apply.c

   1 /*
   2  * apply.c
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  *
   6  * This applies patches on top of some (arbitrary) version of the SCM.
   7  *
   8  */
   9 #include <fnmatch.h>
  10 #include "cache.h"
  11 #include "quote.h"
  12
  13 //  --check turns on checking that the working tree matches the
  14 //    files that are being modified, but doesn't apply the patch
  15 //  --stat does just a diffstat, and doesn't actually apply
  16 //  --numstat does numeric diffstat, and doesn't actually apply
  17 //  --index-info shows the old and new index info for paths if available.
  18 //
  19 static const char *prefix;
  20 static int prefix_length = -1;
  21
  22 static int p_value = 1;
  23 static int allow_binary_replacement = 0;
  24 static int check_index = 0;
  25 static int write_index = 0;
  26 static int diffstat = 0;
  27 static int numstat = 0;
  28 static int summary = 0;
  29 static int check = 0;
  30 static int apply = 1;
  31 static int no_add = 0;
  32 static int show_index_info = 0;
  33 static int line_termination = '\n';
  34 static const char apply_usage[] =
  35 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] <patch>...";
  36
  37 static enum whitespace_eol {
  38         nowarn_whitespace,
  39         warn_on_whitespace,
  40         error_on_whitespace,
  41         strip_whitespace,
  42 } new_whitespace = warn_on_whitespace;
  43 static int whitespace_error = 0;
  44 static int squelch_whitespace_errors = 5;
  45 static int applied_after_stripping = 0;
  46 static const char *patch_input_file = NULL;
  47
  48 static void parse_whitespace_option(const char *option)
  49 {
  50         if (!option) {
  51                 new_whitespace = warn_on_whitespace;
  52                 return;
  53         }
  54         if (!strcmp(option, "warn")) {
  55                 new_whitespace = warn_on_whitespace;
  56                 return;
  57         }
  58         if (!strcmp(option, "nowarn")) {
  59                 new_whitespace = nowarn_whitespace;
  60                 return;
  61         }
  62         if (!strcmp(option, "error")) {
  63                 new_whitespace = error_on_whitespace;
  64                 return;
  65         }
  66         if (!strcmp(option, "error-all")) {
  67                 new_whitespace = error_on_whitespace;
  68                 squelch_whitespace_errors = 0;
  69                 return;
  70         }
  71         if (!strcmp(option, "strip")) {
  72                 new_whitespace = strip_whitespace;
  73                 return;
  74         }
  75         die("unrecognized whitespace option '%s'", option);
  76 }
  77
  78 /*
  79  * For "diff-stat" like behaviour, we keep track of the biggest change
  80  * we've seen, and the longest filename. That allows us to do simple
  81  * scaling.
  82  */
  83 static int max_change, max_len;
  84
  85 /*
  86  * Various "current state", notably line numbers and what
  87  * file (and how) we're patching right now.. The "is_xxxx"
  88  * things are flags, where -1 means "don't know yet".
  89  */
  90 static int linenr = 1;
  91
  92 struct fragment {
  93         unsigned long oldpos, oldlines;
  94         unsigned long newpos, newlines;
  95         const char *patch;
  96         int size;
  97         struct fragment *next;
  98 };
  99
 100 struct patch {
 101         char *new_name, *old_name, *def_name;
 102         unsigned int old_mode, new_mode;
 103         int is_rename, is_copy, is_new, is_delete, is_binary;
 104         int lines_added, lines_deleted;
 105         int score;
 106         struct fragment *fragments;
 107         char *result;
 108         unsigned long resultsize;
 109         char old_sha1_prefix[41];
 110         char new_sha1_prefix[41];
 111         struct patch *next;
 112 };
 113
 114 #define CHUNKSIZE (8192)
 115 #define SLOP (16)
 116
 117 static void *read_patch_file(int fd, unsigned long *sizep)
 118 {
 119         unsigned long size = 0, alloc = CHUNKSIZE;
 120         void *buffer = xmalloc(alloc);
 121
 122         for (;;) {
 123                 int nr = alloc - size;
 124                 if (nr < 1024) {
 125                         alloc += CHUNKSIZE;
 126                         buffer = xrealloc(buffer, alloc);
 127                         nr = alloc - size;
 128                 }
 129                 nr = xread(fd, buffer + size, nr);
 130                 if (!nr)
 131                         break;
 132                 if (nr < 0)
 133                         die("git-apply: read returned %s", strerror(errno));
 134                 size += nr;
 135         }
 136         *sizep = size;
 137
 138         /*
 139          * Make sure that we have some slop in the buffer
 140          * so that we can do speculative "memcmp" etc, and
 141          * see to it that it is NUL-filled.
 142          */
 143         if (alloc < size + SLOP)
 144                 buffer = xrealloc(buffer, size + SLOP);
 145         memset(buffer + size, 0, SLOP);
 146         return buffer;
 147 }
 148
 149 static unsigned long linelen(const char *buffer, unsigned long size)
 150 {
 151         unsigned long len = 0;
 152         while (size--) {
 153                 len++;
 154                 if (*buffer++ == '\n')
 155                         break;
 156         }
 157         return len;
 158 }
 159
 160 static int is_dev_null(const char *str)
 161 {
 162         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 163 }
 164
 165 #define TERM_SPACE      1
 166 #define TERM_TAB        2
 167
 168 static int name_terminate(const char *name, int namelen, int c, int terminate)
 169 {
 170         if (c == ' ' && !(terminate & TERM_SPACE))
 171                 return 0;
 172         if (c == '\t' && !(terminate & TERM_TAB))
 173                 return 0;
 174
 175         return 1;
 176 }
 177
 178 static char * find_name(const char *line, char *def, int p_value, int terminate)
 179 {
 180         int len;
 181         const char *start = line;
 182         char *name;
 183
 184         if (*line == '"') {
 185                 /* Proposed "new-style" GNU patch/diff format; see
 186                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
 187                  */
 188                 name = unquote_c_style(line, NULL);
 189                 if (name) {
 190                         char *cp = name;
 191                         while (p_value) {
 192                                 cp = strchr(name, '/');
 193                                 if (!cp)
 194                                         break;
 195                                 cp++;
 196                                 p_value--;
 197                         }
 198                         if (cp) {
 199                                 /* name can later be freed, so we need
 200                                  * to memmove, not just return cp
 201                                  */
 202                                 memmove(name, cp, strlen(cp) + 1);
 203                                 free(def);
 204                                 return name;
 205                         }
 206                         else {
 207                                 free(name);
 208                                 name = NULL;
 209                         }
 210                 }
 211         }
 212
 213         for (;;) {
 214                 char c = *line;
 215
 216                 if (isspace(c)) {
 217                         if (c == '\n')
 218                                 break;
 219                         if (name_terminate(start, line-start, c, terminate))
 220                                 break;
 221                 }
 222                 line++;
 223                 if (c == '/' && !--p_value)
 224                         start = line;
 225         }
 226         if (!start)
 227                 return def;
 228         len = line - start;
 229         if (!len)
 230                 return def;
 231
 232         /*
 233          * Generally we prefer the shorter name, especially
 234          * if the other one is just a variation of that with
 235          * something else tacked on to the end (ie "file.orig"
 236          * or "file~").
