apply.c

   1 /*
   2  * apply.c
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  *
   6  * This applies patches on top of some (arbitrary) version of the SCM.
   7  *
   8  */
   9 #include <fnmatch.h>
  10 #include "cache.h"
  11 #include "quote.h"
  12
  13 //  --check turns on checking that the working tree matches the
  14 //    files that are being modified, but doesn't apply the patch
  15 //  --stat does just a diffstat, and doesn't actually apply
  16 //  --numstat does numeric diffstat, and doesn't actually apply
  17 //  --index-info shows the old and new index info for paths if available.
  18 //
  19 static const char *prefix;
  20 static int prefix_length = -1;
  21
  22 static int p_value = 1;
  23 static int allow_binary_replacement = 0;
  24 static int check_index = 0;
  25 static int write_index = 0;
  26 static int diffstat = 0;
  27 static int numstat = 0;
  28 static int summary = 0;
  29 static int check = 0;
  30 static int apply = 1;
  31 static int no_add = 0;
  32 static int show_index_info = 0;
  33 static int line_termination = '\n';
  34 static const char apply_usage[] =
  35 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] <patch>...";
  36
  37 static enum whitespace_eol {
  38         nowarn_whitespace,
  39         warn_on_whitespace,
  40         error_on_whitespace,
  41         strip_whitespace,
  42 } new_whitespace = nowarn_whitespace;
  43 static int whitespace_error = 0;
  44 static int squelch_whitespace_errors = 5;
  45 static int applied_after_stripping = 0;
  46 static const char *patch_input_file = NULL;
  47
  48 static void parse_whitespace_option(const char *option)
  49 {
  50         if (!option) {
  51                 new_whitespace = nowarn_whitespace;
  52                 return;
  53         }
  54         if (!strcmp(option, "warn")) {
  55                 new_whitespace = warn_on_whitespace;
  56                 return;
  57         }
  58         if (!strcmp(option, "error")) {
  59                 new_whitespace = error_on_whitespace;
  60                 return;
  61         }
  62         if (!strcmp(option, "error-all")) {
  63                 new_whitespace = error_on_whitespace;
  64                 squelch_whitespace_errors = 0;
  65                 return;
  66         }
  67         if (!strcmp(option, "strip")) {
  68                 new_whitespace = strip_whitespace;
  69                 return;
  70         }
  71         die("unrecognized whitespace option '%s'", option);
  72 }
  73
  74 /*
  75  * For "diff-stat" like behaviour, we keep track of the biggest change
  76  * we've seen, and the longest filename. That allows us to do simple
  77  * scaling.
  78  */
  79 static int max_change, max_len;
  80
  81 /*
  82  * Various "current state", notably line numbers and what
  83  * file (and how) we're patching right now.. The "is_xxxx"
  84  * things are flags, where -1 means "don't know yet".
  85  */
  86 static int linenr = 1;
  87
  88 struct fragment {
  89         unsigned long oldpos, oldlines;
  90         unsigned long newpos, newlines;
  91         const char *patch;
  92         int size;
  93         struct fragment *next;
  94 };
  95
  96 struct patch {
  97         char *new_name, *old_name, *def_name;
  98         unsigned int old_mode, new_mode;
  99         int is_rename, is_copy, is_new, is_delete, is_binary;
 100         int lines_added, lines_deleted;
 101         int score;
 102         struct fragment *fragments;
 103         char *result;
 104         unsigned long resultsize;
 105         char old_sha1_prefix[41];
 106         char new_sha1_prefix[41];
 107         struct patch *next;
 108 };
 109
 110 #define CHUNKSIZE (8192)
 111 #define SLOP (16)
 112
 113 static void *read_patch_file(int fd, unsigned long *sizep)
 114 {
 115         unsigned long size = 0, alloc = CHUNKSIZE;
 116         void *buffer = xmalloc(alloc);
 117
 118         for (;;) {
 119                 int nr = alloc - size;
 120                 if (nr < 1024) {
 121                         alloc += CHUNKSIZE;
 122                         buffer = xrealloc(buffer, alloc);
 123                         nr = alloc - size;
 124                 }
 125                 nr = xread(fd, buffer + size, nr);
 126                 if (!nr)
 127                         break;
 128                 if (nr < 0)
 129                         die("git-apply: read returned %s", strerror(errno));
 130                 size += nr;
 131         }
 132         *sizep = size;
 133
 134         /*
 135          * Make sure that we have some slop in the buffer
 136          * so that we can do speculative "memcmp" etc, and
 137          * see to it that it is NUL-filled.
 138          */
 139         if (alloc < size + SLOP)
 140                 buffer = xrealloc(buffer, size + SLOP);
 141         memset(buffer + size, 0, SLOP);
 142         return buffer;
 143 }
 144
 145 static unsigned long linelen(const char *buffer, unsigned long size)
 146 {
 147         unsigned long len = 0;
 148         while (size--) {
 149                 len++;
 150                 if (*buffer++ == '\n')
 151                         break;
 152         }
 153         return len;
 154 }
 155
 156 static int is_dev_null(const char *str)
 157 {
 158         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 159 }
 160
 161 #define TERM_SPACE      1
 162 #define TERM_TAB        2
 163
 164 static int name_terminate(const char *name, int namelen, int c, int terminate)
 165 {
 166         if (c == ' ' && !(terminate & TERM_SPACE))
 167                 return 0;
 168         if (c == '\t' && !(terminate & TERM_TAB))
 169                 return 0;
 170
 171         return 1;
 172 }
 173
 174 static char * find_name(const char *line, char *def, int p_value, int terminate)
 175 {
 176         int len;
 177         const char *start = line;
 178         char *name;
 179
 180         if (*line == '"') {
 181                 /* Proposed "new-style" GNU patch/diff format; see
 182                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
 183                  */
 184                 name = unquote_c_style(line, NULL);
 185                 if (name) {
 186                         char *cp = name;
 187                         while (p_value) {
 188                                 cp = strchr(name, '/');
 189                                 if (!cp)
 190                                         break;
 191                                 cp++;
 192                                 p_value--;
 193                         }
 194                         if (cp) {
 195                                 /* name can later be freed, so we need
 196                                  * to memmove, not just return cp
 197                                  */
 198                                 memmove(name, cp, strlen(cp) + 1);
 199                                 free(def);
 200                                 return name;
 201                         }
 202                         else {
 203                                 free(name);
 204                                 name = NULL;
 205                         }
 206                 }
 207         }
 208
 209         for (;;) {
 210                 char c = *line;
 211
 212                 if (isspace(c)) {
 213                         if (c == '\n')
 214                                 break;
 215                         if (name_terminate(start, line-start, c, terminate))
 216                                 break;
 217                 }
 218                 line++;
 219                 if (c == '/' && !--p_value)
 220                         start = line;
 221         }
 222         if (!start)
 223                 return def;
 224         len = line - start;
 225         if (!len)
 226                 return def;
 227
 228         /*
 229          * Generally we prefer the shorter name, especially
 230          * if the other one is just a variation of that with
 231          * something else tacked on to the end (ie "file.orig"
 232          * or "file~").
 233          */
 234         if (def) {
 235                 int deflen = strlen(def);
 236                 if (deflen < len && !strncmp(start, def, deflen))
 237                         return def;
 238         }
 239
 240         name = xmalloc(len + 1);
 241         memcpy(name, start, len);
 242         name[len] = 0;
 243         free(def);
 244         return name;
 245 }
 246
 247 /*
 248  * Get the name etc info from the --/+++ lines of a traditional patch header
 249  *
 250  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 251  *
 252  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 253  * files, we can happily check the index for a match, but for creating a
 254  * new file we should try to match whatever "patch" does. I have no idea.
