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
  12 #ifdef NO_FAST_WORKING_DIRECTORY
  13 #define FAST_WORKING_DIRECTORY 0
  14 #else
  15 #define FAST_WORKING_DIRECTORY 1
  16 #endif
  17
  18 static int use_size_cache;
  19
  20 static int diff_detect_rename_default;
  21 static int diff_rename_limit_default = -1;
  22 static int diff_use_color_default;
  23
  24 static char diff_colors[][COLOR_MAXLEN] = {
  25         "\033[m",       /* reset */
  26         "",             /* PLAIN (normal) */
  27         "\033[1m",      /* METAINFO (bold) */
  28         "\033[36m",     /* FRAGINFO (cyan) */
  29         "\033[31m",     /* OLD (red) */
  30         "\033[32m",     /* NEW (green) */
  31         "\033[33m",     /* COMMIT (yellow) */
  32         "\033[41m",     /* WHITESPACE (red background) */
  33 };
  34
  35 static int parse_diff_color_slot(const char *var, int ofs)
  36 {
  37         if (!strcasecmp(var+ofs, "plain"))
  38                 return DIFF_PLAIN;
  39         if (!strcasecmp(var+ofs, "meta"))
  40                 return DIFF_METAINFO;
  41         if (!strcasecmp(var+ofs, "frag"))
  42                 return DIFF_FRAGINFO;
  43         if (!strcasecmp(var+ofs, "old"))
  44                 return DIFF_FILE_OLD;
  45         if (!strcasecmp(var+ofs, "new"))
  46                 return DIFF_FILE_NEW;
  47         if (!strcasecmp(var+ofs, "commit"))
  48                 return DIFF_COMMIT;
  49         if (!strcasecmp(var+ofs, "whitespace"))
  50                 return DIFF_WHITESPACE;
  51         die("bad config variable '%s'", var);
  52 }
  53
  54 /*
  55  * These are to give UI layer defaults.
  56  * The core-level commands such as git-diff-files should
  57  * never be affected by the setting of diff.renames
  58  * the user happens to have in the configuration file.
  59  */
  60 int git_diff_ui_config(const char *var, const char *value)
  61 {
  62         if (!strcmp(var, "diff.renamelimit")) {
  63                 diff_rename_limit_default = git_config_int(var, value);
  64                 return 0;
  65         }
  66         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  67                 diff_use_color_default = git_config_colorbool(var, value);
  68                 return 0;
  69         }
  70         if (!strcmp(var, "diff.renames")) {
  71                 if (!value)
  72                         diff_detect_rename_default = DIFF_DETECT_RENAME;
  73                 else if (!strcasecmp(value, "copies") ||
  74                          !strcasecmp(value, "copy"))
  75                         diff_detect_rename_default = DIFF_DETECT_COPY;
  76                 else if (git_config_bool(var,value))
  77                         diff_detect_rename_default = DIFF_DETECT_RENAME;
  78                 return 0;
  79         }
  80         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
  81                 int slot = parse_diff_color_slot(var, 11);
  82                 color_parse(value, var, diff_colors[slot]);
  83                 return 0;
  84         }
  85         return git_default_config(var, value);
  86 }
  87
  88 static char *quote_one(const char *str)
  89 {
  90         int needlen;
  91         char *xp;
  92
  93         if (!str)
  94                 return NULL;
  95         needlen = quote_c_style(str, NULL, NULL, 0);
  96         if (!needlen)
  97                 return xstrdup(str);
  98         xp = xmalloc(needlen + 1);
  99         quote_c_style(str, xp, NULL, 0);
 100         return xp;
 101 }
 102
 103 static char *quote_two(const char *one, const char *two)
 104 {
 105         int need_one = quote_c_style(one, NULL, NULL, 1);
 106         int need_two = quote_c_style(two, NULL, NULL, 1);
 107         char *xp;
 108
 109         if (need_one + need_two) {
 110                 if (!need_one) need_one = strlen(one);
 111                 if (!need_two) need_one = strlen(two);
 112
 113                 xp = xmalloc(need_one + need_two + 3);
 114                 xp[0] = '"';
 115                 quote_c_style(one, xp + 1, NULL, 1);
 116                 quote_c_style(two, xp + need_one + 1, NULL, 1);
 117                 strcpy(xp + need_one + need_two + 1, "\"");
 118                 return xp;
 119         }
 120         need_one = strlen(one);
 121         need_two = strlen(two);
 122         xp = xmalloc(need_one + need_two + 1);
 123         strcpy(xp, one);
 124         strcpy(xp + need_one, two);
 125         return xp;
 126 }
 127
 128 static const char *external_diff(void)
 129 {
 130         static const char *external_diff_cmd = NULL;
 131         static int done_preparing = 0;
 132
 133         if (done_preparing)
 134                 return external_diff_cmd;
 135         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 136         done_preparing = 1;
 137         return external_diff_cmd;
 138 }
 139
 140 #define TEMPFILE_PATH_LEN               50
 141
 142 static struct diff_tempfile {
 143         const char *name; /* filename external diff should read from */
 144         char hex[41];
 145         char mode[10];
 146         char tmp_path[TEMPFILE_PATH_LEN];
 147 } diff_temp[2];
 148
 149 static int count_lines(const char *data, int size)
 150 {
 151         int count, ch, completely_empty = 1, nl_just_seen = 0;
 152         count = 0;
 153         while (0 < size--) {
 154                 ch = *data++;
 155                 if (ch == '\n') {
 156                         count++;
 157                         nl_just_seen = 1;
 158                         completely_empty = 0;
 159                 }
 160                 else {
 161                         nl_just_seen = 0;
 162                         completely_empty = 0;
 163                 }
 164         }
 165         if (completely_empty)
 166                 return 0;
 167         if (!nl_just_seen)
 168                 count++; /* no trailing newline */
 169         return count;
 170 }
 171
 172 static void print_line_count(int count)
 173 {
 174         switch (count) {
 175         case 0:
 176                 printf("0,0");
 177                 break;
 178         case 1:
 179                 printf("1");
 180                 break;
 181         default:
 182                 printf("1,%d", count);
 183                 break;
 184         }
 185 }
 186
 187 static void copy_file(int prefix, const char *data, int size,
 188                 const char *set, const char *reset)
 189 {
 190         int ch, nl_just_seen = 1;
 191         while (0 < size--) {
 192                 ch = *data++;
 193                 if (nl_just_seen) {
 194                         fputs(set, stdout);
 195                         putchar(prefix);
 196                 }
 197                 if (ch == '\n') {
 198                         nl_just_seen = 1;
 199                         fputs(reset, stdout);
 200                 } else
 201                         nl_just_seen = 0;
 202                 putchar(ch);
 203         }
 204         if (!nl_just_seen)
 205                 printf("%s\n\\ No newline at end of file\n", reset);
 206 }
 207
 208 static void emit_rewrite_diff(const char *name_a,
 209                               const char *name_b,
 210                               struct diff_filespec *one,
 211                               struct diff_filespec *two,
 212                               int color_diff)
 213 {
 214         int lc_a, lc_b;
 215         const char *name_a_tab, *name_b_tab;
 216         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 217         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 218         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 219         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 220         const char *reset = diff_get_color(color_diff, DIFF_RESET);
 221
 222         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 223         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 224
 225         diff_populate_filespec(one, 0);
 226         diff_populate_filespec(two, 0);
 227         lc_a = count_lines(one->data, one->size);
 228         lc_b = count_lines(two->data, two->size);
 229         printf("%s--- a/%s%s%s\n%s+++ b/%s%s%s\n%s@@ -",
 230                metainfo, name_a, name_a_tab, reset,
 231                metainfo, name_b, name_b_tab, reset, fraginfo);
 232         print_line_count(lc_a);
 233         printf(" +");
 234         print_line_count(lc_b);
 235         printf(" @@%s\n", reset);
 236         if (lc_a)
 237                 copy_file('-', one->data, one->size, old, reset);
 238         if (lc_b)
 239                 copy_file('+', two->data, two->size, new, reset);
 240 }
 241
 242 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 243 {
 244         if (!DIFF_FILE_VALID(one)) {
 245                 mf->ptr = (char *)""; /* does not matter */
 246                 mf->size = 0;
 247                 return 0;
 248         }
 249         else if (diff_populate_filespec(one, 0))
 250                 return -1;
 251         mf->ptr = one->data;
 252         mf->size = one->size;
 253         return 0;
 254 }
 255
 256 struct diff_words_buffer {
 257         mmfile_t text;
 258         long alloc;
 259         long current; /* output pointer */
 260         int suppressed_newline;
 261 };
 262
 263 static void diff_words_append(char *line, unsigned long len,
 264                 struct diff_words_buffer *buffer)
 265 {
 266         if (buffer->text.size + len > buffer->alloc) {
 267                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
 268                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 269         }
 270         line++;
 271         len--;
 272         memcpy(buffer->text.ptr + buffer->text.size, line, len);
 273         buffer->text.size += len;
 274 }
 275
 276 struct diff_words_data {
 277         struct xdiff_emit_state xm;
 278         struct diff_words_buffer minus, plus;
 279 };
 280
 281 static void print_word(struct diff_words_buffer *buffer, int len, int color,
 282                 int suppress_newline)
 283 {
 284         const char *ptr;
 285         int eol = 0;
 286
 287         if (len == 0)
 288                 return;
 289
 290         ptr  = buffer->text.ptr + buffer->current;
 291         buffer->current += len;
 292
 293         if (ptr[len - 1] == '\n') {
 294                 eol = 1;
 295                 len--;
 296         }
 297
 298         fputs(diff_get_color(1, color), stdout);
 299         fwrite(ptr, len, 1, stdout);
 300         fputs(diff_get_color(1, DIFF_RESET), stdout);
 301
 302         if (eol) {
 303                 if (suppress_newline)
 304                         buffer->suppressed_newline = 1;
 305                 else
 306                         putchar('\n');
 307         }
 308 }
 309
 310 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 311 {
 312         struct diff_words_data *diff_words = priv;
 313
 314         if (diff_words->minus.suppressed_newline) {
 315                 if (line[0] != '+')
 316                         putchar('\n');
 317                 diff_words->minus.suppressed_newline = 0;
 318         }
 319
 320         len--;
 321         switch (line[0]) {
 322                 case '-':
 323                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
 324                         break;
 325                 case '+':
 326                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
 327                         break;
 328                 case ' ':
 329                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
 330                         diff_words->minus.current += len;
 331                         break;
 332         }
 333 }
 334
 335 /* this executes the word diff on the accumulated buffers */
 336 static void diff_words_show(struct diff_words_data *diff_words)
 337 {
 338         xpparam_t xpp;
 339         xdemitconf_t xecfg;
 340         xdemitcb_t ecb;
 341         mmfile_t minus, plus;
 342         int i;
 343
 344         minus.size = diff_words->minus.text.size;
 345         minus.ptr = xmalloc(minus.size);
 346         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 347         for (i = 0; i < minus.size; i++)
 348                 if (isspace(minus.ptr[i]))
 349                         minus.ptr[i] = '\n';
 350         diff_words->minus.current = 0;
 351
 352         plus.size = diff_words->plus.text.size;
 353         plus.ptr = xmalloc(plus.size);
 354         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 355         for (i = 0; i < plus.size; i++)
 356                 if (isspace(plus.ptr[i]))
 357                         plus.ptr[i] = '\n';
 358         diff_words->plus.current = 0;
 359
 360         xpp.flags = XDF_NEED_MINIMAL;
 361         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 362         xecfg.flags = 0;
 363         ecb.outf = xdiff_outf;
 364         ecb.priv = diff_words;
 365         diff_words->xm.consume = fn_out_diff_words_aux;
 366         xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 367
 368         free(minus.ptr);
 369         free(plus.ptr);
 370         diff_words->minus.text.size = diff_words->plus.text.size = 0;
 371
 372         if (diff_words->minus.suppressed_newline) {
 373                 putchar('\n');
 374                 diff_words->minus.suppressed_newline = 0;
 375         }
 376 }
 377
 378 struct emit_callback {
 379         struct xdiff_emit_state xm;
 380         int nparents, color_diff;
 381         const char **label_path;
 382         struct diff_words_data *diff_words;
 383 };
 384
 385 static void free_diff_words_data(struct emit_callback *ecbdata)
 386 {
 387         if (ecbdata->diff_words) {
 388                 /* flush buffers */
 389                 if (ecbdata->diff_words->minus.text.size ||
 390                                 ecbdata->diff_words->plus.text.size)
 391                         diff_words_show(ecbdata->diff_words);
 392
 393                 if (ecbdata->diff_words->minus.text.ptr)
 394                         free (ecbdata->diff_words->minus.text.ptr);
 395                 if (ecbdata->diff_words->plus.text.ptr)
 396                         free (ecbdata->diff_words->plus.text.ptr);
 397                 free(ecbdata->diff_words);
 398                 ecbdata->diff_words = NULL;
 399         }
 400 }
 401
 402 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 403 {
 404         if (diff_use_color)
 405                 return diff_colors[ix];
 406         return "";
 407 }
 408
 409 static void emit_line(const char *set, const char *reset, const char *line, int len)
 410 {
 411         if (len > 0 && line[len-1] == '\n')
 412                 len--;
 413         fputs(set, stdout);
 414         fwrite(line, len, 1, stdout);
 415         puts(reset);
 416 }
 417
 418 static void emit_line_with_ws(int nparents,
 419                 const char *set, const char *reset, const char *ws,
 420                 const char *line, int len)
 421 {
 422         int col0 = nparents;
 423         int last_tab_in_indent = -1;
 424         int last_space_in_indent = -1;
 425         int i;
 426         int tail = len;
 427         int need_highlight_leading_space = 0;
 428         /* The line is a newly added line.  Does it have funny leading
 429          * whitespaces?  In indent, SP should never precede a TAB.
