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 #ifdef NO_ACCURATE_DIFF
1223         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1224                         newsize > 0 && new[newsize - 1] == '\n') {
1225                 oldsize--;
1226                 newsize--;
1227         }
1228 #endif
1229
1230         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1231         if (offset >= 0) {
1232                 int diff = newsize - oldsize;
1233                 unsigned long size = desc->size + diff;
1234                 unsigned long alloc = desc->alloc;
1235
1236                 if (size > alloc) {
1237                         alloc = size + 8192;
1238                         desc->alloc = alloc;
1239                         buf = xrealloc(buf, alloc);
1240                         desc->buffer = buf;
1241                 }
1242                 desc->size = size;
1243                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1244                 memcpy(buf + offset, new, newsize);
1245                 offset = 0;
1246         }
1247
1248         free(old);
1249         free(new);
1250         return offset;
1251 }
1252
1253 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1254 {
1255         struct fragment *frag = patch->fragments;
1256         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1257
1258         if (patch->is_binary) {
1259                 unsigned char sha1[20];
1260
1261                 if (!allow_binary_replacement)
1262                         return error("cannot apply binary patch to '%s' "
1263                                      "without --allow-binary-replacement",
1264                                      name);
1265
1266                 /* For safety, we require patch index line to contain
1267                  * full 40-byte textual SHA1 for old and new, at least for now.
1268                  */
1269                 if (strlen(patch->old_sha1_prefix) != 40 ||
1270                     strlen(patch->new_sha1_prefix) != 40 ||
1271                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1272                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1273                         return error("cannot apply binary patch to '%s' "
1274                                      "without full index line", name);
1275
1276                 if (patch->old_name) {
1277                         unsigned char hdr[50];
1278                         int hdrlen;
1279
1280                         /* See if the old one matches what the patch
1281                          * applies to.
1282                          */
1283                         write_sha1_file_prepare(desc->buffer, desc->size,
1284                                                 "blob", sha1, hdr, &hdrlen);
1285                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1286                                 return error("the patch applies to '%s' (%s), "
1287                                              "which does not match the "
1288                                              "current contents.",
1289                                              name, sha1_to_hex(sha1));
1290                 }
1291                 else {
1292                         /* Otherwise, the old one must be empty. */
1293                         if (desc->size)
1294                                 return error("the patch applies to an empty "
1295                                              "'%s' but it is not empty", name);
1296                 }
1297
1298                 /* For now, we do not record post-image data in the patch,
1299                  * and require the object already present in the recipient's
1300                  * object database.
1301                  */
1302                 if (desc->buffer) {
1303                         free(desc->buffer);
1304                         desc->alloc = desc->size = 0;
1305                 }
1306                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1307
1308                 if (memcmp(sha1, null_sha1, 20)) {
1309                         char type[10];
1310                         unsigned long size;
1311
1312                         desc->buffer = read_sha1_file(sha1, type, &size);
1313                         if (!desc->buffer)
1314                                 return error("the necessary postimage %s for "
1315                                              "'%s' does not exist",
1316                                              patch->new_sha1_prefix, name);
1317                         desc->alloc = desc->size = size;
1318                 }
1319
1320                 return 0;
1321         }
1322
1323         while (frag) {
1324                 if (apply_one_fragment(desc, frag) < 0)
1325                         return error("patch failed: %s:%ld",
1326                                      name, frag->oldpos);
1327                 frag = frag->next;
1328         }
1329         return 0;
1330 }
1331
1332 static int apply_data(struct patch *patch, struct stat *st)
1333 {
1334         char *buf;
1335         unsigned long size, alloc;
1336         struct buffer_desc desc;
1337
1338         size = 0;
1339         alloc = 0;
1340         buf = NULL;
1341         if (patch->old_name) {
1342                 size = st->st_size;
1343                 alloc = size + 8192;
1344                 buf = xmalloc(alloc);
