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 "cache-tree.h"
  12 #include "quote.h"
  13 #include "blob.h"
  14
  15 static unsigned char active_cache_sha1[20];
  16 static struct cache_tree *active_cache_tree;
  17
  18
  19 //  --check turns on checking that the working tree matches the
  20 //    files that are being modified, but doesn't apply the patch
  21 //  --stat does just a diffstat, and doesn't actually apply
  22 //  --numstat does numeric diffstat, and doesn't actually apply
  23 //  --index-info shows the old and new index info for paths if available.
  24 //
  25 static const char *prefix;
  26 static int prefix_length = -1;
  27
  28 static int p_value = 1;
  29 static int allow_binary_replacement = 0;
  30 static int check_index = 0;
  31 static int write_index = 0;
  32 static int diffstat = 0;
  33 static int numstat = 0;
  34 static int summary = 0;
  35 static int check = 0;
  36 static int apply = 1;
  37 static int no_add = 0;
  38 static int show_index_info = 0;
  39 static int line_termination = '\n';
  40 static unsigned long p_context = -1;
  41 static const char apply_usage[] =
  42 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
  43
  44 static enum whitespace_eol {
  45         nowarn_whitespace,
  46         warn_on_whitespace,
  47         error_on_whitespace,
  48         strip_whitespace,
  49 } new_whitespace = warn_on_whitespace;
  50 static int whitespace_error = 0;
  51 static int squelch_whitespace_errors = 5;
  52 static int applied_after_stripping = 0;
  53 static const char *patch_input_file = NULL;
  54
  55 static void parse_whitespace_option(const char *option)
  56 {
  57         if (!option) {
  58                 new_whitespace = warn_on_whitespace;
  59                 return;
  60         }
  61         if (!strcmp(option, "warn")) {
  62                 new_whitespace = warn_on_whitespace;
  63                 return;
  64         }
  65         if (!strcmp(option, "nowarn")) {
  66                 new_whitespace = nowarn_whitespace;
  67                 return;
  68         }
  69         if (!strcmp(option, "error")) {
  70                 new_whitespace = error_on_whitespace;
  71                 return;
  72         }
  73         if (!strcmp(option, "error-all")) {
  74                 new_whitespace = error_on_whitespace;
  75                 squelch_whitespace_errors = 0;
  76                 return;
  77         }
  78         if (!strcmp(option, "strip")) {
  79                 new_whitespace = strip_whitespace;
  80                 return;
  81         }
  82         die("unrecognized whitespace option '%s'", option);
  83 }
  84
  85 static void set_default_whitespace_mode(const char *whitespace_option)
  86 {
  87         if (!whitespace_option && !apply_default_whitespace) {
  88                 new_whitespace = (apply
  89                                   ? warn_on_whitespace
  90                                   : nowarn_whitespace);
  91         }
  92 }
  93
  94 /*
  95  * For "diff-stat" like behaviour, we keep track of the biggest change
  96  * we've seen, and the longest filename. That allows us to do simple
  97  * scaling.
  98  */
  99 static int max_change, max_len;
 100
 101 /*
 102  * Various "current state", notably line numbers and what
 103  * file (and how) we're patching right now.. The "is_xxxx"
 104  * things are flags, where -1 means "don't know yet".
 105  */
 106 static int linenr = 1;
 107
 108 struct fragment {
 109         unsigned long leading, trailing;
 110         unsigned long oldpos, oldlines;
 111         unsigned long newpos, newlines;
 112         const char *patch;
 113         int size;
 114         struct fragment *next;
 115 };
 116
 117 struct patch {
 118         char *new_name, *old_name, *def_name;
 119         unsigned int old_mode, new_mode;
 120         int is_rename, is_copy, is_new, is_delete, is_binary;
 121         int lines_added, lines_deleted;
 122         int score;
 123         struct fragment *fragments;
 124         char *result;
 125         unsigned long resultsize;
 126         char old_sha1_prefix[41];
 127         char new_sha1_prefix[41];
 128         struct patch *next;
 129 };
 130
 131 #define CHUNKSIZE (8192)
 132 #define SLOP (16)
 133
 134 static void *read_patch_file(int fd, unsigned long *sizep)
 135 {
 136         unsigned long size = 0, alloc = CHUNKSIZE;
 137         void *buffer = xmalloc(alloc);
 138
 139         for (;;) {
 140                 int nr = alloc - size;
 141                 if (nr < 1024) {
 142                         alloc += CHUNKSIZE;
 143                         buffer = xrealloc(buffer, alloc);
 144                         nr = alloc - size;
 145                 }
 146                 nr = xread(fd, buffer + size, nr);
 147                 if (!nr)
 148                         break;
 149                 if (nr < 0)
 150                         die("git-apply: read returned %s", strerror(errno));
 151                 size += nr;
 152         }
 153         *sizep = size;
 154
 155         /*
 156          * Make sure that we have some slop in the buffer
 157          * so that we can do speculative "memcmp" etc, and
 158          * see to it that it is NUL-filled.
 159          */
 160         if (alloc < size + SLOP)
 161                 buffer = xrealloc(buffer, size + SLOP);
 162         memset(buffer + size, 0, SLOP);
 163         return buffer;
 164 }
 165
 166 static unsigned long linelen(const char *buffer, unsigned long size)
 167 {
 168         unsigned long len = 0;
 169         while (size--) {
 170                 len++;
 171                 if (*buffer++ == '\n')
 172                         break;
 173         }
 174         return len;
 175 }
 176
 177 static int is_dev_null(const char *str)
 178 {
 179         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 180 }
 181
 182 #define TERM_SPACE      1
 183 #define TERM_TAB        2
 184
 185 static int name_terminate(const char *name, int namelen, int c, int terminate)
 186 {
 187         if (c == ' ' && !(terminate & TERM_SPACE))
 188                 return 0;
 189         if (c == '\t' && !(terminate & TERM_TAB))
 190                 return 0;
 191
 192         return 1;
 193 }
 194
 195 static char * find_name(const char *line, char *def, int p_value, int terminate)
 196 {
 197         int len;
 198         const char *start = line;
 199         char *name;
 200
 201         if (*line == '"') {
 202                 /* Proposed "new-style" GNU patch/diff format; see
 203                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
 204                  */
 205                 name = unquote_c_style(line, NULL);
 206                 if (name) {
 207                         char *cp = name;
 208                         while (p_value) {
 209                                 cp = strchr(name, '/');
 210                                 if (!cp)
 211                                         break;
 212                                 cp++;
 213                                 p_value--;
 214                         }
 215                         if (cp) {
 216                                 /* name can later be freed, so we need
 217                                  * to memmove, not just return cp
 218                                  */
 219                                 memmove(name, cp, strlen(cp) + 1);
 220                                 free(def);
 221                                 return name;
 222                         }
 223                         else {
 224                                 free(name);
 225                                 name = NULL;
 226                         }
 227                 }
 228         }
 229
 230         for (;;) {
 231                 char c = *line;
 232
 233                 if (isspace(c)) {
 234                         if (c == '\n')
 235                                 break;
 236                         if (name_terminate(start, line-start, c, terminate))
 237                                 break;
 238                 }
 239                 line++;
 240                 if (c == '/' && !--p_value)
 241                         start = line;
 242         }
 243         if (!start)
 244                 return def;
 245         len = line - start;
 246         if (!len)
 247                 return def;
 248
 249         /*
 250          * Generally we prefer the shorter name, especially
 251          * if the other one is just a variation of that with
 252          * something else tacked on to the end (ie "file.orig"
 253          * or "file~").
 254          */
 255         if (def) {
 256                 int deflen = strlen(def);
 257                 if (deflen < len && !strncmp(start, def, deflen))
 258                         return def;
 259         }
 260
 261         name = xmalloc(len + 1);
 262         memcpy(name, start, len);
 263         name[len] = 0;
 264         free(def);
 265         return name;
 266 }
 267
 268 /*
 269  * Get the name etc info from the --/+++ lines of a traditional patch header
 270  *
 271  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 272  *
 273  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 274  * files, we can happily check the index for a match, but for creating a
 275  * new file we should try to match whatever "patch" does. I have no idea.