 430          */
 431         for (i = col0; i < len; i++) {
 432                 if (line[i] == '\t') {
 433                         last_tab_in_indent = i;
 434                         if (0 <= last_space_in_indent)
 435                                 need_highlight_leading_space = 1;
 436                 }
 437                 else if (line[i] == ' ')
 438                         last_space_in_indent = i;
 439                 else
 440                         break;
 441         }
 442         fputs(set, stdout);
 443         fwrite(line, col0, 1, stdout);
 444         fputs(reset, stdout);
 445         if (((i == len) || line[i] == '\n') && i != col0) {
 446                 /* The whole line was indent */
 447                 emit_line(ws, reset, line + col0, len - col0);
 448                 return;
 449         }
 450         i = col0;
 451         if (need_highlight_leading_space) {
 452                 while (i < last_tab_in_indent) {
 453                         if (line[i] == ' ') {
 454                                 fputs(ws, stdout);
 455                                 putchar(' ');
 456                                 fputs(reset, stdout);
 457                         }
 458                         else
 459                                 putchar(line[i]);
 460                         i++;
 461                 }
 462         }
 463         tail = len - 1;
 464         if (line[tail] == '\n' && i < tail)
 465                 tail--;
 466         while (i < tail) {
 467                 if (!isspace(line[tail]))
 468                         break;
 469                 tail--;
 470         }
 471         if ((i < tail && line[tail + 1] != '\n')) {
 472                 /* This has whitespace between tail+1..len */
 473                 fputs(set, stdout);
 474                 fwrite(line + i, tail - i + 1, 1, stdout);
 475                 fputs(reset, stdout);
 476                 emit_line(ws, reset, line + tail + 1, len - tail - 1);
 477         }
 478         else
 479                 emit_line(set, reset, line + i, len - i);
 480 }
 481
 482 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 483 {
 484         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 485         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 486
 487         if (!*ws)
 488                 emit_line(set, reset, line, len);
 489         else
 490                 emit_line_with_ws(ecbdata->nparents, set, reset, ws,
 491                                 line, len);
 492 }
 493
 494 static void fn_out_consume(void *priv, char *line, unsigned long len)
 495 {
 496         int i;
 497         int color;
 498         struct emit_callback *ecbdata = priv;
 499         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 500         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 501
 502         if (ecbdata->label_path[0]) {
 503                 const char *name_a_tab, *name_b_tab;
 504
 505                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 506                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 507
 508                 printf("%s--- %s%s%s\n",
 509                        set, ecbdata->label_path[0], reset, name_a_tab);
 510                 printf("%s+++ %s%s%s\n",
 511                        set, ecbdata->label_path[1], reset, name_b_tab);
 512                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 513         }
 514
 515         /* This is not really necessary for now because
 516          * this codepath only deals with two-way diffs.
 517          */
 518         for (i = 0; i < len && line[i] == '@'; i++)
 519                 ;
 520         if (2 <= i && i < len && line[i] == ' ') {
 521                 ecbdata->nparents = i - 1;
 522                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 523                           reset, line, len);
 524                 return;
 525         }
 526
 527         if (len < ecbdata->nparents) {
 528                 set = reset;
 529                 emit_line(reset, reset, line, len);
 530                 return;
 531         }
 532
 533         color = DIFF_PLAIN;
 534         if (ecbdata->diff_words && ecbdata->nparents != 1)
 535                 /* fall back to normal diff */
 536                 free_diff_words_data(ecbdata);
 537         if (ecbdata->diff_words) {
 538                 if (line[0] == '-') {
 539                         diff_words_append(line, len,
 540                                           &ecbdata->diff_words->minus);
 541                         return;
 542                 } else if (line[0] == '+') {
 543                         diff_words_append(line, len,
 544                                           &ecbdata->diff_words->plus);
 545                         return;
 546                 }
 547                 if (ecbdata->diff_words->minus.text.size ||
 548                     ecbdata->diff_words->plus.text.size)
 549                         diff_words_show(ecbdata->diff_words);
 550                 line++;
 551                 len--;
 552                 emit_line(set, reset, line, len);
 553                 return;
 554         }
 555         for (i = 0; i < ecbdata->nparents && len; i++) {
 556                 if (line[i] == '-')
 557                         color = DIFF_FILE_OLD;
 558                 else if (line[i] == '+')
 559                         color = DIFF_FILE_NEW;
 560         }
 561
 562         if (color != DIFF_FILE_NEW) {
 563                 emit_line(diff_get_color(ecbdata->color_diff, color),
 564                           reset, line, len);
 565                 return;
 566         }
 567         emit_add_line(reset, ecbdata, line, len);
 568 }
 569
 570 static char *pprint_rename(const char *a, const char *b)
 571 {
 572         const char *old = a;
 573         const char *new = b;
 574         char *name = NULL;
 575         int pfx_length, sfx_length;
 576         int len_a = strlen(a);
 577         int len_b = strlen(b);
 578         int qlen_a = quote_c_style(a, NULL, NULL, 0);
 579         int qlen_b = quote_c_style(b, NULL, NULL, 0);
 580
 581         if (qlen_a || qlen_b) {
 582                 if (qlen_a) len_a = qlen_a;
 583                 if (qlen_b) len_b = qlen_b;
 584                 name = xmalloc( len_a + len_b + 5 );
 585                 if (qlen_a)
 586                         quote_c_style(a, name, NULL, 0);
 587                 else
 588                         memcpy(name, a, len_a);
 589                 memcpy(name + len_a, " => ", 4);
 590                 if (qlen_b)
 591                         quote_c_style(b, name + len_a + 4, NULL, 0);
 592                 else
 593                         memcpy(name + len_a + 4, b, len_b + 1);
 594                 return name;
 595         }
 596
 597         /* Find common prefix */
 598         pfx_length = 0;
 599         while (*old && *new && *old == *new) {
 600                 if (*old == '/')
 601                         pfx_length = old - a + 1;
 602                 old++;
 603                 new++;
 604         }
 605
 606         /* Find common suffix */
 607         old = a + len_a;
 608         new = b + len_b;
 609         sfx_length = 0;
 610         while (a <= old && b <= new && *old == *new) {
 611                 if (*old == '/')
 612                         sfx_length = len_a - (old - a);
 613                 old--;
 614                 new--;
 615         }
 616
 617         /*
 618          * pfx{mid-a => mid-b}sfx
 619          * {pfx-a => pfx-b}sfx
 620          * pfx{sfx-a => sfx-b}
 621          * name-a => name-b
 622          */
 623         if (pfx_length + sfx_length) {
 624                 int a_midlen = len_a - pfx_length - sfx_length;
 625                 int b_midlen = len_b - pfx_length - sfx_length;
 626                 if (a_midlen < 0) a_midlen = 0;
 627                 if (b_midlen < 0) b_midlen = 0;
 628
 629                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
 630                 sprintf(name, "%.*s{%.*s => %.*s}%s",
 631                         pfx_length, a,
 632                         a_midlen, a + pfx_length,
 633                         b_midlen, b + pfx_length,
 634                         a + len_a - sfx_length);
 635         }
 636         else {
 637                 name = xmalloc(len_a + len_b + 5);
 638                 sprintf(name, "%s => %s", a, b);
 639         }
 640         return name;
 641 }
 642
 643 struct diffstat_t {
 644         struct xdiff_emit_state xm;
 645
 646         int nr;
 647         int alloc;
 648         struct diffstat_file {
 649                 char *name;
 650                 unsigned is_unmerged:1;
 651                 unsigned is_binary:1;
 652                 unsigned is_renamed:1;
 653                 unsigned int added, deleted;
 654         } **files;
 655 };
 656
 657 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 658                                           const char *name_a,
 659                                           const char *name_b)
 660 {
 661         struct diffstat_file *x;
 662         x = xcalloc(sizeof (*x), 1);
 663         if (diffstat->nr == diffstat->alloc) {
 664                 diffstat->alloc = alloc_nr(diffstat->alloc);
 665                 diffstat->files = xrealloc(diffstat->files,
 666                                 diffstat->alloc * sizeof(x));
 667         }
 668         diffstat->files[diffstat->nr++] = x;
 669         if (name_b) {
 670                 x->name = pprint_rename(name_a, name_b);
 671                 x->is_renamed = 1;
 672         }
 673         else
 674                 x->name = xstrdup(name_a);
 675         return x;
 676 }
 677
 678 static void diffstat_consume(void *priv, char *line, unsigned long len)
 679 {
 680         struct diffstat_t *diffstat = priv;
 681         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 682
 683         if (line[0] == '+')
 684                 x->added++;
 685         else if (line[0] == '-')
 686                 x->deleted++;
 687 }
 688
 689 const char mime_boundary_leader[] = "------------";
 690
 691 static int scale_linear(int it, int width, int max_change)
 692 {
 693         /*
 694          * make sure that at least one '-' is printed if there were deletions,
 695          * and likewise for '+'.
 696          */
 697         if (max_change < 2)
 698                 return it;
 699         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 700 }
 701
 702 static void show_name(const char *prefix, const char *name, int len,
 703                       const char *reset, const char *set)
 704 {
 705         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
 706 }
 707
 708 static void show_graph(char ch, int cnt, const char *set, const char *reset)
 709 {
 710         if (cnt <= 0)
 711                 return;
 712         printf("%s", set);
 713         while (cnt--)
 714                 putchar(ch);
 715         printf("%s", reset);
 716 }
 717
 718 static void show_stats(struct diffstat_t* data, struct diff_options *options)
 719 {
 720         int i, len, add, del, total, adds = 0, dels = 0;
 721         int max_change = 0, max_len = 0;
 722         int total_files = data->nr;
 723         int width, name_width;
 724         const char *reset, *set, *add_c, *del_c;
 725
 726         if (data->nr == 0)
 727                 return;
 728
 729         width = options->stat_width ? options->stat_width : 80;
 730         name_width = options->stat_name_width ? options->stat_name_width : 50;
 731
 732         /* Sanity: give at least 5 columns to the graph,
 733          * but leave at least 10 columns for the name.