 237          */
 238         if (def) {
 239                 int deflen = strlen(def);
 240                 if (deflen < len && !strncmp(start, def, deflen))
 241                         return def;
 242         }
 243
 244         name = xmalloc(len + 1);
 245         memcpy(name, start, len);
 246         name[len] = 0;
 247         free(def);
 248         return name;
 249 }
 250
 251 /*
 252  * Get the name etc info from the --/+++ lines of a traditional patch header
 253  *
 254  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 255  *
 256  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 257  * files, we can happily check the index for a match, but for creating a
 258  * new file we should try to match whatever "patch" does. I have no idea.
 259  */
 260 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 261 {
 262         char *name;
 263
 264         first += 4;     // skip "--- "
 265         second += 4;    // skip "+++ "
 266         if (is_dev_null(first)) {
 267                 patch->is_new = 1;
 268                 patch->is_delete = 0;
 269                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 270                 patch->new_name = name;
 271         } else if (is_dev_null(second)) {
 272                 patch->is_new = 0;
 273                 patch->is_delete = 1;
 274                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 275                 patch->old_name = name;
 276         } else {
 277                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 278                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 279                 patch->old_name = patch->new_name = name;
 280         }
 281         if (!name)
 282                 die("unable to find filename in patch at line %d", linenr);
 283 }
 284
 285 static int gitdiff_hdrend(const char *line, struct patch *patch)
 286 {
 287         return -1;
 288 }
 289
 290 /*
 291  * We're anal about diff header consistency, to make
 292  * sure that we don't end up having strange ambiguous
 293  * patches floating around.
 294  *
 295  * As a result, gitdiff_{old|new}name() will check
 296  * their names against any previous information, just
 297  * to make sure..
 298  */
 299 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 300 {
 301         if (!orig_name && !isnull)
 302                 return find_name(line, NULL, 1, 0);
 303
 304         if (orig_name) {
 305                 int len;
 306                 const char *name;
 307                 char *another;
 308                 name = orig_name;
 309                 len = strlen(name);
 310                 if (isnull)
 311                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 312                 another = find_name(line, NULL, 1, 0);
 313                 if (!another || memcmp(another, name, len))
 314                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 315                 free(another);
 316                 return orig_name;
 317         }
 318         else {
 319                 /* expect "/dev/null" */
 320                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 321                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
 322                 return NULL;
 323         }
 324 }
 325
 326 static int gitdiff_oldname(const char *line, struct patch *patch)
 327 {
 328         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 329         return 0;
 330 }
 331
 332 static int gitdiff_newname(const char *line, struct patch *patch)
 333 {
 334         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 335         return 0;
 336 }
 337
 338 static int gitdiff_oldmode(const char *line, struct patch *patch)
 339 {
 340         patch->old_mode = strtoul(line, NULL, 8);
 341         return 0;
 342 }
 343
 344 static int gitdiff_newmode(const char *line, struct patch *patch)
 345 {
 346         patch->new_mode = strtoul(line, NULL, 8);
 347         return 0;
 348 }
 349
 350 static int gitdiff_delete(const char *line, struct patch *patch)
 351 {
 352         patch->is_delete = 1;
 353         patch->old_name = patch->def_name;
 354         return gitdiff_oldmode(line, patch);
 355 }
 356
 357 static int gitdiff_newfile(const char *line, struct patch *patch)
 358 {
 359         patch->is_new = 1;
 360         patch->new_name = patch->def_name;
 361         return gitdiff_newmode(line, patch);
 362 }
 363
 364 static int gitdiff_copysrc(const char *line, struct patch *patch)
 365 {
 366         patch->is_copy = 1;
 367         patch->old_name = find_name(line, NULL, 0, 0);
 368         return 0;
 369 }
 370
 371 static int gitdiff_copydst(const char *line, struct patch *patch)
 372 {
 373         patch->is_copy = 1;
 374         patch->new_name = find_name(line, NULL, 0, 0);
 375         return 0;
 376 }
 377
 378 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 379 {
 380         patch->is_rename = 1;
 381         patch->old_name = find_name(line, NULL, 0, 0);
 382         return 0;
 383 }
 384
 385 static int gitdiff_renamedst(const char *line, struct patch *patch)
 386 {
 387         patch->is_rename = 1;
 388         patch->new_name = find_name(line, NULL, 0, 0);
 389         return 0;
 390 }
 391
 392 static int gitdiff_similarity(const char *line, struct patch *patch)
 393 {
 394         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 395                 patch->score = 0;
 396         return 0;
 397 }
 398
 399 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 400 {
 401         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 402                 patch->score = 0;
 403         return 0;
 404 }
 405
 406 static int gitdiff_index(const char *line, struct patch *patch)
 407 {
 408         /* index line is N hexadecimal, "..", N hexadecimal,
 409          * and optional space with octal mode.
 410          */
 411         const char *ptr, *eol;
 412         int len;
 413
 414         ptr = strchr(line, '.');
 415         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
 416                 return 0;
 417         len = ptr - line;
 418         memcpy(patch->old_sha1_prefix, line, len);
 419         patch->old_sha1_prefix[len] = 0;
 420
 421         line = ptr + 2;
 422         ptr = strchr(line, ' ');
 423         eol = strchr(line, '\n');
 424
 425         if (!ptr || eol < ptr)
 426                 ptr = eol;
 427         len = ptr - line;
 428
 429         if (40 < len)
 430                 return 0;
 431         memcpy(patch->new_sha1_prefix, line, len);
 432         patch->new_sha1_prefix[len] = 0;
 433         if (*ptr == ' ')
 434                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
 435         return 0;
 436 }
 437
 438 /*
 439  * This is normal for a diff that doesn't change anything: we'll fall through
 440  * into the next diff. Tell the parser to break out.
 441  */
 442 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 443 {
 444         return -1;
 445 }
 446
 447 static const char *stop_at_slash(const char *line, int llen)
 448 {
 449         int i;
 450
 451         for (i = 0; i < llen; i++) {
 452                 int ch = line[i];
 453                 if (ch == '/')
 454                         return line + i;
 455         }
 456         return NULL;
 457 }
 458
 459 /* This is to extract the same name that appears on "diff --git"
 460  * line.  We do not find and return anything if it is a rename
 461  * patch, and it is OK because we will find the name elsewhere.
 462  * We need to reliably find name only when it is mode-change only,
 463  * creation or deletion of an empty file.  In any of these cases,
 464  * both sides are the same name under a/ and b/ respectively.
 465  */
 466 static char *git_header_name(char *line, int llen)
 467 {
 468         int len;
 469         const char *name;
 470         const char *second = NULL;
 471
 472         line += strlen("diff --git ");
 473         llen -= strlen("diff --git ");
 474
 475         if (*line == '"') {
 476                 const char *cp;
 477                 char *first = unquote_c_style(line, &second);
 478                 if (!first)
 479                         return NULL;
 480
 481                 /* advance to the first slash */
 482                 cp = stop_at_slash(first, strlen(first));
 483                 if (!cp || cp == first) {
 484                         /* we do not accept absolute paths */
 485                 free_first_and_fail:
 486                         free(first);
 487                         return NULL;
 488                 }
 489                 len = strlen(cp+1);
 490                 memmove(first, cp+1, len+1); /* including NUL */
 491
 492                 /* second points at one past closing dq of name.
 493                  * find the second name.