 255  */
 256 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 257 {
 258         char *name;
 259
 260         first += 4;     // skip "--- "
 261         second += 4;    // skip "+++ "
 262         if (is_dev_null(first)) {
 263                 patch->is_new = 1;
 264                 patch->is_delete = 0;
 265                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 266                 patch->new_name = name;
 267         } else if (is_dev_null(second)) {
 268                 patch->is_new = 0;
 269                 patch->is_delete = 1;
 270                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 271                 patch->old_name = name;
 272         } else {
 273                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 274                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 275                 patch->old_name = patch->new_name = name;
 276         }
 277         if (!name)
 278                 die("unable to find filename in patch at line %d", linenr);
 279 }
 280
 281 static int gitdiff_hdrend(const char *line, struct patch *patch)
 282 {
 283         return -1;
 284 }
 285
 286 /*
 287  * We're anal about diff header consistency, to make
 288  * sure that we don't end up having strange ambiguous
 289  * patches floating around.
 290  *
 291  * As a result, gitdiff_{old|new}name() will check
 292  * their names against any previous information, just
 293  * to make sure..
 294  */
 295 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 296 {
 297         if (!orig_name && !isnull)
 298                 return find_name(line, NULL, 1, 0);
 299
 300         if (orig_name) {
 301                 int len;
 302                 const char *name;
 303                 char *another;
 304                 name = orig_name;
 305                 len = strlen(name);
 306                 if (isnull)
 307                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 308                 another = find_name(line, NULL, 1, 0);
 309                 if (!another || memcmp(another, name, len))
 310                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 311                 free(another);
 312                 return orig_name;
 313         }
 314         else {
 315                 /* expect "/dev/null" */
 316                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 317                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
 318                 return NULL;
 319         }
 320 }
 321
 322 static int gitdiff_oldname(const char *line, struct patch *patch)
 323 {
 324         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 325         return 0;
 326 }
 327
 328 static int gitdiff_newname(const char *line, struct patch *patch)
 329 {
 330         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 331         return 0;
 332 }
 333
 334 static int gitdiff_oldmode(const char *line, struct patch *patch)
 335 {
 336         patch->old_mode = strtoul(line, NULL, 8);
 337         return 0;
 338 }
 339
 340 static int gitdiff_newmode(const char *line, struct patch *patch)
 341 {
 342         patch->new_mode = strtoul(line, NULL, 8);
 343         return 0;
 344 }
 345
 346 static int gitdiff_delete(const char *line, struct patch *patch)
 347 {
 348         patch->is_delete = 1;
 349         patch->old_name = patch->def_name;
 350         return gitdiff_oldmode(line, patch);
 351 }
 352
 353 static int gitdiff_newfile(const char *line, struct patch *patch)
 354 {
 355         patch->is_new = 1;
 356         patch->new_name = patch->def_name;
 357         return gitdiff_newmode(line, patch);
 358 }
 359
 360 static int gitdiff_copysrc(const char *line, struct patch *patch)
 361 {
 362         patch->is_copy = 1;
 363         patch->old_name = find_name(line, NULL, 0, 0);
 364         return 0;
 365 }
 366
 367 static int gitdiff_copydst(const char *line, struct patch *patch)
 368 {
 369         patch->is_copy = 1;
 370         patch->new_name = find_name(line, NULL, 0, 0);
 371         return 0;
 372 }
 373
 374 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 375 {
 376         patch->is_rename = 1;
 377         patch->old_name = find_name(line, NULL, 0, 0);
 378         return 0;
 379 }
 380
 381 static int gitdiff_renamedst(const char *line, struct patch *patch)
 382 {
 383         patch->is_rename = 1;
 384         patch->new_name = find_name(line, NULL, 0, 0);
 385         return 0;
 386 }
 387
 388 static int gitdiff_similarity(const char *line, struct patch *patch)
 389 {
 390         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 391                 patch->score = 0;
 392         return 0;
 393 }
 394
 395 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 396 {
 397         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 398                 patch->score = 0;
 399         return 0;
 400 }
 401
 402 static int gitdiff_index(const char *line, struct patch *patch)
 403 {
 404         /* index line is N hexadecimal, "..", N hexadecimal,
 405          * and optional space with octal mode.
 406          */
 407         const char *ptr, *eol;
 408         int len;
 409
 410         ptr = strchr(line, '.');
 411         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
 412                 return 0;
 413         len = ptr - line;
 414         memcpy(patch->old_sha1_prefix, line, len);
 415         patch->old_sha1_prefix[len] = 0;
 416
 417         line = ptr + 2;
 418         ptr = strchr(line, ' ');
 419         eol = strchr(line, '\n');
 420
 421         if (!ptr || eol < ptr)
 422                 ptr = eol;
 423         len = ptr - line;
 424
 425         if (40 < len)
 426                 return 0;
 427         memcpy(patch->new_sha1_prefix, line, len);
 428         patch->new_sha1_prefix[len] = 0;
 429         if (*ptr == ' ')
 430                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
 431         return 0;
 432 }
 433
 434 /*
 435  * This is normal for a diff that doesn't change anything: we'll fall through
 436  * into the next diff. Tell the parser to break out.
 437  */
 438 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 439 {
 440         return -1;
 441 }
 442
 443 static const char *stop_at_slash(const char *line, int llen)
 444 {
 445         int i;
 446
 447         for (i = 0; i < llen; i++) {
 448                 int ch = line[i];
 449                 if (ch == '/')
 450                         return line + i;
 451         }
 452         return NULL;
 453 }
 454
 455 /* This is to extract the same name that appears on "diff --git"
 456  * line.  We do not find and return anything if it is a rename
 457  * patch, and it is OK because we will find the name elsewhere.
 458  * We need to reliably find name only when it is mode-change only,
 459  * creation or deletion of an empty file.  In any of these cases,
 460  * both sides are the same name under a/ and b/ respectively.
 461  */
 462 static char *git_header_name(char *line, int llen)
 463 {
 464         int len;
 465         const char *name;
 466         const char *second = NULL;
 467
 468         line += strlen("diff --git ");
 469         llen -= strlen("diff --git ");
 470
 471         if (*line == '"') {
 472                 const char *cp;
 473                 char *first = unquote_c_style(line, &second);
 474                 if (!first)
 475                         return NULL;
 476
 477                 /* advance to the first slash */
 478                 cp = stop_at_slash(first, strlen(first));
 479                 if (!cp || cp == first) {
 480                         /* we do not accept absolute paths */
 481                 free_first_and_fail:
 482                         free(first);
 483                         return NULL;
 484                 }
 485                 len = strlen(cp+1);
 486                 memmove(first, cp+1, len+1); /* including NUL */
 487
 488                 /* second points at one past closing dq of name.
 489                  * find the second name.