 734          */
 735         if (width < name_width + 15) {
 736                 if (name_width <= 25)
 737                         width = name_width + 15;
 738                 else
 739                         name_width = width - 15;
 740         }
 741
 742         /* Find the longest filename and max number of changes */
 743         reset = diff_get_color(options->color_diff, DIFF_RESET);
 744         set = diff_get_color(options->color_diff, DIFF_PLAIN);
 745         add_c = diff_get_color(options->color_diff, DIFF_FILE_NEW);
 746         del_c = diff_get_color(options->color_diff, DIFF_FILE_OLD);
 747
 748         for (i = 0; i < data->nr; i++) {
 749                 struct diffstat_file *file = data->files[i];
 750                 int change = file->added + file->deleted;
 751
 752                 if (!file->is_renamed) {  /* renames are already quoted by pprint_rename */
 753                         len = quote_c_style(file->name, NULL, NULL, 0);
 754                         if (len) {
 755                                 char *qname = xmalloc(len + 1);
 756                                 quote_c_style(file->name, qname, NULL, 0);
 757                                 free(file->name);
 758                                 file->name = qname;
 759                         }
 760                 }
 761
 762                 len = strlen(file->name);
 763                 if (max_len < len)
 764                         max_len = len;
 765
 766                 if (file->is_binary || file->is_unmerged)
 767                         continue;
 768                 if (max_change < change)
 769                         max_change = change;
 770         }
 771
 772         /* Compute the width of the graph part;
 773          * 10 is for one blank at the beginning of the line plus
 774          * " | count " between the name and the graph.
 775          *
 776          * From here on, name_width is the width of the name area,
 777          * and width is the width of the graph area.
 778          */
 779         name_width = (name_width < max_len) ? name_width : max_len;
 780         if (width < (name_width + 10) + max_change)
 781                 width = width - (name_width + 10);
 782         else
 783                 width = max_change;
 784
 785         for (i = 0; i < data->nr; i++) {
 786                 const char *prefix = "";
 787                 char *name = data->files[i]->name;
 788                 int added = data->files[i]->added;
 789                 int deleted = data->files[i]->deleted;
 790                 int name_len;
 791
 792                 /*
 793                  * "scale" the filename
 794                  */
 795                 len = name_width;
 796                 name_len = strlen(name);
 797                 if (name_width < name_len) {
 798                         char *slash;
 799                         prefix = "...";
 800                         len -= 3;
 801                         name += name_len - len;
 802                         slash = strchr(name, '/');
 803                         if (slash)
 804                                 name = slash;
 805                 }
 806
 807                 if (data->files[i]->is_binary) {
 808                         show_name(prefix, name, len, reset, set);
 809                         printf("  Bin\n");
 810                         goto free_diffstat_file;
 811                 }
 812                 else if (data->files[i]->is_unmerged) {
 813                         show_name(prefix, name, len, reset, set);
 814                         printf("  Unmerged\n");
 815                         goto free_diffstat_file;
 816                 }
 817                 else if (!data->files[i]->is_renamed &&
 818                          (added + deleted == 0)) {
 819                         total_files--;
 820                         goto free_diffstat_file;
 821                 }
 822
 823                 /*
 824                  * scale the add/delete
 825                  */
 826                 add = added;
 827                 del = deleted;
 828                 total = add + del;
 829                 adds += add;
 830                 dels += del;
 831
 832                 if (width <= max_change) {
 833                         add = scale_linear(add, width, max_change);
 834                         del = scale_linear(del, width, max_change);
 835                         total = add + del;
 836                 }
 837                 show_name(prefix, name, len, reset, set);
 838                 printf("%5d ", added + deleted);
 839                 show_graph('+', add, add_c, reset);
 840                 show_graph('-', del, del_c, reset);
 841                 putchar('\n');
 842         free_diffstat_file:
 843                 free(data->files[i]->name);
 844                 free(data->files[i]);
 845         }
 846         free(data->files);
 847         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 848                set, total_files, adds, dels, reset);
 849 }
 850
 851 static void show_shortstats(struct diffstat_t* data)
 852 {
 853         int i, adds = 0, dels = 0, total_files = data->nr;
 854
 855         if (data->nr == 0)
 856                 return;
 857
 858         for (i = 0; i < data->nr; i++) {
 859                 if (!data->files[i]->is_binary &&
 860                     !data->files[i]->is_unmerged) {
 861                         int added = data->files[i]->added;
 862                         int deleted= data->files[i]->deleted;
 863                         if (!data->files[i]->is_renamed &&
 864                             (added + deleted == 0)) {
 865                                 total_files--;
 866                         } else {
 867                                 adds += added;
 868                                 dels += deleted;
 869                         }
 870                 }
 871                 free(data->files[i]->name);
 872                 free(data->files[i]);
 873         }
 874         free(data->files);
 875
 876         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 877                total_files, adds, dels);
 878 }
 879
 880 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 881 {
 882         int i;
 883
 884         for (i = 0; i < data->nr; i++) {
 885                 struct diffstat_file *file = data->files[i];
 886
 887                 if (file->is_binary)
 888                         printf("-\t-\t");
 889                 else
 890                         printf("%d\t%d\t", file->added, file->deleted);
 891                 if (options->line_termination && !file->is_renamed &&
 892                     quote_c_style(file->name, NULL, NULL, 0))
 893                         quote_c_style(file->name, NULL, stdout, 0);
 894                 else
 895                         fputs(file->name, stdout);
 896                 putchar(options->line_termination);
 897         }
 898 }
 899
 900 struct checkdiff_t {
 901         struct xdiff_emit_state xm;
 902         const char *filename;
 903         int lineno, color_diff;
 904 };
 905
 906 static void checkdiff_consume(void *priv, char *line, unsigned long len)
 907 {
 908         struct checkdiff_t *data = priv;
 909         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
 910         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
 911         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
 912
 913         if (line[0] == '+') {
 914                 int i, spaces = 0, space_before_tab = 0, white_space_at_end = 0;
 915
 916                 /* check space before tab */
 917                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
 918                         if (line[i] == ' ')
 919                                 spaces++;
 920                 if (line[i - 1] == '\t' && spaces)
 921                         space_before_tab = 1;
 922
 923                 /* check white space at line end */
 924                 if (line[len - 1] == '\n')
 925                         len--;
 926                 if (isspace(line[len - 1]))
 927                         white_space_at_end = 1;
 928
 929                 if (space_before_tab || white_space_at_end) {
 930                         printf("%s:%d: %s", data->filename, data->lineno, ws);
 931                         if (space_before_tab) {
 932                                 printf("space before tab");
 933                                 if (white_space_at_end)
 934                                         putchar(',');
 935                         }
 936                         if (white_space_at_end)
 937                                 printf("white space at end");
 938                         printf(":%s ", reset);
 939                         emit_line_with_ws(1, set, reset, ws, line, len);
 940                 }
 941
 942                 data->lineno++;
 943         } else if (line[0] == ' ')
 944                 data->lineno++;
 945         else if (line[0] == '@') {
 946                 char *plus = strchr(line, '+');
 947                 if (plus)
 948                         data->lineno = strtol(plus, NULL, 10);
 949                 else
 950                         die("invalid diff");
 951         }
 952 }
 953
 954 static unsigned char *deflate_it(char *data,
 955                                  unsigned long size,
 956                                  unsigned long *result_size)
 957 {
 958         int bound;
 959         unsigned char *deflated;
 960         z_stream stream;
 961
 962         memset(&stream, 0, sizeof(stream));
 963         deflateInit(&stream, zlib_compression_level);
 964         bound = deflateBound(&stream, size);
 965         deflated = xmalloc(bound);
 966         stream.next_out = deflated;
 967         stream.avail_out = bound;
 968
 969         stream.next_in = (unsigned char *)data;
 970         stream.avail_in = size;
 971         while (deflate(&stream, Z_FINISH) == Z_OK)
 972                 ; /* nothing */
 973         deflateEnd(&stream);
 974         *result_size = stream.total_out;
 975         return deflated;
 976 }
 977
 978 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
 979 {
 980         void *cp;
 981         void *delta;
 982         void *deflated;
 983         void *data;
 984         unsigned long orig_size;
 985         unsigned long delta_size;
 986         unsigned long deflate_size;
 987         unsigned long data_size;
 988
 989         /* We could do deflated delta, or we could do just deflated two,
 990          * whichever is smaller.
 991          */
 992         delta = NULL;
 993         deflated = deflate_it(two->ptr, two->size, &deflate_size);
 994         if (one->size && two->size) {
 995                 delta = diff_delta(one->ptr, one->size,
 996                                    two->ptr, two->size,
 997                                    &delta_size, deflate_size);
 998                 if (delta) {
 999                         void *to_free = delta;
1000                         orig_size = delta_size;
1001                         delta = deflate_it(delta, delta_size, &delta_size);
1002                         free(to_free);
1003                 }
1004         }
1005
1006         if (delta && delta_size < deflate_size) {
1007                 printf("delta %lu\n", orig_size);
1008                 free(deflated);
1009                 data = delta;
1010                 data_size = delta_size;
1011         }
1012         else {
1013                 printf("literal %lu\n", two->size);
1014                 free(delta);
1015                 data = deflated;
1016                 data_size = deflate_size;
1017         }
1018
1019         /* emit data encoded in base85 */
1020         cp = data;
1021         while (data_size) {
1022                 int bytes = (52 < data_size) ? 52 : data_size;
1023                 char line[70];
1024                 data_size -= bytes;
1025                 if (bytes <= 26)
1026                         line[0] = bytes + 'A' - 1;
1027                 else
1028                         line[0] = bytes - 26 + 'a' - 1;
1029                 encode_85(line + 1, cp, bytes);
1030                 cp = (char *) cp + bytes;
1031                 puts(line);
1032         }
1033         printf("\n");
1034         free(data);
1035 }
1036
1037 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1038 {
1039         printf("GIT binary patch\n");
1040         emit_binary_diff_body(one, two);
1041         emit_binary_diff_body(two, one);
1042 }
1043
1044 #define FIRST_FEW_BYTES 8000
1045 static int mmfile_is_binary(mmfile_t *mf)
1046 {
1047         long sz = mf->size;
1048         if (FIRST_FEW_BYTES < sz)
1049                 sz = FIRST_FEW_BYTES;
1050         return !!memchr(mf->ptr, 0, sz);
1051 }
1052
1053 static void builtin_diff(const char *name_a,
1054                          const char *name_b,
1055                          struct diff_filespec *one,
1056                          struct diff_filespec *two,
1057                          const char *xfrm_msg,
1058                          struct diff_options *o,
1059                          int complete_rewrite)
1060 {
1061         mmfile_t mf1, mf2;
1062         const char *lbl[2];
1063         char *a_one, *b_two;
1064         const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
1065         const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
1066
1067         a_one = quote_two("a/", name_a);
1068         b_two = quote_two("b/", name_b);
1069         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1070         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1071         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1072         if (lbl[0][0] == '/') {
1073                 /* /dev/null */
1074                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1075                 if (xfrm_msg && xfrm_msg[0])
1076                         printf("%s%s%s\n", set, xfrm_msg, reset);
1077         }
1078         else if (lbl[1][0] == '/') {
1079                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1080                 if (xfrm_msg && xfrm_msg[0])
1081                         printf("%s%s%s\n", set, xfrm_msg, reset);
1082         }
1083         else {
1084                 if (one->mode != two->mode) {
1085                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1086                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1087                 }
1088                 if (xfrm_msg && xfrm_msg[0])
1089                         printf("%s%s%s\n", set, xfrm_msg, reset);
1090                 /*
1091                  * we do not run diff between different kind
1092                  * of objects.