 276  */
 277 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 278 {
 279         char *name;
 280
 281         first += 4;     // skip "--- "
 282         second += 4;    // skip "+++ "
 283         if (is_dev_null(first)) {
 284                 patch->is_new = 1;
 285                 patch->is_delete = 0;
 286                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 287                 patch->new_name = name;
 288         } else if (is_dev_null(second)) {
 289                 patch->is_new = 0;
 290                 patch->is_delete = 1;
 291                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 292                 patch->old_name = name;
 293         } else {
 294                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 295                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 296                 patch->old_name = patch->new_name = name;
 297         }
 298         if (!name)
 299                 die("unable to find filename in patch at line %d", linenr);
 300 }
 301
 302 static int gitdiff_hdrend(const char *line, struct patch *patch)
 303 {
 304         return -1;
 305 }
 306
 307 /*
 308  * We're anal about diff header consistency, to make
 309  * sure that we don't end up having strange ambiguous
 310  * patches floating around.
 311  *
 312  * As a result, gitdiff_{old|new}name() will check
 313  * their names against any previous information, just
 314  * to make sure..
 315  */
 316 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 317 {
 318         if (!orig_name && !isnull)
 319                 return find_name(line, NULL, 1, 0);
 320
 321         if (orig_name) {
 322                 int len;
 323                 const char *name;
 324                 char *another;
 325                 name = orig_name;
 326                 len = strlen(name);
 327                 if (isnull)
 328                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 329                 another = find_name(line, NULL, 1, 0);
 330                 if (!another || memcmp(another, name, len))
 331                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 332                 free(another);
 333                 return orig_name;
 334         }
 335         else {
 336                 /* expect "/dev/null" */
 337                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 338                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
 339                 return NULL;
 340         }
 341 }
 342
 343 static int gitdiff_oldname(const char *line, struct patch *patch)
 344 {
 345         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 346         return 0;
 347 }
 348
 349 static int gitdiff_newname(const char *line, struct patch *patch)
 350 {
 351         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 352         return 0;
 353 }
 354
 355 static int gitdiff_oldmode(const char *line, struct patch *patch)
 356 {
 357         patch->old_mode = strtoul(line, NULL, 8);
 358         return 0;
 359 }
 360
 361 static int gitdiff_newmode(const char *line, struct patch *patch)
 362 {
 363         patch->new_mode = strtoul(line, NULL, 8);
 364         return 0;
 365 }
 366
 367 static int gitdiff_delete(const char *line, struct patch *patch)
 368 {
 369         patch->is_delete = 1;
 370         patch->old_name = patch->def_name;
 371         return gitdiff_oldmode(line, patch);
 372 }
 373
 374 static int gitdiff_newfile(const char *line, struct patch *patch)
 375 {
 376         patch->is_new = 1;
 377         patch->new_name = patch->def_name;
 378         return gitdiff_newmode(line, patch);
 379 }
 380
 381 static int gitdiff_copysrc(const char *line, struct patch *patch)
 382 {
 383         patch->is_copy = 1;
 384         patch->old_name = find_name(line, NULL, 0, 0);
 385         return 0;
 386 }
 387
 388 static int gitdiff_copydst(const char *line, struct patch *patch)
 389 {
 390         patch->is_copy = 1;
 391         patch->new_name = find_name(line, NULL, 0, 0);
 392         return 0;
 393 }
 394
 395 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 396 {
 397         patch->is_rename = 1;
 398         patch->old_name = find_name(line, NULL, 0, 0);
 399         return 0;
 400 }
 401
 402 static int gitdiff_renamedst(const char *line, struct patch *patch)
 403 {
 404         patch->is_rename = 1;
 405         patch->new_name = find_name(line, NULL, 0, 0);
 406         return 0;
 407 }
 408
 409 static int gitdiff_similarity(const char *line, struct patch *patch)
 410 {
 411         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 412                 patch->score = 0;
 413         return 0;
 414 }
 415
 416 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 417 {
 418         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 419                 patch->score = 0;
 420         return 0;
 421 }
 422
 423 static int gitdiff_index(const char *line, struct patch *patch)
 424 {
 425         /* index line is N hexadecimal, "..", N hexadecimal,
 426          * and optional space with octal mode.
 427          */
 428         const char *ptr, *eol;
 429         int len;
 430
 431         ptr = strchr(line, '.');
 432         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
 433                 return 0;
 434         len = ptr - line;
 435         memcpy(patch->old_sha1_prefix, line, len);
 436         patch->old_sha1_prefix[len] = 0;
 437
 438         line = ptr + 2;
 439         ptr = strchr(line, ' ');
 440         eol = strchr(line, '\n');
 441
 442         if (!ptr || eol < ptr)
 443                 ptr = eol;
 444         len = ptr - line;
 445
 446         if (40 < len)
 447                 return 0;
 448         memcpy(patch->new_sha1_prefix, line, len);
 449         patch->new_sha1_prefix[len] = 0;
 450         if (*ptr == ' ')
 451                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
 452         return 0;
 453 }
 454
 455 /*
 456  * This is normal for a diff that doesn't change anything: we'll fall through
 457  * into the next diff. Tell the parser to break out.
 458  */
 459 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 460 {
 461         return -1;
 462 }
 463
 464 static const char *stop_at_slash(const char *line, int llen)
 465 {
 466         int i;
 467
 468         for (i = 0; i < llen; i++) {
 469                 int ch = line[i];
 470                 if (ch == '/')
 471                         return line + i;
 472         }
 473         return NULL;
 474 }
 475
 476 /* This is to extract the same name that appears on "diff --git"
 477  * line.  We do not find and return anything if it is a rename
 478  * patch, and it is OK because we will find the name elsewhere.
 479  * We need to reliably find name only when it is mode-change only,
 480  * creation or deletion of an empty file.  In any of these cases,
 481  * both sides are the same name under a/ and b/ respectively.
 482  */
 483 static char *git_header_name(char *line, int llen)
 484 {
 485         int len;
 486         const char *name;
 487         const char *second = NULL;
 488
 489         line += strlen("diff --git ");
 490         llen -= strlen("diff --git ");
 491
 492         if (*line == '"') {
 493                 const char *cp;
 494                 char *first = unquote_c_style(line, &second);
 495                 if (!first)
 496                         return NULL;
 497
 498                 /* advance to the first slash */
 499                 cp = stop_at_slash(first, strlen(first));
 500                 if (!cp || cp == first) {
 501                         /* we do not accept absolute paths */
 502                 free_first_and_fail:
 503                         free(first);
 504                         return NULL;
 505                 }
 506                 len = strlen(cp+1);
 507                 memmove(first, cp+1, len+1); /* including NUL */
 508
 509                 /* second points at one past closing dq of name.
 510                  * find the second name.
 511                  */
 512                 while ((second < line + llen) && isspace(*second))
 513                         second++;
 514
 515                 if (line + llen <= second)
 516                         goto free_first_and_fail;
 517                 if (*second == '"') {
 518                         char *sp = unquote_c_style(second, NULL);
 519                         if (!sp)
 520                                 goto free_first_and_fail;
 521                         cp = stop_at_slash(sp, strlen(sp));
 522                         if (!cp || cp == sp) {
 523                         free_both_and_fail:
 524                                 free(sp);
 525                                 goto free_first_and_fail;
 526                         }
 527                         /* They must match, otherwise ignore */
 528                         if (strcmp(cp+1, first))
 529                                 goto free_both_and_fail;
 530                         free(sp);
 531                         return first;
 532                 }
 533
 534                 /* unquoted second */
 535                 cp = stop_at_slash(second, line + llen - second);
 536                 if (!cp || cp == second)
 537                         goto free_first_and_fail;
 538                 cp++;
 539                 if (line + llen - cp != len + 1 ||
 540                     memcmp(first, cp, len))
 541                         goto free_first_and_fail;
 542                 return first;
 543         }
 544
 545         /* unquoted first name */
 546         name = stop_at_slash(line, llen);
 547         if (!name || name == line)
 548                 return NULL;
 549
 550         name++;
 551
 552         /* since the first name is unquoted, a dq if exists must be
 553          * the beginning of the second name.