1345                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1346                         return error("read of %s failed", patch->old_name);
1347         }
1348
1349         desc.size = size;
1350         desc.alloc = alloc;
1351         desc.buffer = buf;
1352         if (apply_fragments(&desc, patch) < 0)
1353                 return -1;
1354         patch->result = desc.buffer;
1355         patch->resultsize = desc.size;
1356
1357         if (patch->is_delete && patch->resultsize)
1358                 return error("removal patch leaves file contents");
1359
1360         return 0;
1361 }
1362
1363 static int check_patch(struct patch *patch)
1364 {
1365         struct stat st;
1366         const char *old_name = patch->old_name;
1367         const char *new_name = patch->new_name;
1368         const char *name = old_name ? old_name : new_name;
1369
1370         if (old_name) {
1371                 int changed;
1372                 int stat_ret = lstat(old_name, &st);
1373
1374                 if (check_index) {
1375                         int pos = cache_name_pos(old_name, strlen(old_name));
1376                         if (pos < 0)
1377                                 return error("%s: does not exist in index",
1378                                              old_name);
1379                         if (stat_ret < 0) {
1380                                 struct checkout costate;
1381                                 if (errno != ENOENT)
1382                                         return error("%s: %s", old_name,
1383                                                      strerror(errno));
1384                                 /* checkout */
1385                                 costate.base_dir = "";
1386                                 costate.base_dir_len = 0;
1387                                 costate.force = 0;
1388                                 costate.quiet = 0;
1389                                 costate.not_new = 0;
1390                                 costate.refresh_cache = 1;
1391                                 if (checkout_entry(active_cache[pos],
1392                                                    &costate) ||
1393                                     lstat(old_name, &st))
1394                                         return -1;
1395                         }
1396
1397                         changed = ce_match_stat(active_cache[pos], &st, 1);
1398                         if (changed)
1399                                 return error("%s: does not match index",
1400                                              old_name);
1401                 }
1402                 else if (stat_ret < 0)
1403                         return error("%s: %s", old_name, strerror(errno));
1404
1405                 if (patch->is_new < 0)
1406                         patch->is_new = 0;
1407                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1408                 if (!patch->old_mode)
1409                         patch->old_mode = st.st_mode;
1410                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1411                         return error("%s: wrong type", old_name);
1412                 if (st.st_mode != patch->old_mode)
1413                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1414                                 old_name, st.st_mode, patch->old_mode);
1415         }
1416
1417         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1418                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1419                         return error("%s: already exists in index", new_name);
1420                 if (!lstat(new_name, &st))
1421                         return error("%s: already exists in working directory", new_name);
1422                 if (errno != ENOENT)
1423                         return error("%s: %s", new_name, strerror(errno));
1424                 if (!patch->new_mode) {
1425                         if (patch->is_new)
1426                                 patch->new_mode = S_IFREG | 0644;
1427                         else
1428                                 patch->new_mode = patch->old_mode;
1429                 }
1430         }
1431
1432         if (new_name && old_name) {
1433                 int same = !strcmp(old_name, new_name);
1434                 if (!patch->new_mode)
1435                         patch->new_mode = patch->old_mode;
1436                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1437                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1438                                 patch->new_mode, new_name, patch->old_mode,
1439                                 same ? "" : " of ", same ? "" : old_name);
1440         }
1441
1442         if (apply_data(patch, &st) < 0)
1443                 return error("%s: patch does not apply", name);
1444         return 0;
1445 }
1446
1447 static int check_patch_list(struct patch *patch)
1448 {
1449         int error = 0;
1450
1451         for (;patch ; patch = patch->next)
1452                 error |= check_patch(patch);
1453         return error;
1454 }
1455
1456 static inline int is_null_sha1(const unsigned char *sha1)
1457 {
1458         return !memcmp(sha1, null_sha1, 20);
1459 }
1460
1461 static void show_index_list(struct patch *list)
1462 {
1463         struct patch *patch;
1464
1465         /* Once we start supporting the reverse patch, it may be
1466          * worth showing the new sha1 prefix, but until then...