1093                  */
1094                 if ((one->mode ^ two->mode) & S_IFMT)
1095                         goto free_ab_and_return;
1096                 if (complete_rewrite) {
1097                         emit_rewrite_diff(name_a, name_b, one, two,
1098                                         o->color_diff);
1099                         goto free_ab_and_return;
1100                 }
1101         }
1102
1103         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1104                 die("unable to read files to diff");
1105
1106         if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
1107                 /* Quite common confusing case */
1108                 if (mf1.size == mf2.size &&
1109                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1110                         goto free_ab_and_return;
1111                 if (o->binary)
1112                         emit_binary_diff(&mf1, &mf2);
1113                 else
1114                         printf("Binary files %s and %s differ\n",
1115                                lbl[0], lbl[1]);
1116         }
1117         else {
1118                 /* Crazy xdl interfaces.. */
1119                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1120                 xpparam_t xpp;
1121                 xdemitconf_t xecfg;
1122                 xdemitcb_t ecb;
1123                 struct emit_callback ecbdata;
1124
1125                 memset(&ecbdata, 0, sizeof(ecbdata));
1126                 ecbdata.label_path = lbl;
1127                 ecbdata.color_diff = o->color_diff;
1128                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1129                 xecfg.ctxlen = o->context;
1130                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1131                 if (!diffopts)
1132                         ;
1133                 else if (!prefixcmp(diffopts, "--unified="))
1134                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1135                 else if (!prefixcmp(diffopts, "-u"))
1136                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1137                 ecb.outf = xdiff_outf;
1138                 ecb.priv = &ecbdata;
1139                 ecbdata.xm.consume = fn_out_consume;
1140                 if (o->color_diff_words)
1141                         ecbdata.diff_words =
1142                                 xcalloc(1, sizeof(struct diff_words_data));
1143                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1144                 if (o->color_diff_words)
1145                         free_diff_words_data(&ecbdata);
1146         }
1147
1148  free_ab_and_return:
1149         free(a_one);
1150         free(b_two);
1151         return;
1152 }
1153
1154 static void builtin_diffstat(const char *name_a, const char *name_b,
1155                              struct diff_filespec *one,
1156                              struct diff_filespec *two,
1157                              struct diffstat_t *diffstat,
1158                              struct diff_options *o,
1159                              int complete_rewrite)
1160 {
1161         mmfile_t mf1, mf2;
1162         struct diffstat_file *data;
1163
1164         data = diffstat_add(diffstat, name_a, name_b);
1165
1166         if (!one || !two) {
1167                 data->is_unmerged = 1;
1168                 return;
1169         }
1170         if (complete_rewrite) {
1171                 diff_populate_filespec(one, 0);
1172                 diff_populate_filespec(two, 0);
1173                 data->deleted = count_lines(one->data, one->size);
1174                 data->added = count_lines(two->data, two->size);
1175                 return;
1176         }
1177         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1178                 die("unable to read files to diff");
1179
1180         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
1181                 data->is_binary = 1;
1182         else {
1183                 /* Crazy xdl interfaces.. */
1184                 xpparam_t xpp;
1185                 xdemitconf_t xecfg;
1186                 xdemitcb_t ecb;
1187
1188                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1189                 xecfg.ctxlen = 0;
1190                 xecfg.flags = 0;
1191                 ecb.outf = xdiff_outf;
1192                 ecb.priv = diffstat;
1193                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1194         }
1195 }
1196
1197 static void builtin_checkdiff(const char *name_a, const char *name_b,
1198                              struct diff_filespec *one,
1199                              struct diff_filespec *two, struct diff_options *o)
1200 {
1201         mmfile_t mf1, mf2;
1202         struct checkdiff_t data;
1203
1204         if (!two)
1205                 return;
1206
1207         memset(&data, 0, sizeof(data));
1208         data.xm.consume = checkdiff_consume;
1209         data.filename = name_b ? name_b : name_a;
1210         data.lineno = 0;
1211         data.color_diff = o->color_diff;
1212
1213         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1214                 die("unable to read files to diff");
1215
1216         if (mmfile_is_binary(&mf2))
1217                 return;
1218         else {
1219                 /* Crazy xdl interfaces.. */
1220                 xpparam_t xpp;
1221                 xdemitconf_t xecfg;
1222                 xdemitcb_t ecb;
1223
1224                 xpp.flags = XDF_NEED_MINIMAL;
1225                 xecfg.ctxlen = 0;
1226                 xecfg.flags = 0;
1227                 ecb.outf = xdiff_outf;
1228                 ecb.priv = &data;
1229                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1230         }
1231 }
1232
1233 struct diff_filespec *alloc_filespec(const char *path)
1234 {
1235         int namelen = strlen(path);
1236         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1237
1238         memset(spec, 0, sizeof(*spec));
1239         spec->path = (char *)(spec + 1);
1240         memcpy(spec->path, path, namelen+1);
1241         return spec;
1242 }
1243
1244 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1245                    unsigned short mode)
1246 {
1247         if (mode) {
1248                 spec->mode = canon_mode(mode);
1249                 hashcpy(spec->sha1, sha1);
1250                 spec->sha1_valid = !is_null_sha1(sha1);
1251         }
1252 }
1253
1254 /*
1255  * Given a name and sha1 pair, if the dircache tells us the file in
1256  * the work tree has that object contents, return true, so that
1257  * prepare_temp_file() does not have to inflate and extract.
1258  */
1259 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1260 {
1261         struct cache_entry *ce;
1262         struct stat st;
1263         int pos, len;
1264
1265         /* We do not read the cache ourselves here, because the
1266          * benchmark with my previous version that always reads cache
1267          * shows that it makes things worse for diff-tree comparing
1268          * two linux-2.6 kernel trees in an already checked out work
1269          * tree.  This is because most diff-tree comparisons deal with
1270          * only a small number of files, while reading the cache is
1271          * expensive for a large project, and its cost outweighs the
1272          * savings we get by not inflating the object to a temporary
1273          * file.  Practically, this code only helps when we are used
1274          * by diff-cache --cached, which does read the cache before
1275          * calling us.
1276          */
1277         if (!active_cache)
1278                 return 0;
1279
1280         /* We want to avoid the working directory if our caller
1281          * doesn't need the data in a normal file, this system
1282          * is rather slow with its stat/open/mmap/close syscalls,
1283          * and the object is contained in a pack file.  The pack
1284          * is probably already open and will be faster to obtain
1285          * the data through than the working directory.  Loose
1286          * objects however would tend to be slower as they need
1287          * to be individually opened and inflated.
1288          */
1289         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1290                 return 0;
1291
1292         len = strlen(name);
1293         pos = cache_name_pos(name, len);
1294         if (pos < 0)
1295                 return 0;
1296         ce = active_cache[pos];
1297         if ((lstat(name, &st) < 0) ||
1298             !S_ISREG(st.st_mode) || /* careful! */
1299             ce_match_stat(ce, &st, 0) ||
1300             hashcmp(sha1, ce->sha1))
1301                 return 0;
1302         /* we return 1 only when we can stat, it is a regular file,
1303          * stat information matches, and sha1 recorded in the cache
1304          * matches.  I.e. we know the file in the work tree really is
1305          * the same as the <name, sha1> pair.
1306          */
1307         return 1;
1308 }
1309
1310 static struct sha1_size_cache {
1311         unsigned char sha1[20];
1312         unsigned long size;
1313 } **sha1_size_cache;
1314 static int sha1_size_cache_nr, sha1_size_cache_alloc;
1315
1316 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
1317                                                  int find_only,
1318                                                  unsigned long size)
1319 {
1320         int first, last;
1321         struct sha1_size_cache *e;
1322
1323         first = 0;
1324         last = sha1_size_cache_nr;
1325         while (last > first) {
1326                 int cmp, next = (last + first) >> 1;
1327                 e = sha1_size_cache[next];
1328                 cmp = hashcmp(e->sha1, sha1);
1329                 if (!cmp)
1330                         return e;
1331                 if (cmp < 0) {
1332                         last = next;
1333                         continue;
1334                 }
1335                 first = next+1;
1336         }
1337         /* not found */
1338         if (find_only)
1339                 return NULL;
1340         /* insert to make it at "first" */
1341         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
1342                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
1343                 sha1_size_cache = xrealloc(sha1_size_cache,
1344                                            sha1_size_cache_alloc *
1345                                            sizeof(*sha1_size_cache));
1346         }
1347         sha1_size_cache_nr++;
1348         if (first < sha1_size_cache_nr)
1349                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
1350                         (sha1_size_cache_nr - first - 1) *
1351                         sizeof(*sha1_size_cache));
1352         e = xmalloc(sizeof(struct sha1_size_cache));
1353         sha1_size_cache[first] = e;
1354         hashcpy(e->sha1, sha1);
1355         e->size = size;
1356         return e;
1357 }
1358
1359 /*
1360  * While doing rename detection and pickaxe operation, we may need to
1361  * grab the data for the blob (or file) for our own in-core comparison.
1362  * diff_filespec has data and size fields for this purpose.
1363  */
1364 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1365 {
1366         int err = 0;
1367         if (!DIFF_FILE_VALID(s))
1368                 die("internal error: asking to populate invalid file.");
1369         if (S_ISDIR(s->mode))
1370                 return -1;
1371
1372         if (!use_size_cache)
1373                 size_only = 0;
1374
1375         if (s->data)
1376                 return err;
1377         if (!s->sha1_valid ||
1378             reuse_worktree_file(s->path, s->sha1, 0)) {
1379                 struct stat st;
1380                 int fd;
1381                 char *buf;
1382                 unsigned long size;
1383
1384                 if (lstat(s->path, &st) < 0) {
1385                         if (errno == ENOENT) {
1386                         err_empty:
1387                                 err = -1;
1388                         empty:
1389                                 s->data = (char *)"";
1390                                 s->size = 0;
1391                                 return err;
1392                         }
1393                 }
1394                 s->size = st.st_size;
1395                 if (!s->size)
1396                         goto empty;
1397                 if (size_only)
1398                         return 0;
1399                 if (S_ISLNK(st.st_mode)) {
1400                         int ret;
1401                         s->data = xmalloc(s->size);
1402                         s->should_free = 1;
1403                         ret = readlink(s->path, s->data, s->size);
1404                         if (ret < 0) {
1405                                 free(s->data);
1406                                 goto err_empty;
1407                         }
1408                         return 0;
1409                 }
1410                 fd = open(s->path, O_RDONLY);
1411                 if (fd < 0)
1412                         goto err_empty;
1413                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1414                 close(fd);
1415                 s->should_munmap = 1;
1416
1417                 /*
1418                  * Convert from working tree format to canonical git format
1419                  */
1420                 buf = s->data;
1421                 size = s->size;
1422                 if (convert_to_git(s->path, &buf, &size)) {
1423                         munmap(s->data, s->size);
1424                         s->should_munmap = 0;
1425                         s->data = buf;
1426                         s->size = size;
1427                         s->should_free = 1;
1428                 }
1429         }
1430         else {
1431                 char type[20];
1432                 struct sha1_size_cache *e;
1433
1434                 if (size_only) {
1435                         e = locate_size_cache(s->sha1, 1, 0);
1436                         if (e) {
1437                                 s->size = e->size;
1438                                 return 0;
1439                         }
1440                         if (!sha1_object_info(s->sha1, type, &s->size))
1441                                 locate_size_cache(s->sha1, 0, s->size);
1442                 }
1443                 else {
1444                         s->data = read_sha1_file(s->sha1, type, &s->size);
1445                         s->should_free = 1;
1446                 }
1447         }
1448         return 0;
1449 }
1450
1451 void diff_free_filespec_data(struct diff_filespec *s)
1452 {
1453         if (s->should_free)
1454                 free(s->data);
1455         else if (s->should_munmap)
1456                 munmap(s->data, s->size);
1457         s->should_free = s->should_munmap = 0;
1458         s->data = NULL;
1459         free(s->cnt_data);
1460         s->cnt_data = NULL;
1461 }
1462
1463 static void prep_temp_blob(struct diff_tempfile *temp,
1464                            void *blob,
1465                            unsigned long size,
1466                            const unsigned char *sha1,
1467                            int mode)
1468 {
1469         int fd;
1470
1471         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1472         if (fd < 0)
1473                 die("unable to create temp-file");
1474         if (write_in_full(fd, blob, size) != size)
1475                 die("unable to write temp-file");
1476         close(fd);
1477         temp->name = temp->tmp_path;
1478         strcpy(temp->hex, sha1_to_hex(sha1));
1479         temp->hex[40] = 0;
1480         sprintf(temp->mode, "%06o", mode);
1481 }
1482
1483 static void prepare_temp_file(const char *name,
1484                               struct diff_tempfile *temp,
1485                               struct diff_filespec *one)
1486 {
1487         if (!DIFF_FILE_VALID(one)) {
1488         not_a_valid_file:
1489                 /* A '-' entry produces this for file-2, and
1490                  * a '+' entry produces this for file-1.
