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