1467          */
1468         for (patch = list; patch; patch = patch->next) {
1469                 const unsigned char *sha1_ptr;
1470                 unsigned char sha1[20];
1471                 const char *name;
1472
1473                 name = patch->old_name ? patch->old_name : patch->new_name;
1474                 if (patch->is_new)
1475                         sha1_ptr = null_sha1;
1476                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1477                         die("sha1 information is lacking or useless (%s).",
1478                             name);
1479                 else
1480                         sha1_ptr = sha1;
1481
1482                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1483                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1484                         quote_c_style(name, NULL, stdout, 0);
1485                 else
1486                         fputs(name, stdout);
1487                 putchar(line_termination);
1488         }
1489 }
1490
1491 static void stat_patch_list(struct patch *patch)
1492 {
1493         int files, adds, dels;
1494
1495         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1496                 files++;
1497                 adds += patch->lines_added;
1498                 dels += patch->lines_deleted;
1499                 show_stats(patch);
1500         }
1501
1502         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1503 }
1504
1505 static void numstat_patch_list(struct patch *patch)
1506 {
1507         for ( ; patch; patch = patch->next) {
1508                 const char *name;
1509                 name = patch->old_name ? patch->old_name : patch->new_name;
1510                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1511                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1512                         quote_c_style(name, NULL, stdout, 0);
1513                 else
1514                         fputs(name, stdout);
1515                 putchar('\n');
1516         }
1517 }
1518
1519 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1520 {
1521         if (mode)
1522                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1523         else
1524                 printf(" %s %s\n", newdelete, name);
1525 }
1526
1527 static void show_mode_change(struct patch *p, int show_name)
1528 {
1529         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1530                 if (show_name)
1531                         printf(" mode change %06o => %06o %s\n",
1532                                p->old_mode, p->new_mode, p->new_name);
1533                 else
1534                         printf(" mode change %06o => %06o\n",
1535                                p->old_mode, p->new_mode);
1536         }
1537 }
1538
1539 static void show_rename_copy(struct patch *p)
1540 {
1541         const char *renamecopy = p->is_rename ? "rename" : "copy";
1542         const char *old, *new;
1543
1544         /* Find common prefix */
1545         old = p->old_name;
1546         new = p->new_name;
1547         while (1) {
1548                 const char *slash_old, *slash_new;
1549                 slash_old = strchr(old, '/');
1550                 slash_new = strchr(new, '/');
1551                 if (!slash_old ||
1552                     !slash_new ||
1553                     slash_old - old != slash_new - new ||
1554                     memcmp(old, new, slash_new - new))
1555                         break;
1556                 old = slash_old + 1;
1557                 new = slash_new + 1;
1558         }
1559         /* p->old_name thru old is the common prefix, and old and new
1560          * through the end of names are renames
1561          */
1562         if (old != p->old_name)
1563                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1564                        (int)(old - p->old_name), p->old_name,
1565                        old, new, p->score);
1566         else
1567                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1568                        p->old_name, p->new_name, p->score);
1569         show_mode_change(p, 0);
1570 }
1571
1572 static void summary_patch_list(struct patch *patch)
1573 {
1574         struct patch *p;
1575
1576         for (p = patch; p; p = p->next) {
1577                 if (p->is_new)
1578                         show_file_mode_name("create", p->new_mode, p->new_name);
1579                 else if (p->is_delete)
1580                         show_file_mode_name("delete", p->old_mode, p->old_name);
1581                 else {
1582                         if (p->is_rename || p->is_copy)
1583                                 show_rename_copy(p);
1584                         else {
1585                                 if (p->score) {
1586                                         printf(" rewrite %s (%d%%)\n",
1587                                                p->new_name, p->score);
1588                                         show_mode_change(p, 0);