 490                  */
 491                 while ((second < line + llen) && isspace(*second))
 492                         second++;
 493
 494                 if (line + llen <= second)
 495                         goto free_first_and_fail;
 496                 if (*second == '"') {
 497                         char *sp = unquote_c_style(second, NULL);
 498                         if (!sp)
 499                                 goto free_first_and_fail;
 500                         cp = stop_at_slash(sp, strlen(sp));
 501                         if (!cp || cp == sp) {
 502                         free_both_and_fail:
 503                                 free(sp);
 504                                 goto free_first_and_fail;
 505                         }
 506                         /* They must match, otherwise ignore */
 507                         if (strcmp(cp+1, first))
 508                                 goto free_both_and_fail;
 509                         free(sp);
 510                         return first;
 511                 }
 512
 513                 /* unquoted second */
 514                 cp = stop_at_slash(second, line + llen - second);
 515                 if (!cp || cp == second)
 516                         goto free_first_and_fail;
 517                 cp++;
 518                 if (line + llen - cp != len + 1 ||
 519                     memcmp(first, cp, len))
 520                         goto free_first_and_fail;
 521                 return first;
 522         }
 523
 524         /* unquoted first name */
 525         name = stop_at_slash(line, llen);
 526         if (!name || name == line)
 527                 return NULL;
 528
 529         name++;
 530
 531         /* since the first name is unquoted, a dq if exists must be
 532          * the beginning of the second name.
 533          */
 534         for (second = name; second < line + llen; second++) {
 535                 if (*second == '"') {
 536                         const char *cp = second;
 537                         const char *np;
 538                         char *sp = unquote_c_style(second, NULL);
 539
 540                         if (!sp)
 541                                 return NULL;
 542                         np = stop_at_slash(sp, strlen(sp));
 543                         if (!np || np == sp) {
 544                         free_second_and_fail:
 545                                 free(sp);
 546                                 return NULL;
 547                         }
 548                         np++;
 549                         len = strlen(np);
 550                         if (len < cp - name &&
 551                             !strncmp(np, name, len) &&
 552                             isspace(name[len])) {
 553                                 /* Good */
 554                                 memmove(sp, np, len + 1);
 555                                 return sp;
 556                         }
 557                         goto free_second_and_fail;
 558                 }
 559         }
 560
 561         /*
 562          * Accept a name only if it shows up twice, exactly the same
 563          * form.
 564          */
 565         for (len = 0 ; ; len++) {
 566                 char c = name[len];
 567
 568                 switch (c) {
 569                 default:
 570                         continue;
 571                 case '\n':
 572                         return NULL;
 573                 case '\t': case ' ':
 574                         second = name+len;
 575                         for (;;) {
 576                                 char c = *second++;
 577                                 if (c == '\n')
 578                                         return NULL;
 579                                 if (c == '/')
 580                                         break;
 581                         }
 582                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 583                                 char *ret = xmalloc(len + 1);
 584                                 memcpy(ret, name, len);
 585                                 ret[len] = 0;
 586                                 return ret;
 587                         }
 588                 }
 589         }
 590         return NULL;
 591 }
 592
 593 /* Verify that we recognize the lines following a git header */
 594 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 595 {
 596         unsigned long offset;
 597
 598         /* A git diff has explicit new/delete information, so we don't guess */
 599         patch->is_new = 0;
 600         patch->is_delete = 0;
 601
 602         /*
 603          * Some things may not have the old name in the
 604          * rest of the headers anywhere (pure mode changes,
 605          * or removing or adding empty files), so we get
 606          * the default name from the header.
 607          */
 608         patch->def_name = git_header_name(line, len);
 609
 610         line += len;
 611         size -= len;
 612         linenr++;
 613         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 614                 static const struct opentry {
 615                         const char *str;
 616                         int (*fn)(const char *, struct patch *);
 617                 } optable[] = {
 618                         { "@@ -", gitdiff_hdrend },
 619                         { "--- ", gitdiff_oldname },
 620                         { "+++ ", gitdiff_newname },
 621                         { "old mode ", gitdiff_oldmode },
 622                         { "new mode ", gitdiff_newmode },
 623                         { "deleted file mode ", gitdiff_delete },
 624                         { "new file mode ", gitdiff_newfile },
 625                         { "copy from ", gitdiff_copysrc },
 626                         { "copy to ", gitdiff_copydst },
 627                         { "rename old ", gitdiff_renamesrc },
 628                         { "rename new ", gitdiff_renamedst },
 629                         { "rename from ", gitdiff_renamesrc },
 630                         { "rename to ", gitdiff_renamedst },
 631                         { "similarity index ", gitdiff_similarity },
 632                         { "dissimilarity index ", gitdiff_dissimilarity },
 633                         { "index ", gitdiff_index },
 634                         { "", gitdiff_unrecognized },
 635                 };
 636                 int i;
 637
 638                 len = linelen(line, size);
 639                 if (!len || line[len-1] != '\n')
 640                         break;
 641                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 642                         const struct opentry *p = optable + i;
 643                         int oplen = strlen(p->str);
 644                         if (len < oplen || memcmp(p->str, line, oplen))
 645                                 continue;
 646                         if (p->fn(line + oplen, patch) < 0)
 647                                 return offset;
 648                         break;
 649                 }
 650         }
 651
 652         return offset;
 653 }
 654
 655 static int parse_num(const char *line, unsigned long *p)
 656 {
 657         char *ptr;
 658
 659         if (!isdigit(*line))
 660                 return 0;
 661         *p = strtoul(line, &ptr, 10);
 662         return ptr - line;
 663 }
 664
 665 static int parse_range(const char *line, int len, int offset, const char *expect,
 666                         unsigned long *p1, unsigned long *p2)
 667 {
 668         int digits, ex;
 669
 670         if (offset < 0 || offset >= len)
 671                 return -1;
 672         line += offset;
 673         len -= offset;
 674
 675         digits = parse_num(line, p1);
 676         if (!digits)
 677                 return -1;
 678
 679         offset += digits;
 680         line += digits;
 681         len -= digits;
 682
 683         *p2 = *p1;
 684         if (*line == ',') {
 685                 digits = parse_num(line+1, p2);
 686                 if (!digits)
 687                         return -1;
 688
 689                 offset += digits+1;
 690                 line += digits+1;
 691                 len -= digits+1;
 692         }
 693
 694         ex = strlen(expect);
 695         if (ex > len)
 696                 return -1;
 697         if (memcmp(line, expect, ex))
 698                 return -1;
 699
 700         return offset + ex;
 701 }
 702
 703 /*
 704  * Parse a unified diff fragment header of the
 705  * form "@@ -a,b +c,d @@"
 706  */
 707 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 708 {
 709         int offset;
 710
 711         if (!len || line[len-1] != '\n')
 712                 return -1;
 713
 714         /* Figure out the number of lines in a fragment */
 715         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 716         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 717
 718         return offset;
 719 }
 720
 721 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 722 {
 723         unsigned long offset, len;
 724
 725         patch->is_rename = patch->is_copy = 0;
 726         patch->is_new = patch->is_delete = -1;
 727         patch->old_mode = patch->new_mode = 0;
 728         patch->old_name = patch->new_name = NULL;
 729         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 730                 unsigned long nextlen;
 731
 732                 len = linelen(line, size);
 733                 if (!len)
 734                         break;
 735
 736                 /* Testing this early allows us to take a few shortcuts.. */
 737                 if (len < 6)
 738                         continue;
 739
 740                 /*
 741                  * Make sure we don't find any unconnected patch fragmants.
 742                  * That's a sign that we didn't find a header, and that a
 743                  * patch has become corrupted/broken up.