 554          */
 555         for (second = name; second < line + llen; second++) {
 556                 if (*second == '"') {
 557                         const char *cp = second;
 558                         const char *np;
 559                         char *sp = unquote_c_style(second, NULL);
 560
 561                         if (!sp)
 562                                 return NULL;
 563                         np = stop_at_slash(sp, strlen(sp));
 564                         if (!np || np == sp) {
 565                         free_second_and_fail:
 566                                 free(sp);
 567                                 return NULL;
 568                         }
 569                         np++;
 570                         len = strlen(np);
 571                         if (len < cp - name &&
 572                             !strncmp(np, name, len) &&
 573                             isspace(name[len])) {
 574                                 /* Good */
 575                                 memmove(sp, np, len + 1);
 576                                 return sp;
 577                         }
 578                         goto free_second_and_fail;
 579                 }
 580         }
 581
 582         /*
 583          * Accept a name only if it shows up twice, exactly the same
 584          * form.
 585          */
 586         for (len = 0 ; ; len++) {
 587                 char c = name[len];
 588
 589                 switch (c) {
 590                 default:
 591                         continue;
 592                 case '\n':
 593                         return NULL;
 594                 case '\t': case ' ':
 595                         second = name+len;
 596                         for (;;) {
 597                                 char c = *second++;
 598                                 if (c == '\n')
 599                                         return NULL;
 600                                 if (c == '/')
 601                                         break;
 602                         }
 603                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 604                                 char *ret = xmalloc(len + 1);
 605                                 memcpy(ret, name, len);
 606                                 ret[len] = 0;
 607                                 return ret;
 608                         }
 609                 }
 610         }
 611         return NULL;
 612 }
 613
 614 /* Verify that we recognize the lines following a git header */
 615 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 616 {
 617         unsigned long offset;
 618
 619         /* A git diff has explicit new/delete information, so we don't guess */
 620         patch->is_new = 0;
 621         patch->is_delete = 0;
 622
 623         /*
 624          * Some things may not have the old name in the
 625          * rest of the headers anywhere (pure mode changes,
 626          * or removing or adding empty files), so we get
 627          * the default name from the header.
 628          */
 629         patch->def_name = git_header_name(line, len);
 630
 631         line += len;
 632         size -= len;
 633         linenr++;
 634         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 635                 static const struct opentry {
 636                         const char *str;
 637                         int (*fn)(const char *, struct patch *);
 638                 } optable[] = {
 639                         { "@@ -", gitdiff_hdrend },
 640                         { "--- ", gitdiff_oldname },
 641                         { "+++ ", gitdiff_newname },
 642                         { "old mode ", gitdiff_oldmode },
 643                         { "new mode ", gitdiff_newmode },
 644                         { "deleted file mode ", gitdiff_delete },
 645                         { "new file mode ", gitdiff_newfile },
 646                         { "copy from ", gitdiff_copysrc },
 647                         { "copy to ", gitdiff_copydst },
 648                         { "rename old ", gitdiff_renamesrc },
 649                         { "rename new ", gitdiff_renamedst },
 650                         { "rename from ", gitdiff_renamesrc },
 651                         { "rename to ", gitdiff_renamedst },
 652                         { "similarity index ", gitdiff_similarity },
 653                         { "dissimilarity index ", gitdiff_dissimilarity },
 654                         { "index ", gitdiff_index },
 655                         { "", gitdiff_unrecognized },
 656                 };
 657                 int i;
 658
 659                 len = linelen(line, size);
 660                 if (!len || line[len-1] != '\n')
 661                         break;
 662                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
 663                         const struct opentry *p = optable + i;
 664                         int oplen = strlen(p->str);
 665                         if (len < oplen || memcmp(p->str, line, oplen))
 666                                 continue;
 667                         if (p->fn(line + oplen, patch) < 0)
 668                                 return offset;
 669                         break;
 670                 }
 671         }
 672
 673         return offset;
 674 }
 675
 676 static int parse_num(const char *line, unsigned long *p)
 677 {
 678         char *ptr;
 679
 680         if (!isdigit(*line))
 681                 return 0;
 682         *p = strtoul(line, &ptr, 10);
 683         return ptr - line;
 684 }
 685
 686 static int parse_range(const char *line, int len, int offset, const char *expect,
 687                         unsigned long *p1, unsigned long *p2)
 688 {
 689         int digits, ex;
 690
 691         if (offset < 0 || offset >= len)
 692                 return -1;
 693         line += offset;
 694         len -= offset;
 695
 696         digits = parse_num(line, p1);
 697         if (!digits)
 698                 return -1;
 699
 700         offset += digits;
 701         line += digits;
 702         len -= digits;
 703
 704         *p2 = 1;
 705         if (*line == ',') {
 706                 digits = parse_num(line+1, p2);
 707                 if (!digits)
 708                         return -1;
 709
 710                 offset += digits+1;
 711                 line += digits+1;
 712                 len -= digits+1;
 713         }
 714
 715         ex = strlen(expect);
 716         if (ex > len)
 717                 return -1;
 718         if (memcmp(line, expect, ex))
 719                 return -1;
 720
 721         return offset + ex;
 722 }
 723
 724 /*
 725  * Parse a unified diff fragment header of the
 726  * form "@@ -a,b +c,d @@"
 727  */
 728 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 729 {
 730         int offset;
 731
 732         if (!len || line[len-1] != '\n')
 733                 return -1;
 734
 735         /* Figure out the number of lines in a fragment */
 736         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 737         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 738
 739         return offset;
 740 }
 741
 742 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 743 {
 744         unsigned long offset, len;
 745
 746         patch->is_rename = patch->is_copy = 0;
 747         patch->is_new = patch->is_delete = -1;
 748         patch->old_mode = patch->new_mode = 0;
 749         patch->old_name = patch->new_name = NULL;
 750         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 751                 unsigned long nextlen;
 752
 753                 len = linelen(line, size);
 754                 if (!len)
 755                         break;
 756
 757                 /* Testing this early allows us to take a few shortcuts.. */
 758                 if (len < 6)
 759                         continue;
 760
 761                 /*
 762                  * Make sure we don't find any unconnected patch fragmants.
 763                  * That's a sign that we didn't find a header, and that a
 764                  * patch has become corrupted/broken up.
 765                  */
 766                 if (!memcmp("@@ -", line, 4)) {
 767                         struct fragment dummy;
 768                         if (parse_fragment_header(line, len, &dummy) < 0)
 769                                 continue;
 770                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
 771                 }
 772
 773                 if (size < len + 6)
 774                         break;
 775
 776                 /*
 777                  * Git patch? It might not have a real patch, just a rename
 778                  * or mode change, so we handle that specially
 779                  */
 780                 if (!memcmp("diff --git ", line, 11)) {
 781                         int git_hdr_len = parse_git_header(line, len, size, patch);
 782                         if (git_hdr_len <= len)
 783                                 continue;
 784                         if (!patch->old_name && !patch->new_name) {
 785                                 if (!patch->def_name)
 786                                         die("git diff header lacks filename information (line %d)", linenr);
 787                                 patch->old_name = patch->new_name = patch->def_name;
 788                         }
 789                         *hdrsize = git_hdr_len;
 790                         return offset;
 791                 }
 792
 793                 /** --- followed by +++ ? */
 794                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 795                         continue;
 796
 797                 /*
 798                  * We only accept unified patches, so we want it to
 799                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 800                  * minimum
 801                  */
 802                 nextlen = linelen(line + len, size - len);
 803                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 804                         continue;
 805
 806                 /* Ok, we'll consider it a patch */
 807                 parse_traditional_patch(line, line+len, patch);
 808                 *hdrsize = len + nextlen;
 809                 linenr += 2;
 810                 return offset;
 811         }
 812         return -1;
 813 }
 814
 815 /*
 816  * Parse a unified diff. Note that this really needs
 817  * to parse each fragment separately, since the only
 818  * way to know the difference between a "---" that is
 819  * part of a patch, and a "---" that starts the next
 820  * patch is to look at the line counts..
