
 105         const char *name;
 106         int namelen;
 107         struct funcname_pattern *pp;
 108
 109         name = var + 5; /* "diff." */
 110         namelen = ep - name;
 111
 112         for (pp = funcname_pattern_list; pp; pp = pp->next)
 113                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
 114                         break;
 115         if (!pp) {
 116                 pp = xcalloc(1, sizeof(*pp));
 117                 pp->name = xmemdupz(name, namelen);
 118                 pp->next = funcname_pattern_list;
 119                 funcname_pattern_list = pp;
 120         }
 121         free(pp->pattern);
 122         pp->pattern = xstrdup(value);
 123         return 0;
 124 }
 125
 126 /*
 127  * These are to give UI layer defaults.
 128  * The core-level commands such as git-diff-files should
 129  * never be affected by the setting of diff.renames
 130  * the user happens to have in the configuration file.
 131  */
 132 int git_diff_ui_config(const char *var, const char *value, void *cb)
 133 {
 134         if (!strcmp(var, "diff.renamelimit")) {
 135                 diff_rename_limit_default = git_config_int(var, value);
 136                 return 0;
 137         }
 138         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 139                 diff_use_color_default = git_config_colorbool(var, value, -1);
 140                 return 0;
 141         }
 142         if (!strcmp(var, "diff.renames")) {
 143                 if (!value)
 144                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 145                 else if (!strcasecmp(value, "copies") ||
 146                          !strcasecmp(value, "copy"))
 147                         diff_detect_rename_default = DIFF_DETECT_COPY;
 148                 else if (git_config_bool(var,value))
 149                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 150                 return 0;
 151         }
 152         if (!strcmp(var, "diff.autorefreshindex")) {
 153                 diff_auto_refresh_index = git_config_bool(var, value);
 154                 return 0;
 155         }
 156         if (!strcmp(var, "diff.external")) {
 157                 if (!value)
 158                         return config_error_nonbool(var);
 159                 external_diff_cmd_cfg = xstrdup(value);
 160                 return 0;
 161         }
 162         if (!prefixcmp(var, "diff.")) {
 163                 const char *ep = strrchr(var, '.');
 164
 165                 if (ep != var + 4 && !strcmp(ep, ".command"))
 166                         return parse_lldiff_command(var, ep, value);
 167         }
 168
 169         return git_diff_basic_config(var, value, cb);
 170 }
 171
 172 int git_diff_basic_config(const char *var, const char *value, void *cb)
 173 {
 174         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 175                 int slot = parse_diff_color_slot(var, 11);
 176                 if (!value)
 177                         return config_error_nonbool(var);
 178                 color_parse(value, var, diff_colors[slot]);
 179                 return 0;
 180         }
 181
 182         if (!prefixcmp(var, "diff.")) {
 183                 const char *ep = strrchr(var, '.');
 184                 if (ep != var + 4) {
 185                         if (!strcmp(ep, ".funcname")) {
 186                                 if (!value)
 187                                         return config_error_nonbool(var);
 188                                 return parse_funcname_pattern(var, ep, value);
 189                         }
 190                 }
 191         }
 192
 193         return git_color_default_config(var, value, cb);
 194 }
 195
 196 static char *quote_two(const char *one, const char *two)
 197 {
 198         int need_one = quote_c_style(one, NULL, NULL, 1);
 199         int need_two = quote_c_style(two, NULL, NULL, 1);
 200         struct strbuf res;
 201
 202         strbuf_init(&res, 0);
 203         if (need_one + need_two) {
 204                 strbuf_addch(&res, '"');
 205                 quote_c_style(one, &res, NULL, 1);
 206                 quote_c_style(two, &res, NULL, 1);
 207                 strbuf_addch(&res, '"');
 208         } else {
 209                 strbuf_addstr(&res, one);
 210                 strbuf_addstr(&res, two);
 211         }
 212         return strbuf_detach(&res, NULL);
 213 }
 214
 215 static const char *external_diff(void)
 216 {
 217         static const char *external_diff_cmd = NULL;
 218         static int done_preparing = 0;
 219
 220         if (done_preparing)
 221                 return external_diff_cmd;
 222         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 223         if (!external_diff_cmd)
 224                 external_diff_cmd = external_diff_cmd_cfg;
 225         done_preparing = 1;
 226         return external_diff_cmd;
 227 }
 228
 229 static struct diff_tempfile {
 230         const char *name; /* filename external diff should read from */
 231         char hex[41];
 232         char mode[10];
 233         char tmp_path[PATH_MAX];
 234 } diff_temp[2];
 235
 236 static int count_lines(const char *data, int size)
 237 {
 238         int count, ch, completely_empty = 1, nl_just_seen = 0;
 239         count = 0;
 240         while (0 < size--) {
 241                 ch = *data++;
 242                 if (ch == '\n') {
 243                         count++;
 244                         nl_just_seen = 1;
 245                         completely_empty = 0;
 246                 }
 247                 else {
 248                         nl_just_seen = 0;
 249                         completely_empty = 0;
 250                 }
 251         }
 252         if (completely_empty)
 253                 return 0;
 254         if (!nl_just_seen)
 255                 count++; /* no trailing newline */
 256         return count;
 257 }
 258
 259 static void print_line_count(FILE *file, int count)
 260 {
 261         switch (count) {
 262         case 0:
 263                 fprintf(file, "0,0");
 264                 break;
 265         case 1:
 266                 fprintf(file, "1");
 267                 break;
 268         default:
 269                 fprintf(file, "1,%d", count);
 270                 break;
 271         }
 272 }
 273
 274 static void copy_file_with_prefix(FILE *file,
 275                                   int prefix, const char *data, int size,
 276                                   const char *set, const char *reset)
 277 {
 278         int ch, nl_just_seen = 1;
 279         while (0 < size--) {
 280                 ch = *data++;
 281                 if (nl_just_seen) {
 282                         fputs(set, file);
 283                         putc(prefix, file);
 284                 }
 285                 if (ch == '\n') {
 286                         nl_just_seen = 1;
 287                         fputs(reset, file);
 288                 } else
 289                         nl_just_seen = 0;
 290                 putc(ch, file);
 291         }
 292         if (!nl_just_seen)
 293                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 294 }
 295
 296 static void emit_rewrite_diff(const char *name_a,
 297                               const char *name_b,
 298                               struct diff_filespec *one,
 299                               struct diff_filespec *two,
 300                               struct diff_options *o)
 301 {
 302         int lc_a, lc_b;
 303         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 304         const char *name_a_tab, *name_b_tab;
 305         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 306         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 307         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 308         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 309         const char *reset = diff_get_color(color_diff, DIFF_RESET);
 310         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 311
 312         name_a += (*name_a == '/');
 313         name_b += (*name_b == '/');
 314         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 315         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 316
 317         strbuf_reset(&a_name);
 318         strbuf_reset(&b_name);
 319         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
 320         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
 321
 322         diff_populate_filespec(one, 0);
 323         diff_populate_filespec(two, 0);
 324         lc_a = count_lines(one->data, one->size);
 325         lc_b = count_lines(two->data, two->size);
 326         fprintf(o->file,
 327                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 328                 metainfo, a_name.buf, name_a_tab, reset,
 329                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 330         print_line_count(o->file, lc_a);
 331         fprintf(o->file, " +");
 332         print_line_count(o->file, lc_b);
 333         fprintf(o->file, " @@%s\n", reset);
 334         if (lc_a)
 335                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
 336         if (lc_b)
 337                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
 338 }
 339
 340 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 341 {
 342         if (!DIFF_FILE_VALID(one)) {
 343                 mf->ptr = (char *)""; /* does not matter */
 344                 mf->size = 0;
 345                 return 0;
 346         }
 347         else if (diff_populate_filespec(one, 0))
 348                 return -1;
 349         mf->ptr = one->data;
 350         mf->size = one->size;
 351         return 0;
 352 }
 353
 354 struct diff_words_buffer {
 355         mmfile_t text;
 356         long alloc;
 357         long current; /* output pointer */
 358         int suppressed_newline;
 359 };
 360
 361 static void diff_words_append(char *line, unsigned long len,
 362                 struct diff_words_buffer *buffer)
 363 {
 364         if (buffer->text.size + len > buffer->alloc) {
 365                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
 366                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 367         }
 368         line++;
 369         len--;
 370         memcpy(buffer->text.ptr + buffer->text.size, line, len);
 371         buffer->text.size += len;
 372 }
 373
 374 struct diff_words_data {
 375         struct xdiff_emit_state xm;
 376         struct diff_words_buffer minus, plus;
 377         FILE *file;
 378 };
 379
 380 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 381                 int suppress_newline)
 382 {
 383         const char *ptr;
 384         int eol = 0;
 385
 386         if (len == 0)
 387                 return;
 388
 389         ptr  = buffer->text.ptr + buffer->current;
 390         buffer->current += len;
 391
 392         if (ptr[len - 1] == '\n') {
 393                 eol = 1;
 394                 len--;
 395         }
 396
 397         fputs(diff_get_color(1, color), file);
 398         fwrite(ptr, len, 1, file);
 399         fputs(diff_get_color(1, DIFF_RESET), file);
 400
 401         if (eol) {
 402                 if (suppress_newline)
 403                         buffer->suppressed_newline = 1;
 404                 else
 405                         putc('\n', file);
 406         }
 407 }
 408
 409 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 410 {
 411         struct diff_words_data *diff_words = priv;
 412
 413         if (diff_words->minus.suppressed_newline) {
 414                 if (line[0] != '+')
 415                         putc('\n', diff_words->file);
 416                 diff_words->minus.suppressed_newline = 0;
 417         }
 418
 419         len--;
 420         switch (line[0]) {
 421                 case '-':
 422                         print_word(diff_words->file,
 423                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
 424                         break;
 425                 case '+':
 426                         print_word(diff_words->file,
 427                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
 428                         break;
 429                 case ' ':
 430                         print_word(diff_words->file,
 431                                    &diff_words->plus, len, DIFF_PLAIN, 0);
 432                         diff_words->minus.current += len;
 433                         break;
 434         }
 435 }
 436
 437 /* this executes the word diff on the accumulated buffers */
 438 static void diff_words_show(struct diff_words_data *diff_words)
 439 {
 440         xpparam_t xpp;
 441         xdemitconf_t xecfg;
 442         xdemitcb_t ecb;
 443         mmfile_t minus, plus;
 444         int i;
 445
 446         memset(&xecfg, 0, sizeof(xecfg));
 447         minus.size = diff_words->minus.text.size;
 448         minus.ptr = xmalloc(minus.size);
 449         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 450         for (i = 0; i < minus.size; i++)
 451                 if (isspace(minus.ptr[i]))
 452                         minus.ptr[i] = '\n';
 453         diff_words->minus.current = 0;
 454
 455         plus.size = diff_words->plus.text.size;
 456         plus.ptr = xmalloc(plus.size);
 457         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 458         for (i = 0; i < plus.size; i++)
 459                 if (isspace(plus.ptr[i]))
 460                         plus.ptr[i] = '\n';
 461         diff_words->plus.current = 0;
 462
 463         xpp.flags = XDF_NEED_MINIMAL;
 464         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 465         ecb.outf = xdiff_outf;
 466         ecb.priv = diff_words;
 467         diff_words->xm.consume = fn_out_diff_words_aux;
 468         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 469
 470         free(minus.ptr);
 471         free(plus.ptr);
 472         diff_words->minus.text.size = diff_words->plus.text.size = 0;
 473
 474         if (diff_words->minus.suppressed_newline) {
 475                 putc('\n', diff_words->file);
 476                 diff_words->minus.suppressed_newline = 0;
 477         }
 478 }
 479
 480 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 481
 482 struct emit_callback {
 483         struct xdiff_emit_state xm;
 484         int nparents, color_diff;
 485         unsigned ws_rule;
 486         sane_truncate_fn truncate;
 487         const char **label_path;
 488         struct diff_words_data *diff_words;
 489         int *found_changesp;
 490         FILE *file;
 491 };
 492
 493 static void free_diff_words_data(struct emit_callback *ecbdata)
 494 {
 495         if (ecbdata->diff_words) {
 496                 /* flush buffers */
 497                 if (ecbdata->diff_words->minus.text.size ||
 498                                 ecbdata->diff_words->plus.text.size)
 499                         diff_words_show(ecbdata->diff_words);
 500
 501                 free (ecbdata->diff_words->minus.text.ptr);
 502                 free (ecbdata->diff_words->plus.text.ptr);
 503                 free(ecbdata->diff_words);
 504                 ecbdata->diff_words = NULL;
 505         }
 506 }
 507
 508 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 509 {
 510         if (diff_use_color)
 511                 return diff_colors[ix];
 512         return "";
 513 }
 514
 515 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 516 {
 517         int has_trailing_newline = (len > 0 && line[len-1] == '\n');
 518         if (has_trailing_newline)
 519                 len--;
 520
 521         fputs(set, file);
 522         fwrite(line, len, 1, file);
 523         fputs(reset, file);
 524         if (has_trailing_newline)
 525                 fputc('\n', file);
 526 }
 527
 528 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 529 {
 530         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 531         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 532
 533         if (!*ws)
 534                 emit_line(ecbdata->file, set, reset, line, len);
 535         else {
 536                 /* Emit just the prefix, then the rest. */
 537                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 538                 (void)check_and_emit_line(line + ecbdata->nparents,
 539                     len - ecbdata->nparents, ecbdata->ws_rule,
 540                     ecbdata->file, set, reset, ws);
 541         }
 542 }
 543
 544 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 545 {
 546         const char *cp;
 547         unsigned long allot;
 548         size_t l = len;
 549
 550         if (ecb->truncate)
 551                 return ecb->truncate(line, len);
 552         cp = line;
 553         allot = l;
 554         while (0 < l) {
 555                 (void) utf8_width(&cp, &l);
 556                 if (!cp)
 557                         break; /* truncated in the middle? */
 558         }
 559         return allot - l;
 560 }
 561
 562 static void fn_out_consume(void *priv, char *line, unsigned long len)
 563 {
 564         int i;
 565         int color;
 566         struct emit_callback *ecbdata = priv;
 567         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 568         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 569         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 570
 571         *(ecbdata->found_changesp) = 1;
 572
 573         if (ecbdata->label_path[0]) {
 574                 const char *name_a_tab, *name_b_tab;
 575
 576                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 577                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 578
 579                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
 580                         meta, ecbdata->label_path[0], reset, name_a_tab);
 581                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 582                         meta, ecbdata->label_path[1], reset, name_b_tab);
 583                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 584         }
 585
 586         /* This is not really necessary for now because
 587          * this codepath only deals with two-way diffs.