1491                  */
1492                 temp->name = "/dev/null";
1493                 strcpy(temp->hex, ".");
1494                 strcpy(temp->mode, ".");
1495                 return;
1496         }
1497
1498         if (!one->sha1_valid ||
1499             reuse_worktree_file(name, one->sha1, 1)) {
1500                 struct stat st;
1501                 if (lstat(name, &st) < 0) {
1502                         if (errno == ENOENT)
1503                                 goto not_a_valid_file;
1504                         die("stat(%s): %s", name, strerror(errno));
1505                 }
1506                 if (S_ISLNK(st.st_mode)) {
1507                         int ret;
1508                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1509                         if (sizeof(buf) <= st.st_size)
1510                                 die("symlink too long: %s", name);
1511                         ret = readlink(name, buf, st.st_size);
1512                         if (ret < 0)
1513                                 die("readlink(%s)", name);
1514                         prep_temp_blob(temp, buf, st.st_size,
1515                                        (one->sha1_valid ?
1516                                         one->sha1 : null_sha1),
1517                                        (one->sha1_valid ?
1518                                         one->mode : S_IFLNK));
1519                 }
1520                 else {
1521                         /* we can borrow from the file in the work tree */
1522                         temp->name = name;
1523                         if (!one->sha1_valid)
1524                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1525                         else
1526                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1527                         /* Even though we may sometimes borrow the
1528                          * contents from the work tree, we always want
1529                          * one->mode.  mode is trustworthy even when
1530                          * !(one->sha1_valid), as long as
1531                          * DIFF_FILE_VALID(one).
1532                          */
1533                         sprintf(temp->mode, "%06o", one->mode);
1534                 }
1535                 return;
1536         }
1537         else {
1538                 if (diff_populate_filespec(one, 0))
1539                         die("cannot read data blob for %s", one->path);
1540                 prep_temp_blob(temp, one->data, one->size,
1541                                one->sha1, one->mode);
1542         }
1543 }
1544
1545 static void remove_tempfile(void)
1546 {
1547         int i;
1548
1549         for (i = 0; i < 2; i++)
1550                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1551                         unlink(diff_temp[i].name);
1552                         diff_temp[i].name = NULL;
1553                 }
1554 }
1555
1556 static void remove_tempfile_on_signal(int signo)
1557 {
1558         remove_tempfile();
1559         signal(SIGINT, SIG_DFL);
1560         raise(signo);
1561 }
1562
1563 static int spawn_prog(const char *pgm, const char **arg)
1564 {
1565         pid_t pid;
1566         int status;
1567
1568         fflush(NULL);
1569         pid = fork();
1570         if (pid < 0)
1571                 die("unable to fork");
1572         if (!pid) {
1573                 execvp(pgm, (char *const*) arg);
1574                 exit(255);
1575         }
1576
1577         while (waitpid(pid, &status, 0) < 0) {
1578                 if (errno == EINTR)
1579                         continue;
1580                 return -1;
1581         }
1582
1583         /* Earlier we did not check the exit status because
1584          * diff exits non-zero if files are different, and
1585          * we are not interested in knowing that.  It was a
1586          * mistake which made it harder to quit a diff-*
1587          * session that uses the git-apply-patch-script as
1588          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1589          * should also exit non-zero only when it wants to
1590          * abort the entire diff-* session.
1591          */
1592         if (WIFEXITED(status) && !WEXITSTATUS(status))
1593                 return 0;
1594         return -1;
1595 }
1596
1597 /* An external diff command takes:
1598  *
1599  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1600  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1601  *
1602  */
1603 static void run_external_diff(const char *pgm,
1604                               const char *name,
1605                               const char *other,
1606                               struct diff_filespec *one,
1607                               struct diff_filespec *two,
1608                               const char *xfrm_msg,
1609                               int complete_rewrite)
1610 {
1611         const char *spawn_arg[10];
1612         struct diff_tempfile *temp = diff_temp;
1613         int retval;
1614         static int atexit_asked = 0;
1615         const char *othername;
1616         const char **arg = &spawn_arg[0];
1617
1618         othername = (other? other : name);
1619         if (one && two) {
1620                 prepare_temp_file(name, &temp[0], one);
1621                 prepare_temp_file(othername, &temp[1], two);
1622                 if (! atexit_asked &&
1623                     (temp[0].name == temp[0].tmp_path ||
1624                      temp[1].name == temp[1].tmp_path)) {
1625                         atexit_asked = 1;
1626                         atexit(remove_tempfile);
1627                 }
1628                 signal(SIGINT, remove_tempfile_on_signal);
1629         }
1630
1631         if (one && two) {
1632                 *arg++ = pgm;
1633                 *arg++ = name;
1634                 *arg++ = temp[0].name;
1635                 *arg++ = temp[0].hex;
1636                 *arg++ = temp[0].mode;
1637                 *arg++ = temp[1].name;
1638                 *arg++ = temp[1].hex;
1639                 *arg++ = temp[1].mode;
1640                 if (other) {
1641                         *arg++ = other;
1642                         *arg++ = xfrm_msg;
1643                 }
1644         } else {
1645                 *arg++ = pgm;
1646                 *arg++ = name;
1647         }
1648         *arg = NULL;
1649         retval = spawn_prog(pgm, spawn_arg);
1650         remove_tempfile();
1651         if (retval) {
1652                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1653                 exit(1);
1654         }
1655 }
1656
1657 static void run_diff_cmd(const char *pgm,
1658                          const char *name,
1659                          const char *other,
1660                          struct diff_filespec *one,
1661                          struct diff_filespec *two,
1662                          const char *xfrm_msg,
1663                          struct diff_options *o,
1664                          int complete_rewrite)
1665 {
1666         if (pgm) {
1667                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1668                                   complete_rewrite);
1669                 return;
1670         }
1671         if (one && two)
1672                 builtin_diff(name, other ? other : name,
1673                              one, two, xfrm_msg, o, complete_rewrite);
1674         else
1675                 printf("* Unmerged path %s\n", name);
1676 }
1677
1678 static void diff_fill_sha1_info(struct diff_filespec *one)
1679 {
1680         if (DIFF_FILE_VALID(one)) {
1681                 if (!one->sha1_valid) {
1682                         struct stat st;
1683                         if (lstat(one->path, &st) < 0)
1684                                 die("stat %s", one->path);
1685                         if (index_path(one->sha1, one->path, &st, 0))
1686                                 die("cannot hash %s\n", one->path);
1687                 }
1688         }
1689         else
1690                 hashclr(one->sha1);
1691 }
1692
1693 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1694 {
1695         const char *pgm = external_diff();
1696         char msg[PATH_MAX*2+300], *xfrm_msg;
1697         struct diff_filespec *one;
1698         struct diff_filespec *two;
1699         const char *name;
1700         const char *other;
1701         char *name_munged, *other_munged;
1702         int complete_rewrite = 0;
1703         int len;
1704
1705         if (DIFF_PAIR_UNMERGED(p)) {
1706                 /* unmerged */
1707                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1708                 return;
1709         }
1710
1711         name = p->one->path;
1712         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1713         name_munged = quote_one(name);
1714         other_munged = quote_one(other);
1715         one = p->one; two = p->two;
1716
1717         diff_fill_sha1_info(one);
1718         diff_fill_sha1_info(two);
1719
1720         len = 0;
1721         switch (p->status) {
1722         case DIFF_STATUS_COPIED:
1723                 len += snprintf(msg + len, sizeof(msg) - len,
1724                                 "similarity index %d%%\n"
1725                                 "copy from %s\n"
1726                                 "copy to %s\n",
1727                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1728                                 name_munged, other_munged);
1729                 break;
1730         case DIFF_STATUS_RENAMED:
1731                 len += snprintf(msg + len, sizeof(msg) - len,
1732                                 "similarity index %d%%\n"
1733                                 "rename from %s\n"
1734                                 "rename to %s\n",
1735                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1736                                 name_munged, other_munged);
1737                 break;
1738         case DIFF_STATUS_MODIFIED:
1739                 if (p->score) {
1740                         len += snprintf(msg + len, sizeof(msg) - len,
1741                                         "dissimilarity index %d%%\n",
1742                                         (int)(0.5 + p->score *
1743                                               100.0/MAX_SCORE));
1744                         complete_rewrite = 1;
1745                         break;
1746                 }
1747                 /* fallthru */
1748         default:
1749                 /* nothing */
1750                 ;
1751         }
1752
1753         if (hashcmp(one->sha1, two->sha1)) {
1754                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1755
1756                 if (o->binary) {
1757                         mmfile_t mf;
1758                         if ((!fill_mmfile(&mf, one) && mmfile_is_binary(&mf)) ||
1759                             (!fill_mmfile(&mf, two) && mmfile_is_binary(&mf)))
1760                                 abbrev = 40;
1761                 }
1762                 len += snprintf(msg + len, sizeof(msg) - len,
1763                                 "index %.*s..%.*s",
1764                                 abbrev, sha1_to_hex(one->sha1),
1765                                 abbrev, sha1_to_hex(two->sha1));
1766                 if (one->mode == two->mode)
1767                         len += snprintf(msg + len, sizeof(msg) - len,
1768                                         " %06o", one->mode);
1769                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1770         }
1771
1772         if (len)
1773                 msg[--len] = 0;
1774         xfrm_msg = len ? msg : NULL;
1775
1776         if (!pgm &&
1777             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1778             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1779                 /* a filepair that changes between file and symlink
1780                  * needs to be split into deletion and creation.
1781                  */
1782                 struct diff_filespec *null = alloc_filespec(two->path);
1783                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1784                 free(null);
1785                 null = alloc_filespec(one->path);
1786                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1787                 free(null);
1788         }
1789         else
1790                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1791                              complete_rewrite);
1792
1793         free(name_munged);
1794         free(other_munged);
1795 }
1796
1797 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1798                          struct diffstat_t *diffstat)
1799 {
1800         const char *name;
1801         const char *other;
1802         int complete_rewrite = 0;
1803
1804         if (DIFF_PAIR_UNMERGED(p)) {
1805                 /* unmerged */
1806                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1807                 return;
1808         }
1809
1810         name = p->one->path;
1811         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1812
1813         diff_fill_sha1_info(p->one);
1814         diff_fill_sha1_info(p->two);
1815
1816         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1817                 complete_rewrite = 1;
1818         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1819 }
1820
1821 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1822 {
1823         const char *name;
1824         const char *other;
1825
1826         if (DIFF_PAIR_UNMERGED(p)) {
1827                 /* unmerged */
1828                 return;
1829         }
1830
1831         name = p->one->path;
1832         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1833
1834         diff_fill_sha1_info(p->one);
1835         diff_fill_sha1_info(p->two);
1836
1837         builtin_checkdiff(name, other, p->one, p->two, o);
1838 }
1839
1840 void diff_setup(struct diff_options *options)
1841 {
1842         memset(options, 0, sizeof(*options));
1843         options->line_termination = '\n';
1844         options->break_opt = -1;
1845         options->rename_limit = -1;
1846         options->context = 3;
1847         options->msg_sep = "";
1848
1849         options->change = diff_change;
1850         options->add_remove = diff_addremove;
1851         options->color_diff = diff_use_color_default;
1852         options->detect_rename = diff_detect_rename_default;
1853 }
1854
1855 int diff_setup_done(struct diff_options *options)
1856 {
1857         int count = 0;
1858
1859         if (options->output_format & DIFF_FORMAT_NAME)
1860                 count++;
1861         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
1862                 count++;
1863         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
1864                 count++;
1865         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
1866                 count++;
1867         if (count > 1)
1868                 die("--name-only, --name-status, --check and -s are mutually exclusive");
1869
1870         if (options->find_copies_harder)
1871                 options->detect_rename = DIFF_DETECT_COPY;
1872
1873         if (options->output_format & (DIFF_FORMAT_NAME |
1874                                       DIFF_FORMAT_NAME_STATUS |
1875                                       DIFF_FORMAT_CHECKDIFF |
1876                                       DIFF_FORMAT_NO_OUTPUT))
1877                 options->output_format &= ~(DIFF_FORMAT_RAW |
1878                                             DIFF_FORMAT_NUMSTAT |
1879                                             DIFF_FORMAT_DIFFSTAT |
1880                                             DIFF_FORMAT_SHORTSTAT |
1881                                             DIFF_FORMAT_SUMMARY |
1882                                             DIFF_FORMAT_PATCH);
1883
1884         /*
1885          * These cases always need recursive; we do not drop caller-supplied
1886          * recursive bits for other formats here.