 821  */
 822 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 823 {
 824         int added, deleted;
 825         int len = linelen(line, size), offset;
 826         unsigned long oldlines, newlines;
 827         unsigned long leading, trailing;
 828
 829         offset = parse_fragment_header(line, len, fragment);
 830         if (offset < 0)
 831                 return -1;
 832         oldlines = fragment->oldlines;
 833         newlines = fragment->newlines;
 834         leading = 0;
 835         trailing = 0;
 836
 837         if (patch->is_new < 0) {
 838                 patch->is_new =  !oldlines;
 839                 if (!oldlines)
 840                         patch->old_name = NULL;
 841         }
 842         if (patch->is_delete < 0) {
 843                 patch->is_delete = !newlines;
 844                 if (!newlines)
 845                         patch->new_name = NULL;
 846         }
 847
 848         if (patch->is_new && oldlines)
 849                 return error("new file depends on old contents");
 850         if (patch->is_delete != !newlines) {
 851                 if (newlines)
 852                         return error("deleted file still has contents");
 853                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
 854         }
 855
 856         /* Parse the thing.. */
 857         line += len;
 858         size -= len;
 859         linenr++;
 860         added = deleted = 0;
 861         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 862                 if (!oldlines && !newlines)
 863                         break;
 864                 len = linelen(line, size);
 865                 if (!len || line[len-1] != '\n')
 866                         return -1;
 867                 switch (*line) {
 868                 default:
 869                         return -1;
 870                 case ' ':
 871                         oldlines--;
 872                         newlines--;
 873                         if (!deleted && !added)
 874                                 leading++;
 875                         trailing++;
 876                         break;
 877                 case '-':
 878                         deleted++;
 879                         oldlines--;
 880                         trailing = 0;
 881                         break;
 882                 case '+':
 883                         /*
 884                          * We know len is at least two, since we have a '+' and
 885                          * we checked that the last character was a '\n' above.
 886                          * That is, an addition of an empty line would check
 887                          * the '+' here.  Sneaky...
 888                          */
 889                         if ((new_whitespace != nowarn_whitespace) &&
 890                             isspace(line[len-2])) {
 891                                 whitespace_error++;
 892                                 if (squelch_whitespace_errors &&
 893                                     squelch_whitespace_errors <
 894                                     whitespace_error)
 895                                         ;
 896                                 else {
 897                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
 898                                                 patch_input_file,
 899                                                 linenr, len-2, line+1);
 900                                 }
 901                         }
 902                         added++;
 903                         newlines--;
 904                         trailing = 0;
 905                         break;
 906
 907                 /* We allow "\ No newline at end of file". Depending
 908                  * on locale settings when the patch was produced we
 909                  * don't know what this line looks like. The only
 910                  * thing we do know is that it begins with "\ ".
 911                  * Checking for 12 is just for sanity check -- any
 912                  * l10n of "\ No newline..." is at least that long.
 913                  */
 914                 case '\\':
 915                         if (len < 12 || memcmp(line, "\\ ", 2))
 916                                 return -1;
 917                         break;
 918                 }
 919         }
 920         if (oldlines || newlines)
 921                 return -1;
 922         fragment->leading = leading;
 923         fragment->trailing = trailing;
 924
 925         /* If a fragment ends with an incomplete line, we failed to include
 926          * it in the above loop because we hit oldlines == newlines == 0
 927          * before seeing it.
 928          */
 929         if (12 < size && !memcmp(line, "\\ ", 2))
 930                 offset += linelen(line, size);
 931
 932         patch->lines_added += added;
 933         patch->lines_deleted += deleted;
 934         return offset;
 935 }
 936
 937 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 938 {
 939         unsigned long offset = 0;
 940         struct fragment **fragp = &patch->fragments;
 941
 942         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 943                 struct fragment *fragment;
 944                 int len;
 945
 946                 fragment = xcalloc(1, sizeof(*fragment));
 947                 len = parse_fragment(line, size, patch, fragment);
 948                 if (len <= 0)
 949                         die("corrupt patch at line %d", linenr);
 950
 951                 fragment->patch = line;
 952                 fragment->size = len;
 953
 954                 *fragp = fragment;
 955                 fragp = &fragment->next;
 956
 957                 offset += len;
 958                 line += len;
 959                 size -= len;
 960         }
 961         return offset;
 962 }
 963
 964 static inline int metadata_changes(struct patch *patch)
 965 {
 966         return  patch->is_rename > 0 ||
 967                 patch->is_copy > 0 ||
 968                 patch->is_new > 0 ||
 969                 patch->is_delete ||
 970                 (patch->old_mode && patch->new_mode &&
 971                  patch->old_mode != patch->new_mode);
 972 }
 973
 974 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 975 {
 976         int hdrsize, patchsize;
 977         int offset = find_header(buffer, size, &hdrsize, patch);
 978
 979         if (offset < 0)
 980                 return offset;
 981
 982         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 983
 984         if (!patchsize) {
 985                 static const char *binhdr[] = {
 986                         "Binary files ",
 987                         "Files ",
 988                         NULL,
 989                 };
 990                 int i;
 991                 int hd = hdrsize + offset;
 992                 unsigned long llen = linelen(buffer + hd, size - hd);
 993
 994                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
 995                         for (i = 0; binhdr[i]; i++) {
 996                                 int len = strlen(binhdr[i]);
 997                                 if (len < size - hd &&
 998                                     !memcmp(binhdr[i], buffer + hd, len)) {
 999                                         patch->is_binary = 1;
1000                                         break;
1001                                 }
1002                         }
1003
1004                 /* Empty patch cannot be applied if:
1005                  * - it is a binary patch and we do not do binary_replace, or
1006                  * - text patch without metadata change
1007                  */
1008                 if ((apply || check) &&
1009                     (patch->is_binary
1010                      ? !allow_binary_replacement
1011                      : !metadata_changes(patch)))
1012                         die("patch with only garbage at line %d", linenr);
1013         }
1014
1015         return offset + hdrsize + patchsize;
1016 }
1017
1018 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1019 static const char minuses[]= "----------------------------------------------------------------------";
1020
1021 static void show_stats(struct patch *patch)
1022 {
1023         const char *prefix = "";
1024         char *name = patch->new_name;
1025         char *qname = NULL;
1026         int len, max, add, del, total;
1027
1028         if (!name)
1029                 name = patch->old_name;
1030
1031         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1032                 qname = xmalloc(len + 1);
1033                 quote_c_style(name, qname, NULL, 0);
1034                 name = qname;
1035         }
1036
1037         /*
1038          * "scale" the filename
1039          */
1040         len = strlen(name);
1041         max = max_len;
1042         if (max > 50)
1043                 max = 50;
1044         if (len > max) {
1045                 char *slash;
1046                 prefix = "...";
1047                 max -= 3;
1048                 name += len - max;
1049                 slash = strchr(name, '/');
1050                 if (slash)
1051                         name = slash;
1052         }
1053         len = max;
1054
1055         /*
1056          * scale the add/delete
1057          */
1058         max = max_change;
1059         if (max + len > 70)
1060                 max = 70 - len;
1061
1062         add = patch->lines_added;
1063         del = patch->lines_deleted;
1064         total = add + del;
1065
1066         if (max_change > 0) {
1067                 total = (total * max + max_change / 2) / max_change;
1068                 add = (add * max + max_change / 2) / max_change;
1069                 del = total - add;
1070         }
1071         if (patch->is_binary)
1072                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1073         else
1074                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1075                        len, name, patch->lines_added + patch->lines_deleted,
1076                        add, pluses, del, minuses);
1077         if (qname)
1078                 free(qname);
1079 }
1080
1081 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1082 {
1083         int fd;
1084         unsigned long got;
1085
1086         switch (st->st_mode & S_IFMT) {
1087         case S_IFLNK:
1088                 return readlink(path, buf, size);
1089         case S_IFREG:
1090                 fd = open(path, O_RDONLY);
1091                 if (fd < 0)
1092                         return error("unable to open %s", path);
1093                 got = 0;
1094                 for (;;) {
1095                         int ret = xread(fd, buf + got, size - got);
1096                         if (ret <= 0)
1097                                 break;
1098                         got += ret;
1099                 }
1100                 close(fd);
1101                 return got;
1102
1103         default:
1104                 return -1;
1105         }
1106 }
1107
1108 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
1109 {
1110         int i;
1111         unsigned long start, backwards, forwards;
1112
1113         if (fragsize > size)
1114                 return -1;
1115
1116         start = 0;
1117         if (line > 1) {
1118                 unsigned long offset = 0;
1119                 i = line-1;
1120                 while (offset + fragsize <= size) {
1121                         if (buf[offset++] == '\n') {
1122                                 start = offset;
1123                                 if (!--i)
1124                                         break;
1125                         }
1126                 }
1127         }
1128
1129         /* Exact line number? */
1130         if (!memcmp(buf + start, fragment, fragsize))
1131                 return start;
1132
1133         /*
1134          * There's probably some smart way to do this, but I'll leave
1135          * that to the smart and beautiful people. I'm simple and stupid.