 494                  */
 495                 while ((second < line + llen) && isspace(*second))
 496                         second++;
 497
 498                 if (line + llen <= second)
 499                         goto free_first_and_fail;
 500                 if (*second == '"') {
 501                         char *sp = unquote_c_style(second, NULL);
 502                         if (!sp)
 503                                 goto free_first_and_fail;
 504                         cp = stop_at_slash(sp, strlen(sp));
 505                         if (!cp || cp == sp) {
 506                         free_both_and_fail:
 507                                 free(sp);
 508                                 goto free_first_and_fail;
 509                         }
 510                         /* They must match, otherwise ignore */
 511                         if (strcmp(cp+1, first))
 512                                 goto free_both_and_fail;
 513                         free(sp);
 514                         return first;
 515                 }
 516
 517                 /* unquoted second */
 518                 cp = stop_at_slash(second, line + llen - second);
 519                 if (!cp || cp == second)
 520                         goto free_first_and_fail;
 521                 cp++;
 522                 if (line + llen - cp != len + 1 ||
 523                     memcmp(first, cp, len))
 524                         goto free_first_and_fail;
 525                 return first;
 526         }
 527
 528         /* unquoted first name */
 529         name = stop_at_slash(line, llen);
 530         if (!name || name == line)
 531                 return NULL;
 532
 533         name++;
 534
 535         /* since the first name is unquoted, a dq if exists must be
 536          * the beginning of the second name.
 537          */
 538         for (second = name; second < line + llen; second++) {
 539                 if (*second == '"') {
 540                         const char *cp = second;
 541                         const char *np;
 542                         char *sp = unquote_c_style(second, NULL);
 543
 544                         if (!sp)
 545                                 return NULL;
 546                         np = stop_at_slash(sp, strlen(sp));
 547                         if (!np || np == sp) {
 548                         free_second_and_fail:
 549                                 free(sp);
 550                                 return NULL;
 551                         }
 552                         np++;
 553                         len = strlen(np);
 554                         if (len < cp - name &&
 555                             !strncmp(np, name, len) &&
 556                             isspace(name[len])) {
 557                                 /* Good */
 558                                 memmove(sp, np, len + 1);
 559                                 return sp;
 560                         }
 561                         goto free_second_and_fail;
 562                 }
 563         }
 564
 565         /*
 566          * Accept a name only if it shows up twice, exactly the same
 567          * form.
 568          */
 569         for (len = 0 ; ; len++) {
 570                 char c = name[len];
 571
 572                 switch (c) {
 573                 default:
 574                         continue;
 575                 case '\n':
 576                         return NULL;
 577                 case '\t': case ' ':
 578                         second = name+len;
 579                         for (;;) {
 580                                 char c = *second++;
 581                                 if (c == '\n')
 582                                         return NULL;
 583                                 if (c == '/')
 584                                         break;
 585                         }
 586                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 587                                 char *ret = xmalloc(len + 1);
 588                                 memcpy(ret, name, len);
 589                                 ret[len] = 0;
 590                                 return ret;
 591                         }
 592                 }
 593         }
 594         return NULL;
 595 }
 596
 597 /* Verify that we recognize the lines following a git header */
 598 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 599 {
 600         unsigned long offset;
 601
 602         /* A git diff has explicit new/delete information, so we don't guess */
 603         patch->is_new = 0;
 604         patch->is_delete = 0;
 605
 606         /*
 607          * Some things may not have the old name in the
 608          * rest of the headers anywhere (pure mode changes,
 609          * or removing or adding empty files), so we get
 610          * the default name from the header.
 611          */
 612         patch->def_name = git_header_name(line, len);
 613
 614         line += len;
 615         size -= len;
 616         linenr++;
 617         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 618                 static const struct opentry {
 619                         const char *str;
 620                         int (*fn)(const char *, struct patch *);
 621                 } optable[] = {
 622                         { "@@ -", gitdiff_hdrend },
 623                         { "--- ", gitdiff_oldname },
 624                         { "+++ ", gitdiff_newname },
 625                         { "old mode ", gitdiff_oldmode },
 626                         { "new mode ", gitdiff_newmode },
 627                         { "deleted file mode ", gitdiff_delete },
 628                         { "new file mode ", gitdiff_newfile },
 629                         { "copy from ", gitdiff_copysrc },
 630                         { "copy to ", gitdiff_copydst },
 631                         { "rename old ", gitdiff_renamesrc },
 632                         { "rename new ", gitdiff_renamedst },
 633                         { "rename from ", gitdiff_renamesrc },
 634                         { "rename to ", gitdiff_renamedst },
 635                         { "similarity index ", gitdiff_similarity },
 636                         { "dissimilarity index ", gitdiff_dissimilarity },
 637                         { "index ", gitdiff_index },
 638                         { "", gitdiff_unrecognized },
 639                 };
 640                 int i;
 641
 642                 len = linelen(line, size);
 643                 if (!len || line[len-1] != '\n')
 644                         break;
 645                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 646                         const struct opentry *p = optable + i;
 647                         int oplen = strlen(p->str);
 648                         if (len < oplen || memcmp(p->str, line, oplen))
 649                                 continue;
 650                         if (p->fn(line + oplen, patch) < 0)
 651                                 return offset;
 652                         break;
 653                 }
 654         }
 655
 656         return offset;
 657 }
 658
 659 static int parse_num(const char *line, unsigned long *p)
 660 {
 661         char *ptr;
 662
 663         if (!isdigit(*line))
 664                 return 0;
 665         *p = strtoul(line, &ptr, 10);
 666         return ptr - line;
 667 }
 668
 669 static int parse_range(const char *line, int len, int offset, const char *expect,
 670                         unsigned long *p1, unsigned long *p2)
 671 {
 672         int digits, ex;
 673
 674         if (offset < 0 || offset >= len)
 675                 return -1;
 676         line += offset;
 677         len -= offset;
 678
 679         digits = parse_num(line, p1);
 680         if (!digits)
 681                 return -1;
 682
 683         offset += digits;
 684         line += digits;
 685         len -= digits;
 686
 687         *p2 = *p1;
 688         if (*line == ',') {
 689                 digits = parse_num(line+1, p2);
 690                 if (!digits)
 691                         return -1;
 692
 693                 offset += digits+1;
 694                 line += digits+1;
 695                 len -= digits+1;
 696         }
 697
 698         ex = strlen(expect);
 699         if (ex > len)
 700                 return -1;
 701         if (memcmp(line, expect, ex))
 702                 return -1;
 703
 704         return offset + ex;
 705 }
 706
 707 /*
 708  * Parse a unified diff fragment header of the
 709  * form "@@ -a,b +c,d @@"
 710  */
 711 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 712 {
 713         int offset;
 714
 715         if (!len || line[len-1] != '\n')
 716                 return -1;
 717
 718         /* Figure out the number of lines in a fragment */
 719         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 720         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 721
 722         return offset;
 723 }
 724
 725 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 726 {
 727         unsigned long offset, len;
 728
 729         patch->is_rename = patch->is_copy = 0;
 730         patch->is_new = patch->is_delete = -1;
 731         patch->old_mode = patch->new_mode = 0;
 732         patch->old_name = patch->new_name = NULL;
 733         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 734                 unsigned long nextlen;
 735
 736                 len = linelen(line, size);
 737                 if (!len)
 738                         break;
 739
 740                 /* Testing this early allows us to take a few shortcuts.. */
 741                 if (len < 6)
 742                         continue;
 743
 744                 /*
 745                  * Make sure we don't find any unconnected patch fragmants.
 746                  * That's a sign that we didn't find a header, and that a
 747                  * patch has become corrupted/broken up.