 744                  */
 745                 if (!memcmp("@@ -", line, 4)) {
 746                         struct fragment dummy;
 747                         if (parse_fragment_header(line, len, &dummy) < 0)
 748                                 continue;
 749                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
 750                 }
 751
 752                 if (size < len + 6)
 753                         break;
 754
 755                 /*
 756                  * Git patch? It might not have a real patch, just a rename
 757                  * or mode change, so we handle that specially
 758                  */
 759                 if (!memcmp("diff --git ", line, 11)) {
 760                         int git_hdr_len = parse_git_header(line, len, size, patch);
 761                         if (git_hdr_len <= len)
 762                                 continue;
 763                         if (!patch->old_name && !patch->new_name) {
 764                                 if (!patch->def_name)
 765                                         die("git diff header lacks filename information (line %d)", linenr);
 766                                 patch->old_name = patch->new_name = patch->def_name;
 767                         }
 768                         *hdrsize = git_hdr_len;
 769                         return offset;
 770                 }
 771
 772                 /** --- followed by +++ ? */
 773                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 774                         continue;
 775
 776                 /*
 777                  * We only accept unified patches, so we want it to
 778                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 779                  * minimum
 780                  */
 781                 nextlen = linelen(line + len, size - len);
 782                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 783                         continue;
 784
 785                 /* Ok, we'll consider it a patch */
 786                 parse_traditional_patch(line, line+len, patch);
 787                 *hdrsize = len + nextlen;
 788                 linenr += 2;
 789                 return offset;
 790         }
 791         return -1;
 792 }
 793
 794 /*
 795  * Parse a unified diff. Note that this really needs
 796  * to parse each fragment separately, since the only
 797  * way to know the difference between a "---" that is
 798  * part of a patch, and a "---" that starts the next
 799  * patch is to look at the line counts..
 800  */
 801 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 802 {
 803         int added, deleted;
 804         int len = linelen(line, size), offset;
 805         unsigned long oldlines, newlines;
 806
 807         offset = parse_fragment_header(line, len, fragment);
 808         if (offset < 0)
 809                 return -1;
 810         oldlines = fragment->oldlines;
 811         newlines = fragment->newlines;
 812
 813         if (patch->is_new < 0) {
 814                 patch->is_new =  !oldlines;
 815                 if (!oldlines)
 816                         patch->old_name = NULL;
 817         }
 818         if (patch->is_delete < 0) {
 819                 patch->is_delete = !newlines;
 820                 if (!newlines)
 821                         patch->new_name = NULL;
 822         }
 823
 824         if (patch->is_new != !oldlines)
 825                 return error("new file depends on old contents");
 826         if (patch->is_delete != !newlines) {
 827                 if (newlines)
 828                         return error("deleted file still has contents");
 829                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
 830         }
 831
 832         /* Parse the thing.. */
 833         line += len;
 834         size -= len;
 835         linenr++;
 836         added = deleted = 0;
 837         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 838                 if (!oldlines && !newlines)
 839                         break;
 840                 len = linelen(line, size);
 841                 if (!len || line[len-1] != '\n')
 842                         return -1;
 843                 switch (*line) {
 844                 default:
 845                         return -1;
 846                 case ' ':
 847                         oldlines--;
 848                         newlines--;
 849                         break;
 850                 case '-':
 851                         deleted++;
 852                         oldlines--;
 853                         break;
 854                 case '+':
 855                         /*
 856                          * We know len is at least two, since we have a '+' and
 857                          * we checked that the last character was a '\n' above.
 858                          * That is, an addition of an empty line would check
 859                          * the '+' here.  Sneaky...
 860                          */
 861                         if ((new_whitespace != nowarn_whitespace) &&
 862                             isspace(line[len-2])) {
 863                                 whitespace_error++;
 864                                 if (squelch_whitespace_errors &&
 865                                     squelch_whitespace_errors <
 866                                     whitespace_error)
 867                                         ;
 868                                 else {
 869                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
 870                                                 patch_input_file,
 871                                                 linenr, len-2, line+1);
 872                                 }
 873                         }
 874                         added++;
 875                         newlines--;
 876                         break;
 877
 878                 /* We allow "\ No newline at end of file". Depending
 879                  * on locale settings when the patch was produced we
 880                  * don't know what this line looks like. The only
 881                  * thing we do know is that it begins with "\ ".
 882                  * Checking for 12 is just for sanity check -- any
 883                  * l10n of "\ No newline..." is at least that long.
 884                  */
 885                 case '\\':
 886                         if (len < 12 || memcmp(line, "\\ ", 2))
 887                                 return -1;
 888                         break;
 889                 }
 890         }
 891         /* If a fragment ends with an incomplete line, we failed to include
 892          * it in the above loop because we hit oldlines == newlines == 0
 893          * before seeing it.
 894          */
 895         if (12 < size && !memcmp(line, "\\ ", 2))
 896                 offset += linelen(line, size);
 897
 898         patch->lines_added += added;
 899         patch->lines_deleted += deleted;
 900         return offset;
 901 }
 902
 903 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 904 {
 905         unsigned long offset = 0;
 906         struct fragment **fragp = &patch->fragments;
 907
 908         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 909                 struct fragment *fragment;
 910                 int len;
 911
 912                 fragment = xmalloc(sizeof(*fragment));
 913                 memset(fragment, 0, sizeof(*fragment));
 914                 len = parse_fragment(line, size, patch, fragment);
 915                 if (len <= 0)
 916                         die("corrupt patch at line %d", linenr);
 917
 918                 fragment->patch = line;
 919                 fragment->size = len;
 920
 921                 *fragp = fragment;
 922                 fragp = &fragment->next;
 923
 924                 offset += len;
 925                 line += len;
 926                 size -= len;
 927         }
 928         return offset;
 929 }
 930
 931 static inline int metadata_changes(struct patch *patch)
 932 {
 933         return  patch->is_rename > 0 ||
 934                 patch->is_copy > 0 ||
 935                 patch->is_new > 0 ||
 936                 patch->is_delete ||
 937                 (patch->old_mode && patch->new_mode &&
 938                  patch->old_mode != patch->new_mode);
 939 }
 940
 941 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 942 {
 943         int hdrsize, patchsize;
 944         int offset = find_header(buffer, size, &hdrsize, patch);
 945
 946         if (offset < 0)
 947                 return offset;
 948
 949         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 950
 951         if (!patchsize) {
 952                 static const char *binhdr[] = {
 953                         "Binary files ",
 954                         "Files ",
 955                         NULL,
 956                 };
 957                 int i;
 958                 int hd = hdrsize + offset;
 959                 unsigned long llen = linelen(buffer + hd, size - hd);
 960
 961                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
 962                         for (i = 0; binhdr[i]; i++) {
 963                                 int len = strlen(binhdr[i]);
 964                                 if (len < size - hd &&
 965                                     !memcmp(binhdr[i], buffer + hd, len)) {
 966                                         patch->is_binary = 1;
 967                                         break;
 968                                 }
 969                         }
 970
 971                 /* Empty patch cannot be applied if:
 972                  * - it is a binary patch and we do not do binary_replace, or
 973                  * - text patch without metadata change
 974                  */
 975                 if ((apply || check) &&
 976                     (patch->is_binary
 977                      ? !allow_binary_replacement
 978                      : !metadata_changes(patch)))
 979                         die("patch with only garbage at line %d", linenr);
 980         }
 981
 982         return offset + hdrsize + patchsize;