 588          */
 589         for (i = 0; i < len && line[i] == '@'; i++)
 590                 ;
 591         if (2 <= i && i < len && line[i] == ' ') {
 592                 ecbdata->nparents = i - 1;
 593                 len = sane_truncate_line(ecbdata, line, len);
 594                 emit_line(ecbdata->file,
 595                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 596                           reset, line, len);
 597                 if (line[len-1] != '\n')
 598                         putc('\n', ecbdata->file);
 599                 return;
 600         }
 601
 602         if (len < ecbdata->nparents) {
 603                 emit_line(ecbdata->file, reset, reset, line, len);
 604                 return;
 605         }
 606
 607         color = DIFF_PLAIN;
 608         if (ecbdata->diff_words && ecbdata->nparents != 1)
 609                 /* fall back to normal diff */
 610                 free_diff_words_data(ecbdata);
 611         if (ecbdata->diff_words) {
 612                 if (line[0] == '-') {
 613                         diff_words_append(line, len,
 614                                           &ecbdata->diff_words->minus);
 615                         return;
 616                 } else if (line[0] == '+') {
 617                         diff_words_append(line, len,
 618                                           &ecbdata->diff_words->plus);
 619                         return;
 620                 }
 621                 if (ecbdata->diff_words->minus.text.size ||
 622                     ecbdata->diff_words->plus.text.size)
 623                         diff_words_show(ecbdata->diff_words);
 624                 line++;
 625                 len--;
 626                 emit_line(ecbdata->file, plain, reset, line, len);
 627                 return;
 628         }
 629         for (i = 0; i < ecbdata->nparents && len; i++) {
 630                 if (line[i] == '-')
 631                         color = DIFF_FILE_OLD;
 632                 else if (line[i] == '+')
 633                         color = DIFF_FILE_NEW;
 634         }
 635
 636         if (color != DIFF_FILE_NEW) {
 637                 emit_line(ecbdata->file,
 638                           diff_get_color(ecbdata->color_diff, color),
 639                           reset, line, len);
 640                 return;
 641         }
 642         emit_add_line(reset, ecbdata, line, len);
 643 }
 644
 645 static char *pprint_rename(const char *a, const char *b)
 646 {
 647         const char *old = a;
 648         const char *new = b;
 649         struct strbuf name;
 650         int pfx_length, sfx_length;
 651         int len_a = strlen(a);
 652         int len_b = strlen(b);
 653         int a_midlen, b_midlen;
 654         int qlen_a = quote_c_style(a, NULL, NULL, 0);
 655         int qlen_b = quote_c_style(b, NULL, NULL, 0);
 656
 657         strbuf_init(&name, 0);
 658         if (qlen_a || qlen_b) {
 659                 quote_c_style(a, &name, NULL, 0);
 660                 strbuf_addstr(&name, " => ");
 661                 quote_c_style(b, &name, NULL, 0);
 662                 return strbuf_detach(&name, NULL);
 663         }
 664
 665         /* Find common prefix */
 666         pfx_length = 0;
 667         while (*old && *new && *old == *new) {
 668                 if (*old == '/')
 669                         pfx_length = old - a + 1;
 670                 old++;
 671                 new++;
 672         }
 673
 674         /* Find common suffix */
 675         old = a + len_a;
 676         new = b + len_b;
 677         sfx_length = 0;
 678         while (a <= old && b <= new && *old == *new) {
 679                 if (*old == '/')
 680                         sfx_length = len_a - (old - a);
 681                 old--;
 682                 new--;
 683         }
 684
 685         /*
 686          * pfx{mid-a => mid-b}sfx
 687          * {pfx-a => pfx-b}sfx
 688          * pfx{sfx-a => sfx-b}
 689          * name-a => name-b
 690          */
 691         a_midlen = len_a - pfx_length - sfx_length;
 692         b_midlen = len_b - pfx_length - sfx_length;
 693         if (a_midlen < 0)
 694                 a_midlen = 0;
 695         if (b_midlen < 0)
 696                 b_midlen = 0;
 697
 698         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 699         if (pfx_length + sfx_length) {
 700                 strbuf_add(&name, a, pfx_length);
 701                 strbuf_addch(&name, '{');
 702         }
 703         strbuf_add(&name, a + pfx_length, a_midlen);
 704         strbuf_addstr(&name, " => ");
 705         strbuf_add(&name, b + pfx_length, b_midlen);
 706         if (pfx_length + sfx_length) {
 707                 strbuf_addch(&name, '}');
 708                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 709         }
 710         return strbuf_detach(&name, NULL);
 711 }
 712
 713 struct diffstat_t {
 714         struct xdiff_emit_state xm;
 715
 716         int nr;
 717         int alloc;
 718         struct diffstat_file {
 719                 char *from_name;
 720                 char *name;
 721                 char *print_name;
 722                 unsigned is_unmerged:1;
 723                 unsigned is_binary:1;
 724                 unsigned is_renamed:1;
 725                 unsigned int added, deleted;
 726         } **files;
 727 };
 728
 729 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 730                                           const char *name_a,
 731                                           const char *name_b)
 732 {
 733         struct diffstat_file *x;
 734         x = xcalloc(sizeof (*x), 1);
 735         if (diffstat->nr == diffstat->alloc) {
 736                 diffstat->alloc = alloc_nr(diffstat->alloc);
 737                 diffstat->files = xrealloc(diffstat->files,
 738                                 diffstat->alloc * sizeof(x));
 739         }
 740         diffstat->files[diffstat->nr++] = x;
 741         if (name_b) {
 742                 x->from_name = xstrdup(name_a);
 743                 x->name = xstrdup(name_b);
 744                 x->is_renamed = 1;
 745         }
 746         else {
 747                 x->from_name = NULL;
 748                 x->name = xstrdup(name_a);
 749         }
 750         return x;
 751 }
 752
 753 static void diffstat_consume(void *priv, char *line, unsigned long len)
 754 {
 755         struct diffstat_t *diffstat = priv;
 756         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 757
 758         if (line[0] == '+')
 759                 x->added++;
 760         else if (line[0] == '-')
 761                 x->deleted++;
 762 }
 763
 764 const char mime_boundary_leader[] = "------------";
 765
 766 static int scale_linear(int it, int width, int max_change)
 767 {
 768         /*
 769          * make sure that at least one '-' is printed if there were deletions,
 770          * and likewise for '+'.
 771          */
 772         if (max_change < 2)
 773                 return it;
 774         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 775 }
 776
 777 static void show_name(FILE *file,
 778                       const char *prefix, const char *name, int len,
 779                       const char *reset, const char *set)
 780 {
 781         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 782 }
 783
 784 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 785 {
 786         if (cnt <= 0)
 787                 return;
 788         fprintf(file, "%s", set);
 789         while (cnt--)
 790                 putc(ch, file);
 791         fprintf(file, "%s", reset);
 792 }
 793
 794 static void fill_print_name(struct diffstat_file *file)
 795 {
 796         char *pname;
 797
 798         if (file->print_name)
 799                 return;
 800
 801         if (!file->is_renamed) {
 802                 struct strbuf buf;
 803                 strbuf_init(&buf, 0);
 804                 if (quote_c_style(file->name, &buf, NULL, 0)) {
 805                         pname = strbuf_detach(&buf, NULL);
 806                 } else {
 807                         pname = file->name;
 808                         strbuf_release(&buf);
 809                 }
 810         } else {
 811                 pname = pprint_rename(file->from_name, file->name);
 812         }
 813         file->print_name = pname;
 814 }
 815
 816 static void show_stats(struct diffstat_t* data, struct diff_options *options)
 817 {
 818         int i, len, add, del, total, adds = 0, dels = 0;
 819         int max_change = 0, max_len = 0;
 820         int total_files = data->nr;
 821         int width, name_width;
 822         const char *reset, *set, *add_c, *del_c;
 823
 824         if (data->nr == 0)
 825                 return;
 826
 827         width = options->stat_width ? options->stat_width : 80;
 828         name_width = options->stat_name_width ? options->stat_name_width : 50;
 829
 830         /* Sanity: give at least 5 columns to the graph,
 831          * but leave at least 10 columns for the name.
 832          */
 833         if (width < 25)
 834                 width = 25;
 835         if (name_width < 10)
 836                 name_width = 10;
 837         else if (width < name_width + 15)
 838                 name_width = width - 15;
 839
 840         /* Find the longest filename and max number of changes */
 841         reset = diff_get_color_opt(options, DIFF_RESET);
 842         set   = diff_get_color_opt(options, DIFF_PLAIN);
 843         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 844         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 845
 846         for (i = 0; i < data->nr; i++) {
 847                 struct diffstat_file *file = data->files[i];
 848                 int change = file->added + file->deleted;
 849                 fill_print_name(file);
 850                 len = strlen(file->print_name);
 851                 if (max_len < len)
 852                         max_len = len;
 853
 854                 if (file->is_binary || file->is_unmerged)
 855                         continue;
 856                 if (max_change < change)
 857                         max_change = change;
 858         }
 859
 860         /* Compute the width of the graph part;
 861          * 10 is for one blank at the beginning of the line plus
 862          * " | count " between the name and the graph.
 863          *
 864          * From here on, name_width is the width of the name area,
 865          * and width is the width of the graph area.