1589                                 }
1590                                 else
1591                                         show_mode_change(p, 1);
1592                         }
1593                 }
1594         }
1595 }
1596
1597 static void patch_stats(struct patch *patch)
1598 {
1599         int lines = patch->lines_added + patch->lines_deleted;
1600
1601         if (lines > max_change)
1602                 max_change = lines;
1603         if (patch->old_name) {
1604                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1605                 if (!len)
1606                         len = strlen(patch->old_name);
1607                 if (len > max_len)
1608                         max_len = len;
1609         }
1610         if (patch->new_name) {
1611                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1612                 if (!len)
1613                         len = strlen(patch->new_name);
1614                 if (len > max_len)
1615                         max_len = len;
1616         }
1617 }
1618
1619 static void remove_file(struct patch *patch)
1620 {
1621         if (write_index) {
1622                 if (remove_file_from_cache(patch->old_name) < 0)
1623                         die("unable to remove %s from index", patch->old_name);
1624         }
1625         unlink(patch->old_name);
1626 }
1627
1628 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1629 {
1630         struct stat st;
1631         struct cache_entry *ce;
1632         int namelen = strlen(path);
1633         unsigned ce_size = cache_entry_size(namelen);
1634
1635         if (!write_index)
1636                 return;
1637
1638         ce = xmalloc(ce_size);
1639         memset(ce, 0, ce_size);
1640         memcpy(ce->name, path, namelen);
1641         ce->ce_mode = create_ce_mode(mode);
1642         ce->ce_flags = htons(namelen);
1643         if (lstat(path, &st) < 0)
1644                 die("unable to stat newly created file %s", path);
1645         fill_stat_cache_info(ce, &st);
1646         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1647                 die("unable to create backing store for newly created file %s", path);
1648         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1649                 die("unable to add cache entry for %s", path);
1650 }
1651
1652 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1653 {
1654         int fd;
1655
1656         if (S_ISLNK(mode))
1657                 return symlink(buf, path);
1658         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1659         if (fd < 0)
1660                 return -1;
1661         while (size) {
1662                 int written = xwrite(fd, buf, size);
1663                 if (written < 0)
1664                         die("writing file %s: %s", path, strerror(errno));
1665                 if (!written)
1666                         die("out of space writing file %s", path);
1667                 buf += written;
1668                 size -= written;
1669         }
1670         if (close(fd) < 0)
1671                 die("closing file %s: %s", path, strerror(errno));
1672         return 0;
1673 }
1674
1675 /*
1676  * We optimistically assume that the directories exist,
1677  * which is true 99% of the time anyway. If they don't,
1678  * we create them and try again.
1679  */
1680 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1681 {
1682         if (!try_create_file(path, mode, buf, size))
1683                 return;
1684
1685         if (errno == ENOENT) {
1686                 if (safe_create_leading_directories(path))
1687                         return;
1688                 if (!try_create_file(path, mode, buf, size))
1689                         return;
1690         }
1691
1692         if (errno == EEXIST) {
1693                 unsigned int nr = getpid();
1694
1695                 for (;;) {
1696                         const char *newpath;
1697                         newpath = mkpath("%s~%u", path, nr);
1698                         if (!try_create_file(newpath, mode, buf, size)) {
1699                                 if (!rename(newpath, path))
1700                                         return;
1701                                 unlink(newpath);
1702                                 break;
1703                         }
1704                         if (errno != EEXIST)
1705                                 break;
1706                         ++nr;
1707                 }
1708         }
1709         die("unable to write file %s mode %o", path, mode);
1710 }
1711
1712 static void create_file(struct patch *patch)
1713 {
1714         char *path = patch->new_name;
1715         unsigned mode = patch->new_mode;
1716         unsigned long size = patch->resultsize;
1717         char *buf = patch->result;
1718
1719         if (!mode)
1720                 mode = S_IFREG | 0644;
1721         create_one_file(path, mode, buf, size);
1722         add_index_file(path, mode, buf, size);
1723 }
1724