1136          */
1137         backwards = start;
1138         forwards = start;
1139         for (i = 0; ; i++) {
1140                 unsigned long try;
1141                 int n;
1142
1143                 /* "backward" */
1144                 if (i & 1) {
1145                         if (!backwards) {
1146                                 if (forwards + fragsize > size)
1147                                         break;
1148                                 continue;
1149                         }
1150                         do {
1151                                 --backwards;
1152                         } while (backwards && buf[backwards-1] != '\n');
1153                         try = backwards;
1154                 } else {
1155                         while (forwards + fragsize <= size) {
1156                                 if (buf[forwards++] == '\n')
1157                                         break;
1158                         }
1159                         try = forwards;
1160                 }
1161
1162                 if (try + fragsize > size)
1163                         continue;
1164                 if (memcmp(buf + try, fragment, fragsize))
1165                         continue;
1166                 n = (i >> 1)+1;
1167                 if (i & 1)
1168                         n = -n;
1169                 *lines = n;
1170                 return try;
1171         }
1172
1173         /*
1174          * We should start searching forward and backward.
1175          */
1176         return -1;
1177 }
1178
1179 static void remove_first_line(const char **rbuf, int *rsize)
1180 {
1181         const char *buf = *rbuf;
1182         int size = *rsize;
1183         unsigned long offset;
1184         offset = 0;
1185         while (offset <= size) {
1186                 if (buf[offset++] == '\n')
1187                         break;
1188         }
1189         *rsize = size - offset;
1190         *rbuf = buf + offset;
1191 }
1192
1193 static void remove_last_line(const char **rbuf, int *rsize)
1194 {
1195         const char *buf = *rbuf;
1196         int size = *rsize;
1197         unsigned long offset;
1198         offset = size - 1;
1199         while (offset > 0) {
1200                 if (buf[--offset] == '\n')
1201                         break;
1202         }
1203         *rsize = offset + 1;
1204 }
1205
1206 struct buffer_desc {
1207         char *buffer;
1208         unsigned long size;
1209         unsigned long alloc;
1210 };
1211
1212 static int apply_line(char *output, const char *patch, int plen)
1213 {
1214         /* plen is number of bytes to be copied from patch,
1215          * starting at patch+1 (patch[0] is '+').  Typically
1216          * patch[plen] is '\n'.
1217          */
1218         int add_nl_to_tail = 0;
1219         if ((new_whitespace == strip_whitespace) &&
1220             1 < plen && isspace(patch[plen-1])) {
1221                 if (patch[plen] == '\n')
1222                         add_nl_to_tail = 1;
1223                 plen--;
1224                 while (0 < plen && isspace(patch[plen]))
1225                         plen--;
1226                 applied_after_stripping++;
1227         }
1228         memcpy(output, patch + 1, plen);
1229         if (add_nl_to_tail)
1230                 output[plen++] = '\n';
1231         return plen;
1232 }
1233
1234 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1235 {
1236         char *buf = desc->buffer;
1237         const char *patch = frag->patch;
1238         int offset, size = frag->size;
1239         char *old = xmalloc(size);
1240         char *new = xmalloc(size);
1241         const char *oldlines, *newlines;
1242         int oldsize = 0, newsize = 0;
1243         unsigned long leading, trailing;
1244         int pos, lines;
1245
1246         while (size > 0) {
1247                 int len = linelen(patch, size);
1248                 int plen;
1249
1250                 if (!len)
1251                         break;
1252
1253                 /*
1254                  * "plen" is how much of the line we should use for
1255                  * the actual patch data. Normally we just remove the
1256                  * first character on the line, but if the line is
1257                  * followed by "\ No newline", then we also remove the
1258                  * last one (which is the newline, of course).
1259                  */
1260                 plen = len-1;
1261                 if (len < size && patch[len] == '\\')
1262                         plen--;
1263                 switch (*patch) {
1264                 case ' ':
1265                 case '-':
1266                         memcpy(old + oldsize, patch + 1, plen);
1267                         oldsize += plen;
1268                         if (*patch == '-')
1269                                 break;
1270                 /* Fall-through for ' ' */
1271                 case '+':
1272                         if (*patch != '+' || !no_add)
1273                                 newsize += apply_line(new + newsize, patch,
1274                                                       plen);
1275                         break;
1276                 case '@': case '\\':
1277                         /* Ignore it, we already handled it */
1278                         break;
1279                 default:
1280                         return -1;
1281                 }
1282                 patch += len;
1283                 size -= len;
1284         }
1285
1286 #ifdef NO_ACCURATE_DIFF
1287         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1288                         newsize > 0 && new[newsize - 1] == '\n') {
1289                 oldsize--;
1290                 newsize--;
1291         }
1292 #endif
1293
1294         oldlines = old;
1295         newlines = new;
1296         leading = frag->leading;
1297         trailing = frag->trailing;
1298         lines = 0;
1299         pos = frag->newpos;
1300         for (;;) {
1301                 offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
1302                 if (offset >= 0) {
1303                         int diff = newsize - oldsize;
1304                         unsigned long size = desc->size + diff;
1305                         unsigned long alloc = desc->alloc;
1306
1307                         /* Warn if it was necessary to reduce the number
1308                          * of context lines.
1309                          */
1310                         if ((leading != frag->leading) || (trailing != frag->trailing))
1311                                 fprintf(stderr, "Context reduced to (%ld/%ld) to apply fragment at %d\n",
1312                                         leading, trailing, pos + lines);
1313
1314                         if (size > alloc) {
1315                                 alloc = size + 8192;
1316                                 desc->alloc = alloc;
1317                                 buf = xrealloc(buf, alloc);
1318                                 desc->buffer = buf;
1319                         }
1320                         desc->size = size;
1321                         memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1322                         memcpy(buf + offset, newlines, newsize);
1323                         offset = 0;
1324
1325                         break;
1326                 }
1327
1328                 /* Am I at my context limits? */
1329                 if ((leading <= p_context) && (trailing <= p_context))
1330                         break;
1331                 /* Reduce the number of context lines
1332                  * Reduce both leading and trailing if they are equal
1333                  * otherwise just reduce the larger context.
