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