 748                  */
 749                 if (!memcmp("@@ -", line, 4)) {
 750                         struct fragment dummy;
 751                         if (parse_fragment_header(line, len, &dummy) < 0)
 752                                 continue;
 753                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
 754                 }
 755
 756                 if (size < len + 6)
 757                         break;
 758
 759                 /*
 760                  * Git patch? It might not have a real patch, just a rename
 761                  * or mode change, so we handle that specially
 762                  */
 763                 if (!memcmp("diff --git ", line, 11)) {
 764                         int git_hdr_len = parse_git_header(line, len, size, patch);
 765                         if (git_hdr_len <= len)
 766                                 continue;
 767                         if (!patch->old_name && !patch->new_name) {
 768                                 if (!patch->def_name)
 769                                         die("git diff header lacks filename information (line %d)", linenr);
 770                                 patch->old_name = patch->new_name = patch->def_name;
 771                         }
 772                         *hdrsize = git_hdr_len;
 773                         return offset;
 774                 }
 775
 776                 /** --- followed by +++ ? */
 777                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 778                         continue;
 779
 780                 /*
 781                  * We only accept unified patches, so we want it to
 782                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 783                  * minimum
 784                  */
 785                 nextlen = linelen(line + len, size - len);
 786                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 787                         continue;
 788
 789                 /* Ok, we'll consider it a patch */
 790                 parse_traditional_patch(line, line+len, patch);
 791                 *hdrsize = len + nextlen;
 792                 linenr += 2;
 793                 return offset;
 794         }
 795         return -1;
 796 }
 797
 798 /*
 799  * Parse a unified diff. Note that this really needs
 800  * to parse each fragment separately, since the only
 801  * way to know the difference between a "---" that is
 802  * part of a patch, and a "---" that starts the next
 803  * patch is to look at the line counts..
 804  */
 805 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 806 {
 807         int added, deleted;
 808         int len = linelen(line, size), offset;
 809         unsigned long oldlines, newlines;
 810
 811         offset = parse_fragment_header(line, len, fragment);
 812         if (offset < 0)
 813                 return -1;
 814         oldlines = fragment->oldlines;
 815         newlines = fragment->newlines;
 816
 817         if (patch->is_new < 0) {
 818                 patch->is_new =  !oldlines;
 819                 if (!oldlines)
 820                         patch->old_name = NULL;
 821         }
 822         if (patch->is_delete < 0) {
 823                 patch->is_delete = !newlines;
 824                 if (!newlines)
 825                         patch->new_name = NULL;
 826         }
 827
 828         if (patch->is_new != !oldlines)
 829                 return error("new file depends on old contents");
 830         if (patch->is_delete != !newlines) {
 831                 if (newlines)
 832                         return error("deleted file still has contents");
 833                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
 834         }
 835
 836         /* Parse the thing.. */
 837         line += len;
 838         size -= len;
 839         linenr++;
 840         added = deleted = 0;
 841         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 842                 if (!oldlines && !newlines)
 843                         break;
 844                 len = linelen(line, size);
 845                 if (!len || line[len-1] != '\n')
 846                         return -1;
 847                 switch (*line) {
 848                 default:
 849                         return -1;
 850                 case ' ':
 851                         oldlines--;
 852                         newlines--;
 853                         break;
 854                 case '-':
 855                         deleted++;
 856                         oldlines--;
 857                         break;
 858                 case '+':
 859                         /*
 860                          * We know len is at least two, since we have a '+' and
 861                          * we checked that the last character was a '\n' above.
 862                          * That is, an addition of an empty line would check
 863                          * the '+' here.  Sneaky...
 864                          */
 865                         if ((new_whitespace != nowarn_whitespace) &&
 866                             isspace(line[len-2])) {
 867                                 whitespace_error++;
 868                                 if (squelch_whitespace_errors &&
 869                                     squelch_whitespace_errors <
 870                                     whitespace_error)
 871                                         ;
 872                                 else {
 873                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
 874                                                 patch_input_file,
 875                                                 linenr, len-2, line+1);
 876                                 }
 877                         }
 878                         added++;
 879                         newlines--;
 880                         break;
 881
 882                 /* We allow "\ No newline at end of file". Depending
 883                  * on locale settings when the patch was produced we
 884                  * don't know what this line looks like. The only
 885                  * thing we do know is that it begins with "\ ".
 886                  * Checking for 12 is just for sanity check -- any
 887                  * l10n of "\ No newline..." is at least that long.
 888                  */
 889                 case '\\':
 890                         if (len < 12 || memcmp(line, "\\ ", 2))
 891                                 return -1;
 892                         break;
 893                 }
 894         }
 895         /* If a fragment ends with an incomplete line, we failed to include
 896          * it in the above loop because we hit oldlines == newlines == 0
 897          * before seeing it.
 898          */
 899         if (12 < size && !memcmp(line, "\\ ", 2))
 900                 offset += linelen(line, size);
 901
 902         patch->lines_added += added;
 903         patch->lines_deleted += deleted;
 904         return offset;
 905 }
 906
 907 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 908 {
 909         unsigned long offset = 0;
 910         struct fragment **fragp = &patch->fragments;
 911
 912         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 913                 struct fragment *fragment;
 914                 int len;
 915
 916                 fragment = xmalloc(sizeof(*fragment));
 917                 memset(fragment, 0, sizeof(*fragment));
 918                 len = parse_fragment(line, size, patch, fragment);
 919                 if (len <= 0)
 920                         die("corrupt patch at line %d", linenr);
 921
 922                 fragment->patch = line;
 923                 fragment->size = len;
 924
 925                 *fragp = fragment;
 926                 fragp = &fragment->next;
 927
 928                 offset += len;
 929                 line += len;
 930                 size -= len;
 931         }
 932         return offset;
 933 }
 934
 935 static inline int metadata_changes(struct patch *patch)
 936 {
 937         return  patch->is_rename > 0 ||
 938                 patch->is_copy > 0 ||
 939                 patch->is_new > 0 ||
 940                 patch->is_delete ||
 941                 (patch->old_mode && patch->new_mode &&
 942                  patch->old_mode != patch->new_mode);
 943 }
 944
 945 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 946 {
 947         int hdrsize, patchsize;
 948         int offset = find_header(buffer, size, &hdrsize, patch);
 949
 950         if (offset < 0)
 951                 return offset;
 952
 953         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 954
 955         if (!patchsize) {
 956                 static const char *binhdr[] = {
 957                         "Binary files ",
 958                         "Files ",
 959                         NULL,
 960                 };
 961                 int i;
 962                 int hd = hdrsize + offset;
 963                 unsigned long llen = linelen(buffer + hd, size - hd);
 964
 965                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
 966                         for (i = 0; binhdr[i]; i++) {
 967                                 int len = strlen(binhdr[i]);
 968                                 if (len < size - hd &&
 969                                     !memcmp(binhdr[i], buffer + hd, len)) {
 970                                         patch->is_binary = 1;
 971                                         break;
 972                                 }
 973                         }
 974
 975                 /* Empty patch cannot be applied if:
 976                  * - it is a binary patch and we do not do binary_replace, or
 977                  * - text patch without metadata change
 978                  */
 979                 if ((apply || check) &&
 980                     (patch->is_binary
 981                      ? !allow_binary_replacement
 982                      : !metadata_changes(patch)))
 983                         die("patch with only garbage at line %d", linenr);
 984         }
 985
 986         return offset + hdrsize + patchsize;
 987 }
 988
 989 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 990 static const char minuses[]= "----------------------------------------------------------------------";