 983 }
 984
 985 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 986 static const char minuses[]= "----------------------------------------------------------------------";
 987
 988 static void show_stats(struct patch *patch)
 989 {
 990         const char *prefix = "";
 991         char *name = patch->new_name;
 992         char *qname = NULL;
 993         int len, max, add, del, total;
 994
 995         if (!name)
 996                 name = patch->old_name;
 997
 998         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 999                 qname = xmalloc(len + 1);
1000                 quote_c_style(name, qname, NULL, 0);
1001                 name = qname;
1002         }
1003
1004         /*
1005          * "scale" the filename
1006          */
1007         len = strlen(name);
1008         max = max_len;
1009         if (max > 50)
1010                 max = 50;
1011         if (len > max) {
1012                 char *slash;
1013                 prefix = "...";
1014                 max -= 3;
1015                 name += len - max;
1016                 slash = strchr(name, '/');
1017                 if (slash)
1018                         name = slash;
1019         }
1020         len = max;
1021
1022         /*
1023          * scale the add/delete
1024          */
1025         max = max_change;
1026         if (max + len > 70)
1027                 max = 70 - len;
1028
1029         add = patch->lines_added;
1030         del = patch->lines_deleted;
1031         total = add + del;
1032
1033         if (max_change > 0) {
1034                 total = (total * max + max_change / 2) / max_change;
1035                 add = (add * max + max_change / 2) / max_change;
1036                 del = total - add;
1037         }
1038         if (patch->is_binary)
1039                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1040         else
1041                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1042                        len, name, patch->lines_added + patch->lines_deleted,
1043                        add, pluses, del, minuses);
1044         if (qname)
1045                 free(qname);
1046 }
1047
1048 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1049 {
1050         int fd;
1051         unsigned long got;
1052
1053         switch (st->st_mode & S_IFMT) {
1054         case S_IFLNK:
1055                 return readlink(path, buf, size);
1056         case S_IFREG:
1057                 fd = open(path, O_RDONLY);
1058                 if (fd < 0)
1059                         return error("unable to open %s", path);
1060                 got = 0;
1061                 for (;;) {
1062                         int ret = xread(fd, buf + got, size - got);
1063                         if (ret <= 0)
1064                                 break;
1065                         got += ret;
1066                 }
1067                 close(fd);
1068                 return got;
1069
1070         default:
1071                 return -1;
1072         }
1073 }
1074
1075 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1076 {
1077         int i;
1078         unsigned long start, backwards, forwards;
1079
1080         if (fragsize > size)
1081                 return -1;
1082
1083         start = 0;
1084         if (line > 1) {
1085                 unsigned long offset = 0;
1086                 i = line-1;
1087                 while (offset + fragsize <= size) {
1088                         if (buf[offset++] == '\n') {
1089                                 start = offset;
1090                                 if (!--i)
1091                                         break;
1092                         }
1093                 }
1094         }
1095
1096         /* Exact line number? */
1097         if (!memcmp(buf + start, fragment, fragsize))
1098                 return start;
1099
1100         /*
1101          * There's probably some smart way to do this, but I'll leave
1102          * that to the smart and beautiful people. I'm simple and stupid.
1103          */
1104         backwards = start;
1105         forwards = start;
1106         for (i = 0; ; i++) {
1107                 unsigned long try;
1108                 int n;
1109
1110                 /* "backward" */
1111                 if (i & 1) {
1112                         if (!backwards) {
1113                                 if (forwards + fragsize > size)
1114                                         break;
1115                                 continue;
1116                         }
1117                         do {
1118                                 --backwards;
1119                         } while (backwards && buf[backwards-1] != '\n');
1120                         try = backwards;
1121                 } else {
1122                         while (forwards + fragsize <= size) {
1123                                 if (buf[forwards++] == '\n')
1124                                         break;
1125                         }
1126                         try = forwards;
1127                 }
1128
1129                 if (try + fragsize > size)
1130                         continue;
1131                 if (memcmp(buf + try, fragment, fragsize))
1132                         continue;
1133                 n = (i >> 1)+1;
1134                 if (i & 1)
1135                         n = -n;
1136                 return try;
1137         }
1138
1139         /*
1140          * We should start searching forward and backward.
1141          */
1142         return -1;
1143 }
1144
1145 struct buffer_desc {
1146         char *buffer;
1147         unsigned long size;
1148         unsigned long alloc;
1149 };
1150
1151 static int apply_line(char *output, const char *patch, int plen)
1152 {
1153         /* plen is number of bytes to be copied from patch,
1154          * starting at patch+1 (patch[0] is '+').  Typically
1155          * patch[plen] is '\n'.
1156          */
1157         int add_nl_to_tail = 0;
1158         if ((new_whitespace == strip_whitespace) &&
1159             1 < plen && isspace(patch[plen-1])) {
1160                 if (patch[plen] == '\n')
1161                         add_nl_to_tail = 1;
1162                 plen--;
1163                 while (0 < plen && isspace(patch[plen]))
1164                         plen--;
1165                 applied_after_stripping++;
1166         }
1167         memcpy(output, patch + 1, plen);
1168         if (add_nl_to_tail)
1169                 output[plen++] = '\n';
1170         return plen;
1171 }
1172
1173 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1174 {
1175         char *buf = desc->buffer;
1176         const char *patch = frag->patch;
1177         int offset, size = frag->size;
1178         char *old = xmalloc(size);
1179         char *new = xmalloc(size);
1180         int oldsize = 0, newsize = 0;
1181
1182         while (size > 0) {
1183                 int len = linelen(patch, size);
1184                 int plen;
1185
1186                 if (!len)
1187                         break;
1188
1189                 /*
1190                  * "plen" is how much of the line we should use for
1191                  * the actual patch data. Normally we just remove the
1192                  * first character on the line, but if the line is
1193                  * followed by "\ No newline", then we also remove the
1194                  * last one (which is the newline, of course).
1195                  */
1196                 plen = len-1;
1197                 if (len < size && patch[len] == '\\')
1198                         plen--;
1199                 switch (*patch) {
1200                 case ' ':
1201                 case '-':
1202                         memcpy(old + oldsize, patch + 1, plen);
1203                         oldsize += plen;
1204                         if (*patch == '-')
1205                                 break;
1206                 /* Fall-through for ' ' */
1207                 case '+':
1208                         if (*patch != '+' || !no_add)
1209                                 newsize += apply_line(new + newsize, patch,
1210                                                       plen);
1211                         break;
1212                 case '@': case '\\':
1213                         /* Ignore it, we already handled it */
1214                         break;
1215                 default:
1216                         return -1;
1217                 }
1218                 patch += len;
1219                 size -= len;
1220         }
1221
1222         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1223         if (offset >= 0) {
1224                 int diff = newsize - oldsize;
1225                 unsigned long size = desc->size + diff;
1226                 unsigned long alloc = desc->alloc;
1227
1228                 if (size > alloc) {
1229                         alloc = size + 8192;
1230                         desc->alloc = alloc;
1231                         buf = xrealloc(buf, alloc);
1232                         desc->buffer = buf;
1233                 }
1234                 desc->size = size;
1235                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1236                 memcpy(buf + offset, new, newsize);
1237                 offset = 0;
1238         }
1239
1240         free(old);
1241         free(new);
1242         return offset;
1243 }
1244
1245 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1246 {
1247         struct fragment *frag = patch->fragments;
1248         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1249
1250         if (patch->is_binary) {
1251                 unsigned char sha1[20];
1252
1253                 if (!allow_binary_replacement)
1254                         return error("cannot apply binary patch to '%s' "
1255                                      "without --allow-binary-replacement",
1256                                      name);
1257
1258                 /* For safety, we require patch index line to contain
1259                  * full 40-byte textual SHA1 for old and new, at least for now.