1887          */
1888         if (options->output_format & (DIFF_FORMAT_PATCH |
1889                                       DIFF_FORMAT_NUMSTAT |
1890                                       DIFF_FORMAT_DIFFSTAT |
1891                                       DIFF_FORMAT_SHORTSTAT |
1892                                       DIFF_FORMAT_SUMMARY |
1893                                       DIFF_FORMAT_CHECKDIFF))
1894                 options->recursive = 1;
1895         /*
1896          * Also pickaxe would not work very well if you do not say recursive
1897          */
1898         if (options->pickaxe)
1899                 options->recursive = 1;
1900
1901         if (options->detect_rename && options->rename_limit < 0)
1902                 options->rename_limit = diff_rename_limit_default;
1903         if (options->setup & DIFF_SETUP_USE_CACHE) {
1904                 if (!active_cache)
1905                         /* read-cache does not die even when it fails
1906                          * so it is safe for us to do this here.  Also
1907                          * it does not smudge active_cache or active_nr
1908                          * when it fails, so we do not have to worry about
1909                          * cleaning it up ourselves either.
1910                          */
1911                         read_cache();
1912         }
1913         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1914                 use_size_cache = 1;
1915         if (options->abbrev <= 0 || 40 < options->abbrev)
1916                 options->abbrev = 40; /* full */
1917
1918         return 0;
1919 }
1920
1921 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
1922 {
1923         char c, *eq;
1924         int len;
1925
1926         if (*arg != '-')
1927                 return 0;
1928         c = *++arg;
1929         if (!c)
1930                 return 0;
1931         if (c == arg_short) {
1932                 c = *++arg;
1933                 if (!c)
1934                         return 1;
1935                 if (val && isdigit(c)) {
1936                         char *end;
1937                         int n = strtoul(arg, &end, 10);
1938                         if (*end)
1939                                 return 0;
1940                         *val = n;
1941                         return 1;
1942                 }
1943                 return 0;
1944         }
1945         if (c != '-')
1946                 return 0;
1947         arg++;
1948         eq = strchr(arg, '=');
1949         if (eq)
1950                 len = eq - arg;
1951         else
1952                 len = strlen(arg);
1953         if (!len || strncmp(arg, arg_long, len))
1954                 return 0;
1955         if (eq) {
1956                 int n;
1957                 char *end;
1958                 if (!isdigit(*++eq))
1959                         return 0;
1960                 n = strtoul(eq, &end, 10);
1961                 if (*end)
1962                         return 0;
1963                 *val = n;
1964         }
1965         return 1;
1966 }
1967
1968 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1969 {
1970         const char *arg = av[0];
1971         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1972                 options->output_format |= DIFF_FORMAT_PATCH;
1973         else if (opt_arg(arg, 'U', "unified", &options->context))
1974                 options->output_format |= DIFF_FORMAT_PATCH;
1975         else if (!strcmp(arg, "--raw"))
1976                 options->output_format |= DIFF_FORMAT_RAW;
1977         else if (!strcmp(arg, "--patch-with-raw")) {
1978                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
1979         }
1980         else if (!strcmp(arg, "--numstat")) {
1981                 options->output_format |= DIFF_FORMAT_NUMSTAT;
1982         }
1983         else if (!strcmp(arg, "--shortstat")) {
1984                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
1985         }
1986         else if (!prefixcmp(arg, "--stat")) {
1987                 char *end;
1988                 int width = options->stat_width;
1989                 int name_width = options->stat_name_width;
1990                 arg += 6;
1991                 end = (char *)arg;
1992
1993                 switch (*arg) {
1994                 case '-':
1995                         if (!prefixcmp(arg, "-width="))
1996                                 width = strtoul(arg + 7, &end, 10);
1997                         else if (!prefixcmp(arg, "-name-width="))
1998                                 name_width = strtoul(arg + 12, &end, 10);
1999                         break;
2000                 case '=':
2001                         width = strtoul(arg+1, &end, 10);
2002                         if (*end == ',')
2003                                 name_width = strtoul(end+1, &end, 10);
2004                 }
2005
2006                 /* Important! This checks all the error cases! */
2007                 if (*end)
2008                         return 0;
2009                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2010                 options->stat_name_width = name_width;
2011                 options->stat_width = width;
2012         }
2013         else if (!strcmp(arg, "--check"))
2014                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2015         else if (!strcmp(arg, "--summary"))
2016                 options->output_format |= DIFF_FORMAT_SUMMARY;
2017         else if (!strcmp(arg, "--patch-with-stat")) {
2018                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2019         }
2020         else if (!strcmp(arg, "-z"))
2021                 options->line_termination = 0;
2022         else if (!prefixcmp(arg, "-l"))
2023                 options->rename_limit = strtoul(arg+2, NULL, 10);
2024         else if (!strcmp(arg, "--full-index"))
2025                 options->full_index = 1;
2026         else if (!strcmp(arg, "--binary")) {
2027                 options->output_format |= DIFF_FORMAT_PATCH;
2028                 options->binary = 1;
2029         }
2030         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
2031                 options->text = 1;
2032         }
2033         else if (!strcmp(arg, "--name-only"))
2034                 options->output_format |= DIFF_FORMAT_NAME;
2035         else if (!strcmp(arg, "--name-status"))
2036                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2037         else if (!strcmp(arg, "-R"))
2038                 options->reverse_diff = 1;
2039         else if (!prefixcmp(arg, "-S"))
2040                 options->pickaxe = arg + 2;
2041         else if (!strcmp(arg, "-s")) {
2042                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2043         }
2044         else if (!prefixcmp(arg, "-O"))
2045                 options->orderfile = arg + 2;
2046         else if (!prefixcmp(arg, "--diff-filter="))
2047                 options->filter = arg + 14;
2048         else if (!strcmp(arg, "--pickaxe-all"))
2049                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2050         else if (!strcmp(arg, "--pickaxe-regex"))
2051                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2052         else if (!prefixcmp(arg, "-B")) {
2053                 if ((options->break_opt =
2054                      diff_scoreopt_parse(arg)) == -1)
2055                         return -1;
2056         }
2057         else if (!prefixcmp(arg, "-M")) {
2058                 if ((options->rename_score =
2059                      diff_scoreopt_parse(arg)) == -1)
2060                         return -1;
2061                 options->detect_rename = DIFF_DETECT_RENAME;
2062         }
2063         else if (!prefixcmp(arg, "-C")) {
2064                 if ((options->rename_score =
2065                      diff_scoreopt_parse(arg)) == -1)
2066                         return -1;
2067                 options->detect_rename = DIFF_DETECT_COPY;
2068         }
2069         else if (!strcmp(arg, "--find-copies-harder"))
2070                 options->find_copies_harder = 1;
2071         else if (!strcmp(arg, "--abbrev"))
2072                 options->abbrev = DEFAULT_ABBREV;
2073         else if (!prefixcmp(arg, "--abbrev=")) {
2074                 options->abbrev = strtoul(arg + 9, NULL, 10);
2075                 if (options->abbrev < MINIMUM_ABBREV)
2076                         options->abbrev = MINIMUM_ABBREV;
2077                 else if (40 < options->abbrev)
2078                         options->abbrev = 40;
2079         }
2080         else if (!strcmp(arg, "--color"))
2081                 options->color_diff = 1;
2082         else if (!strcmp(arg, "--no-color"))
2083                 options->color_diff = 0;
2084         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2085                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2086         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2087                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2088         else if (!strcmp(arg, "--ignore-space-at-eol"))
2089                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2090         else if (!strcmp(arg, "--color-words"))
2091                 options->color_diff = options->color_diff_words = 1;
2092         else if (!strcmp(arg, "--no-renames"))
2093                 options->detect_rename = 0;
2094         else
2095                 return 0;
2096         return 1;
2097 }
2098
2099 static int parse_num(const char **cp_p)
2100 {
2101         unsigned long num, scale;
2102         int ch, dot;
2103         const char *cp = *cp_p;
2104
2105         num = 0;
2106         scale = 1;
2107         dot = 0;
2108         for(;;) {
2109                 ch = *cp;
2110                 if ( !dot && ch == '.' ) {
2111                         scale = 1;
2112                         dot = 1;
2113                 } else if ( ch == '%' ) {
2114                         scale = dot ? scale*100 : 100;
2115                         cp++;   /* % is always at the end */
2116                         break;
2117                 } else if ( ch >= '0' && ch <= '9' ) {
2118                         if ( scale < 100000 ) {
2119                                 scale *= 10;
2120                                 num = (num*10) + (ch-'0');
2121                         }
2122                 } else {
2123                         break;
2124                 }
2125                 cp++;
2126         }
2127         *cp_p = cp;
2128
2129         /* user says num divided by scale and we say internally that
2130          * is MAX_SCORE * num / scale.
2131          */
2132         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
2133 }
2134
2135 int diff_scoreopt_parse(const char *opt)
2136 {
2137         int opt1, opt2, cmd;
2138
2139         if (*opt++ != '-')
2140                 return -1;
2141         cmd = *opt++;
2142         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2143                 return -1; /* that is not a -M, -C nor -B option */
2144
2145         opt1 = parse_num(&opt);
2146         if (cmd != 'B')
2147                 opt2 = 0;
2148         else {
2149                 if (*opt == 0)
2150                         opt2 = 0;
2151                 else if (*opt != '/')
2152                         return -1; /* we expect -B80/99 or -B80 */
2153                 else {
2154                         opt++;
2155                         opt2 = parse_num(&opt);
2156                 }
2157         }
2158         if (*opt != 0)
2159                 return -1;
2160         return opt1 | (opt2 << 16);
2161 }
2162
2163 struct diff_queue_struct diff_queued_diff;
2164
2165 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2166 {
2167         if (queue->alloc <= queue->nr) {
2168                 queue->alloc = alloc_nr(queue->alloc);
2169                 queue->queue = xrealloc(queue->queue,
2170                                         sizeof(dp) * queue->alloc);
2171         }
2172         queue->queue[queue->nr++] = dp;
2173 }
2174
2175 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2176                                  struct diff_filespec *one,
2177                                  struct diff_filespec *two)
2178 {
2179         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2180         dp->one = one;
2181         dp->two = two;
2182         if (queue)
2183                 diff_q(queue, dp);
2184         return dp;
2185 }
2186
2187 void diff_free_filepair(struct diff_filepair *p)
2188 {
2189         diff_free_filespec_data(p->one);
2190         diff_free_filespec_data(p->two);
2191         free(p->one);
2192         free(p->two);
2193         free(p);
2194 }
2195
2196 /* This is different from find_unique_abbrev() in that
2197  * it stuffs the result with dots for alignment.