 991
 992 static void show_stats(struct patch *patch)
 993 {
 994         const char *prefix = "";
 995         char *name = patch->new_name;
 996         char *qname = NULL;
 997         int len, max, add, del, total;
 998
 999         if (!name)
1000                 name = patch->old_name;
1001
1002         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1003                 qname = xmalloc(len + 1);
1004                 quote_c_style(name, qname, NULL, 0);
1005                 name = qname;
1006         }
1007
1008         /*
1009          * "scale" the filename
1010          */
1011         len = strlen(name);
1012         max = max_len;
1013         if (max > 50)
1014                 max = 50;
1015         if (len > max) {
1016                 char *slash;
1017                 prefix = "...";
1018                 max -= 3;
1019                 name += len - max;
1020                 slash = strchr(name, '/');
1021                 if (slash)
1022                         name = slash;
1023         }
1024         len = max;
1025
1026         /*
1027          * scale the add/delete
1028          */
1029         max = max_change;
1030         if (max + len > 70)
1031                 max = 70 - len;
1032
1033         add = patch->lines_added;
1034         del = patch->lines_deleted;
1035         total = add + del;
1036
1037         if (max_change > 0) {
1038                 total = (total * max + max_change / 2) / max_change;
1039                 add = (add * max + max_change / 2) / max_change;
1040                 del = total - add;
1041         }
1042         if (patch->is_binary)
1043                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1044         else
1045                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1046                        len, name, patch->lines_added + patch->lines_deleted,
1047                        add, pluses, del, minuses);
1048         if (qname)
1049                 free(qname);
1050 }
1051
1052 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1053 {
1054         int fd;
1055         unsigned long got;
1056
1057         switch (st->st_mode & S_IFMT) {
1058         case S_IFLNK:
1059                 return readlink(path, buf, size);
1060         case S_IFREG:
1061                 fd = open(path, O_RDONLY);
1062                 if (fd < 0)
1063                         return error("unable to open %s", path);
1064                 got = 0;
1065                 for (;;) {
1066                         int ret = xread(fd, buf + got, size - got);
1067                         if (ret <= 0)
1068                                 break;
1069                         got += ret;
1070                 }
1071                 close(fd);
1072                 return got;
1073
1074         default:
1075                 return -1;
1076         }
1077 }
1078
1079 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1080 {
1081         int i;
1082         unsigned long start, backwards, forwards;
1083
1084         if (fragsize > size)
1085                 return -1;
1086
1087         start = 0;
1088         if (line > 1) {
1089                 unsigned long offset = 0;
1090                 i = line-1;
1091                 while (offset + fragsize <= size) {
1092                         if (buf[offset++] == '\n') {
1093                                 start = offset;
1094                                 if (!--i)
1095                                         break;
1096                         }
1097                 }
1098         }
1099
1100         /* Exact line number? */
1101         if (!memcmp(buf + start, fragment, fragsize))
1102                 return start;
1103
1104         /*
1105          * There's probably some smart way to do this, but I'll leave
1106          * that to the smart and beautiful people. I'm simple and stupid.
1107          */
1108         backwards = start;
1109         forwards = start;
1110         for (i = 0; ; i++) {
1111                 unsigned long try;
1112                 int n;
1113
1114                 /* "backward" */
1115                 if (i & 1) {
1116                         if (!backwards) {
1117                                 if (forwards + fragsize > size)
1118                                         break;
1119                                 continue;
1120                         }
1121                         do {
1122                                 --backwards;
1123                         } while (backwards && buf[backwards-1] != '\n');
1124                         try = backwards;
1125                 } else {
1126                         while (forwards + fragsize <= size) {
1127                                 if (buf[forwards++] == '\n')
1128                                         break;
1129                         }
1130                         try = forwards;
1131                 }
1132
1133                 if (try + fragsize > size)
1134                         continue;
1135                 if (memcmp(buf + try, fragment, fragsize))
1136                         continue;
1137                 n = (i >> 1)+1;
1138                 if (i & 1)
1139                         n = -n;
1140                 return try;
1141         }
1142
1143         /*
1144          * We should start searching forward and backward.
1145          */
1146         return -1;
1147 }
1148
1149 struct buffer_desc {
1150         char *buffer;
1151         unsigned long size;
1152         unsigned long alloc;
1153 };
1154
1155 static int apply_line(char *output, const char *patch, int plen)
1156 {
1157         /* plen is number of bytes to be copied from patch,
1158          * starting at patch+1 (patch[0] is '+').  Typically
1159          * patch[plen] is '\n'.
1160          */
1161         int add_nl_to_tail = 0;
1162         if ((new_whitespace == strip_whitespace) &&
1163             1 < plen && isspace(patch[plen-1])) {
1164                 if (patch[plen] == '\n')
1165                         add_nl_to_tail = 1;
1166                 plen--;
1167                 while (0 < plen && isspace(patch[plen]))
1168                         plen--;
1169                 applied_after_stripping++;
1170         }
1171         memcpy(output, patch + 1, plen);
1172         if (add_nl_to_tail)
1173                 output[plen++] = '\n';
1174         return plen;
1175 }
1176
1177 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1178 {
1179         char *buf = desc->buffer;
1180         const char *patch = frag->patch;
1181         int offset, size = frag->size;
1182         char *old = xmalloc(size);
1183         char *new = xmalloc(size);
1184         int oldsize = 0, newsize = 0;
1185
1186         while (size > 0) {
1187                 int len = linelen(patch, size);
1188                 int plen;
1189
1190                 if (!len)
1191                         break;
1192
1193                 /*
1194                  * "plen" is how much of the line we should use for
1195                  * the actual patch data. Normally we just remove the
1196                  * first character on the line, but if the line is
1197                  * followed by "\ No newline", then we also remove the
1198                  * last one (which is the newline, of course).
1199                  */
1200                 plen = len-1;
1201                 if (len < size && patch[len] == '\\')
1202                         plen--;
1203                 switch (*patch) {
1204                 case ' ':
1205                 case '-':
1206                         memcpy(old + oldsize, patch + 1, plen);
1207                         oldsize += plen;
1208                         if (*patch == '-')
1209                                 break;
1210                 /* Fall-through for ' ' */
1211                 case '+':
1212                         if (*patch != '+' || !no_add)
1213                                 newsize += apply_line(new + newsize, patch,
1214                                                       plen);
1215                         break;
1216                 case '@': case '\\':
1217                         /* Ignore it, we already handled it */
1218                         break;
1219                 default:
1220                         return -1;
1221                 }
1222                 patch += len;
1223                 size -= len;
1224         }
1225
1226 #ifdef NO_ACCURATE_DIFF
1227         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1228                         newsize > 0 && new[newsize - 1] == '\n') {
1229                 oldsize--;
1230                 newsize--;
1231         }
1232 #endif
1233
1234         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1235         if (offset >= 0) {
1236                 int diff = newsize - oldsize;
1237                 unsigned long size = desc->size + diff;
1238                 unsigned long alloc = desc->alloc;
1239
1240                 if (size > alloc) {
1241                         alloc = size + 8192;
1242                         desc->alloc = alloc;
1243                         buf = xrealloc(buf, alloc);
1244                         desc->buffer = buf;
1245                 }
1246                 desc->size = size;
1247                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1248                 memcpy(buf + offset, new, newsize);
1249                 offset = 0;
1250         }
1251
1252         free(old);
1253         free(new);
1254         return offset;
1255 }
1256
1257 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1258 {
1259         struct fragment *frag = patch->fragments;
1260         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1261
1262         if (patch->is_binary) {
1263                 unsigned char sha1[20];
1264
1265                 if (!allow_binary_replacement)
1266                         return error("cannot apply binary patch to '%s' "
1267                                      "without --allow-binary-replacement",
1268                                      name);
1269
1270                 /* For safety, we require patch index line to contain
1271                  * full 40-byte textual SHA1 for old and new, at least for now.