1260                  */
1261                 if (strlen(patch->old_sha1_prefix) != 40 ||
1262                     strlen(patch->new_sha1_prefix) != 40 ||
1263                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1264                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1265                         return error("cannot apply binary patch to '%s' "
1266                                      "without full index line", name);
1267
1268                 if (patch->old_name) {
1269                         unsigned char hdr[50];
1270                         int hdrlen;
1271
1272                         /* See if the old one matches what the patch
1273                          * applies to.
1274                          */
1275                         write_sha1_file_prepare(desc->buffer, desc->size,
1276                                                 "blob", sha1, hdr, &hdrlen);
1277                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1278                                 return error("the patch applies to '%s' (%s), "
1279                                              "which does not match the "
1280                                              "current contents.",
1281                                              name, sha1_to_hex(sha1));
1282                 }
1283                 else {
1284                         /* Otherwise, the old one must be empty. */
1285                         if (desc->size)
1286                                 return error("the patch applies to an empty "
1287                                              "'%s' but it is not empty", name);
1288                 }
1289
1290                 /* For now, we do not record post-image data in the patch,
1291                  * and require the object already present in the recipient's
1292                  * object database.
1293                  */
1294                 if (desc->buffer) {
1295                         free(desc->buffer);
1296                         desc->alloc = desc->size = 0;
1297                 }
1298                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1299
1300                 if (memcmp(sha1, null_sha1, 20)) {
1301                         char type[10];
1302                         unsigned long size;
1303
1304                         desc->buffer = read_sha1_file(sha1, type, &size);
1305                         if (!desc->buffer)
1306                                 return error("the necessary postimage %s for "
1307                                              "'%s' does not exist",
1308                                              patch->new_sha1_prefix, name);
1309                         desc->alloc = desc->size = size;
1310                 }
1311
1312                 return 0;
1313         }
1314
1315         while (frag) {
1316                 if (apply_one_fragment(desc, frag) < 0)
1317                         return error("patch failed: %s:%ld",
1318                                      name, frag->oldpos);
1319                 frag = frag->next;
1320         }
1321         return 0;
1322 }
1323
1324 static int apply_data(struct patch *patch, struct stat *st)
1325 {
1326         char *buf;
1327         unsigned long size, alloc;
1328         struct buffer_desc desc;
1329
1330         size = 0;
1331         alloc = 0;
1332         buf = NULL;
1333         if (patch->old_name) {
1334                 size = st->st_size;
1335                 alloc = size + 8192;
1336                 buf = xmalloc(alloc);
1337                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1338                         return error("read of %s failed", patch->old_name);
1339         }
1340
1341         desc.size = size;
1342         desc.alloc = alloc;
1343         desc.buffer = buf;
1344         if (apply_fragments(&desc, patch) < 0)
1345                 return -1;
1346         patch->result = desc.buffer;
1347         patch->resultsize = desc.size;
1348
1349         if (patch->is_delete && patch->resultsize)
1350                 return error("removal patch leaves file contents");
1351
1352         return 0;
1353 }
1354
1355 static int check_patch(struct patch *patch)
1356 {
1357         struct stat st;
1358         const char *old_name = patch->old_name;
1359         const char *new_name = patch->new_name;
1360         const char *name = old_name ? old_name : new_name;
1361
1362         if (old_name) {
1363                 int changed;
1364                 int stat_ret = lstat(old_name, &st);
1365
1366                 if (check_index) {
1367                         int pos = cache_name_pos(old_name, strlen(old_name));
1368                         if (pos < 0)
1369                                 return error("%s: does not exist in index",
1370                                              old_name);
1371                         if (stat_ret < 0) {
1372                                 struct checkout costate;
1373                                 if (errno != ENOENT)
1374                                         return error("%s: %s", old_name,
1375                                                      strerror(errno));
1376                                 /* checkout */
1377                                 costate.base_dir = "";
1378                                 costate.base_dir_len = 0;
1379                                 costate.force = 0;
1380                                 costate.quiet = 0;
1381                                 costate.not_new = 0;
1382                                 costate.refresh_cache = 1;
1383                                 if (checkout_entry(active_cache[pos],
1384                                                    &costate) ||
1385                                     lstat(old_name, &st))
1386                                         return -1;
1387                         }
1388
1389                         changed = ce_match_stat(active_cache[pos], &st);
1390                         if (changed)
1391                                 return error("%s: does not match index",
1392                                              old_name);
1393                 }
1394                 else if (stat_ret < 0)
1395                         return error("%s: %s", old_name, strerror(errno));
1396
1397                 if (patch->is_new < 0)
1398                         patch->is_new = 0;
1399                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1400                 if (!patch->old_mode)
1401                         patch->old_mode = st.st_mode;
1402                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1403                         return error("%s: wrong type", old_name);
1404                 if (st.st_mode != patch->old_mode)
1405                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1406                                 old_name, st.st_mode, patch->old_mode);
1407         }
1408
1409         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1410                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1411                         return error("%s: already exists in index", new_name);
1412                 if (!lstat(new_name, &st))
1413                         return error("%s: already exists in working directory", new_name);
1414                 if (errno != ENOENT)
1415                         return error("%s: %s", new_name, strerror(errno));
1416                 if (!patch->new_mode) {
1417                         if (patch->is_new)
1418                                 patch->new_mode = S_IFREG | 0644;
1419                         else
1420                                 patch->new_mode = patch->old_mode;
1421                 }
1422         }
1423
1424         if (new_name && old_name) {
1425                 int same = !strcmp(old_name, new_name);
1426                 if (!patch->new_mode)
1427                         patch->new_mode = patch->old_mode;
1428                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1429                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1430                                 patch->new_mode, new_name, patch->old_mode,
1431                                 same ? "" : " of ", same ? "" : old_name);
1432         }
1433
1434         if (apply_data(patch, &st) < 0)
1435                 return error("%s: patch does not apply", name);
1436         return 0;
1437 }
1438
1439 static int check_patch_list(struct patch *patch)
1440 {
1441         int error = 0;
1442
1443         for (;patch ; patch = patch->next)
1444                 error |= check_patch(patch);
1445         return error;
1446 }
1447
1448 static inline int is_null_sha1(const unsigned char *sha1)
1449 {
1450         return !memcmp(sha1, null_sha1, 20);
1451 }
1452
1453 static void show_index_list(struct patch *list)
1454 {
1455         struct patch *patch;
1456
1457         /* Once we start supporting the reverse patch, it may be
1458          * worth showing the new sha1 prefix, but until then...