1334                  */
1335                 if (leading >= trailing) {
1336                         remove_first_line(&oldlines, &oldsize);
1337                         remove_first_line(&newlines, &newsize);
1338                         pos--;
1339                         leading--;
1340                 }
1341                 if (trailing > leading) {
1342                         remove_last_line(&oldlines, &oldsize);
1343                         remove_last_line(&newlines, &newsize);
1344                         trailing--;
1345                 }
1346         }
1347
1348         free(old);
1349         free(new);
1350         return offset;
1351 }
1352
1353 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1354 {
1355         struct fragment *frag = patch->fragments;
1356         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1357
1358         if (patch->is_binary) {
1359                 unsigned char sha1[20];
1360
1361                 if (!allow_binary_replacement)
1362                         return error("cannot apply binary patch to '%s' "
1363                                      "without --allow-binary-replacement",
1364                                      name);
1365
1366                 /* For safety, we require patch index line to contain
1367                  * full 40-byte textual SHA1 for old and new, at least for now.
1368                  */
1369                 if (strlen(patch->old_sha1_prefix) != 40 ||
1370                     strlen(patch->new_sha1_prefix) != 40 ||
1371                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1372                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1373                         return error("cannot apply binary patch to '%s' "
1374                                      "without full index line", name);
1375
1376                 if (patch->old_name) {
1377                         unsigned char hdr[50];
1378                         int hdrlen;
1379
1380                         /* See if the old one matches what the patch
1381                          * applies to.
1382                          */
1383                         write_sha1_file_prepare(desc->buffer, desc->size,
1384                                                 blob_type, sha1, hdr, &hdrlen);
1385                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1386                                 return error("the patch applies to '%s' (%s), "
1387                                              "which does not match the "
1388                                              "current contents.",
1389                                              name, sha1_to_hex(sha1));
1390                 }
1391                 else {
1392                         /* Otherwise, the old one must be empty. */
1393                         if (desc->size)
1394                                 return error("the patch applies to an empty "
1395                                              "'%s' but it is not empty", name);
1396                 }
1397
1398                 /* For now, we do not record post-image data in the patch,
1399                  * and require the object already present in the recipient's
1400                  * object database.
1401                  */
1402                 if (desc->buffer) {
1403                         free(desc->buffer);
1404                         desc->alloc = desc->size = 0;
1405                 }
1406                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1407
1408                 if (memcmp(sha1, null_sha1, 20)) {
1409                         char type[10];
1410                         unsigned long size;
1411
1412                         desc->buffer = read_sha1_file(sha1, type, &size);
1413                         if (!desc->buffer)
1414                                 return error("the necessary postimage %s for "
1415                                              "'%s' does not exist",
1416                                              patch->new_sha1_prefix, name);
1417                         desc->alloc = desc->size = size;
1418                 }
1419
1420                 return 0;
1421         }
1422
1423         while (frag) {
1424                 if (apply_one_fragment(desc, frag) < 0)
1425                         return error("patch failed: %s:%ld",
1426                                      name, frag->oldpos);
1427                 frag = frag->next;
1428         }
1429         return 0;
1430 }
1431
1432 static int apply_data(struct patch *patch, struct stat *st)
1433 {
1434         char *buf;
1435         unsigned long size, alloc;
1436         struct buffer_desc desc;
1437
1438         size = 0;
1439         alloc = 0;
1440         buf = NULL;
1441         if (patch->old_name) {
1442                 size = st->st_size;
1443                 alloc = size + 8192;
1444                 buf = xmalloc(alloc);
1445                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1446                         return error("read of %s failed", patch->old_name);
1447         }
1448
1449         desc.size = size;
1450         desc.alloc = alloc;
1451         desc.buffer = buf;
1452         if (apply_fragments(&desc, patch) < 0)
1453                 return -1;
1454         patch->result = desc.buffer;
1455         patch->resultsize = desc.size;
1456
1457         if (patch->is_delete && patch->resultsize)
1458                 return error("removal patch leaves file contents");
1459
1460         return 0;
1461 }
1462
1463 static int check_patch(struct patch *patch)
1464 {
1465         struct stat st;
1466         const char *old_name = patch->old_name;
1467         const char *new_name = patch->new_name;
1468         const char *name = old_name ? old_name : new_name;
1469
1470         if (old_name) {
1471                 int changed;
1472                 int stat_ret = lstat(old_name, &st);
1473
1474                 if (check_index) {
1475                         int pos = cache_name_pos(old_name, strlen(old_name));
1476                         if (pos < 0)
1477                                 return error("%s: does not exist in index",
1478                                              old_name);
1479                         if (stat_ret < 0) {
1480                                 struct checkout costate;
1481                                 if (errno != ENOENT)
1482                                         return error("%s: %s", old_name,
1483                                                      strerror(errno));
1484                                 /* checkout */
1485                                 costate.base_dir = "";
1486                                 costate.base_dir_len = 0;
1487                                 costate.force = 0;
1488                                 costate.quiet = 0;
1489                                 costate.not_new = 0;
1490                                 costate.refresh_cache = 1;
1491                                 if (checkout_entry(active_cache[pos],
1492                                                    &costate,
1493                                                    NULL) ||
1494                                     lstat(old_name, &st))
1495                                         return -1;
1496                         }
1497
1498                         changed = ce_match_stat(active_cache[pos], &st, 1);
1499                         if (changed)
1500                                 return error("%s: does not match index",
1501                                              old_name);
1502                 }
1503                 else if (stat_ret < 0)
1504                         return error("%s: %s", old_name, strerror(errno));
1505
1506                 if (patch->is_new < 0)
1507                         patch->is_new = 0;
1508                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1509                 if (!patch->old_mode)
1510                         patch->old_mode = st.st_mode;
1511                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1512                         return error("%s: wrong type", old_name);
1513                 if (st.st_mode != patch->old_mode)
1514                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1515                                 old_name, st.st_mode, patch->old_mode);
1516         }
1517
1518         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1519                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1520                         return error("%s: already exists in index", new_name);
1521                 if (!lstat(new_name, &st))
1522                         return error("%s: already exists in working directory", new_name);
1523                 if (errno != ENOENT)
1524                         return error("%s: %s", new_name, strerror(errno));
1525                 if (!patch->new_mode) {
1526                         if (patch->is_new)
1527                                 patch->new_mode = S_IFREG | 0644;
1528                         else
1529                                 patch->new_mode = patch->old_mode;
1530                 }
1531         }
1532
1533         if (new_name && old_name) {
1534                 int same = !strcmp(old_name, new_name);
1535                 if (!patch->new_mode)
1536                         patch->new_mode = patch->old_mode;
1537                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1538                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1539                                 patch->new_mode, new_name, patch->old_mode,
1540                                 same ? "" : " of ", same ? "" : old_name);
1541         }
1542
1543         if (apply_data(patch, &st) < 0)
1544                 return error("%s: patch does not apply", name);
1545         return 0;
1546 }
1547
1548 static int check_patch_list(struct patch *patch)
1549 {
1550         int error = 0;
1551
1552         for (;patch ; patch = patch->next)
1553                 error |= check_patch(patch);
1554         return error;
1555 }
1556
1557 static inline int is_null_sha1(const unsigned char *sha1)
1558 {
1559         return !memcmp(sha1, null_sha1, 20);
1560 }
1561
1562 static void show_index_list(struct patch *list)
1563 {
1564         struct patch *patch;
1565
1566         /* Once we start supporting the reverse patch, it may be
1567          * worth showing the new sha1 prefix, but until then...