1272                  */
1273                 if (strlen(patch->old_sha1_prefix) != 40 ||
1274                     strlen(patch->new_sha1_prefix) != 40 ||
1275                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1276                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1277                         return error("cannot apply binary patch to '%s' "
1278                                      "without full index line", name);
1279
1280                 if (patch->old_name) {
1281                         unsigned char hdr[50];
1282                         int hdrlen;
1283
1284                         /* See if the old one matches what the patch
1285                          * applies to.
1286                          */
1287                         write_sha1_file_prepare(desc->buffer, desc->size,
1288                                                 "blob", sha1, hdr, &hdrlen);
1289                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1290                                 return error("the patch applies to '%s' (%s), "
1291                                              "which does not match the "
1292                                              "current contents.",
1293                                              name, sha1_to_hex(sha1));
1294                 }
1295                 else {
1296                         /* Otherwise, the old one must be empty. */
1297                         if (desc->size)
1298                                 return error("the patch applies to an empty "
1299                                              "'%s' but it is not empty", name);
1300                 }
1301
1302                 /* For now, we do not record post-image data in the patch,
1303                  * and require the object already present in the recipient's
1304                  * object database.
1305                  */
1306                 if (desc->buffer) {
1307                         free(desc->buffer);
1308                         desc->alloc = desc->size = 0;
1309                 }
1310                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1311
1312                 if (memcmp(sha1, null_sha1, 20)) {
1313                         char type[10];
1314                         unsigned long size;
1315
1316                         desc->buffer = read_sha1_file(sha1, type, &size);
1317                         if (!desc->buffer)
1318                                 return error("the necessary postimage %s for "
1319                                              "'%s' does not exist",
1320                                              patch->new_sha1_prefix, name);
1321                         desc->alloc = desc->size = size;
1322                 }
1323
1324                 return 0;
1325         }
1326
1327         while (frag) {
1328                 if (apply_one_fragment(desc, frag) < 0)
1329                         return error("patch failed: %s:%ld",
1330                                      name, frag->oldpos);
1331                 frag = frag->next;
1332         }
1333         return 0;
1334 }
1335
1336 static int apply_data(struct patch *patch, struct stat *st)
1337 {
1338         char *buf;
1339         unsigned long size, alloc;
1340         struct buffer_desc desc;
1341
1342         size = 0;
1343         alloc = 0;
1344         buf = NULL;
1345         if (patch->old_name) {
1346                 size = st->st_size;
1347                 alloc = size + 8192;
1348                 buf = xmalloc(alloc);
1349                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1350                         return error("read of %s failed", patch->old_name);
1351         }
1352
1353         desc.size = size;
1354         desc.alloc = alloc;
1355         desc.buffer = buf;
1356         if (apply_fragments(&desc, patch) < 0)
1357                 return -1;
1358         patch->result = desc.buffer;
1359         patch->resultsize = desc.size;
1360
1361         if (patch->is_delete && patch->resultsize)
1362                 return error("removal patch leaves file contents");
1363
1364         return 0;
1365 }
1366
1367 static int check_patch(struct patch *patch)
1368 {
1369         struct stat st;
1370         const char *old_name = patch->old_name;
1371         const char *new_name = patch->new_name;
1372         const char *name = old_name ? old_name : new_name;
1373
1374         if (old_name) {
1375                 int changed;
1376                 int stat_ret = lstat(old_name, &st);
1377
1378                 if (check_index) {
1379                         int pos = cache_name_pos(old_name, strlen(old_name));
1380                         if (pos < 0)
1381                                 return error("%s: does not exist in index",
1382                                              old_name);
1383                         if (stat_ret < 0) {
1384                                 struct checkout costate;
1385                                 if (errno != ENOENT)
1386                                         return error("%s: %s", old_name,
1387                                                      strerror(errno));
1388                                 /* checkout */
1389                                 costate.base_dir = "";
1390                                 costate.base_dir_len = 0;
1391                                 costate.force = 0;
1392                                 costate.quiet = 0;
1393                                 costate.not_new = 0;
1394                                 costate.refresh_cache = 1;
1395                                 if (checkout_entry(active_cache[pos],
1396                                                    &costate) ||
1397                                     lstat(old_name, &st))
1398                                         return -1;
1399                         }
1400
1401                         changed = ce_match_stat(active_cache[pos], &st, 1);
1402                         if (changed)
1403                                 return error("%s: does not match index",
1404                                              old_name);
1405                 }
1406                 else if (stat_ret < 0)
1407                         return error("%s: %s", old_name, strerror(errno));
1408
1409                 if (patch->is_new < 0)
1410                         patch->is_new = 0;
1411                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1412                 if (!patch->old_mode)
1413                         patch->old_mode = st.st_mode;
1414                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1415                         return error("%s: wrong type", old_name);
1416                 if (st.st_mode != patch->old_mode)
1417                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1418                                 old_name, st.st_mode, patch->old_mode);
1419         }
1420
1421         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1422                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1423                         return error("%s: already exists in index", new_name);
1424                 if (!lstat(new_name, &st))
1425                         return error("%s: already exists in working directory", new_name);
1426                 if (errno != ENOENT)
1427                         return error("%s: %s", new_name, strerror(errno));
1428                 if (!patch->new_mode) {
1429                         if (patch->is_new)
1430                                 patch->new_mode = S_IFREG | 0644;
1431                         else
1432                                 patch->new_mode = patch->old_mode;
1433                 }
1434         }
1435
1436         if (new_name && old_name) {
1437                 int same = !strcmp(old_name, new_name);
1438                 if (!patch->new_mode)
1439                         patch->new_mode = patch->old_mode;
1440                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1441                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1442                                 patch->new_mode, new_name, patch->old_mode,
1443                                 same ? "" : " of ", same ? "" : old_name);
1444         }
1445
1446         if (apply_data(patch, &st) < 0)
1447                 return error("%s: patch does not apply", name);
1448         return 0;
1449 }
1450
1451 static int check_patch_list(struct patch *patch)
1452 {
1453         int error = 0;
1454
1455         for (;patch ; patch = patch->next)
1456                 error |= check_patch(patch);
1457         return error;
1458 }
1459
1460 static inline int is_null_sha1(const unsigned char *sha1)
1461 {
1462         return !memcmp(sha1, null_sha1, 20);
1463 }
1464
1465 static void show_index_list(struct patch *list)
1466 {
1467         struct patch *patch;
1468
1469         /* Once we start supporting the reverse patch, it may be
1470          * worth showing the new sha1 prefix, but until then...