1725 static void write_out_one_result(struct patch *patch)
1726 {
1727         if (patch->is_delete > 0) {
1728                 remove_file(patch);
1729                 return;
1730         }
1731         if (patch->is_new > 0 || patch->is_copy) {
1732                 create_file(patch);
1733                 return;
1734         }
1735         /*
1736          * Rename or modification boils down to the same
1737          * thing: remove the old, write the new
1738          */
1739         remove_file(patch);
1740         create_file(patch);
1741 }
1742
1743 static void write_out_results(struct patch *list, int skipped_patch)
1744 {
1745         if (!list && !skipped_patch)
1746                 die("No changes");
1747
1748         while (list) {
1749                 write_out_one_result(list);
1750                 list = list->next;
1751         }
1752 }
1753
1754 static struct cache_file cache_file;
1755
1756 static struct excludes {
1757         struct excludes *next;
1758         const char *path;
1759 } *excludes;
1760
1761 static int use_patch(struct patch *p)
1762 {
1763         const char *pathname = p->new_name ? p->new_name : p->old_name;
1764         struct excludes *x = excludes;
1765         while (x) {
1766                 if (fnmatch(x->path, pathname, 0) == 0)
1767                         return 0;
1768                 x = x->next;
1769         }
1770         if (0 < prefix_length) {
1771                 int pathlen = strlen(pathname);
1772                 if (pathlen <= prefix_length ||
1773                     memcmp(prefix, pathname, prefix_length))
1774                         return 0;
1775         }
1776         return 1;
1777 }
1778
1779 static int apply_patch(int fd, const char *filename)
1780 {
1781         int newfd;
1782         unsigned long offset, size;
1783         char *buffer = read_patch_file(fd, &size);
1784         struct patch *list = NULL, **listp = &list;
1785         int skipped_patch = 0;
1786
1787         patch_input_file = filename;
1788         if (!buffer)
1789                 return -1;
1790         offset = 0;
1791         while (size > 0) {
1792                 struct patch *patch;
1793                 int nr;
1794
1795                 patch = xmalloc(sizeof(*patch));
1796                 memset(patch, 0, sizeof(*patch));
1797                 nr = parse_chunk(buffer + offset, size, patch);
1798                 if (nr < 0)
1799                         break;
1800                 if (use_patch(patch)) {
1801                         patch_stats(patch);
1802                         *listp = patch;
1803                         listp = &patch->next;
1804                 } else {
1805                         /* perhaps free it a bit better? */
1806                         free(patch);
1807                         skipped_patch++;
1808                 }
1809                 offset += nr;
1810                 size -= nr;
1811         }
1812
1813         newfd = -1;
1814         if (whitespace_error && (new_whitespace == error_on_whitespace))
1815                 apply = 0;
1816
1817         write_index = check_index && apply;
1818         if (write_index)
1819                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1820         if (check_index) {
1821                 if (read_cache() < 0)
1822                         die("unable to read index file");
1823         }
1824
1825         if ((check || apply) && check_patch_list(list) < 0)
1826                 exit(1);
1827
1828         if (apply)
1829                 write_out_results(list, skipped_patch);
1830
1831         if (write_index) {
1832                 if (write_cache(newfd, active_cache, active_nr) ||
1833                     commit_index_file(&cache_file))
1834                         die("Unable to write new cachefile");
1835         }
1836
1837         if (show_index_info)
1838                 show_index_list(list);
1839
1840         if (diffstat)
1841                 stat_patch_list(list);
1842
1843         if (numstat)
1844                 numstat_patch_list(list);
1845
1846         if (summary)
1847                 summary_patch_list(list);
1848
1849         free(buffer);
1850         return 0;
1851 }
1852
1853 static int git_apply_config(const char *var, const char *value)
1854 {
1855         if (!strcmp(var, "apply.whitespace")) {
1856                 apply_default_whitespace = strdup(value);
1857                 return 0;
1858         }
1859         return git_default_config(var, value);
1860 }
1861
1862
1863 int main(int argc, char **argv)
1864 {
1865         int i;
1866         int read_stdin = 1;
1867         const char *whitespace_option = NULL;
1868
1869         for (i = 1; i < argc; i++) {
1870                 const char *arg = argv[i];
1871                 int fd;
1872
1873                 if (!strcmp(arg, "-")) {
1874                         apply_patch(0, "<stdin>");
1875                         read_stdin = 0;
1876                         continue;
1877                 }
1878                 if (!strncmp(arg, "--exclude=", 10)) {