 866          */
 867         name_width = (name_width < max_len) ? name_width : max_len;
 868         if (width < (name_width + 10) + max_change)
 869                 width = width - (name_width + 10);
 870         else
 871                 width = max_change;
 872
 873         for (i = 0; i < data->nr; i++) {
 874                 const char *prefix = "";
 875                 char *name = data->files[i]->print_name;
 876                 int added = data->files[i]->added;
 877                 int deleted = data->files[i]->deleted;
 878                 int name_len;
 879
 880                 /*
 881                  * "scale" the filename
 882                  */
 883                 len = name_width;
 884                 name_len = strlen(name);
 885                 if (name_width < name_len) {
 886                         char *slash;
 887                         prefix = "...";
 888                         len -= 3;
 889                         name += name_len - len;
 890                         slash = strchr(name, '/');
 891                         if (slash)
 892                                 name = slash;
 893                 }
 894
 895                 if (data->files[i]->is_binary) {
 896                         show_name(options->file, prefix, name, len, reset, set);
 897                         fprintf(options->file, "  Bin ");
 898                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 899                         fprintf(options->file, " -> ");
 900                         fprintf(options->file, "%s%d%s", add_c, added, reset);
 901                         fprintf(options->file, " bytes");
 902                         fprintf(options->file, "\n");
 903                         continue;
 904                 }
 905                 else if (data->files[i]->is_unmerged) {
 906                         show_name(options->file, prefix, name, len, reset, set);
 907                         fprintf(options->file, "  Unmerged\n");
 908                         continue;
 909                 }
 910                 else if (!data->files[i]->is_renamed &&
 911                          (added + deleted == 0)) {
 912                         total_files--;
 913                         continue;
 914                 }
 915
 916                 /*
 917                  * scale the add/delete
 918                  */
 919                 add = added;
 920                 del = deleted;
 921                 total = add + del;
 922                 adds += add;
 923                 dels += del;
 924
 925                 if (width <= max_change) {
 926                         add = scale_linear(add, width, max_change);
 927                         del = scale_linear(del, width, max_change);
 928                         total = add + del;
 929                 }
 930                 show_name(options->file, prefix, name, len, reset, set);
 931                 fprintf(options->file, "%5d%s", added + deleted,
 932                                 added + deleted ? " " : "");
 933                 show_graph(options->file, '+', add, add_c, reset);
 934                 show_graph(options->file, '-', del, del_c, reset);
 935                 fprintf(options->file, "\n");
 936         }
 937         fprintf(options->file,
 938                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 939                set, total_files, adds, dels, reset);
 940 }
 941
 942 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 943 {
 944         int i, adds = 0, dels = 0, total_files = data->nr;
 945
 946         if (data->nr == 0)
 947                 return;
 948
 949         for (i = 0; i < data->nr; i++) {
 950                 if (!data->files[i]->is_binary &&
 951                     !data->files[i]->is_unmerged) {
 952                         int added = data->files[i]->added;
 953                         int deleted= data->files[i]->deleted;
 954                         if (!data->files[i]->is_renamed &&
 955                             (added + deleted == 0)) {
 956                                 total_files--;
 957                         } else {
 958                                 adds += added;
 959                                 dels += deleted;
 960                         }
 961                 }
 962         }
 963         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 964                total_files, adds, dels);
 965 }
 966
 967 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 968 {
 969         int i;
 970
 971         if (data->nr == 0)
 972                 return;
 973
 974         for (i = 0; i < data->nr; i++) {
 975                 struct diffstat_file *file = data->files[i];
 976
 977                 if (file->is_binary)
 978                         fprintf(options->file, "-\t-\t");
 979                 else
 980                         fprintf(options->file,
 981                                 "%d\t%d\t", file->added, file->deleted);
 982                 if (options->line_termination) {
 983                         fill_print_name(file);
 984                         if (!file->is_renamed)
 985                                 write_name_quoted(file->name, options->file,
 986                                                   options->line_termination);
 987                         else {
 988                                 fputs(file->print_name, options->file);
 989                                 putc(options->line_termination, options->file);
 990                         }
 991                 } else {
 992                         if (file->is_renamed) {
 993                                 putc('\0', options->file);
 994                                 write_name_quoted(file->from_name, options->file, '\0');
 995                         }
 996                         write_name_quoted(file->name, options->file, '\0');
 997                 }
 998         }
 999 }
1000
1001 struct dirstat_file {
1002         const char *name;
1003         unsigned long changed;
1004 };
1005
1006 struct dirstat_dir {
1007         struct dirstat_file *files;
1008         int alloc, nr, percent, cumulative;
1009 };
1010
1011 static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1012 {
1013         unsigned long this_dir = 0;
1014         unsigned int sources = 0;
1015
1016         while (dir->nr) {
1017                 struct dirstat_file *f = dir->files;
1018                 int namelen = strlen(f->name);
1019                 unsigned long this;
1020                 char *slash;
1021
1022                 if (namelen < baselen)
1023                         break;
1024                 if (memcmp(f->name, base, baselen))
1025                         break;
1026                 slash = strchr(f->name + baselen, '/');
1027                 if (slash) {
1028                         int newbaselen = slash + 1 - f->name;
1029                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1030                         sources++;
1031                 } else {
1032                         this = f->changed;
1033                         dir->files++;
1034                         dir->nr--;
1035                         sources += 2;
1036                 }
1037                 this_dir += this;
1038         }
1039
1040         /*
1041          * We don't report dirstat's for
1042          *  - the top level
1043          *  - or cases where everything came from a single directory
1044          *    under this directory (sources == 1).
1045          */
1046         if (baselen && sources != 1) {
1047                 int permille = this_dir * 1000 / changed;
1048                 if (permille) {
1049                         int percent = permille / 10;
1050                         if (percent >= dir->percent) {
1051                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1052                                 if (!dir->cumulative)
1053                                         return 0;
1054                         }
1055                 }
1056         }
1057         return this_dir;
1058 }
1059
1060 static 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 = options->output_format & DIFF_FORMAT_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.
1104                  */
1105                 damage = (p->one->size - copied) + added;
1106
1107                 ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1108                 dir.files[dir.nr].name = name;
1109                 dir.files[dir.nr].changed = damage;
1110                 changed += damage;
1111                 dir.nr++;
1112         }
1113
1114         /* This can happen even with many files, if everything was renames */
1115         if (!changed)
1116                 return;
1117
1118         /* Show all directories with more than x% of the changes */
1119         gather_dirstat(options->file, &dir, changed, "", 0);
1120 }
1121
1122 static void free_diffstat_info(struct diffstat_t *diffstat)
1123 {
1124         int i;
1125         for (i = 0; i < diffstat->nr; i++) {
1126                 struct diffstat_file *f = diffstat->files[i];
1127                 if (f->name != f->print_name)
1128                         free(f->print_name);
1129                 free(f->name);
1130                 free(f->from_name);
1131                 free(f);
1132         }
1133         free(diffstat->files);
1134 }
1135
1136 struct checkdiff_t {
1137         struct xdiff_emit_state xm;
1138         const char *filename;
1139         int lineno, color_diff;
1140         unsigned ws_rule;
1141         unsigned status;
1142         FILE *file;
1143 };
1144
1145 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1146 {
1147         struct checkdiff_t *data = priv;
1148         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
1149         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
1150         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
1151         char *err;
1152
1153         if (line[0] == '+') {
1154                 unsigned bad;
1155                 data->lineno++;
1156                 bad = check_and_emit_line(line + 1, len - 1,
1157                     data->ws_rule, NULL, NULL, NULL, NULL);
1158                 if (!bad)
1159                         return;
1160                 data->status |= bad;
1161                 err = whitespace_error_string(bad);
1162                 fprintf(data->file, "%s:%d: %s.\n", data->filename, data->lineno, err);
1163                 free(err);
1164                 emit_line(data->file, set, reset, line, 1);
1165                 (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
1166                     data->file, set, reset, ws);
1167         } else if (line[0] == ' ')
1168                 data->lineno++;
1169         else if (line[0] == '@') {
1170                 char *plus = strchr(line, '+');
1171                 if (plus)
1172                         data->lineno = strtol(plus, NULL, 10) - 1;
1173                 else
1174                         die("invalid diff");
1175         }
1176 }
1177
1178 static unsigned char *deflate_it(char *data,
1179                                  unsigned long size,
1180                                  unsigned long *result_size)
1181 {
1182         int bound;
1183         unsigned char *deflated;
1184         z_stream stream;
1185
1186         memset(&stream, 0, sizeof(stream));
1187         deflateInit(&stream, zlib_compression_level);
1188         bound = deflateBound(&stream, size);
1189         deflated = xmalloc(bound);
1190         stream.next_out = deflated;
1191         stream.avail_out = bound;
1192
1193         stream.next_in = (unsigned char *)data;
1194         stream.avail_in = size;
1195         while (deflate(&stream, Z_FINISH) == Z_OK)
1196                 ; /* nothing */
1197         deflateEnd(&stream);
1198         *result_size = stream.total_out;
1199         return deflated;
1200 }
1201
1202 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1203 {
1204         void *cp;
1205         void *delta;
1206         void *deflated;
1207         void *data;
1208         unsigned long orig_size;
1209         unsigned long delta_size;
1210         unsigned long deflate_size;
1211         unsigned long data_size;
1212
1213         /* We could do deflated delta, or we could do just deflated two,
1214          * whichever is smaller.
1215          */
1216         delta = NULL;
1217         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1218         if (one->size && two->size) {
1219                 delta = diff_delta(one->ptr, one->size,
1220                                    two->ptr, two->size,
1221                                    &delta_size, deflate_size);
1222                 if (delta) {
1223                         void *to_free = delta;
1224                         orig_size = delta_size;
1225                         delta = deflate_it(delta, delta_size, &delta_size);
1226                         free(to_free);
1227                 }
1228         }
1229
1230         if (delta && delta_size < deflate_size) {
1231                 fprintf(file, "delta %lu\n", orig_size);
1232                 free(deflated);
1233                 data = delta;
1234                 data_size = delta_size;
1235         }
1236         else {
1237                 fprintf(file, "literal %lu\n", two->size);
1238                 free(delta);
1239                 data = deflated;
1240                 data_size = deflate_size;
1241         }
1242
1243         /* emit data encoded in base85 */
1244         cp = data;
1245         while (data_size) {
1246                 int bytes = (52 < data_size) ? 52 : data_size;
1247                 char line[70];
1248                 data_size -= bytes;
1249                 if (bytes <= 26)
1250                         line[0] = bytes + 'A' - 1;
1251                 else
1252                         line[0] = bytes - 26 + 'a' - 1;
1253                 encode_85(line + 1, cp, bytes);
1254                 cp = (char *) cp + bytes;
1255                 fputs(line, file);
1256                 fputc('\n', file);
1257         }
1258         fprintf(file, "\n");
1259         free(data);
1260 }
1261
1262 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1263 {
1264         fprintf(file, "GIT binary patch\n");
1265         emit_binary_diff_body(file, one, two);
1266         emit_binary_diff_body(file, two, one);
1267 }
1268
1269 static void setup_diff_attr_check(struct git_attr_check *check)
1270 {
1271         static struct git_attr *attr_diff;
1272
1273         if (!attr_diff) {
1274                 attr_diff = git_attr("diff", 4);
1275         }
1276         check[0].attr = attr_diff;
1277 }
1278
1279 static void diff_filespec_check_attr(struct diff_filespec *one)
1280 {
1281         struct git_attr_check attr_diff_check;
1282         int check_from_data = 0;
1283
1284         if (one->checked_attr)
1285                 return;
1286
1287         setup_diff_attr_check(&attr_diff_check);
1288         one->is_binary = 0;
1289         one->funcname_pattern_ident = NULL;
1290
1291         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1292                 const char *value;
1293
1294                 /* binaryness */
1295                 value = attr_diff_check.value;
1296                 if (ATTR_TRUE(value))
1297                         ;
1298                 else if (ATTR_FALSE(value))
1299                         one->is_binary = 1;
1300                 else
1301                         check_from_data = 1;
1302
1303                 /* funcname pattern ident */
1304                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1305                         ;
1306                 else
1307                         one->funcname_pattern_ident = value;
1308         }
1309
1310         if (check_from_data) {
1311                 if (!one->data && DIFF_FILE_VALID(one))
1312                         diff_populate_filespec(one, 0);
1313
1314                 if (one->data)
1315                         one->is_binary = buffer_is_binary(one->data, one->size);
1316         }
1317 }
1318
1319 int diff_filespec_is_binary(struct diff_filespec *one)
1320 {
1321         diff_filespec_check_attr(one);
1322         return one->is_binary;
1323 }
1324
1325 static const char *funcname_pattern(const char *ident)
1326 {
1327         struct funcname_pattern *pp;
1328
1329         for (pp = funcname_pattern_list; pp; pp = pp->next)
1330                 if (!strcmp(ident, pp->name))
1331                         return pp->pattern;
1332         return NULL;
1333 }
1334
1335 static struct builtin_funcname_pattern {
1336         const char *name;
1337         const char *pattern;
1338 } builtin_funcname_pattern[] = {
1339         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1340                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1341                         "^[     ]*\\(\\([       ]*"
1342                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1343                         "[      ]*([^;]*\\)$" },
1344         { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1345 };
1346
1347 static const char *diff_funcname_pattern(struct diff_filespec *one)
1348 {
1349         const char *ident, *pattern;
1350         int i;
1351
1352         diff_filespec_check_attr(one);
1353         ident = one->funcname_pattern_ident;
1354
1355         if (!ident)
1356                 /*
1357                  * If the config file has "funcname.default" defined, that
1358                  * regexp is used; otherwise NULL is returned and xemit uses
1359                  * the built-in default.
1360                  */
1361                 return funcname_pattern("default");
1362
1363         /* Look up custom "funcname.$ident" regexp from config. */
1364         pattern = funcname_pattern(ident);
1365         if (pattern)
1366                 return pattern;
1367
1368         /*
1369          * And define built-in fallback patterns here.  Note that
1370          * these can be overridden by the user's config settings.
1371          */
1372         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1373                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1374                         return builtin_funcname_pattern[i].pattern;
1375
1376         return NULL;
1377 }
1378
1379 static void builtin_diff(const char *name_a,
1380                          const char *name_b,
1381                          struct diff_filespec *one,
1382                          struct diff_filespec *two,
1383                          const char *xfrm_msg,
1384                          struct diff_options *o,
1385                          int complete_rewrite)
1386 {
1387         mmfile_t mf1, mf2;
1388         const char *lbl[2];
1389         char *a_one, *b_two;
1390         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1391         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1392
1393         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1394         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1395         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1396         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1397         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1398         if (lbl[0][0] == '/') {
1399                 /* /dev/null */
1400                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1401                 if (xfrm_msg && xfrm_msg[0])
1402                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1403         }
1404         else if (lbl[1][0] == '/') {
1405                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1406                 if (xfrm_msg && xfrm_msg[0])
1407                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1408         }
1409         else {
1410                 if (one->mode != two->mode) {
1411                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1412                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1413                 }
1414                 if (xfrm_msg && xfrm_msg[0])
1415                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1416                 /*
1417                  * we do not run diff between different kind
1418                  * of objects.