1459          */
1460         for (patch = list; patch; patch = patch->next) {
1461                 const unsigned char *sha1_ptr;
1462                 unsigned char sha1[20];
1463                 const char *name;
1464
1465                 name = patch->old_name ? patch->old_name : patch->new_name;
1466                 if (patch->is_new)
1467                         sha1_ptr = null_sha1;
1468                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1469                         die("sha1 information is lacking or useless (%s).",
1470                             name);
1471                 else
1472                         sha1_ptr = sha1;
1473
1474                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1475                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1476                         quote_c_style(name, NULL, stdout, 0);
1477                 else
1478                         fputs(name, stdout);
1479                 putchar(line_termination);
1480         }
1481 }
1482
1483 static void stat_patch_list(struct patch *patch)
1484 {
1485         int files, adds, dels;
1486
1487         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1488                 files++;
1489                 adds += patch->lines_added;
1490                 dels += patch->lines_deleted;
1491                 show_stats(patch);
1492         }
1493
1494         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1495 }
1496
1497 static void numstat_patch_list(struct patch *patch)
1498 {
1499         for ( ; patch; patch = patch->next) {
1500                 const char *name;
1501                 name = patch->old_name ? patch->old_name : patch->new_name;
1502                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1503                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1504                         quote_c_style(name, NULL, stdout, 0);
1505                 else
1506                         fputs(name, stdout);
1507                 putchar('\n');
1508         }
1509 }
1510
1511 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1512 {
1513         if (mode)
1514                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1515         else
1516                 printf(" %s %s\n", newdelete, name);
1517 }
1518
1519 static void show_mode_change(struct patch *p, int show_name)
1520 {
1521         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1522                 if (show_name)
1523                         printf(" mode change %06o => %06o %s\n",
1524                                p->old_mode, p->new_mode, p->new_name);
1525                 else
1526                         printf(" mode change %06o => %06o\n",
1527                                p->old_mode, p->new_mode);
1528         }
1529 }
1530
1531 static void show_rename_copy(struct patch *p)
1532 {
1533         const char *renamecopy = p->is_rename ? "rename" : "copy";
1534         const char *old, *new;
1535
1536         /* Find common prefix */
1537         old = p->old_name;
1538         new = p->new_name;
1539         while (1) {
1540                 const char *slash_old, *slash_new;
1541                 slash_old = strchr(old, '/');
1542                 slash_new = strchr(new, '/');
1543                 if (!slash_old ||
1544                     !slash_new ||
1545                     slash_old - old != slash_new - new ||
1546                     memcmp(old, new, slash_new - new))
1547                         break;
1548                 old = slash_old + 1;
1549                 new = slash_new + 1;
1550         }
1551         /* p->old_name thru old is the common prefix, and old and new
1552          * through the end of names are renames
1553          */
1554         if (old != p->old_name)
1555                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1556                        (int)(old - p->old_name), p->old_name,
1557                        old, new, p->score);
1558         else
1559                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1560                        p->old_name, p->new_name, p->score);
1561         show_mode_change(p, 0);
1562 }
1563
1564 static void summary_patch_list(struct patch *patch)
1565 {
1566         struct patch *p;
1567
1568         for (p = patch; p; p = p->next) {
1569                 if (p->is_new)
1570                         show_file_mode_name("create", p->new_mode, p->new_name);
1571                 else if (p->is_delete)
1572                         show_file_mode_name("delete", p->old_mode, p->old_name);
1573                 else {
1574                         if (p->is_rename || p->is_copy)
1575                                 show_rename_copy(p);
1576                         else {
1577                                 if (p->score) {
1578                                         printf(" rewrite %s (%d%%)\n",
1579                                                p->new_name, p->score);
1580                                         show_mode_change(p, 0);
1581                                 }
1582                                 else
1583                                         show_mode_change(p, 1);
1584                         }
1585                 }
1586         }
1587 }
1588
1589 static void patch_stats(struct patch *patch)
1590 {
1591         int lines = patch->lines_added + patch->lines_deleted;
1592
1593         if (lines > max_change)
1594                 max_change = lines;
1595         if (patch->old_name) {
1596                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1597                 if (!len)
1598                         len = strlen(patch->old_name);
1599                 if (len > max_len)
1600                         max_len = len;
1601         }
1602         if (patch->new_name) {
1603                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1604                 if (!len)
1605                         len = strlen(patch->new_name);
1606                 if (len > max_len)
1607                         max_len = len;
1608         }
1609 }
1610
1611 static void remove_file(struct patch *patch)
1612 {
1613         if (write_index) {
1614                 if (remove_file_from_cache(patch->old_name) < 0)
1615                         die("unable to remove %s from index", patch->old_name);
1616         }
1617         unlink(patch->old_name);
1618 }
1619
1620 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1621 {
1622         struct stat st;
1623         struct cache_entry *ce;
1624         int namelen = strlen(path);
1625         unsigned ce_size = cache_entry_size(namelen);
1626
1627         if (!write_index)
1628                 return;
1629
1630         ce = xmalloc(ce_size);
1631         memset(ce, 0, ce_size);
1632         memcpy(ce->name, path, namelen);
1633         ce->ce_mode = create_ce_mode(mode);
1634         ce->ce_flags = htons(namelen);
1635         if (lstat(path, &st) < 0)
1636                 die("unable to stat newly created file %s", path);
1637         fill_stat_cache_info(ce, &st);
1638         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1639                 die("unable to create backing store for newly created file %s", path);
1640         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1641                 die("unable to add cache entry for %s", path);
1642 }
1643
1644 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1645 {
1646         int fd;
1647
1648         if (S_ISLNK(mode))
1649                 return symlink(buf, path);
1650         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1651         if (fd < 0)
1652                 return -1;
1653         while (size) {
1654                 int written = xwrite(fd, buf, size);
1655                 if (written < 0)
1656                         die("writing file %s: %s", path, strerror(errno));
1657                 if (!written)
1658                         die("out of space writing file %s", path);
1659                 buf += written;
1660                 size -= written;
1661         }
1662         if (close(fd) < 0)
1663                 die("closing file %s: %s", path, strerror(errno));
1664         return 0;
1665 }
1666
1667 /*
1668  * We optimistically assume that the directories exist,
1669  * which is true 99% of the time anyway. If they don't,
1670  * we create them and try again.
1671  */
1672 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1673 {
1674         if (!try_create_file(path, mode, buf, size))
1675                 return;
1676
1677         if (errno == ENOENT) {
1678                 if (safe_create_leading_directories(path))
1679                         return;
1680                 if (!try_create_file(path, mode, buf, size))
1681                         return;
1682         }
1683
1684         if (errno == EEXIST) {
1685                 unsigned int nr = getpid();
1686
1687                 for (;;) {
1688                         const char *newpath;
1689                         newpath = mkpath("%s~%u", path, nr);
1690                         if (!try_create_file(newpath, mode, buf, size)) {
1691                                 if (!rename(newpath, path))
1692                                         return;
1693                                 unlink(newpath);
1694                                 break;
1695                         }
1696                         if (errno != EEXIST)
1697                                 break;
1698                         ++nr;
1699                 }
1700         }
1701         die("unable to write file %s mode %o", path, mode);
1702 }
1703
1704 static void create_file(struct patch *patch)
1705 {
1706         char *path = patch->new_name;
1707         unsigned mode = patch->new_mode;
1708         unsigned long size = patch->resultsize;
1709         char *buf = patch->result;
1710
1711         if (!mode)
1712                 mode = S_IFREG | 0644;
1713         create_one_file(path, mode, buf, size);
1714         add_index_file(path, mode, buf, size);
1715 }
1716