1879                         struct excludes *x = xmalloc(sizeof(*x));
1880                         x->path = arg + 10;
1881                         x->next = excludes;
1882                         excludes = x;
1883                         continue;
1884                 }
1885                 if (!strncmp(arg, "-p", 2)) {
1886                         p_value = atoi(arg + 2);
1887                         continue;
1888                 }
1889                 if (!strcmp(arg, "--no-add")) {
1890                         no_add = 1;
1891                         continue;
1892                 }
1893                 if (!strcmp(arg, "--stat")) {
1894                         apply = 0;
1895                         diffstat = 1;
1896                         continue;
1897                 }
1898                 if (!strcmp(arg, "--allow-binary-replacement")) {
1899                         allow_binary_replacement = 1;
1900                         continue;
1901                 }
1902                 if (!strcmp(arg, "--numstat")) {
1903                         apply = 0;
1904                         numstat = 1;
1905                         continue;
1906                 }
1907                 if (!strcmp(arg, "--summary")) {
1908                         apply = 0;
1909                         summary = 1;
1910                         continue;
1911                 }
1912                 if (!strcmp(arg, "--check")) {
1913                         apply = 0;
1914                         check = 1;
1915                         continue;
1916                 }
1917                 if (!strcmp(arg, "--index")) {
1918                         check_index = 1;
1919                         continue;
1920                 }
1921                 if (!strcmp(arg, "--apply")) {
1922                         apply = 1;
1923                         continue;
1924                 }
1925                 if (!strcmp(arg, "--index-info")) {
1926                         apply = 0;
1927                         show_index_info = 1;
1928                         continue;
1929                 }
1930                 if (!strcmp(arg, "-z")) {
1931                         line_termination = 0;
1932                         continue;
1933                 }
1934                 if (!strncmp(arg, "--whitespace=", 13)) {
1935                         whitespace_option = arg + 13;
1936                         parse_whitespace_option(arg + 13);
1937                         continue;
1938                 }
1939
1940                 if (check_index && prefix_length < 0) {
1941                         prefix = setup_git_directory();
1942                         prefix_length = prefix ? strlen(prefix) : 0;
1943                         git_config(git_apply_config);
1944                         if (!whitespace_option && apply_default_whitespace)
1945                                 parse_whitespace_option(apply_default_whitespace);
1946                 }
1947                 if (0 < prefix_length)
1948                         arg = prefix_filename(prefix, prefix_length, arg);
1949
1950                 fd = open(arg, O_RDONLY);
1951                 if (fd < 0)
1952                         usage(apply_usage);
1953                 read_stdin = 0;
1954                 apply_patch(fd, arg);
1955                 close(fd);
1956         }
1957         if (read_stdin)
1958                 apply_patch(0, "<stdin>");
1959         if (whitespace_error) {
1960                 if (squelch_whitespace_errors &&
1961                     squelch_whitespace_errors < whitespace_error) {
1962                         int squelched =
1963                                 whitespace_error - squelch_whitespace_errors;
1964                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
1965                                 squelched,
1966                                 squelched == 1 ? "" : "s");
1967                 }
1968                 if (new_whitespace == error_on_whitespace)
1969                         die("%d line%s add%s trailing whitespaces.",
1970                             whitespace_error,
1971                             whitespace_error == 1 ? "" : "s",
1972                             whitespace_error == 1 ? "s" : "");
1973                 if (applied_after_stripping)
1974                         fprintf(stderr, "warning: %d line%s applied after"
1975                                 " stripping trailing whitespaces.\n",
1976                                 applied_after_stripping,
1977                                 applied_after_stripping == 1 ? "" : "s");
1978                 else if (whitespace_error)
1979                         fprintf(stderr, "warning: %d line%s add%s trailing"
1980                                 " whitespaces.\n",
1981                                 whitespace_error,
1982                                 whitespace_error == 1 ? "" : "s",
1983                                 whitespace_error == 1 ? "s" : "");
1984         }
1985         return 0;
1986 }