1419                  */
1420                 if ((one->mode ^ two->mode) & S_IFMT)
1421                         goto free_ab_and_return;
1422                 if (complete_rewrite) {
1423                         emit_rewrite_diff(name_a, name_b, one, two, o);
1424                         o->found_changes = 1;
1425                         goto free_ab_and_return;
1426                 }
1427         }
1428
1429         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1430                 die("unable to read files to diff");
1431
1432         if (!DIFF_OPT_TST(o, TEXT) &&
1433             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1434                 /* Quite common confusing case */
1435                 if (mf1.size == mf2.size &&
1436                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1437                         goto free_ab_and_return;
1438                 if (DIFF_OPT_TST(o, BINARY))
1439                         emit_binary_diff(o->file, &mf1, &mf2);
1440                 else
1441                         fprintf(o->file, "Binary files %s and %s differ\n",
1442                                 lbl[0], lbl[1]);
1443                 o->found_changes = 1;
1444         }
1445         else {
1446                 /* Crazy xdl interfaces.. */
1447                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1448                 xpparam_t xpp;
1449                 xdemitconf_t xecfg;
1450                 xdemitcb_t ecb;
1451                 struct emit_callback ecbdata;
1452                 const char *funcname_pattern;
1453
1454                 funcname_pattern = diff_funcname_pattern(one);
1455                 if (!funcname_pattern)
1456                         funcname_pattern = diff_funcname_pattern(two);
1457
1458                 memset(&xecfg, 0, sizeof(xecfg));
1459                 memset(&ecbdata, 0, sizeof(ecbdata));
1460                 ecbdata.label_path = lbl;
1461                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1462                 ecbdata.found_changesp = &o->found_changes;
1463                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1464                 ecbdata.file = o->file;
1465                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1466                 xecfg.ctxlen = o->context;
1467                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1468                 if (funcname_pattern)
1469                         xdiff_set_find_func(&xecfg, funcname_pattern);
1470                 if (!diffopts)
1471                         ;
1472                 else if (!prefixcmp(diffopts, "--unified="))
1473                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1474                 else if (!prefixcmp(diffopts, "-u"))
1475                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1476                 ecb.outf = xdiff_outf;
1477                 ecb.priv = &ecbdata;
1478                 ecbdata.xm.consume = fn_out_consume;
1479                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1480                         ecbdata.diff_words =
1481                                 xcalloc(1, sizeof(struct diff_words_data));
1482                         ecbdata.diff_words->file = o->file;
1483                 }
1484                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1485                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1486                         free_diff_words_data(&ecbdata);
1487         }
1488
1489  free_ab_and_return:
1490         diff_free_filespec_data(one);
1491         diff_free_filespec_data(two);
1492         free(a_one);
1493         free(b_two);
1494         return;
1495 }
1496
1497 static void builtin_diffstat(const char *name_a, const char *name_b,
1498                              struct diff_filespec *one,
1499                              struct diff_filespec *two,
1500                              struct diffstat_t *diffstat,
1501                              struct diff_options *o,
1502                              int complete_rewrite)
1503 {
1504         mmfile_t mf1, mf2;
1505         struct diffstat_file *data;
1506
1507         data = diffstat_add(diffstat, name_a, name_b);
1508
1509         if (!one || !two) {
1510                 data->is_unmerged = 1;
1511                 return;
1512         }
1513         if (complete_rewrite) {
1514                 diff_populate_filespec(one, 0);
1515                 diff_populate_filespec(two, 0);
1516                 data->deleted = count_lines(one->data, one->size);
1517                 data->added = count_lines(two->data, two->size);
1518                 goto free_and_return;
1519         }
1520         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1521                 die("unable to read files to diff");
1522
1523         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1524                 data->is_binary = 1;
1525                 data->added = mf2.size;
1526                 data->deleted = mf1.size;
1527         } else {
1528                 /* Crazy xdl interfaces.. */
1529                 xpparam_t xpp;
1530                 xdemitconf_t xecfg;
1531                 xdemitcb_t ecb;
1532
1533                 memset(&xecfg, 0, sizeof(xecfg));
1534                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1535                 ecb.outf = xdiff_outf;
1536                 ecb.priv = diffstat;
1537                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1538         }
1539
1540  free_and_return:
1541         diff_free_filespec_data(one);
1542         diff_free_filespec_data(two);
1543 }
1544
1545 static void builtin_checkdiff(const char *name_a, const char *name_b,
1546                               const char *attr_path,
1547                              struct diff_filespec *one,
1548                              struct diff_filespec *two, struct diff_options *o)
1549 {
1550         mmfile_t mf1, mf2;
1551         struct checkdiff_t data;
1552
1553         if (!two)
1554                 return;
1555
1556         memset(&data, 0, sizeof(data));
1557         data.xm.consume = checkdiff_consume;
1558         data.filename = name_b ? name_b : name_a;
1559         data.lineno = 0;
1560         data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1561         data.ws_rule = whitespace_rule(attr_path);
1562         data.file = o->file;
1563
1564         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1565                 die("unable to read files to diff");
1566
1567         if (diff_filespec_is_binary(two))
1568                 goto free_and_return;
1569         else {
1570                 /* Crazy xdl interfaces.. */
1571                 xpparam_t xpp;
1572                 xdemitconf_t xecfg;
1573                 xdemitcb_t ecb;
1574
1575                 memset(&xecfg, 0, sizeof(xecfg));
1576                 xpp.flags = XDF_NEED_MINIMAL;
1577                 ecb.outf = xdiff_outf;
1578                 ecb.priv = &data;
1579                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1580         }
1581  free_and_return:
1582         diff_free_filespec_data(one);
1583         diff_free_filespec_data(two);
1584         if (data.status)
1585                 DIFF_OPT_SET(o, CHECK_FAILED);
1586 }
1587
1588 struct diff_filespec *alloc_filespec(const char *path)
1589 {
1590         int namelen = strlen(path);
1591         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1592
1593         memset(spec, 0, sizeof(*spec));
1594         spec->path = (char *)(spec + 1);
1595         memcpy(spec->path, path, namelen+1);
1596         spec->count = 1;
1597         return spec;
1598 }
1599
1600 void free_filespec(struct diff_filespec *spec)
1601 {
1602         if (!--spec->count) {
1603                 diff_free_filespec_data(spec);
1604                 free(spec);
1605         }
1606 }
1607
1608 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1609                    unsigned short mode)
1610 {
1611         if (mode) {
1612                 spec->mode = canon_mode(mode);
1613                 hashcpy(spec->sha1, sha1);
1614                 spec->sha1_valid = !is_null_sha1(sha1);
1615         }
1616 }
1617
1618 /*
1619  * Given a name and sha1 pair, if the index tells us the file in
1620  * the work tree has that object contents, return true, so that
1621  * prepare_temp_file() does not have to inflate and extract.
1622  */
1623 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1624 {
1625         struct cache_entry *ce;
1626         struct stat st;
1627         int pos, len;
1628
1629         /* We do not read the cache ourselves here, because the
1630          * benchmark with my previous version that always reads cache
1631          * shows that it makes things worse for diff-tree comparing
1632          * two linux-2.6 kernel trees in an already checked out work
1633          * tree.  This is because most diff-tree comparisons deal with
1634          * only a small number of files, while reading the cache is
1635          * expensive for a large project, and its cost outweighs the
1636          * savings we get by not inflating the object to a temporary
1637          * file.  Practically, this code only helps when we are used
1638          * by diff-cache --cached, which does read the cache before
1639          * calling us.
1640          */
1641         if (!active_cache)
1642                 return 0;
1643
1644         /* We want to avoid the working directory if our caller
1645          * doesn't need the data in a normal file, this system
1646          * is rather slow with its stat/open/mmap/close syscalls,
1647          * and the object is contained in a pack file.  The pack
1648          * is probably already open and will be faster to obtain
1649          * the data through than the working directory.  Loose
1650          * objects however would tend to be slower as they need
1651          * to be individually opened and inflated.
1652          */
1653         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1654                 return 0;
1655
1656         len = strlen(name);
1657         pos = cache_name_pos(name, len);
1658         if (pos < 0)
1659                 return 0;
1660         ce = active_cache[pos];
1661
1662         /*
1663          * This is not the sha1 we are looking for, or
1664          * unreusable because it is not a regular file.
1665          */
1666         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1667                 return 0;
1668
1669         /*
1670          * If ce matches the file in the work tree, we can reuse it.
1671          */
1672         if (ce_uptodate(ce) ||
1673             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1674                 return 1;
1675
1676         return 0;
1677 }
1678
1679 static int populate_from_stdin(struct diff_filespec *s)
1680 {
1681         struct strbuf buf;
1682         size_t size = 0;
1683
1684         strbuf_init(&buf, 0);
1685         if (strbuf_read(&buf, 0, 0) < 0)
1686                 return error("error while reading from stdin %s",
1687                                      strerror(errno));
1688
1689         s->should_munmap = 0;
1690         s->data = strbuf_detach(&buf, &size);
1691         s->size = size;
1692         s->should_free = 1;
1693         return 0;
1694 }
1695
1696 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1697 {
1698         int len;
1699         char *data = xmalloc(100);
1700         len = snprintf(data, 100,
1701                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1702         s->data = data;
1703         s->size = len;
1704         s->should_free = 1;
1705         if (size_only) {
1706                 s->data = NULL;
1707                 free(data);
1708         }
1709         return 0;
1710 }
1711
1712 /*
1713  * While doing rename detection and pickaxe operation, we may need to
1714  * grab the data for the blob (or file) for our own in-core comparison.
1715  * diff_filespec has data and size fields for this purpose.
1716  */
1717 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1718 {
1719         int err = 0;
1720         if (!DIFF_FILE_VALID(s))
1721                 die("internal error: asking to populate invalid file.");
1722         if (S_ISDIR(s->mode))
1723                 return -1;
1724
1725         if (s->data)
1726                 return 0;
1727
1728         if (size_only && 0 < s->size)
1729                 return 0;
1730
1731         if (S_ISGITLINK(s->mode))
1732                 return diff_populate_gitlink(s, size_only);
1733
1734         if (!s->sha1_valid ||
1735             reuse_worktree_file(s->path, s->sha1, 0)) {
1736                 struct strbuf buf;
1737                 struct stat st;
1738                 int fd;
1739
1740                 if (!strcmp(s->path, "-"))
1741                         return populate_from_stdin(s);
1742
1743                 if (lstat(s->path, &st) < 0) {
1744                         if (errno == ENOENT) {
1745                         err_empty:
1746                                 err = -1;
1747                         empty:
1748                                 s->data = (char *)"";
1749                                 s->size = 0;
1750                                 return err;
1751                         }
1752                 }
1753                 s->size = xsize_t(st.st_size);
1754                 if (!s->size)
1755                         goto empty;
1756                 if (size_only)
1757                         return 0;
1758                 if (S_ISLNK(st.st_mode)) {
1759                         int ret;
1760                         s->data = xmalloc(s->size);
1761                         s->should_free = 1;
1762                         ret = readlink(s->path, s->data, s->size);
1763                         if (ret < 0) {
1764                                 free(s->data);
1765                                 goto err_empty;
1766                         }
1767                         return 0;
1768                 }
1769                 fd = open(s->path, O_RDONLY);
1770                 if (fd < 0)
1771                         goto err_empty;
1772                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1773                 close(fd);
1774                 s->should_munmap = 1;
1775
1776                 /*
1777                  * Convert from working tree format to canonical git format
1778                  */
1779                 strbuf_init(&buf, 0);
1780                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1781                         size_t size = 0;
1782                         munmap(s->data, s->size);
1783                         s->should_munmap = 0;
1784                         s->data = strbuf_detach(&buf, &size);
1785                         s->size = size;
1786                         s->should_free = 1;
1787                 }
1788         }
1789         else {
1790                 enum object_type type;
1791                 if (size_only)
1792                         type = sha1_object_info(s->sha1, &s->size);
1793                 else {
1794                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1795                         s->should_free = 1;
1796                 }
1797         }
1798         return 0;
1799 }
1800
1801 void diff_free_filespec_blob(struct diff_filespec *s)
1802 {
1803         if (s->should_free)
1804                 free(s->data);
1805         else if (s->should_munmap)
1806                 munmap(s->data, s->size);
1807
1808         if (s->should_free || s->should_munmap) {
1809                 s->should_free = s->should_munmap = 0;
1810                 s->data = NULL;
1811         }
1812 }
1813
1814 void diff_free_filespec_data(struct diff_filespec *s)
1815 {
1816         diff_free_filespec_blob(s);
1817         free(s->cnt_data);
1818         s->cnt_data = NULL;
1819 }
1820
1821 static void prep_temp_blob(struct diff_tempfile *temp,
1822                            void *blob,
1823                            unsigned long size,
1824                            const unsigned char *sha1,
1825                            int mode)
1826 {
1827         int fd;
1828
1829         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1830         if (fd < 0)
1831                 die("unable to create temp-file: %s", strerror(errno));
1832         if (write_in_full(fd, blob, size) != size)
1833                 die("unable to write temp-file");
1834         close(fd);
1835         temp->name = temp->tmp_path;
1836         strcpy(temp->hex, sha1_to_hex(sha1));
1837         temp->hex[40] = 0;
1838         sprintf(temp->mode, "%06o", mode);
1839 }
1840
1841 static void prepare_temp_file(const char *name,
1842                               struct diff_tempfile *temp,
1843                               struct diff_filespec *one)
1844 {
1845         if (!DIFF_FILE_VALID(one)) {
1846         not_a_valid_file:
1847                 /* A '-' entry produces this for file-2, and
1848                  * a '+' entry produces this for file-1.