2198  */
2199 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2200 {
2201         int abblen;
2202         const char *abbrev;
2203         if (len == 40)
2204                 return sha1_to_hex(sha1);
2205
2206         abbrev = find_unique_abbrev(sha1, len);
2207         if (!abbrev)
2208                 return sha1_to_hex(sha1);
2209         abblen = strlen(abbrev);
2210         if (abblen < 37) {
2211                 static char hex[41];
2212                 if (len < abblen && abblen <= len + 2)
2213                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2214                 else
2215                         sprintf(hex, "%s...", abbrev);
2216                 return hex;
2217         }
2218         return sha1_to_hex(sha1);
2219 }
2220
2221 static void diff_flush_raw(struct diff_filepair *p,
2222                            struct diff_options *options)
2223 {
2224         int two_paths;
2225         char status[10];
2226         int abbrev = options->abbrev;
2227         const char *path_one, *path_two;
2228         int inter_name_termination = '\t';
2229         int line_termination = options->line_termination;
2230
2231         if (!line_termination)
2232                 inter_name_termination = 0;
2233
2234         path_one = p->one->path;
2235         path_two = p->two->path;
2236         if (line_termination) {
2237                 path_one = quote_one(path_one);
2238                 path_two = quote_one(path_two);
2239         }
2240
2241         if (p->score)
2242                 sprintf(status, "%c%03d", p->status,
2243                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
2244         else {
2245                 status[0] = p->status;
2246                 status[1] = 0;
2247         }
2248         switch (p->status) {
2249         case DIFF_STATUS_COPIED:
2250         case DIFF_STATUS_RENAMED:
2251                 two_paths = 1;
2252                 break;
2253         case DIFF_STATUS_ADDED:
2254         case DIFF_STATUS_DELETED:
2255                 two_paths = 0;
2256                 break;
2257         default:
2258                 two_paths = 0;
2259                 break;
2260         }
2261         if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
2262                 printf(":%06o %06o %s ",
2263                        p->one->mode, p->two->mode,
2264                        diff_unique_abbrev(p->one->sha1, abbrev));
2265                 printf("%s ",
2266                        diff_unique_abbrev(p->two->sha1, abbrev));
2267         }
2268         printf("%s%c%s", status, inter_name_termination, path_one);
2269         if (two_paths)
2270                 printf("%c%s", inter_name_termination, path_two);
2271         putchar(line_termination);
2272         if (path_one != p->one->path)
2273                 free((void*)path_one);
2274         if (path_two != p->two->path)
2275                 free((void*)path_two);
2276 }
2277
2278 static void diff_flush_name(struct diff_filepair *p, struct diff_options *opt)
2279 {
2280         char *path = p->two->path;
2281
2282         if (opt->line_termination)
2283                 path = quote_one(p->two->path);
2284         printf("%s%c", path, opt->line_termination);
2285         if (p->two->path != path)
2286                 free(path);
2287 }
2288
2289 int diff_unmodified_pair(struct diff_filepair *p)
2290 {
2291         /* This function is written stricter than necessary to support
2292          * the currently implemented transformers, but the idea is to
2293          * let transformers to produce diff_filepairs any way they want,
2294          * and filter and clean them up here before producing the output.
2295          */
2296         struct diff_filespec *one, *two;
2297
2298         if (DIFF_PAIR_UNMERGED(p))
2299                 return 0; /* unmerged is interesting */
2300
2301         one = p->one;
2302         two = p->two;
2303
2304         /* deletion, addition, mode or type change
2305          * and rename are all interesting.
2306          */
2307         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2308             DIFF_PAIR_MODE_CHANGED(p) ||
2309             strcmp(one->path, two->path))
2310                 return 0;
2311
2312         /* both are valid and point at the same path.  that is, we are
2313          * dealing with a change.
2314          */
2315         if (one->sha1_valid && two->sha1_valid &&
2316             !hashcmp(one->sha1, two->sha1))
2317                 return 1; /* no change */
2318         if (!one->sha1_valid && !two->sha1_valid)
2319                 return 1; /* both look at the same file on the filesystem. */
2320         return 0;
2321 }
2322
2323 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2324 {
2325         if (diff_unmodified_pair(p))
2326                 return;
2327
2328         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2329             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2330                 return; /* no tree diffs in patch format */
2331
2332         run_diff(p, o);
2333 }
2334
2335 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2336                             struct diffstat_t *diffstat)
2337 {
2338         if (diff_unmodified_pair(p))
2339                 return;
2340
2341         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2342             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2343                 return; /* no tree diffs in patch format */
2344
2345         run_diffstat(p, o, diffstat);
2346 }
2347
2348 static void diff_flush_checkdiff(struct diff_filepair *p,
2349                 struct diff_options *o)
2350 {
2351         if (diff_unmodified_pair(p))
2352                 return;
2353
2354         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2355             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2356                 return; /* no tree diffs in patch format */
2357
2358         run_checkdiff(p, o);
2359 }
2360
2361 int diff_queue_is_empty(void)
2362 {
2363         struct diff_queue_struct *q = &diff_queued_diff;
2364         int i;
2365         for (i = 0; i < q->nr; i++)
2366                 if (!diff_unmodified_pair(q->queue[i]))
2367                         return 0;
2368         return 1;
2369 }
2370
2371 #if DIFF_DEBUG
2372 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2373 {
2374         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2375                 x, one ? one : "",
2376                 s->path,
2377                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2378                 s->mode,
2379                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2380         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2381                 x, one ? one : "",
2382                 s->size, s->xfrm_flags);
2383 }
2384
2385 void diff_debug_filepair(const struct diff_filepair *p, int i)
2386 {
2387         diff_debug_filespec(p->one, i, "one");
2388         diff_debug_filespec(p->two, i, "two");
2389         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2390                 p->score, p->status ? p->status : '?',
2391                 p->source_stays, p->broken_pair);
2392 }
2393
2394 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2395 {
2396         int i;
2397         if (msg)
2398                 fprintf(stderr, "%s\n", msg);
2399         fprintf(stderr, "q->nr = %d\n", q->nr);
2400         for (i = 0; i < q->nr; i++) {
2401                 struct diff_filepair *p = q->queue[i];
2402                 diff_debug_filepair(p, i);
2403         }
2404 }
2405 #endif
2406
2407 static void diff_resolve_rename_copy(void)
2408 {
2409         int i, j;
2410         struct diff_filepair *p, *pp;
2411         struct diff_queue_struct *q = &diff_queued_diff;
2412
2413         diff_debug_queue("resolve-rename-copy", q);
2414
2415         for (i = 0; i < q->nr; i++) {
2416                 p = q->queue[i];
2417                 p->status = 0; /* undecided */
2418                 if (DIFF_PAIR_UNMERGED(p))
2419                         p->status = DIFF_STATUS_UNMERGED;
2420                 else if (!DIFF_FILE_VALID(p->one))
2421                         p->status = DIFF_STATUS_ADDED;
2422                 else if (!DIFF_FILE_VALID(p->two))
2423                         p->status = DIFF_STATUS_DELETED;
2424                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2425                         p->status = DIFF_STATUS_TYPE_CHANGED;
2426
2427                 /* from this point on, we are dealing with a pair
2428                  * whose both sides are valid and of the same type, i.e.
2429                  * either in-place edit or rename/copy edit.
2430                  */
2431                 else if (DIFF_PAIR_RENAME(p)) {
2432                         if (p->source_stays) {
2433                                 p->status = DIFF_STATUS_COPIED;
2434                                 continue;
2435                         }
2436                         /* See if there is some other filepair that
2437                          * copies from the same source as us.  If so
2438                          * we are a copy.  Otherwise we are either a
2439                          * copy if the path stays, or a rename if it
2440                          * does not, but we already handled "stays" case.
2441                          */
2442                         for (j = i + 1; j < q->nr; j++) {
2443                                 pp = q->queue[j];
2444                                 if (strcmp(pp->one->path, p->one->path))
2445                                         continue; /* not us */
2446                                 if (!DIFF_PAIR_RENAME(pp))
2447                                         continue; /* not a rename/copy */
2448                                 /* pp is a rename/copy from the same source */
2449                                 p->status = DIFF_STATUS_COPIED;
2450                                 break;
2451                         }
2452                         if (!p->status)
2453                                 p->status = DIFF_STATUS_RENAMED;
2454                 }
2455                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2456                          p->one->mode != p->two->mode)
2457                         p->status = DIFF_STATUS_MODIFIED;
2458                 else {
2459                         /* This is a "no-change" entry and should not
2460                          * happen anymore, but prepare for broken callers.
2461                          */
2462                         error("feeding unmodified %s to diffcore",
2463                               p->one->path);
2464                         p->status = DIFF_STATUS_UNKNOWN;
2465                 }
2466         }
2467         diff_debug_queue("resolve-rename-copy done", q);
2468 }
2469
2470 static int check_pair_status(struct diff_filepair *p)
2471 {
2472         switch (p->status) {
2473         case DIFF_STATUS_UNKNOWN:
2474                 return 0;
2475         case 0:
2476                 die("internal error in diff-resolve-rename-copy");
2477         default:
2478                 return 1;
2479         }
2480 }
2481
2482 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2483 {
2484         int fmt = opt->output_format;
2485
2486         if (fmt & DIFF_FORMAT_CHECKDIFF)
2487                 diff_flush_checkdiff(p, opt);
2488         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2489                 diff_flush_raw(p, opt);
2490         else if (fmt & DIFF_FORMAT_NAME)
2491                 diff_flush_name(p, opt);
2492 }
2493
2494 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2495 {
2496         char *name = quote_one(fs->path);
2497         if (fs->mode)
2498                 printf(" %s mode %06o %s\n", newdelete, fs->mode, name);
2499         else
2500                 printf(" %s %s\n", newdelete, name);
2501         free(name);
2502 }
2503
2504
2505 static void show_mode_change(struct diff_filepair *p, int show_name)
2506 {
2507         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2508                 if (show_name) {
2509                         char *name = quote_one(p->two->path);
2510                         printf(" mode change %06o => %06o %s\n",
2511                                p->one->mode, p->two->mode, name);
2512                         free(name);
2513                 }
2514                 else
2515                         printf(" mode change %06o => %06o\n",
2516                                p->one->mode, p->two->mode);
2517         }
2518 }
2519
2520 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2521 {
2522         char *names = pprint_rename(p->one->path, p->two->path);
2523
2524         printf(" %s %s (%d%%)\n", renamecopy, names,
2525                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2526         free(names);
2527         show_mode_change(p, 0);
2528 }
2529
2530 static void diff_summary(struct diff_filepair *p)
2531 {
2532         switch(p->status) {
2533         case DIFF_STATUS_DELETED:
2534                 show_file_mode_name("delete", p->one);
2535                 break;
2536         case DIFF_STATUS_ADDED:
2537                 show_file_mode_name("create", p->two);
2538                 break;
2539         case DIFF_STATUS_COPIED:
2540                 show_rename_copy("copy", p);
2541                 break;
2542         case DIFF_STATUS_RENAMED:
2543                 show_rename_copy("rename", p);
2544                 break;
2545         default:
2546                 if (p->score) {
2547                         char *name = quote_one(p->two->path);
2548                         printf(" rewrite %s (%d%%)\n", name,
2549                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2550                         free(name);
2551                         show_mode_change(p, 0);
2552                 } else  show_mode_change(p, 1);
2553                 break;
2554         }
2555 }
2556
2557 struct patch_id_t {
2558         struct xdiff_emit_state xm;
2559         SHA_CTX *ctx;
2560         int patchlen;
2561 };
2562
2563 static int remove_space(char *line, int len)
2564 {
2565         int i;
2566         char *dst = line;
2567         unsigned char c;
2568
2569         for (i = 0; i < len; i++)
2570                 if (!isspace((c = line[i])))
2571                         *dst++ = c;
2572
2573         return dst - line;
2574 }
2575
2576 static void patch_id_consume(void *priv, char *line, unsigned long len)
2577 {
2578         struct patch_id_t *data = priv;
2579         int new_len;
2580
2581         /* Ignore line numbers when computing the SHA1 of the patch */
2582         if (!prefixcmp(line, "@@ -"))
2583                 return;
2584
2585         new_len = remove_space(line, len);
2586
2587         SHA1_Update(data->ctx, line, new_len);
2588         data->patchlen += new_len;
2589 }
2590
2591 /* returns 0 upon success, and writes result into sha1 */
2592 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2593 {
2594         struct diff_queue_struct *q = &diff_queued_diff;
2595         int i;