1471          */
1472         for (patch = list; patch; patch = patch->next) {
1473                 const unsigned char *sha1_ptr;
1474                 unsigned char sha1[20];
1475                 const char *name;
1476
1477                 name = patch->old_name ? patch->old_name : patch->new_name;
1478                 if (patch->is_new)
1479                         sha1_ptr = null_sha1;
1480                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1481                         die("sha1 information is lacking or useless (%s).",
1482                             name);
1483                 else
1484                         sha1_ptr = sha1;
1485
1486                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1487                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1488                         quote_c_style(name, NULL, stdout, 0);
1489                 else
1490                         fputs(name, stdout);
1491                 putchar(line_termination);
1492         }
1493 }
1494
1495 static void stat_patch_list(struct patch *patch)
1496 {
1497         int files, adds, dels;
1498
1499         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1500                 files++;
1501                 adds += patch->lines_added;
1502                 dels += patch->lines_deleted;
1503                 show_stats(patch);
1504         }
1505
1506         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1507 }
1508
1509 static void numstat_patch_list(struct patch *patch)
1510 {
1511         for ( ; patch; patch = patch->next) {
1512                 const char *name;
1513                 name = patch->old_name ? patch->old_name : patch->new_name;
1514                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1515                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1516                         quote_c_style(name, NULL, stdout, 0);
1517                 else
1518                         fputs(name, stdout);
1519                 putchar('\n');
1520         }
1521 }
1522
1523 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1524 {
1525         if (mode)
1526                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1527         else
1528                 printf(" %s %s\n", newdelete, name);
1529 }
1530
1531 static void show_mode_change(struct patch *p, int show_name)
1532 {
1533         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1534                 if (show_name)
1535                         printf(" mode change %06o => %06o %s\n",
1536                                p->old_mode, p->new_mode, p->new_name);
1537                 else
1538                         printf(" mode change %06o => %06o\n",
1539                                p->old_mode, p->new_mode);
1540         }
1541 }
1542
1543 static void show_rename_copy(struct patch *p)
1544 {
1545         const char *renamecopy = p->is_rename ? "rename" : "copy";
1546         const char *old, *new;
1547
1548         /* Find common prefix */
1549         old = p->old_name;
1550         new = p->new_name;
1551         while (1) {
1552                 const char *slash_old, *slash_new;
1553                 slash_old = strchr(old, '/');
1554                 slash_new = strchr(new, '/');
1555                 if (!slash_old ||
1556                     !slash_new ||
1557                     slash_old - old != slash_new - new ||
1558                     memcmp(old, new, slash_new - new))
1559                         break;
1560                 old = slash_old + 1;
1561                 new = slash_new + 1;
1562         }
1563         /* p->old_name thru old is the common prefix, and old and new
1564          * through the end of names are renames
1565          */
1566         if (old != p->old_name)
1567                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1568                        (int)(old - p->old_name), p->old_name,
1569                        old, new, p->score);
1570         else
1571                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1572                        p->old_name, p->new_name, p->score);
1573         show_mode_change(p, 0);
1574 }
1575
1576 static void summary_patch_list(struct patch *patch)
1577 {
1578         struct patch *p;
1579
1580         for (p = patch; p; p = p->next) {
1581                 if (p->is_new)
1582                         show_file_mode_name("create", p->new_mode, p->new_name);
1583                 else if (p->is_delete)
1584                         show_file_mode_name("delete", p->old_mode, p->old_name);
1585                 else {
1586                         if (p->is_rename || p->is_copy)
1587                                 show_rename_copy(p);
1588                         else {
1589                                 if (p->score) {
1590                                         printf(" rewrite %s (%d%%)\n",
1591                                                p->new_name, p->score);
1592                                         show_mode_change(p, 0);
1593                                 }
1594                                 else
1595                                         show_mode_change(p, 1);
1596                         }
1597                 }
1598         }
1599 }
1600
1601 static void patch_stats(struct patch *patch)
1602 {
1603         int lines = patch->lines_added + patch->lines_deleted;
1604
1605         if (lines > max_change)
1606                 max_change = lines;
1607         if (patch->old_name) {
1608                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1609                 if (!len)
1610                         len = strlen(patch->old_name);
1611                 if (len > max_len)
1612                         max_len = len;
1613         }
1614         if (patch->new_name) {
1615                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1616                 if (!len)
1617                         len = strlen(patch->new_name);
1618                 if (len > max_len)
1619                         max_len = len;
1620         }
1621 }
1622
1623 static void remove_file(struct patch *patch)
1624 {
1625         if (write_index) {
1626                 if (remove_file_from_cache(patch->old_name) < 0)
1627                         die("unable to remove %s from index", patch->old_name);
1628         }
1629         unlink(patch->old_name);
1630 }
1631
1632 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1633 {
1634         struct stat st;
1635         struct cache_entry *ce;
1636         int namelen = strlen(path);
1637         unsigned ce_size = cache_entry_size(namelen);
1638
1639         if (!write_index)
1640                 return;
1641
1642         ce = xmalloc(ce_size);
1643         memset(ce, 0, ce_size);
1644         memcpy(ce->name, path, namelen);
1645         ce->ce_mode = create_ce_mode(mode);
1646         ce->ce_flags = htons(namelen);
1647         if (lstat(path, &st) < 0)
1648                 die("unable to stat newly created file %s", path);
1649         fill_stat_cache_info(ce, &st);
1650         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1651                 die("unable to create backing store for newly created file %s", path);
1652         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1653                 die("unable to add cache entry for %s", path);
1654 }
1655
1656 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1657 {
1658         int fd;
1659
1660         if (S_ISLNK(mode))
1661                 return symlink(buf, path);
1662         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1663         if (fd < 0)
1664                 return -1;
1665         while (size) {
1666                 int written = xwrite(fd, buf, size);
1667                 if (written < 0)
1668                         die("writing file %s: %s", path, strerror(errno));
1669                 if (!written)
1670                         die("out of space writing file %s", path);
1671                 buf += written;
1672                 size -= written;
1673         }
1674         if (close(fd) < 0)
1675                 die("closing file %s: %s", path, strerror(errno));
1676         return 0;
1677 }
1678
1679 /*
1680  * We optimistically assume that the directories exist,
1681  * which is true 99% of the time anyway. If they don't,
1682  * we create them and try again.