1849                  */
1850                 temp->name = "/dev/null";
1851                 strcpy(temp->hex, ".");
1852                 strcpy(temp->mode, ".");
1853                 return;
1854         }
1855
1856         if (!one->sha1_valid ||
1857             reuse_worktree_file(name, one->sha1, 1)) {
1858                 struct stat st;
1859                 if (lstat(name, &st) < 0) {
1860                         if (errno == ENOENT)
1861                                 goto not_a_valid_file;
1862                         die("stat(%s): %s", name, strerror(errno));
1863                 }
1864                 if (S_ISLNK(st.st_mode)) {
1865                         int ret;
1866                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1867                         size_t sz = xsize_t(st.st_size);
1868                         if (sizeof(buf) <= st.st_size)
1869                                 die("symlink too long: %s", name);
1870                         ret = readlink(name, buf, sz);
1871                         if (ret < 0)
1872                                 die("readlink(%s)", name);
1873                         prep_temp_blob(temp, buf, sz,
1874                                        (one->sha1_valid ?
1875                                         one->sha1 : null_sha1),
1876                                        (one->sha1_valid ?
1877                                         one->mode : S_IFLNK));
1878                 }
1879                 else {
1880                         /* we can borrow from the file in the work tree */
1881                         temp->name = name;
1882                         if (!one->sha1_valid)
1883                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1884                         else
1885                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1886                         /* Even though we may sometimes borrow the
1887                          * contents from the work tree, we always want
1888                          * one->mode.  mode is trustworthy even when
1889                          * !(one->sha1_valid), as long as
1890                          * DIFF_FILE_VALID(one).
1891                          */
1892                         sprintf(temp->mode, "%06o", one->mode);
1893                 }
1894                 return;
1895         }
1896         else {
1897                 if (diff_populate_filespec(one, 0))
1898                         die("cannot read data blob for %s", one->path);
1899                 prep_temp_blob(temp, one->data, one->size,
1900                                one->sha1, one->mode);
1901         }
1902 }
1903
1904 static void remove_tempfile(void)
1905 {
1906         int i;
1907
1908         for (i = 0; i < 2; i++)
1909                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1910                         unlink(diff_temp[i].name);
1911                         diff_temp[i].name = NULL;
1912                 }
1913 }
1914
1915 static void remove_tempfile_on_signal(int signo)
1916 {
1917         remove_tempfile();
1918         signal(SIGINT, SIG_DFL);
1919         raise(signo);
1920 }
1921
1922 /* An external diff command takes:
1923  *
1924  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1925  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1926  *
1927  */
1928 static void run_external_diff(const char *pgm,
1929                               const char *name,
1930                               const char *other,
1931                               struct diff_filespec *one,
1932                               struct diff_filespec *two,
1933                               const char *xfrm_msg,
1934                               int complete_rewrite)
1935 {
1936         const char *spawn_arg[10];
1937         struct diff_tempfile *temp = diff_temp;
1938         int retval;
1939         static int atexit_asked = 0;
1940         const char *othername;
1941         const char **arg = &spawn_arg[0];
1942
1943         othername = (other? other : name);
1944         if (one && two) {
1945                 prepare_temp_file(name, &temp[0], one);
1946                 prepare_temp_file(othername, &temp[1], two);
1947                 if (! atexit_asked &&
1948                     (temp[0].name == temp[0].tmp_path ||
1949                      temp[1].name == temp[1].tmp_path)) {
1950                         atexit_asked = 1;
1951                         atexit(remove_tempfile);
1952                 }
1953                 signal(SIGINT, remove_tempfile_on_signal);
1954         }
1955
1956         if (one && two) {
1957                 *arg++ = pgm;
1958                 *arg++ = name;
1959                 *arg++ = temp[0].name;
1960                 *arg++ = temp[0].hex;
1961                 *arg++ = temp[0].mode;
1962                 *arg++ = temp[1].name;
1963                 *arg++ = temp[1].hex;
1964                 *arg++ = temp[1].mode;
1965                 if (other) {
1966                         *arg++ = other;
1967                         *arg++ = xfrm_msg;
1968                 }
1969         } else {
1970                 *arg++ = pgm;
1971                 *arg++ = name;
1972         }
1973         *arg = NULL;
1974         fflush(NULL);
1975         retval = run_command_v_opt(spawn_arg, 0);
1976         remove_tempfile();
1977         if (retval) {
1978                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1979                 exit(1);
1980         }
1981 }
1982
1983 static const char *external_diff_attr(const char *name)
1984 {
1985         struct git_attr_check attr_diff_check;
1986
1987         if (!name)
1988                 return NULL;
1989
1990         setup_diff_attr_check(&attr_diff_check);
1991         if (!git_checkattr(name, 1, &attr_diff_check)) {
1992                 const char *value = attr_diff_check.value;
1993                 if (!ATTR_TRUE(value) &&
1994                     !ATTR_FALSE(value) &&
1995                     !ATTR_UNSET(value)) {
1996                         struct ll_diff_driver *drv;
1997
1998                         for (drv = user_diff; drv; drv = drv->next)
1999                                 if (!strcmp(drv->name, value))
2000                                         return drv->cmd;
2001                 }
2002         }
2003         return NULL;
2004 }
2005
2006 static void run_diff_cmd(const char *pgm,
2007                          const char *name,
2008                          const char *other,
2009                          const char *attr_path,
2010                          struct diff_filespec *one,
2011                          struct diff_filespec *two,
2012                          const char *xfrm_msg,
2013                          struct diff_options *o,
2014                          int complete_rewrite)
2015 {
2016         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2017                 pgm = NULL;
2018         else {
2019                 const char *cmd = external_diff_attr(attr_path);
2020                 if (cmd)
2021                         pgm = cmd;
2022         }
2023
2024         if (pgm) {
2025                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
2026                                   complete_rewrite);
2027                 return;
2028         }
2029         if (one && two)
2030                 builtin_diff(name, other ? other : name,
2031                              one, two, xfrm_msg, o, complete_rewrite);
2032         else
2033                 fprintf(o->file, "* Unmerged path %s\n", name);
2034 }
2035
2036 static void diff_fill_sha1_info(struct diff_filespec *one)
2037 {
2038         if (DIFF_FILE_VALID(one)) {
2039                 if (!one->sha1_valid) {
2040                         struct stat st;
2041                         if (!strcmp(one->path, "-")) {
2042                                 hashcpy(one->sha1, null_sha1);
2043                                 return;
2044                         }
2045                         if (lstat(one->path, &st) < 0)
2046                                 die("stat %s", one->path);
2047                         if (index_path(one->sha1, one->path, &st, 0))
2048                                 die("cannot hash %s\n", one->path);
2049                 }
2050         }
2051         else
2052                 hashclr(one->sha1);
2053 }
2054
2055 static int similarity_index(struct diff_filepair *p)
2056 {
2057         return p->score * 100 / MAX_SCORE;
2058 }
2059
2060 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2061 {
2062         /* Strip the prefix but do not molest /dev/null and absolute paths */
2063         if (*namep && **namep != '/')
2064                 *namep += prefix_length;
2065         if (*otherp && **otherp != '/')
2066                 *otherp += prefix_length;
2067 }
2068
2069 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2070 {
2071         const char *pgm = external_diff();
2072         struct strbuf msg;
2073         char *xfrm_msg;
2074         struct diff_filespec *one = p->one;
2075         struct diff_filespec *two = p->two;
2076         const char *name;
2077         const char *other;
2078         const char *attr_path;
2079         int complete_rewrite = 0;
2080
2081         name  = p->one->path;
2082         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2083         attr_path = name;
2084         if (o->prefix_length)
2085                 strip_prefix(o->prefix_length, &name, &other);
2086
2087         if (DIFF_PAIR_UNMERGED(p)) {
2088                 run_diff_cmd(pgm, name, NULL, attr_path,
2089                              NULL, NULL, NULL, o, 0);
2090                 return;
2091         }
2092
2093         diff_fill_sha1_info(one);
2094         diff_fill_sha1_info(two);
2095
2096         strbuf_init(&msg, PATH_MAX * 2 + 300);
2097         switch (p->status) {
2098         case DIFF_STATUS_COPIED:
2099                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2100                 strbuf_addstr(&msg, "\ncopy from ");
2101                 quote_c_style(name, &msg, NULL, 0);
2102                 strbuf_addstr(&msg, "\ncopy to ");
2103                 quote_c_style(other, &msg, NULL, 0);
2104                 strbuf_addch(&msg, '\n');
2105                 break;
2106         case DIFF_STATUS_RENAMED:
2107                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2108                 strbuf_addstr(&msg, "\nrename from ");
2109                 quote_c_style(name, &msg, NULL, 0);
2110                 strbuf_addstr(&msg, "\nrename to ");
2111                 quote_c_style(other, &msg, NULL, 0);
2112                 strbuf_addch(&msg, '\n');
2113                 break;
2114         case DIFF_STATUS_MODIFIED:
2115                 if (p->score) {
2116                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2117                                         similarity_index(p));
2118                         complete_rewrite = 1;
2119                         break;
2120                 }
2121                 /* fallthru */
2122         default:
2123                 /* nothing */
2124                 ;
2125         }
2126
2127         if (hashcmp(one->sha1, two->sha1)) {
2128                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2129
2130                 if (DIFF_OPT_TST(o, BINARY)) {
2131                         mmfile_t mf;
2132                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2133                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2134                                 abbrev = 40;
2135                 }
2136                 strbuf_addf(&msg, "index %.*s..%.*s",
2137                                 abbrev, sha1_to_hex(one->sha1),
2138                                 abbrev, sha1_to_hex(two->sha1));
2139                 if (one->mode == two->mode)
2140                         strbuf_addf(&msg, " %06o", one->mode);
2141                 strbuf_addch(&msg, '\n');
2142         }
2143
2144         if (msg.len)
2145                 strbuf_setlen(&msg, msg.len - 1);
2146         xfrm_msg = msg.len ? msg.buf : NULL;
2147
2148         if (!pgm &&
2149             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2150             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2151                 /* a filepair that changes between file and symlink
2152                  * needs to be split into deletion and creation.
2153                  */
2154                 struct diff_filespec *null = alloc_filespec(two->path);
2155                 run_diff_cmd(NULL, name, other, attr_path,
2156                              one, null, xfrm_msg, o, 0);
2157                 free(null);
2158                 null = alloc_filespec(one->path);
2159                 run_diff_cmd(NULL, name, other, attr_path,
2160                              null, two, xfrm_msg, o, 0);
2161                 free(null);
2162         }
2163         else
2164                 run_diff_cmd(pgm, name, other, attr_path,
2165                              one, two, xfrm_msg, o, complete_rewrite);
2166
2167         strbuf_release(&msg);
2168 }
2169
2170 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2171                          struct diffstat_t *diffstat)
2172 {
2173         const char *name;
2174         const char *other;
2175         int complete_rewrite = 0;
2176
2177         if (DIFF_PAIR_UNMERGED(p)) {
2178                 /* unmerged */
2179                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2180                 return;
2181         }
2182
2183         name = p->one->path;
2184         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2185
2186         if (o->prefix_length)
2187                 strip_prefix(o->prefix_length, &name, &other);
2188
2189         diff_fill_sha1_info(p->one);
2190         diff_fill_sha1_info(p->two);
2191
2192         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2193                 complete_rewrite = 1;
2194         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2195 }
2196
2197 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2198 {
2199         const char *name;
2200         const char *other;
2201         const char *attr_path;
2202
2203         if (DIFF_PAIR_UNMERGED(p)) {
2204                 /* unmerged */
2205                 return;
2206         }
2207
2208         name = p->one->path;
2209         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2210         attr_path = other ? other : name;
2211
2212         if (o->prefix_length)
2213                 strip_prefix(o->prefix_length, &name, &other);
2214
2215         diff_fill_sha1_info(p->one);
2216         diff_fill_sha1_info(p->two);
2217
2218         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2219 }
2220
2221 void diff_setup(struct diff_options *options)
2222 {
2223         memset(options, 0, sizeof(*options));
2224
2225         options->file = stdout;
2226
2227         options->line_termination = '\n';
2228         options->break_opt = -1;
2229         options->rename_limit = -1;
2230         options->dirstat_percent = 3;
2231         options->context = 3;
2232
2233         options->change = diff_change;
2234         options->add_remove = diff_addremove;
2235         if (diff_use_color_default > 0)
2236                 DIFF_OPT_SET(options, COLOR_DIFF);
2237         else
2238                 DIFF_OPT_CLR(options, COLOR_DIFF);
2239         options->detect_rename = diff_detect_rename_default;
2240
2241         options->a_prefix = "a/";
2242         options->b_prefix = "b/";
2243 }
2244
2245 int diff_setup_done(struct diff_options *options)
2246 {
2247         int count = 0;
2248
2249         if (options->output_format & DIFF_FORMAT_NAME)
2250                 count++;
2251         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2252                 count++;
2253         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2254                 count++;
2255         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2256                 count++;
2257         if (count > 1)
2258                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2259
2260         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2261                 options->detect_rename = DIFF_DETECT_COPY;
2262
2263         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2264                 options->prefix = NULL;
2265         if (options->prefix)
2266                 options->prefix_length = strlen(options->prefix);
2267         else
2268                 options->prefix_length = 0;
2269
2270         if (options->output_format & (DIFF_FORMAT_NAME |
2271                                       DIFF_FORMAT_NAME_STATUS |
2272                                       DIFF_FORMAT_CHECKDIFF |
2273                                       DIFF_FORMAT_NO_OUTPUT))
2274                 options->output_format &= ~(DIFF_FORMAT_RAW |
2275                                             DIFF_FORMAT_NUMSTAT |
2276                                             DIFF_FORMAT_DIFFSTAT |
2277                                             DIFF_FORMAT_SHORTSTAT |
2278                                             DIFF_FORMAT_DIRSTAT |
2279                                             DIFF_FORMAT_SUMMARY |
2280                                             DIFF_FORMAT_PATCH);
2281
2282         /*
2283          * These cases always need recursive; we do not drop caller-supplied
2284          * recursive bits for other formats here.