1568          */
1569         for (patch = list; patch; patch = patch->next) {
1570                 const unsigned char *sha1_ptr;
1571                 unsigned char sha1[20];
1572                 const char *name;
1573
1574                 name = patch->old_name ? patch->old_name : patch->new_name;
1575                 if (patch->is_new)
1576                         sha1_ptr = null_sha1;
1577                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1578                         die("sha1 information is lacking or useless (%s).",
1579                             name);
1580                 else
1581                         sha1_ptr = sha1;
1582
1583                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1584                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1585                         quote_c_style(name, NULL, stdout, 0);
1586                 else
1587                         fputs(name, stdout);
1588                 putchar(line_termination);
1589         }
1590 }
1591
1592 static void stat_patch_list(struct patch *patch)
1593 {
1594         int files, adds, dels;
1595
1596         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1597                 files++;
1598                 adds += patch->lines_added;
1599                 dels += patch->lines_deleted;
1600                 show_stats(patch);
1601         }
1602
1603         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1604 }
1605
1606 static void numstat_patch_list(struct patch *patch)
1607 {
1608         for ( ; patch; patch = patch->next) {
1609                 const char *name;
1610                 name = patch->old_name ? patch->old_name : patch->new_name;
1611                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1612                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1613                         quote_c_style(name, NULL, stdout, 0);
1614                 else
1615                         fputs(name, stdout);
1616                 putchar('\n');
1617         }
1618 }
1619
1620 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1621 {
1622         if (mode)
1623                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1624         else
1625                 printf(" %s %s\n", newdelete, name);
1626 }
1627
1628 static void show_mode_change(struct patch *p, int show_name)
1629 {
1630         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1631                 if (show_name)
1632                         printf(" mode change %06o => %06o %s\n",
1633                                p->old_mode, p->new_mode, p->new_name);
1634                 else
1635                         printf(" mode change %06o => %06o\n",
1636                                p->old_mode, p->new_mode);
1637         }
1638 }
1639
1640 static void show_rename_copy(struct patch *p)
1641 {
1642         const char *renamecopy = p->is_rename ? "rename" : "copy";
1643         const char *old, *new;
1644
1645         /* Find common prefix */
1646         old = p->old_name;
1647         new = p->new_name;
1648         while (1) {
1649                 const char *slash_old, *slash_new;
1650                 slash_old = strchr(old, '/');
1651                 slash_new = strchr(new, '/');
1652                 if (!slash_old ||
1653                     !slash_new ||
1654                     slash_old - old != slash_new - new ||
1655                     memcmp(old, new, slash_new - new))
1656                         break;
1657                 old = slash_old + 1;
1658                 new = slash_new + 1;
1659         }
1660         /* p->old_name thru old is the common prefix, and old and new
1661          * through the end of names are renames
1662          */
1663         if (old != p->old_name)
1664                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1665                        (int)(old - p->old_name), p->old_name,
1666                        old, new, p->score);
1667         else
1668                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1669                        p->old_name, p->new_name, p->score);
1670         show_mode_change(p, 0);
1671 }
1672
1673 static void summary_patch_list(struct patch *patch)
1674 {
1675         struct patch *p;
1676
1677         for (p = patch; p; p = p->next) {
1678                 if (p->is_new)
1679                         show_file_mode_name("create", p->new_mode, p->new_name);
1680                 else if (p->is_delete)
1681                         show_file_mode_name("delete", p->old_mode, p->old_name);
1682                 else {
1683                         if (p->is_rename || p->is_copy)
1684                                 show_rename_copy(p);
1685                         else {
1686                                 if (p->score) {
1687                                         printf(" rewrite %s (%d%%)\n",
1688                                                p->new_name, p->score);
1689                                         show_mode_change(p, 0);
1690                                 }
1691                                 else
1692                                         show_mode_change(p, 1);
1693                         }
1694                 }
1695         }
1696 }
1697
1698 static void patch_stats(struct patch *patch)
1699 {
1700         int lines = patch->lines_added + patch->lines_deleted;
1701
1702         if (lines > max_change)
1703                 max_change = lines;
1704         if (patch->old_name) {
1705                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1706                 if (!len)
1707                         len = strlen(patch->old_name);
1708                 if (len > max_len)
1709                         max_len = len;
1710         }
1711         if (patch->new_name) {
1712                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1713                 if (!len)
1714                         len = strlen(patch->new_name);
1715                 if (len > max_len)
1716                         max_len = len;
1717         }
1718 }
1719
1720 static void remove_file(struct patch *patch)
1721 {
1722         if (write_index) {
1723                 if (remove_file_from_cache(patch->old_name) < 0)
1724                         die("unable to remove %s from index", patch->old_name);
1725                 cache_tree_invalidate_path(active_cache_tree, patch->old_name);
1726         }
1727         unlink(patch->old_name);
1728 }
1729
1730 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1731 {
1732         struct stat st;
1733         struct cache_entry *ce;
1734         int namelen = strlen(path);
1735         unsigned ce_size = cache_entry_size(namelen);
1736
1737         if (!write_index)
1738                 return;
1739
1740         ce = xcalloc(1, ce_size);
1741         memcpy(ce->name, path, namelen);
1742         ce->ce_mode = create_ce_mode(mode);
1743         ce->ce_flags = htons(namelen);
1744         if (lstat(path, &st) < 0)
1745                 die("unable to stat newly created file %s", path);
1746         fill_stat_cache_info(ce, &st);
1747         if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
1748                 die("unable to create backing store for newly created file %s", path);
1749         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1750                 die("unable to add cache entry for %s", path);
1751 }
1752
1753 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1754 {
1755         int fd;
1756
1757         if (S_ISLNK(mode))
1758                 return symlink(buf, path);
1759         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1760         if (fd < 0)
1761                 return -1;
1762         while (size) {
1763                 int written = xwrite(fd, buf, size);
1764                 if (written < 0)
1765                         die("writing file %s: %s", path, strerror(errno));
1766                 if (!written)
1767                         die("out of space writing file %s", path);
1768                 buf += written;
1769                 size -= written;
1770         }
1771         if (close(fd) < 0)
1772                 die("closing file %s: %s", path, strerror(errno));
1773         return 0;
1774 }
1775
1776 /*
1777  * We optimistically assume that the directories exist,
1778  * which is true 99% of the time anyway. If they don't,
1779  * we create them and try again.