2596         SHA_CTX ctx;
2597         struct patch_id_t data;
2598         char buffer[PATH_MAX * 4 + 20];
2599
2600         SHA1_Init(&ctx);
2601         memset(&data, 0, sizeof(struct patch_id_t));
2602         data.ctx = &ctx;
2603         data.xm.consume = patch_id_consume;
2604
2605         for (i = 0; i < q->nr; i++) {
2606                 xpparam_t xpp;
2607                 xdemitconf_t xecfg;
2608                 xdemitcb_t ecb;
2609                 mmfile_t mf1, mf2;
2610                 struct diff_filepair *p = q->queue[i];
2611                 int len1, len2;
2612
2613                 if (p->status == 0)
2614                         return error("internal diff status error");
2615                 if (p->status == DIFF_STATUS_UNKNOWN)
2616                         continue;
2617                 if (diff_unmodified_pair(p))
2618                         continue;
2619                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2620                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2621                         continue;
2622                 if (DIFF_PAIR_UNMERGED(p))
2623                         continue;
2624
2625                 diff_fill_sha1_info(p->one);
2626                 diff_fill_sha1_info(p->two);
2627                 if (fill_mmfile(&mf1, p->one) < 0 ||
2628                                 fill_mmfile(&mf2, p->two) < 0)
2629                         return error("unable to read files to diff");
2630
2631                 /* Maybe hash p->two? into the patch id? */
2632                 if (mmfile_is_binary(&mf2))
2633                         continue;
2634
2635                 len1 = remove_space(p->one->path, strlen(p->one->path));
2636                 len2 = remove_space(p->two->path, strlen(p->two->path));
2637                 if (p->one->mode == 0)
2638                         len1 = snprintf(buffer, sizeof(buffer),
2639                                         "diff--gita/%.*sb/%.*s"
2640                                         "newfilemode%06o"
2641                                         "---/dev/null"
2642                                         "+++b/%.*s",
2643                                         len1, p->one->path,
2644                                         len2, p->two->path,
2645                                         p->two->mode,
2646                                         len2, p->two->path);
2647                 else if (p->two->mode == 0)
2648                         len1 = snprintf(buffer, sizeof(buffer),
2649                                         "diff--gita/%.*sb/%.*s"
2650                                         "deletedfilemode%06o"
2651                                         "---a/%.*s"
2652                                         "+++/dev/null",
2653                                         len1, p->one->path,
2654                                         len2, p->two->path,
2655                                         p->one->mode,
2656                                         len1, p->one->path);
2657                 else
2658                         len1 = snprintf(buffer, sizeof(buffer),
2659                                         "diff--gita/%.*sb/%.*s"
2660                                         "---a/%.*s"
2661                                         "+++b/%.*s",
2662                                         len1, p->one->path,
2663                                         len2, p->two->path,
2664                                         len1, p->one->path,
2665                                         len2, p->two->path);
2666                 SHA1_Update(&ctx, buffer, len1);
2667
2668                 xpp.flags = XDF_NEED_MINIMAL;
2669                 xecfg.ctxlen = 3;
2670                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2671                 ecb.outf = xdiff_outf;
2672                 ecb.priv = &data;
2673                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2674         }
2675
2676         SHA1_Final(sha1, &ctx);
2677         return 0;
2678 }
2679
2680 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2681 {
2682         struct diff_queue_struct *q = &diff_queued_diff;
2683         int i;
2684         int result = diff_get_patch_id(options, sha1);
2685
2686         for (i = 0; i < q->nr; i++)
2687                 diff_free_filepair(q->queue[i]);
2688
2689         free(q->queue);
2690         q->queue = NULL;
2691         q->nr = q->alloc = 0;
2692
2693         return result;
2694 }
2695
2696 static int is_summary_empty(const struct diff_queue_struct *q)
2697 {
2698         int i;
2699
2700         for (i = 0; i < q->nr; i++) {
2701                 const struct diff_filepair *p = q->queue[i];
2702
2703                 switch (p->status) {
2704                 case DIFF_STATUS_DELETED:
2705                 case DIFF_STATUS_ADDED:
2706                 case DIFF_STATUS_COPIED:
2707                 case DIFF_STATUS_RENAMED:
2708                         return 0;
2709                 default:
2710                         if (p->score)
2711                                 return 0;
2712                         if (p->one->mode && p->two->mode &&
2713                             p->one->mode != p->two->mode)
2714                                 return 0;
2715                         break;
2716                 }
2717         }
2718         return 1;
2719 }
2720
2721 void diff_flush(struct diff_options *options)
2722 {
2723         struct diff_queue_struct *q = &diff_queued_diff;
2724         int i, output_format = options->output_format;
2725         int separator = 0;
2726
2727         /*
2728          * Order: raw, stat, summary, patch
2729          * or:    name/name-status/checkdiff (other bits clear)
2730          */
2731         if (!q->nr)
2732                 goto free_queue;
2733
2734         if (output_format & (DIFF_FORMAT_RAW |
2735                              DIFF_FORMAT_NAME |
2736                              DIFF_FORMAT_NAME_STATUS |
2737                              DIFF_FORMAT_CHECKDIFF)) {
2738                 for (i = 0; i < q->nr; i++) {
2739                         struct diff_filepair *p = q->queue[i];
2740                         if (check_pair_status(p))
2741                                 flush_one_pair(p, options);
2742                 }
2743                 separator++;
2744         }
2745
2746         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2747                 struct diffstat_t diffstat;
2748
2749                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2750                 diffstat.xm.consume = diffstat_consume;
2751                 for (i = 0; i < q->nr; i++) {
2752                         struct diff_filepair *p = q->queue[i];
2753                         if (check_pair_status(p))
2754                                 diff_flush_stat(p, options, &diffstat);
2755                 }
2756                 if (output_format & DIFF_FORMAT_NUMSTAT)
2757                         show_numstat(&diffstat, options);
2758                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2759                         show_stats(&diffstat, options);
2760                 else if (output_format & DIFF_FORMAT_SHORTSTAT)
2761                         show_shortstats(&diffstat);
2762                 separator++;
2763         }
2764
2765         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2766                 for (i = 0; i < q->nr; i++)
2767                         diff_summary(q->queue[i]);
2768                 separator++;
2769         }
2770
2771         if (output_format & DIFF_FORMAT_PATCH) {
2772                 if (separator) {
2773                         if (options->stat_sep) {
2774                                 /* attach patch instead of inline */
2775                                 fputs(options->stat_sep, stdout);
2776                         } else {
2777                                 putchar(options->line_termination);
2778                         }
2779                 }
2780
2781                 for (i = 0; i < q->nr; i++) {
2782                         struct diff_filepair *p = q->queue[i];
2783                         if (check_pair_status(p))
2784                                 diff_flush_patch(p, options);
2785                 }
2786         }
2787
2788         if (output_format & DIFF_FORMAT_CALLBACK)
2789                 options->format_callback(q, options, options->format_callback_data);
2790
2791         for (i = 0; i < q->nr; i++)
2792                 diff_free_filepair(q->queue[i]);
2793 free_queue:
2794         free(q->queue);
2795         q->queue = NULL;
2796         q->nr = q->alloc = 0;
2797 }
2798
2799 static void diffcore_apply_filter(const char *filter)
2800 {
2801         int i;
2802         struct diff_queue_struct *q = &diff_queued_diff;
2803         struct diff_queue_struct outq;
2804         outq.queue = NULL;
2805         outq.nr = outq.alloc = 0;
2806
2807         if (!filter)
2808                 return;
2809
2810         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2811                 int found;
2812                 for (i = found = 0; !found && i < q->nr; i++) {
2813                         struct diff_filepair *p = q->queue[i];
2814                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2815                              ((p->score &&
2816                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2817                               (!p->score &&
2818                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2819                             ((p->status != DIFF_STATUS_MODIFIED) &&
2820                              strchr(filter, p->status)))
2821                                 found++;
2822                 }
2823                 if (found)
2824                         return;
2825
2826                 /* otherwise we will clear the whole queue
2827                  * by copying the empty outq at the end of this
2828                  * function, but first clear the current entries
2829                  * in the queue.
2830                  */
2831                 for (i = 0; i < q->nr; i++)
2832                         diff_free_filepair(q->queue[i]);
2833         }
2834         else {
2835                 /* Only the matching ones */
2836                 for (i = 0; i < q->nr; i++) {
2837                         struct diff_filepair *p = q->queue[i];
2838
2839                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2840                              ((p->score &&
2841                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2842                               (!p->score &&
2843                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2844                             ((p->status != DIFF_STATUS_MODIFIED) &&
2845                              strchr(filter, p->status)))
2846                                 diff_q(&outq, p);
2847                         else
2848                                 diff_free_filepair(p);
2849                 }
2850         }
2851         free(q->queue);
2852         *q = outq;
2853 }
2854
2855 void diffcore_std(struct diff_options *options)
2856 {
2857         if (options->break_opt != -1)
2858                 diffcore_break(options->break_opt);
2859         if (options->detect_rename)
2860                 diffcore_rename(options);
2861         if (options->break_opt != -1)
2862                 diffcore_merge_broken();
2863         if (options->pickaxe)
2864                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2865         if (options->orderfile)
2866                 diffcore_order(options->orderfile);
2867         diff_resolve_rename_copy();
2868         diffcore_apply_filter(options->filter);
2869 }
2870
2871
2872 void diffcore_std_no_resolve(struct diff_options *options)
2873 {
2874         if (options->pickaxe)
2875                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2876         if (options->orderfile)
2877                 diffcore_order(options->orderfile);
2878         diffcore_apply_filter(options->filter);
2879 }
2880
2881 void diff_addremove(struct diff_options *options,
2882                     int addremove, unsigned mode,
2883                     const unsigned char *sha1,
2884                     const char *base, const char *path)
2885 {
2886         char concatpath[PATH_MAX];
2887         struct diff_filespec *one, *two;
2888
2889         /* This may look odd, but it is a preparation for
2890          * feeding "there are unchanged files which should
2891          * not produce diffs, but when you are doing copy
2892          * detection you would need them, so here they are"
2893          * entries to the diff-core.  They will be prefixed
2894          * with something like '=' or '*' (I haven't decided
2895          * which but should not make any difference).
2896          * Feeding the same new and old to diff_change()
2897          * also has the same effect.
2898          * Before the final output happens, they are pruned after
2899          * merged into rename/copy pairs as appropriate.
2900          */
2901         if (options->reverse_diff)
2902                 addremove = (addremove == '+' ? '-' :
2903                              addremove == '-' ? '+' : addremove);
2904
2905         if (!path) path = "";
2906         sprintf(concatpath, "%s%s", base, path);
2907         one = alloc_filespec(concatpath);
2908         two = alloc_filespec(concatpath);
2909
2910         if (addremove != '+')
2911                 fill_filespec(one, sha1, mode);
2912         if (addremove != '-')
2913                 fill_filespec(two, sha1, mode);
2914
2915         diff_queue(&diff_queued_diff, one, two);
2916 }
2917
2918 void diff_change(struct diff_options *options,
2919                  unsigned old_mode, unsigned new_mode,
2920                  const unsigned char *old_sha1,
2921                  const unsigned char *new_sha1,
2922                  const char *base, const char *path)
2923 {
2924         char concatpath[PATH_MAX];
2925         struct diff_filespec *one, *two;
2926
2927         if (options->reverse_diff) {
2928                 unsigned tmp;
2929                 const unsigned char *tmp_c;
2930                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
2931                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
2932         }
2933         if (!path) path = "";
2934         sprintf(concatpath, "%s%s", base, path);
2935         one = alloc_filespec(concatpath);
2936         two = alloc_filespec(concatpath);
2937         fill_filespec(one, old_sha1, old_mode);
2938         fill_filespec(two, new_sha1, new_mode);
2939
2940         diff_queue(&diff_queued_diff, one, two);
2941 }
2942
2943 void diff_unmerge(struct diff_options *options,
2944                   const char *path,
2945                   unsigned mode, const unsigned char *sha1)
2946 {
2947         struct diff_filespec *one, *two;
2948         one = alloc_filespec(path);
2949         two = alloc_filespec(path);
2950         fill_filespec(one, sha1, mode);
2951         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
2952 }