2285          */
2286         if (options->output_format & (DIFF_FORMAT_PATCH |
2287                                       DIFF_FORMAT_NUMSTAT |
2288                                       DIFF_FORMAT_DIFFSTAT |
2289                                       DIFF_FORMAT_SHORTSTAT |
2290                                       DIFF_FORMAT_DIRSTAT |
2291                                       DIFF_FORMAT_SUMMARY |
2292                                       DIFF_FORMAT_CHECKDIFF))
2293                 DIFF_OPT_SET(options, RECURSIVE);
2294         /*
2295          * Also pickaxe would not work very well if you do not say recursive
2296          */
2297         if (options->pickaxe)
2298                 DIFF_OPT_SET(options, RECURSIVE);
2299
2300         if (options->detect_rename && options->rename_limit < 0)
2301                 options->rename_limit = diff_rename_limit_default;
2302         if (options->setup & DIFF_SETUP_USE_CACHE) {
2303                 if (!active_cache)
2304                         /* read-cache does not die even when it fails
2305                          * so it is safe for us to do this here.  Also
2306                          * it does not smudge active_cache or active_nr
2307                          * when it fails, so we do not have to worry about
2308                          * cleaning it up ourselves either.
2309                          */
2310                         read_cache();
2311         }
2312         if (options->abbrev <= 0 || 40 < options->abbrev)
2313                 options->abbrev = 40; /* full */
2314
2315         /*
2316          * It does not make sense to show the first hit we happened
2317          * to have found.  It does not make sense not to return with
2318          * exit code in such a case either.
2319          */
2320         if (DIFF_OPT_TST(options, QUIET)) {
2321                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2322                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2323         }
2324
2325         /*
2326          * If we postprocess in diffcore, we cannot simply return
2327          * upon the first hit.  We need to run diff as usual.
2328          */
2329         if (options->pickaxe || options->filter)
2330                 DIFF_OPT_CLR(options, QUIET);
2331
2332         return 0;
2333 }
2334
2335 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2336 {
2337         char c, *eq;
2338         int len;
2339
2340         if (*arg != '-')
2341                 return 0;
2342         c = *++arg;
2343         if (!c)
2344                 return 0;
2345         if (c == arg_short) {
2346                 c = *++arg;
2347                 if (!c)
2348                         return 1;
2349                 if (val && isdigit(c)) {
2350                         char *end;
2351                         int n = strtoul(arg, &end, 10);
2352                         if (*end)
2353                                 return 0;
2354                         *val = n;
2355                         return 1;
2356                 }
2357                 return 0;
2358         }
2359         if (c != '-')
2360                 return 0;
2361         arg++;
2362         eq = strchr(arg, '=');
2363         if (eq)
2364                 len = eq - arg;
2365         else
2366                 len = strlen(arg);
2367         if (!len || strncmp(arg, arg_long, len))
2368                 return 0;
2369         if (eq) {
2370                 int n;
2371                 char *end;
2372                 if (!isdigit(*++eq))
2373                         return 0;
2374                 n = strtoul(eq, &end, 10);
2375                 if (*end)
2376                         return 0;
2377                 *val = n;
2378         }
2379         return 1;
2380 }
2381
2382 static int diff_scoreopt_parse(const char *opt);
2383
2384 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2385 {
2386         const char *arg = av[0];
2387
2388         /* Output format options */
2389         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2390                 options->output_format |= DIFF_FORMAT_PATCH;
2391         else if (opt_arg(arg, 'U', "unified", &options->context))
2392                 options->output_format |= DIFF_FORMAT_PATCH;
2393         else if (!strcmp(arg, "--raw"))
2394                 options->output_format |= DIFF_FORMAT_RAW;
2395         else if (!strcmp(arg, "--patch-with-raw"))
2396                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2397         else if (!strcmp(arg, "--numstat"))
2398                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2399         else if (!strcmp(arg, "--shortstat"))
2400                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2401         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2402                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2403         else if (!strcmp(arg, "--cumulative"))
2404                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2405         else if (!strcmp(arg, "--check"))
2406                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2407         else if (!strcmp(arg, "--summary"))
2408                 options->output_format |= DIFF_FORMAT_SUMMARY;
2409         else if (!strcmp(arg, "--patch-with-stat"))
2410                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2411         else if (!strcmp(arg, "--name-only"))
2412                 options->output_format |= DIFF_FORMAT_NAME;
2413         else if (!strcmp(arg, "--name-status"))
2414                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2415         else if (!strcmp(arg, "-s"))
2416                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2417         else if (!prefixcmp(arg, "--stat")) {
2418                 char *end;
2419                 int width = options->stat_width;
2420                 int name_width = options->stat_name_width;
2421                 arg += 6;
2422                 end = (char *)arg;
2423
2424                 switch (*arg) {
2425                 case '-':
2426                         if (!prefixcmp(arg, "-width="))
2427                                 width = strtoul(arg + 7, &end, 10);
2428                         else if (!prefixcmp(arg, "-name-width="))
2429                                 name_width = strtoul(arg + 12, &end, 10);
2430                         break;
2431                 case '=':
2432                         width = strtoul(arg+1, &end, 10);
2433                         if (*end == ',')
2434                                 name_width = strtoul(end+1, &end, 10);
2435                 }
2436
2437                 /* Important! This checks all the error cases! */
2438                 if (*end)
2439                         return 0;
2440                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2441                 options->stat_name_width = name_width;
2442                 options->stat_width = width;
2443         }
2444
2445         /* renames options */
2446         else if (!prefixcmp(arg, "-B")) {
2447                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2448                         return -1;
2449         }
2450         else if (!prefixcmp(arg, "-M")) {
2451                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2452                         return -1;
2453                 options->detect_rename = DIFF_DETECT_RENAME;
2454         }
2455         else if (!prefixcmp(arg, "-C")) {
2456                 if (options->detect_rename == DIFF_DETECT_COPY)
2457                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2458                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2459                         return -1;
2460                 options->detect_rename = DIFF_DETECT_COPY;
2461         }
2462         else if (!strcmp(arg, "--no-renames"))
2463                 options->detect_rename = 0;
2464         else if (!strcmp(arg, "--relative"))
2465                 DIFF_OPT_SET(options, RELATIVE_NAME);
2466         else if (!prefixcmp(arg, "--relative=")) {
2467                 DIFF_OPT_SET(options, RELATIVE_NAME);
2468                 options->prefix = arg + 11;
2469         }
2470
2471         /* xdiff options */
2472         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2473                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2474         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2475                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2476         else if (!strcmp(arg, "--ignore-space-at-eol"))
2477                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2478
2479         /* flags options */
2480         else if (!strcmp(arg, "--binary")) {
2481                 options->output_format |= DIFF_FORMAT_PATCH;
2482                 DIFF_OPT_SET(options, BINARY);
2483         }
2484         else if (!strcmp(arg, "--full-index"))
2485                 DIFF_OPT_SET(options, FULL_INDEX);
2486         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2487                 DIFF_OPT_SET(options, TEXT);
2488         else if (!strcmp(arg, "-R"))
2489                 DIFF_OPT_SET(options, REVERSE_DIFF);
2490         else if (!strcmp(arg, "--find-copies-harder"))
2491                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2492         else if (!strcmp(arg, "--follow"))
2493                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2494         else if (!strcmp(arg, "--color"))
2495                 DIFF_OPT_SET(options, COLOR_DIFF);
2496         else if (!strcmp(arg, "--no-color"))
2497                 DIFF_OPT_CLR(options, COLOR_DIFF);
2498         else if (!strcmp(arg, "--color-words"))
2499                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2500         else if (!strcmp(arg, "--exit-code"))
2501                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2502         else if (!strcmp(arg, "--quiet"))
2503                 DIFF_OPT_SET(options, QUIET);
2504         else if (!strcmp(arg, "--ext-diff"))
2505                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2506         else if (!strcmp(arg, "--no-ext-diff"))
2507                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2508         else if (!strcmp(arg, "--ignore-submodules"))
2509                 DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2510
2511         /* misc options */
2512         else if (!strcmp(arg, "-z"))
2513                 options->line_termination = 0;
2514         else if (!prefixcmp(arg, "-l"))
2515                 options->rename_limit = strtoul(arg+2, NULL, 10);
2516         else if (!prefixcmp(arg, "-S"))
2517                 options->pickaxe = arg + 2;
2518         else if (!strcmp(arg, "--pickaxe-all"))
2519                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2520         else if (!strcmp(arg, "--pickaxe-regex"))
2521                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2522         else if (!prefixcmp(arg, "-O"))
2523                 options->orderfile = arg + 2;
2524         else if (!prefixcmp(arg, "--diff-filter="))
2525                 options->filter = arg + 14;
2526         else if (!strcmp(arg, "--abbrev"))
2527                 options->abbrev = DEFAULT_ABBREV;
2528         else if (!prefixcmp(arg, "--abbrev=")) {
2529                 options->abbrev = strtoul(arg + 9, NULL, 10);
2530                 if (options->abbrev < MINIMUM_ABBREV)
2531                         options->abbrev = MINIMUM_ABBREV;
2532                 else if (40 < options->abbrev)
2533                         options->abbrev = 40;
2534         }
2535         else if (!prefixcmp(arg, "--src-prefix="))
2536                 options->a_prefix = arg + 13;
2537         else if (!prefixcmp(arg, "--dst-prefix="))
2538                 options->b_prefix = arg + 13;
2539         else if (!strcmp(arg, "--no-prefix"))
2540                 options->a_prefix = options->b_prefix = "";
2541         else if (!prefixcmp(arg, "--output=")) {
2542                 options->file = fopen(arg + strlen("--output="), "w");
2543                 options->close_file = 1;
2544         } else
2545                 return 0;
2546         return 1;
2547 }
2548
2549 static int parse_num(const char **cp_p)
2550 {
2551         unsigned long num, scale;
2552         int ch, dot;
2553         const char *cp = *cp_p;
2554
2555         num = 0;
2556         scale = 1;
2557         dot = 0;
2558         for(;;) {
2559                 ch = *cp;
2560                 if ( !dot && ch == '.' ) {
2561                         scale = 1;
2562                         dot = 1;
2563                 } else if ( ch == '%' ) {
2564                         scale = dot ? scale*100 : 100;
2565                         cp++;   /* % is always at the end */
2566                         break;
2567                 } else if ( ch >= '0' && ch <= '9' ) {
2568                         if ( scale < 100000 ) {
2569                                 scale *= 10;
2570                                 num = (num*10) + (ch-'0');
2571                         }
2572                 } else {
2573                         break;
2574                 }
2575                 cp++;
2576         }
2577         *cp_p = cp;
2578
2579         /* user says num divided by scale and we say internally that
2580          * is MAX_SCORE * num / scale.
2581          */
2582         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2583 }
2584
2585 static int diff_scoreopt_parse(const char *opt)
2586 {
2587         int opt1, opt2, cmd;
2588
2589         if (*opt++ != '-')
2590                 return -1;
2591         cmd = *opt++;
2592         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2593                 return -1; /* that is not a -M, -C nor -B option */
2594
2595         opt1 = parse_num(&opt);
2596         if (cmd != 'B')
2597                 opt2 = 0;
2598         else {
2599                 if (*opt == 0)
2600                         opt2 = 0;
2601                 else if (*opt != '/')
2602                         return -1; /* we expect -B80/99 or -B80 */
2603                 else {
2604                         opt++;
2605                         opt2 = parse_num(&opt);
2606                 }
2607         }
2608         if (*opt != 0)
2609                 return -1;
2610         return opt1 | (opt2 << 16);
2611 }
2612
2613 struct diff_queue_struct diff_queued_diff;
2614
2615 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2616 {
2617         if (queue->alloc <= queue->nr) {
2618                 queue->alloc = alloc_nr(queue->alloc);
2619                 queue->queue = xrealloc(queue->queue,
2620                                         sizeof(dp) * queue->alloc);
2621         }
2622         queue->queue[queue->nr++] = dp;
2623 }
2624
2625 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2626                                  struct diff_filespec *one,
2627                                  struct diff_filespec *two)
2628 {
2629         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2630         dp->one = one;
2631         dp->two = two;
2632         if (queue)
2633                 diff_q(queue, dp);
2634         return dp;
2635 }
2636
2637 void diff_free_filepair(struct diff_filepair *p)
2638 {
2639         free_filespec(p->one);
2640         free_filespec(p->two);
2641         free(p);
2642 }
2643
2644 /* This is different from find_unique_abbrev() in that
2645  * it stuffs the result with dots for alignment.