1780  */
1781 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1782 {
1783         if (!try_create_file(path, mode, buf, size))
1784                 return;
1785
1786         if (errno == ENOENT) {
1787                 if (safe_create_leading_directories(path))
1788                         return;
1789                 if (!try_create_file(path, mode, buf, size))
1790                         return;
1791         }
1792
1793         if (errno == EEXIST) {
1794                 unsigned int nr = getpid();
1795
1796                 for (;;) {
1797                         const char *newpath;
1798                         newpath = mkpath("%s~%u", path, nr);
1799                         if (!try_create_file(newpath, mode, buf, size)) {
1800                                 if (!rename(newpath, path))
1801                                         return;
1802                                 unlink(newpath);
1803                                 break;
1804                         }
1805                         if (errno != EEXIST)
1806                                 break;
1807                         ++nr;
1808                 }
1809         }
1810         die("unable to write file %s mode %o", path, mode);
1811 }
1812
1813 static void create_file(struct patch *patch)
1814 {
1815         char *path = patch->new_name;
1816         unsigned mode = patch->new_mode;
1817         unsigned long size = patch->resultsize;
1818         char *buf = patch->result;
1819
1820         if (!mode)
1821                 mode = S_IFREG | 0644;
1822         create_one_file(path, mode, buf, size);
1823         add_index_file(path, mode, buf, size);
1824         cache_tree_invalidate_path(active_cache_tree, path);
1825 }
1826
1827 static void write_out_one_result(struct patch *patch)
1828 {
1829         if (patch->is_delete > 0) {
1830                 remove_file(patch);
1831                 return;
1832         }
1833         if (patch->is_new > 0 || patch->is_copy) {
1834                 create_file(patch);
1835                 return;
1836         }
1837         /*
1838          * Rename or modification boils down to the same
1839          * thing: remove the old, write the new
1840          */
1841         remove_file(patch);
1842         create_file(patch);
1843 }
1844
1845 static void write_out_results(struct patch *list, int skipped_patch)
1846 {
1847         if (!list && !skipped_patch)
1848                 die("No changes");
1849
1850         while (list) {
1851                 write_out_one_result(list);
1852                 list = list->next;
1853         }
1854 }
1855
1856 static struct cache_file cache_file;
1857
1858 static struct excludes {
1859         struct excludes *next;
1860         const char *path;
1861 } *excludes;
1862
1863 static int use_patch(struct patch *p)
1864 {
1865         const char *pathname = p->new_name ? p->new_name : p->old_name;
1866         struct excludes *x = excludes;
1867         while (x) {
1868                 if (fnmatch(x->path, pathname, 0) == 0)
1869                         return 0;
1870                 x = x->next;
1871         }
1872         if (0 < prefix_length) {
1873                 int pathlen = strlen(pathname);
1874                 if (pathlen <= prefix_length ||
1875                     memcmp(prefix, pathname, prefix_length))
1876                         return 0;
1877         }
1878         return 1;
1879 }
1880
1881 static int apply_patch(int fd, const char *filename)
1882 {
1883         int newfd;
1884         unsigned long offset, size;
1885         char *buffer = read_patch_file(fd, &size);
1886         struct patch *list = NULL, **listp = &list;
1887         int skipped_patch = 0;
1888
1889         patch_input_file = filename;
1890         if (!buffer)
1891                 return -1;
1892         offset = 0;
1893         while (size > 0) {
1894                 struct patch *patch;
1895                 int nr;
1896
1897                 patch = xcalloc(1, sizeof(*patch));
1898                 nr = parse_chunk(buffer + offset, size, patch);
1899                 if (nr < 0)
1900                         break;
1901                 if (use_patch(patch)) {
1902                         patch_stats(patch);
1903                         *listp = patch;
1904                         listp = &patch->next;
1905                 } else {
1906                         /* perhaps free it a bit better? */
1907                         free(patch);
1908                         skipped_patch++;
1909                 }
1910                 offset += nr;
1911                 size -= nr;
1912         }
1913
1914         newfd = -1;
1915         if (whitespace_error && (new_whitespace == error_on_whitespace))
1916                 apply = 0;
1917
1918         write_index = check_index && apply;
1919         if (write_index)
1920                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1921         if (check_index) {
1922                 if (read_cache_1(active_cache_sha1) < 0)
1923                         die("unable to read index file");
1924                 active_cache_tree = read_cache_tree(active_cache_sha1);
1925         }
1926
1927         if ((check || apply) && check_patch_list(list) < 0)
1928                 exit(1);
1929
1930         if (apply)
1931                 write_out_results(list, skipped_patch);
1932
1933         if (write_index) {
1934                 if (write_cache_1(newfd, active_cache, active_nr,
1935                                   active_cache_sha1) ||
1936                     commit_index_file(&cache_file))
1937                         die("Unable to write new cachefile");
1938                 write_cache_tree(active_cache_sha1, active_cache_tree);
1939         }
1940
1941         if (show_index_info)
1942                 show_index_list(list);
1943
1944         if (diffstat)
1945                 stat_patch_list(list);
1946
1947         if (numstat)
1948                 numstat_patch_list(list);
1949
1950         if (summary)
1951                 summary_patch_list(list);
1952
1953         free(buffer);
1954         return 0;
1955 }
1956
1957 static int git_apply_config(const char *var, const char *value)
1958 {
1959         if (!strcmp(var, "apply.whitespace")) {
1960                 apply_default_whitespace = strdup(value);
1961                 return 0;
1962         }
1963         return git_default_config(var, value);
1964 }
1965
1966
1967 int main(int argc, char **argv)
1968 {
1969         int i;
1970         int read_stdin = 1;
1971         const char *whitespace_option = NULL;
1972
1973         for (i = 1; i < argc; i++) {
1974                 const char *arg = argv[i];
1975                 char *end;
1976                 int fd;
1977
1978                 if (!strcmp(arg, "-")) {
1979                         apply_patch(0, "<stdin>");
1980                         read_stdin = 0;
1981                         continue;
1982                 }
1983                 if (!strncmp(arg, "--exclude=", 10)) {
1984                         struct excludes *x = xmalloc(sizeof(*x));
1985                         x->path = arg + 10;
1986                         x->next = excludes;
1987                         excludes = x;
1988                         continue;
1989                 }
1990                 if (!strncmp(arg, "-p", 2)) {
1991                         p_value = atoi(arg + 2);
1992                         continue;
1993                 }
1994                 if (!strcmp(arg, "--no-add")) {
1995                         no_add = 1;
1996                         continue;
1997                 }
1998                 if (!strcmp(arg, "--stat")) {
1999                         apply = 0;
2000                         diffstat = 1;
2001                         continue;
2002                 }
2003                 if (!strcmp(arg, "--allow-binary-replacement")) {
2004                         allow_binary_replacement = 1;
2005                         continue;
2006                 }
2007                 if (!strcmp(arg, "--numstat")) {
2008                         apply = 0;
2009                         numstat = 1;
2010                         continue;
2011                 }
2012                 if (!strcmp(arg, "--summary")) {
2013                         apply = 0;
2014                         summary = 1;
2015                         continue;
2016                 }
2017                 if (!strcmp(arg, "--check")) {
2018                         apply = 0;
2019                         check = 1;
2020                         continue;
2021                 }
2022                 if (!strcmp(arg, "--index")) {
2023                         check_index = 1;
2024                         continue;
2025                 }
2026                 if (!strcmp(arg, "--apply")) {
2027                         apply = 1;
2028                         continue;
2029                 }
2030                 if (!strcmp(arg, "--index-info")) {
2031                         apply = 0;
2032                         show_index_info = 1;
2033                         continue;
2034                 }
2035                 if (!strcmp(arg, "-z")) {
2036                         line_termination = 0;
2037                         continue;
2038                 }
2039                 if (!strncmp(arg, "-C", 2)) {
2040                         p_context = strtoul(arg + 2, &end, 0);
2041                         if (*end != '\0')
2042                                 die("unrecognized context count '%s'", arg + 2);
2043                         continue;
2044                 }
2045                 if (!strncmp(arg, "--whitespace=", 13)) {
2046                         whitespace_option = arg + 13;
2047                         parse_whitespace_option(arg + 13);
2048                         continue;
2049                 }
2050
2051                 if (check_index && prefix_length < 0) {
2052                         prefix = setup_git_directory();
2053                         prefix_length = prefix ? strlen(prefix) : 0;
2054                         git_config(git_apply_config);
2055                         if (!whitespace_option && apply_default_whitespace)
2056                                 parse_whitespace_option(apply_default_whitespace);
2057                 }
2058                 if (0 < prefix_length)
2059                         arg = prefix_filename(prefix, prefix_length, arg);
2060
2061                 fd = open(arg, O_RDONLY);
2062                 if (fd < 0)
2063                         usage(apply_usage);
2064                 read_stdin = 0;
2065                 set_default_whitespace_mode(whitespace_option);
2066                 apply_patch(fd, arg);
2067                 close(fd);
2068         }
2069         set_default_whitespace_mode(whitespace_option);
2070         if (read_stdin)
2071                 apply_patch(0, "<stdin>");
2072         if (whitespace_error) {
2073                 if (squelch_whitespace_errors &&
2074                     squelch_whitespace_errors < whitespace_error) {
2075                         int squelched =
2076                                 whitespace_error - squelch_whitespace_errors;
2077                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
2078                                 squelched,
2079                                 squelched == 1 ? "" : "s");
2080                 }
2081                 if (new_whitespace == error_on_whitespace)
2082                         die("%d line%s add%s trailing whitespaces.",
2083                             whitespace_error,
2084                             whitespace_error == 1 ? "" : "s",
2085                             whitespace_error == 1 ? "s" : "");
2086                 if (applied_after_stripping)
2087                         fprintf(stderr, "warning: %d line%s applied after"
2088                                 " stripping trailing whitespaces.\n",
2089                                 applied_after_stripping,
2090                                 applied_after_stripping == 1 ? "" : "s");
2091                 else if (whitespace_error)
2092                         fprintf(stderr, "warning: %d line%s add%s trailing"
2093                                 " whitespaces.\n",
2094                                 whitespace_error,
2095                                 whitespace_error == 1 ? "" : "s",
2096                                 whitespace_error == 1 ? "s" : "");
2097         }
2098         return 0;
2099 }