1683  */
1684 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1685 {
1686         if (!try_create_file(path, mode, buf, size))
1687                 return;
1688
1689         if (errno == ENOENT) {
1690                 if (safe_create_leading_directories(path))
1691                         return;
1692                 if (!try_create_file(path, mode, buf, size))
1693                         return;
1694         }
1695
1696         if (errno == EEXIST) {
1697                 unsigned int nr = getpid();
1698
1699                 for (;;) {
1700                         const char *newpath;
1701                         newpath = mkpath("%s~%u", path, nr);
1702                         if (!try_create_file(newpath, mode, buf, size)) {
1703                                 if (!rename(newpath, path))
1704                                         return;
1705                                 unlink(newpath);
1706                                 break;
1707                         }
1708                         if (errno != EEXIST)
1709                                 break;
1710                         ++nr;
1711                 }
1712         }
1713         die("unable to write file %s mode %o", path, mode);
1714 }
1715
1716 static void create_file(struct patch *patch)
1717 {
1718         char *path = patch->new_name;
1719         unsigned mode = patch->new_mode;
1720         unsigned long size = patch->resultsize;
1721         char *buf = patch->result;
1722
1723         if (!mode)
1724                 mode = S_IFREG | 0644;
1725         create_one_file(path, mode, buf, size);
1726         add_index_file(path, mode, buf, size);
1727 }
1728
1729 static void write_out_one_result(struct patch *patch)
1730 {
1731         if (patch->is_delete > 0) {
1732                 remove_file(patch);
1733                 return;
1734         }
1735         if (patch->is_new > 0 || patch->is_copy) {
1736                 create_file(patch);
1737                 return;
1738         }
1739         /*
1740          * Rename or modification boils down to the same
1741          * thing: remove the old, write the new
1742          */
1743         remove_file(patch);
1744         create_file(patch);
1745 }
1746
1747 static void write_out_results(struct patch *list, int skipped_patch)
1748 {
1749         if (!list && !skipped_patch)
1750                 die("No changes");
1751
1752         while (list) {
1753                 write_out_one_result(list);
1754                 list = list->next;
1755         }
1756 }
1757
1758 static struct cache_file cache_file;
1759
1760 static struct excludes {
1761         struct excludes *next;
1762         const char *path;
1763 } *excludes;
1764
1765 static int use_patch(struct patch *p)
1766 {
1767         const char *pathname = p->new_name ? p->new_name : p->old_name;
1768         struct excludes *x = excludes;
1769         while (x) {
1770                 if (fnmatch(x->path, pathname, 0) == 0)
1771                         return 0;
1772                 x = x->next;
1773         }
1774         if (0 < prefix_length) {
1775                 int pathlen = strlen(pathname);
1776                 if (pathlen <= prefix_length ||
1777                     memcmp(prefix, pathname, prefix_length))
1778                         return 0;
1779         }
1780         return 1;
1781 }
1782
1783 static int apply_patch(int fd, const char *filename)
1784 {
1785         int newfd;
1786         unsigned long offset, size;
1787         char *buffer = read_patch_file(fd, &size);
1788         struct patch *list = NULL, **listp = &list;
1789         int skipped_patch = 0;
1790
1791         patch_input_file = filename;
1792         if (!buffer)
1793                 return -1;
1794         offset = 0;
1795         while (size > 0) {
1796                 struct patch *patch;
1797                 int nr;
1798
1799                 patch = xmalloc(sizeof(*patch));
1800                 memset(patch, 0, sizeof(*patch));
1801                 nr = parse_chunk(buffer + offset, size, patch);
1802                 if (nr < 0)
1803                         break;
1804                 if (use_patch(patch)) {
1805                         patch_stats(patch);
1806                         *listp = patch;
1807                         listp = &patch->next;
1808                 } else {
1809                         /* perhaps free it a bit better? */
1810                         free(patch);
1811                         skipped_patch++;
1812                 }
1813                 offset += nr;
1814                 size -= nr;
1815         }
1816
1817         newfd = -1;
1818         if (whitespace_error && (new_whitespace == error_on_whitespace))
1819                 apply = 0;
1820
1821         write_index = check_index && apply;
1822         if (write_index)
1823                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1824         if (check_index) {
1825                 if (read_cache() < 0)
1826                         die("unable to read index file");
1827         }
1828
1829         if ((check || apply) && check_patch_list(list) < 0)
1830                 exit(1);
1831
1832         if (apply)
1833                 write_out_results(list, skipped_patch);
1834
1835         if (write_index) {
1836                 if (write_cache(newfd, active_cache, active_nr) ||
1837                     commit_index_file(&cache_file))
1838                         die("Unable to write new cachefile");
1839         }
1840
1841         if (show_index_info)
1842                 show_index_list(list);
1843
1844         if (diffstat)
1845                 stat_patch_list(list);
1846
1847         if (numstat)
1848                 numstat_patch_list(list);
1849
1850         if (summary)
1851                 summary_patch_list(list);
1852
1853         free(buffer);
1854         return 0;
1855 }
1856
1857 static int git_apply_config(const char *var, const char *value)
1858 {
1859         if (!strcmp(var, "apply.whitespace")) {
1860                 apply_default_whitespace = strdup(value);
1861                 return 0;
1862         }
1863         return git_default_config(var, value);
1864 }
1865
1866
1867 int main(int argc, char **argv)
1868 {
1869         int i;
1870         int read_stdin = 1;
1871         const char *whitespace_option = NULL;
1872
1873         for (i = 1; i < argc; i++) {
1874                 const char *arg = argv[i];
1875                 int fd;
1876
1877                 if (!strcmp(arg, "-")) {
1878                         apply_patch(0, "<stdin>");
1879                         read_stdin = 0;
1880                         continue;
1881                 }
1882                 if (!strncmp(arg, "--exclude=", 10)) {
1883                         struct excludes *x = xmalloc(sizeof(*x));
1884                         x->path = arg + 10;
1885                         x->next = excludes;
1886                         excludes = x;
1887                         continue;
1888                 }
1889                 if (!strncmp(arg, "-p", 2)) {
1890                         p_value = atoi(arg + 2);
1891                         continue;
1892                 }
1893                 if (!strcmp(arg, "--no-add")) {
1894                         no_add = 1;
1895                         continue;
1896                 }
1897                 if (!strcmp(arg, "--stat")) {
1898                         apply = 0;
1899                         diffstat = 1;
1900                         continue;
1901                 }
1902                 if (!strcmp(arg, "--allow-binary-replacement")) {
1903                         allow_binary_replacement = 1;
1904                         continue;
1905                 }
1906                 if (!strcmp(arg, "--numstat")) {
1907                         apply = 0;
1908                         numstat = 1;
1909                         continue;
1910                 }
1911                 if (!strcmp(arg, "--summary")) {
1912                         apply = 0;
1913                         summary = 1;
1914                         continue;
1915                 }
1916                 if (!strcmp(arg, "--check")) {
1917                         apply = 0;
1918                         check = 1;
1919                         continue;
1920                 }
1921                 if (!strcmp(arg, "--index")) {
1922                         check_index = 1;
1923                         continue;
1924                 }
1925                 if (!strcmp(arg, "--apply")) {
1926                         apply = 1;
1927                         continue;
1928                 }
1929                 if (!strcmp(arg, "--index-info")) {
1930                         apply = 0;
1931                         show_index_info = 1;
1932                         continue;
1933                 }
1934                 if (!strcmp(arg, "-z")) {
1935                         line_termination = 0;
1936                         continue;
1937                 }
1938                 if (!strncmp(arg, "--whitespace=", 13)) {
1939                         whitespace_option = arg + 13;
1940                         parse_whitespace_option(arg + 13);
1941                         continue;
1942                 }
1943
1944                 if (check_index && prefix_length < 0) {
1945                         prefix = setup_git_directory();
1946                         prefix_length = prefix ? strlen(prefix) : 0;
1947                         git_config(git_apply_config);
1948                         if (!whitespace_option && apply_default_whitespace)
1949                                 parse_whitespace_option(apply_default_whitespace);
1950                 }
1951                 if (0 < prefix_length)
1952                         arg = prefix_filename(prefix, prefix_length, arg);
1953
1954                 fd = open(arg, O_RDONLY);
1955                 if (fd < 0)
1956                         usage(apply_usage);
1957                 read_stdin = 0;
1958                 apply_patch(fd, arg);
1959                 close(fd);
1960         }
1961         if (read_stdin)
1962                 apply_patch(0, "<stdin>");
1963         if (whitespace_error) {
1964                 if (squelch_whitespace_errors &&
1965                     squelch_whitespace_errors < whitespace_error) {
1966                         int squelched =
1967                                 whitespace_error - squelch_whitespace_errors;
1968                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
1969                                 squelched,
1970                                 squelched == 1 ? "" : "s");
1971                 }
1972                 if (new_whitespace == error_on_whitespace)
1973                         die("%d line%s add%s trailing whitespaces.",
1974                             whitespace_error,
1975                             whitespace_error == 1 ? "" : "s",
1976                             whitespace_error == 1 ? "s" : "");
1977                 if (applied_after_stripping)
1978                         fprintf(stderr, "warning: %d line%s applied after"
1979                                 " stripping trailing whitespaces.\n",
1980                                 applied_after_stripping,
1981                                 applied_after_stripping == 1 ? "" : "s");
1982                 else if (whitespace_error)
1983                         fprintf(stderr, "warning: %d line%s add%s trailing"
1984                                 " whitespaces.\n",
1985                                 whitespace_error,
1986                                 whitespace_error == 1 ? "" : "s",
1987                                 whitespace_error == 1 ? "s" : "");
1988         }
1989         return 0;
1990 }