2646  */
2647 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2648 {
2649         int abblen;
2650         const char *abbrev;
2651         if (len == 40)
2652                 return sha1_to_hex(sha1);
2653
2654         abbrev = find_unique_abbrev(sha1, len);
2655         abblen = strlen(abbrev);
2656         if (abblen < 37) {
2657                 static char hex[41];
2658                 if (len < abblen && abblen <= len + 2)
2659                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2660                 else
2661                         sprintf(hex, "%s...", abbrev);
2662                 return hex;
2663         }
2664         return sha1_to_hex(sha1);
2665 }
2666
2667 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2668 {
2669         int line_termination = opt->line_termination;
2670         int inter_name_termination = line_termination ? '\t' : '\0';
2671
2672         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2673                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2674                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2675                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2676         }
2677         if (p->score) {
2678                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2679                         inter_name_termination);
2680         } else {
2681                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2682         }
2683
2684         if (p->status == DIFF_STATUS_COPIED ||
2685             p->status == DIFF_STATUS_RENAMED) {
2686                 const char *name_a, *name_b;
2687                 name_a = p->one->path;
2688                 name_b = p->two->path;
2689                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2690                 write_name_quoted(name_a, opt->file, inter_name_termination);
2691                 write_name_quoted(name_b, opt->file, line_termination);
2692         } else {
2693                 const char *name_a, *name_b;
2694                 name_a = p->one->mode ? p->one->path : p->two->path;
2695                 name_b = NULL;
2696                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2697                 write_name_quoted(name_a, opt->file, line_termination);
2698         }
2699 }
2700
2701 int diff_unmodified_pair(struct diff_filepair *p)
2702 {
2703         /* This function is written stricter than necessary to support
2704          * the currently implemented transformers, but the idea is to
2705          * let transformers to produce diff_filepairs any way they want,
2706          * and filter and clean them up here before producing the output.
2707          */
2708         struct diff_filespec *one = p->one, *two = p->two;
2709
2710         if (DIFF_PAIR_UNMERGED(p))
2711                 return 0; /* unmerged is interesting */
2712
2713         /* deletion, addition, mode or type change
2714          * and rename are all interesting.
2715          */
2716         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2717             DIFF_PAIR_MODE_CHANGED(p) ||
2718             strcmp(one->path, two->path))
2719                 return 0;
2720
2721         /* both are valid and point at the same path.  that is, we are
2722          * dealing with a change.
2723          */
2724         if (one->sha1_valid && two->sha1_valid &&
2725             !hashcmp(one->sha1, two->sha1))
2726                 return 1; /* no change */
2727         if (!one->sha1_valid && !two->sha1_valid)
2728                 return 1; /* both look at the same file on the filesystem. */
2729         return 0;
2730 }
2731
2732 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2733 {
2734         if (diff_unmodified_pair(p))
2735                 return;
2736
2737         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2738             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2739                 return; /* no tree diffs in patch format */
2740
2741         run_diff(p, o);
2742 }
2743
2744 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2745                             struct diffstat_t *diffstat)
2746 {
2747         if (diff_unmodified_pair(p))
2748                 return;
2749
2750         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2751             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2752                 return; /* no tree diffs in patch format */
2753
2754         run_diffstat(p, o, diffstat);
2755 }
2756
2757 static void diff_flush_checkdiff(struct diff_filepair *p,
2758                 struct diff_options *o)
2759 {
2760         if (diff_unmodified_pair(p))
2761                 return;
2762
2763         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2764             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2765                 return; /* no tree diffs in patch format */
2766
2767         run_checkdiff(p, o);
2768 }
2769
2770 int diff_queue_is_empty(void)
2771 {
2772         struct diff_queue_struct *q = &diff_queued_diff;
2773         int i;
2774         for (i = 0; i < q->nr; i++)
2775                 if (!diff_unmodified_pair(q->queue[i]))
2776                         return 0;
2777         return 1;
2778 }
2779
2780 #if DIFF_DEBUG
2781 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2782 {
2783         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2784                 x, one ? one : "",
2785                 s->path,
2786                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2787                 s->mode,
2788                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2789         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2790                 x, one ? one : "",
2791                 s->size, s->xfrm_flags);
2792 }
2793
2794 void diff_debug_filepair(const struct diff_filepair *p, int i)
2795 {
2796         diff_debug_filespec(p->one, i, "one");
2797         diff_debug_filespec(p->two, i, "two");
2798         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2799                 p->score, p->status ? p->status : '?',
2800                 p->one->rename_used, p->broken_pair);
2801 }
2802
2803 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2804 {
2805         int i;
2806         if (msg)
2807                 fprintf(stderr, "%s\n", msg);
2808         fprintf(stderr, "q->nr = %d\n", q->nr);
2809         for (i = 0; i < q->nr; i++) {
2810                 struct diff_filepair *p = q->queue[i];
2811                 diff_debug_filepair(p, i);
2812         }
2813 }
2814 #endif
2815
2816 static void diff_resolve_rename_copy(void)
2817 {
2818         int i;
2819         struct diff_filepair *p;
2820         struct diff_queue_struct *q = &diff_queued_diff;
2821
2822         diff_debug_queue("resolve-rename-copy", q);
2823
2824         for (i = 0; i < q->nr; i++) {
2825                 p = q->queue[i];
2826                 p->status = 0; /* undecided */
2827                 if (DIFF_PAIR_UNMERGED(p))
2828                         p->status = DIFF_STATUS_UNMERGED;
2829                 else if (!DIFF_FILE_VALID(p->one))
2830                         p->status = DIFF_STATUS_ADDED;
2831                 else if (!DIFF_FILE_VALID(p->two))
2832                         p->status = DIFF_STATUS_DELETED;
2833                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2834                         p->status = DIFF_STATUS_TYPE_CHANGED;
2835
2836                 /* from this point on, we are dealing with a pair
2837                  * whose both sides are valid and of the same type, i.e.
2838                  * either in-place edit or rename/copy edit.
2839                  */
2840                 else if (DIFF_PAIR_RENAME(p)) {
2841                         /*
2842                          * A rename might have re-connected a broken
2843                          * pair up, causing the pathnames to be the
2844                          * same again. If so, that's not a rename at
2845                          * all, just a modification..
2846                          *
2847                          * Otherwise, see if this source was used for
2848                          * multiple renames, in which case we decrement
2849                          * the count, and call it a copy.
2850                          */
2851                         if (!strcmp(p->one->path, p->two->path))
2852                                 p->status = DIFF_STATUS_MODIFIED;
2853                         else if (--p->one->rename_used > 0)
2854                                 p->status = DIFF_STATUS_COPIED;
2855                         else
2856                                 p->status = DIFF_STATUS_RENAMED;
2857                 }
2858                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2859                          p->one->mode != p->two->mode ||
2860                          is_null_sha1(p->one->sha1))
2861                         p->status = DIFF_STATUS_MODIFIED;
2862                 else {
2863                         /* This is a "no-change" entry and should not
2864                          * happen anymore, but prepare for broken callers.
2865                          */
2866                         error("feeding unmodified %s to diffcore",
2867                               p->one->path);
2868                         p->status = DIFF_STATUS_UNKNOWN;
2869                 }
2870         }
2871         diff_debug_queue("resolve-rename-copy done", q);
2872 }
2873
2874 static int check_pair_status(struct diff_filepair *p)
2875 {
2876         switch (p->status) {
2877         case DIFF_STATUS_UNKNOWN:
2878                 return 0;
2879         case 0:
2880                 die("internal error in diff-resolve-rename-copy");
2881         default:
2882                 return 1;
2883         }
2884 }
2885
2886 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2887 {
2888         int fmt = opt->output_format;
2889
2890         if (fmt & DIFF_FORMAT_CHECKDIFF)
2891                 diff_flush_checkdiff(p, opt);
2892         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2893                 diff_flush_raw(p, opt);
2894         else if (fmt & DIFF_FORMAT_NAME) {
2895                 const char *name_a, *name_b;
2896                 name_a = p->two->path;
2897                 name_b = NULL;
2898                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2899                 write_name_quoted(name_a, opt->file, opt->line_termination);
2900         }
2901 }
2902
2903 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2904 {
2905         if (fs->mode)
2906                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2907         else
2908                 fprintf(file, " %s ", newdelete);
2909         write_name_quoted(fs->path, file, '\n');
2910 }
2911
2912
2913 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2914 {
2915         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2916                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2917                         show_name ? ' ' : '\n');
2918                 if (show_name) {
2919                         write_name_quoted(p->two->path, file, '\n');
2920                 }
2921         }
2922 }
2923
2924 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2925 {
2926         char *names = pprint_rename(p->one->path, p->two->path);
2927
2928         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2929         free(names);
2930         show_mode_change(file, p, 0);
2931 }
2932
2933 static void diff_summary(FILE *file, struct diff_filepair *p)
2934 {
2935         switch(p->status) {
2936         case DIFF_STATUS_DELETED:
2937                 show_file_mode_name(file, "delete", p->one);
2938                 break;
2939         case DIFF_STATUS_ADDED:
2940                 show_file_mode_name(file, "create", p->two);
2941                 break;
2942         case DIFF_STATUS_COPIED:
2943                 show_rename_copy(file, "copy", p);
2944                 break;
2945         case DIFF_STATUS_RENAMED:
2946                 show_rename_copy(file, "rename", p);
2947                 break;
2948         default:
2949                 if (p->score) {
2950                         fputs(" rewrite ", file);
2951                         write_name_quoted(p->two->path, file, ' ');
2952                         fprintf(file, "(%d%%)\n", similarity_index(p));
2953                 }
2954                 show_mode_change(file, p, !p->score);
2955                 break;
2956         }
2957 }
2958
2959 struct patch_id_t {
2960         struct xdiff_emit_state xm;
2961         SHA_CTX *ctx;
2962         int patchlen;
2963 };
2964
2965 static int remove_space(char *line, int len)
2966 {
2967         int i;
2968         char *dst = line;
2969         unsigned char c;
2970
2971         for (i = 0; i < len; i++)
2972                 if (!isspace((c = line[i])))
2973                         *dst++ = c;
2974
2975         return dst - line;
2976 }
2977
2978 static void patch_id_consume(void *priv, char *line, unsigned long len)
2979 {
2980         struct patch_id_t *data = priv;
2981         int new_len;
2982
2983         /* Ignore line numbers when computing the SHA1 of the patch */
2984         if (!prefixcmp(line, "@@ -"))
2985                 return;
2986
2987         new_len = remove_space(line, len);
2988
2989         SHA1_Update(data->ctx, line, new_len);
2990         data->patchlen += new_len;
2991 }
2992
2993 /* returns 0 upon success, and writes result into sha1 */
2994 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2995 {
2996         struct diff_queue_struct *q = &diff_queued_diff;
2997         int i;
2998         SHA_CTX ctx;
2999         struct patch_id_t data;
3000         char buffer[PATH_MAX * 4 + 20];
3001
3002         SHA1_Init(&ctx);
3003         memset(&data, 0, sizeof(struct patch_id_t));
3004         data.ctx = &ctx;
3005         data.xm.consume = patch_id_consume;
3006
3007         for (i = 0; i < q->nr; i++) {
3008                 xpparam_t xpp;
3009                 xdemitconf_t xecfg;
3010                 xdemitcb_t ecb;
3011                 mmfile_t mf1, mf2;
3012                 struct diff_filepair *p = q->queue[i];
3013                 int len1, len2;
3014
3015                 memset(&xecfg, 0, sizeof(xecfg));
3016                 if (p->status == 0)
3017                         return error("internal diff status error");
3018                 if (p->status == DIFF_STATUS_UNKNOWN)
3019                         continue;
3020                 if (diff_unmodified_pair(p))
3021                         continue;
3022                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3023                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3024                         continue;
3025                 if (DIFF_PAIR_UNMERGED(p))
3026                         continue;
3027
3028                 diff_fill_sha1_info(p->one);
3029                 diff_fill_sha1_info(p->two);
3030                 if (fill_mmfile(&mf1, p->one) < 0 ||
3031                                 fill_mmfile(&mf2, p->two) < 0)
3032                         return error("unable to read files to diff");
3033
3034                 len1 = remove_space(p->one->path, strlen(p->one->path));
3035                 len2 = remove_space(p->two->path, strlen(p->two->path));
3036                 if (p->one->mode == 0)
3037                         len1 = snprintf(buffer, sizeof(buffer),
3038                                         "diff--gita/%.*sb/%.*s"
3039                                         "newfilemode%06o"
3040                                         "---/dev/null"
3041                                         "+++b/%.*s",
3042                                         len1, p->one->path,
3043                                         len2, p->two->path,
3044                                         p->two->mode,
3045                                         len2, p->two->path);
3046                 else if (p->two->mode == 0)
3047                         len1 = snprintf(buffer, sizeof(buffer),
3048                                         "diff--gita/%.*sb/%.*s"
3049                                         "deletedfilemode%06o"
3050                                         "---a/%.*s"
3051                                         "+++/dev/null",
3052                                         len1, p->one->path,
3053                                         len2, p->two->path,
3054                                         p->one->mode,
3055                                         len1, p->one->path);
3056                 else