1717 static void write_out_one_result(struct patch *patch)
1718 {
1719         if (patch->is_delete > 0) {
1720                 remove_file(patch);
1721                 return;
1722         }
1723         if (patch->is_new > 0 || patch->is_copy) {
1724                 create_file(patch);
1725                 return;
1726         }
1727         /*
1728          * Rename or modification boils down to the same
1729          * thing: remove the old, write the new
1730          */
1731         remove_file(patch);
1732         create_file(patch);
1733 }
1734
1735 static void write_out_results(struct patch *list, int skipped_patch)
1736 {
1737         if (!list && !skipped_patch)
1738                 die("No changes");
1739
1740         while (list) {
1741                 write_out_one_result(list);
1742                 list = list->next;
1743         }
1744 }
1745
1746 static struct cache_file cache_file;
1747
1748 static struct excludes {
1749         struct excludes *next;
1750         const char *path;
1751 } *excludes;
1752
1753 static int use_patch(struct patch *p)
1754 {
1755         const char *pathname = p->new_name ? p->new_name : p->old_name;
1756         struct excludes *x = excludes;
1757         while (x) {
1758                 if (fnmatch(x->path, pathname, 0) == 0)
1759                         return 0;
1760                 x = x->next;
1761         }
1762         if (0 < prefix_length) {
1763                 int pathlen = strlen(pathname);
1764                 if (pathlen <= prefix_length ||
1765                     memcmp(prefix, pathname, prefix_length))
1766                         return 0;
1767         }
1768         return 1;
1769 }
1770
1771 static int apply_patch(int fd, const char *filename)
1772 {
1773         int newfd;
1774         unsigned long offset, size;
1775         char *buffer = read_patch_file(fd, &size);
1776         struct patch *list = NULL, **listp = &list;
1777         int skipped_patch = 0;
1778
1779         patch_input_file = filename;
1780         if (!buffer)
1781                 return -1;
1782         offset = 0;
1783         while (size > 0) {
1784                 struct patch *patch;
1785                 int nr;
1786
1787                 patch = xmalloc(sizeof(*patch));
1788                 memset(patch, 0, sizeof(*patch));
1789                 nr = parse_chunk(buffer + offset, size, patch);
1790                 if (nr < 0)
1791                         break;
1792                 if (use_patch(patch)) {
1793                         patch_stats(patch);
1794                         *listp = patch;
1795                         listp = &patch->next;
1796                 } else {
1797                         /* perhaps free it a bit better? */
1798                         free(patch);
1799                         skipped_patch++;
1800                 }
1801                 offset += nr;
1802                 size -= nr;
1803         }
1804
1805         newfd = -1;
1806         if (whitespace_error && (new_whitespace == error_on_whitespace))
1807                 apply = 0;
1808
1809         write_index = check_index && apply;
1810         if (write_index)
1811                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1812         if (check_index) {
1813                 if (read_cache() < 0)
1814                         die("unable to read index file");
1815         }
1816
1817         if ((check || apply) && check_patch_list(list) < 0)
1818                 exit(1);
1819
1820         if (apply)
1821                 write_out_results(list, skipped_patch);
1822
1823         if (write_index) {
1824                 if (write_cache(newfd, active_cache, active_nr) ||
1825                     commit_index_file(&cache_file))
1826                         die("Unable to write new cachefile");
1827         }
1828
1829         if (show_index_info)
1830                 show_index_list(list);
1831
1832         if (diffstat)
1833                 stat_patch_list(list);
1834
1835         if (numstat)
1836                 numstat_patch_list(list);
1837
1838         if (summary)
1839                 summary_patch_list(list);
1840
1841         free(buffer);
1842         return 0;
1843 }
1844
1845 static int git_apply_config(const char *var, const char *value)
1846 {
1847         if (!strcmp(var, "apply.whitespace")) {
1848                 apply_default_whitespace = strdup(value);
1849                 return 0;
1850         }
1851         return git_default_config(var, value);
1852 }
1853
1854
1855 int main(int argc, char **argv)
1856 {
1857         int i;
1858         int read_stdin = 1;
1859         const char *whitespace_option = NULL;
1860
1861         for (i = 1; i < argc; i++) {
1862                 const char *arg = argv[i];
1863                 int fd;
1864
1865                 if (!strcmp(arg, "-")) {
1866                         apply_patch(0, "<stdin>");
1867                         read_stdin = 0;
1868                         continue;
1869                 }
1870                 if (!strncmp(arg, "--exclude=", 10)) {
1871                         struct excludes *x = xmalloc(sizeof(*x));
1872                         x->path = arg + 10;
1873                         x->next = excludes;
1874                         excludes = x;
1875                         continue;
1876                 }
1877                 if (!strncmp(arg, "-p", 2)) {
1878                         p_value = atoi(arg + 2);
1879                         continue;
1880                 }
1881                 if (!strcmp(arg, "--no-add")) {
1882                         no_add = 1;
1883                         continue;
1884                 }
1885                 if (!strcmp(arg, "--stat")) {
1886                         apply = 0;
1887                         diffstat = 1;
1888                         continue;
1889                 }
1890                 if (!strcmp(arg, "--allow-binary-replacement")) {
1891                         allow_binary_replacement = 1;
1892                         continue;
1893                 }
1894                 if (!strcmp(arg, "--numstat")) {
1895                         apply = 0;
1896                         numstat = 1;
1897                         continue;
1898                 }
1899                 if (!strcmp(arg, "--summary")) {
1900                         apply = 0;
1901                         summary = 1;
1902                         continue;
1903                 }
1904                 if (!strcmp(arg, "--check")) {
1905                         apply = 0;
1906                         check = 1;
1907                         continue;
1908                 }
1909                 if (!strcmp(arg, "--index")) {
1910                         check_index = 1;
1911                         continue;
1912                 }
1913                 if (!strcmp(arg, "--apply")) {
1914                         apply = 1;
1915                         continue;
1916                 }
1917                 if (!strcmp(arg, "--index-info")) {
1918                         apply = 0;
1919                         show_index_info = 1;
1920                         continue;
1921                 }
1922                 if (!strcmp(arg, "-z")) {
1923                         line_termination = 0;
1924                         continue;
1925                 }
1926                 if (!strncmp(arg, "--whitespace=", 13)) {
1927                         whitespace_option = arg + 13;
1928                         parse_whitespace_option(arg + 13);
1929                         continue;
1930                 }
1931
1932                 if (check_index && prefix_length < 0) {
1933                         prefix = setup_git_directory();
1934                         prefix_length = prefix ? strlen(prefix) : 0;
1935                         git_config(git_apply_config);
1936                         if (!whitespace_option && apply_default_whitespace)
1937                                 parse_whitespace_option(apply_default_whitespace);
1938                 }
1939                 if (0 < prefix_length)
1940                         arg = prefix_filename(prefix, prefix_length, arg);
1941
1942                 fd = open(arg, O_RDONLY);
1943                 if (fd < 0)
1944                         usage(apply_usage);
1945                 read_stdin = 0;
1946                 apply_patch(fd, arg);
1947                 close(fd);
1948         }
1949         if (read_stdin)
1950                 apply_patch(0, "<stdin>");
1951         if (whitespace_error) {
1952                 if (squelch_whitespace_errors &&
1953                     squelch_whitespace_errors < whitespace_error) {
1954                         int squelched =
1955                                 whitespace_error - squelch_whitespace_errors;
1956                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
1957                                 squelched,
1958                                 squelched == 1 ? "" : "s");
1959                 }
1960                 if (new_whitespace == error_on_whitespace)
1961                         die("%d line%s add%s trailing whitespaces.",
1962                             whitespace_error,
1963                             whitespace_error == 1 ? "" : "s",
1964                             whitespace_error == 1 ? "s" : "");
1965                 if (applied_after_stripping)
1966                         fprintf(stderr, "warning: %d line%s applied after"
1967                                 " stripping trailing whitespaces.\n",
1968                                 applied_after_stripping,
1969                                 applied_after_stripping == 1 ? "" : "s");
1970                 else if (whitespace_error)
1971                         fprintf(stderr, "warning: %d line%s add%s trailing"
1972                                 " whitespaces.\n",
1973                                 whitespace_error,
1974                                 whitespace_error == 1 ? "" : "s",
1975                                 whitespace_error == 1 ? "s" : "");
1976         }
1977         return 0;
1978 }