3057                         len1 = snprintf(buffer, sizeof(buffer),
3058                                         "diff--gita/%.*sb/%.*s"
3059                                         "---a/%.*s"
3060                                         "+++b/%.*s",
3061                                         len1, p->one->path,
3062                                         len2, p->two->path,
3063                                         len1, p->one->path,
3064                                         len2, p->two->path);
3065                 SHA1_Update(&ctx, buffer, len1);
3066
3067                 xpp.flags = XDF_NEED_MINIMAL;
3068                 xecfg.ctxlen = 3;
3069                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3070                 ecb.outf = xdiff_outf;
3071                 ecb.priv = &data;
3072                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3073         }
3074
3075         SHA1_Final(sha1, &ctx);
3076         return 0;
3077 }
3078
3079 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3080 {
3081         struct diff_queue_struct *q = &diff_queued_diff;
3082         int i;
3083         int result = diff_get_patch_id(options, sha1);
3084
3085         for (i = 0; i < q->nr; i++)
3086                 diff_free_filepair(q->queue[i]);
3087
3088         free(q->queue);
3089         q->queue = NULL;
3090         q->nr = q->alloc = 0;
3091
3092         return result;
3093 }
3094
3095 static int is_summary_empty(const struct diff_queue_struct *q)
3096 {
3097         int i;
3098
3099         for (i = 0; i < q->nr; i++) {
3100                 const struct diff_filepair *p = q->queue[i];
3101
3102                 switch (p->status) {
3103                 case DIFF_STATUS_DELETED:
3104                 case DIFF_STATUS_ADDED:
3105                 case DIFF_STATUS_COPIED:
3106                 case DIFF_STATUS_RENAMED:
3107                         return 0;
3108                 default:
3109                         if (p->score)
3110                                 return 0;
3111                         if (p->one->mode && p->two->mode &&
3112                             p->one->mode != p->two->mode)
3113                                 return 0;
3114                         break;
3115                 }
3116         }
3117         return 1;
3118 }
3119
3120 void diff_flush(struct diff_options *options)
3121 {
3122         struct diff_queue_struct *q = &diff_queued_diff;
3123         int i, output_format = options->output_format;
3124         int separator = 0;
3125
3126         /*
3127          * Order: raw, stat, summary, patch
3128          * or:    name/name-status/checkdiff (other bits clear)
3129          */
3130         if (!q->nr)
3131                 goto free_queue;
3132
3133         if (output_format & (DIFF_FORMAT_RAW |
3134                              DIFF_FORMAT_NAME |
3135                              DIFF_FORMAT_NAME_STATUS |
3136                              DIFF_FORMAT_CHECKDIFF)) {
3137                 for (i = 0; i < q->nr; i++) {
3138                         struct diff_filepair *p = q->queue[i];
3139                         if (check_pair_status(p))
3140                                 flush_one_pair(p, options);
3141                 }
3142                 separator++;
3143         }
3144
3145         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3146                 struct diffstat_t diffstat;
3147
3148                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3149                 diffstat.xm.consume = diffstat_consume;
3150                 for (i = 0; i < q->nr; i++) {
3151                         struct diff_filepair *p = q->queue[i];
3152                         if (check_pair_status(p))
3153                                 diff_flush_stat(p, options, &diffstat);
3154                 }
3155                 if (output_format & DIFF_FORMAT_NUMSTAT)
3156                         show_numstat(&diffstat, options);
3157                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3158                         show_stats(&diffstat, options);
3159                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3160                         show_shortstats(&diffstat, options);
3161                 free_diffstat_info(&diffstat);
3162                 separator++;
3163         }
3164         if (output_format & DIFF_FORMAT_DIRSTAT)
3165                 show_dirstat(options);
3166
3167         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3168                 for (i = 0; i < q->nr; i++)
3169                         diff_summary(options->file, q->queue[i]);
3170                 separator++;
3171         }
3172
3173         if (output_format & DIFF_FORMAT_PATCH) {
3174                 if (separator) {
3175                         if (options->stat_sep) {
3176                                 /* attach patch instead of inline */
3177                                 fputs(options->stat_sep, options->file);
3178                         } else {
3179                                 putc(options->line_termination, options->file);
3180                         }
3181                 }
3182
3183                 for (i = 0; i < q->nr; i++) {
3184                         struct diff_filepair *p = q->queue[i];
3185                         if (check_pair_status(p))
3186                                 diff_flush_patch(p, options);
3187                 }
3188         }
3189
3190         if (output_format & DIFF_FORMAT_CALLBACK)
3191                 options->format_callback(q, options, options->format_callback_data);
3192
3193         for (i = 0; i < q->nr; i++)
3194                 diff_free_filepair(q->queue[i]);
3195 free_queue:
3196         free(q->queue);
3197         q->queue = NULL;
3198         q->nr = q->alloc = 0;
3199         if (options->close_file)
3200                 fclose(options->file);
3201 }
3202
3203 static void diffcore_apply_filter(const char *filter)
3204 {
3205         int i;
3206         struct diff_queue_struct *q = &diff_queued_diff;
3207         struct diff_queue_struct outq;
3208         outq.queue = NULL;
3209         outq.nr = outq.alloc = 0;
3210
3211         if (!filter)
3212                 return;
3213
3214         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3215                 int found;
3216                 for (i = found = 0; !found && i < q->nr; i++) {
3217                         struct diff_filepair *p = q->queue[i];
3218                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3219                              ((p->score &&
3220                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3221                               (!p->score &&
3222                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3223                             ((p->status != DIFF_STATUS_MODIFIED) &&
3224                              strchr(filter, p->status)))
3225                                 found++;
3226                 }
3227                 if (found)
3228                         return;
3229
3230                 /* otherwise we will clear the whole queue
3231                  * by copying the empty outq at the end of this
3232                  * function, but first clear the current entries
3233                  * in the queue.
3234                  */
3235                 for (i = 0; i < q->nr; i++)
3236                         diff_free_filepair(q->queue[i]);
3237         }
3238         else {
3239                 /* Only the matching ones */
3240                 for (i = 0; i < q->nr; i++) {
3241                         struct diff_filepair *p = q->queue[i];
3242
3243                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3244                              ((p->score &&
3245                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3246                               (!p->score &&
3247                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3248                             ((p->status != DIFF_STATUS_MODIFIED) &&
3249                              strchr(filter, p->status)))
3250                                 diff_q(&outq, p);
3251                         else
3252                                 diff_free_filepair(p);
3253                 }
3254         }
3255         free(q->queue);
3256         *q = outq;
3257 }
3258
3259 /* Check whether two filespecs with the same mode and size are identical */
3260 static int diff_filespec_is_identical(struct diff_filespec *one,
3261                                       struct diff_filespec *two)
3262 {
3263         if (S_ISGITLINK(one->mode))
3264                 return 0;
3265         if (diff_populate_filespec(one, 0))
3266                 return 0;
3267         if (diff_populate_filespec(two, 0))
3268                 return 0;
3269         return !memcmp(one->data, two->data, one->size);
3270 }
3271
3272 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3273 {
3274         int i;
3275         struct diff_queue_struct *q = &diff_queued_diff;
3276         struct diff_queue_struct outq;
3277         outq.queue = NULL;
3278         outq.nr = outq.alloc = 0;
3279
3280         for (i = 0; i < q->nr; i++) {
3281                 struct diff_filepair *p = q->queue[i];
3282
3283                 /*
3284                  * 1. Entries that come from stat info dirtyness
3285                  *    always have both sides (iow, not create/delete),
3286                  *    one side of the object name is unknown, with
3287                  *    the same mode and size.  Keep the ones that
3288                  *    do not match these criteria.  They have real
3289                  *    differences.
3290                  *
3291                  * 2. At this point, the file is known to be modified,
3292                  *    with the same mode and size, and the object
3293                  *    name of one side is unknown.  Need to inspect
3294                  *    the identical contents.
3295                  */
3296                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3297                     !DIFF_FILE_VALID(p->two) ||
3298                     (p->one->sha1_valid && p->two->sha1_valid) ||
3299                     (p->one->mode != p->two->mode) ||
3300                     diff_populate_filespec(p->one, 1) ||
3301                     diff_populate_filespec(p->two, 1) ||
3302                     (p->one->size != p->two->size) ||
3303                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3304                         diff_q(&outq, p);
3305                 else {
3306                         /*
3307                          * The caller can subtract 1 from skip_stat_unmatch
3308                          * to determine how many paths were dirty only
3309                          * due to stat info mismatch.
3310                          */
3311                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3312                                 diffopt->skip_stat_unmatch++;
3313                         diff_free_filepair(p);
3314                 }
3315         }
3316         free(q->queue);
3317         *q = outq;
3318 }
3319
3320 void diffcore_std(struct diff_options *options)
3321 {
3322         if (DIFF_OPT_TST(options, QUIET))
3323                 return;
3324
3325         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3326                 diffcore_skip_stat_unmatch(options);
3327         if (options->break_opt != -1)
3328                 diffcore_break(options->break_opt);
3329         if (options->detect_rename)
3330                 diffcore_rename(options);
3331         if (options->break_opt != -1)
3332                 diffcore_merge_broken();
3333         if (options->pickaxe)
3334                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3335         if (options->orderfile)
3336                 diffcore_order(options->orderfile);
3337         diff_resolve_rename_copy();
3338         diffcore_apply_filter(options->filter);
3339
3340         if (diff_queued_diff.nr)
3341                 DIFF_OPT_SET(options, HAS_CHANGES);
3342         else
3343                 DIFF_OPT_CLR(options, HAS_CHANGES);
3344 }
3345
3346 int diff_result_code(struct diff_options *opt, int status)
3347 {
3348         int result = 0;
3349         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3350             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3351                 return status;
3352         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3353             DIFF_OPT_TST(opt, HAS_CHANGES))
3354                 result |= 01;
3355         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3356             DIFF_OPT_TST(opt, CHECK_FAILED))
3357                 result |= 02;
3358         return result;
3359 }
3360
3361 void diff_addremove(struct diff_options *options,
3362                     int addremove, unsigned mode,
3363                     const unsigned char *sha1,
3364                     const char *base, const char *path)
3365 {
3366         char concatpath[PATH_MAX];
3367         struct diff_filespec *one, *two;
3368
3369         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3370                 return;
3371
3372         /* This may look odd, but it is a preparation for
3373          * feeding "there are unchanged files which should
3374          * not produce diffs, but when you are doing copy
3375          * detection you would need them, so here they are"
3376          * entries to the diff-core.  They will be prefixed
3377          * with something like '=' or '*' (I haven't decided
3378          * which but should not make any difference).
3379          * Feeding the same new and old to diff_change()
3380          * also has the same effect.
3381          * Before the final output happens, they are pruned after
3382          * merged into rename/copy pairs as appropriate.
3383          */
3384         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3385                 addremove = (addremove == '+' ? '-' :
3386                              addremove == '-' ? '+' : addremove);
3387
3388         if (!path) path = "";
3389         sprintf(concatpath, "%s%s", base, path);
3390
3391         if (options->prefix &&
3392             strncmp(concatpath, options->prefix, options->prefix_length))
3393                 return;
3394
3395         one = alloc_filespec(concatpath);
3396         two = alloc_filespec(concatpath);
3397
3398         if (addremove != '+')
3399                 fill_filespec(one, sha1, mode);
3400         if (addremove != '-')
3401                 fill_filespec(two, sha1, mode);
3402
3403         diff_queue(&diff_queued_diff, one, two);
3404         DIFF_OPT_SET(options, HAS_CHANGES);
3405 }
3406
3407 void diff_change(struct diff_options *options,
3408                  unsigned old_mode, unsigned new_mode,
3409                  const unsigned char *old_sha1,
3410                  const unsigned char *new_sha1,
3411                  const char *base, const char *path)
3412 {
3413         char concatpath[PATH_MAX];
3414         struct diff_filespec *one, *two;
3415
3416         if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3417                         && S_ISGITLINK(new_mode))
3418                 return;
3419
3420         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3421                 unsigned tmp;
3422                 const unsigned char *tmp_c;
3423                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3424                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3425         }
3426         if (!path) path = "";
3427         sprintf(concatpath, "%s%s", base, path);
3428
3429         if (options->prefix &&
3430             strncmp(concatpath, options->prefix, options->prefix_length))
3431                 return;
3432
3433         one = alloc_filespec(concatpath);
3434         two = alloc_filespec(concatpath);
3435         fill_filespec(one, old_sha1, old_mode);
3436         fill_filespec(two, new_sha1, new_mode);
3437
3438         diff_queue(&diff_queued_diff, one, two);
3439         DIFF_OPT_SET(options, HAS_CHANGES);
3440 }
3441
3442 void diff_unmerge(struct diff_options *options,
3443                   const char *path,
3444                   unsigned mode, const unsigned char *sha1)
3445 {
3446         struct diff_filespec *one, *two;
3447
3448         if (options->prefix &&
3449             strncmp(path, options->prefix, options->prefix_length))
3450                 return;
3451
3452         one = alloc_filespec(path);
3453         two = alloc_filespec(path);
3454         fill_filespec(one, sha1, mode);
3455         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3456 }