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  * NOTE! It does all its work in the index file, and only cares about
   9  * the files in the working directory if you tell it to "merge" the
  10  * patch apply.
  11  *
  12  * Even when merging it always takes the source from the index, and
  13  * uses the working tree as a "branch" for a 3-way merge.
  14  */
  15 #include <ctype.h>
  16
  17 #include "cache.h"
  18
  19 // We default to the merge behaviour, since that's what most people would
  20 // expect.
  21 //
  22 //  --check turns on checking that the working tree matches the
  23 //    files that are being modified, but doesn't apply the patch
  24 //  --stat does just a diffstat, and doesn't actually apply
  25 //  --show-files shows the directory changes
  26 //
  27 static int merge_patch = 1;
  28 static int diffstat = 0;
  29 static int check = 0;
  30 static int apply = 1;
  31 static int show_files = 0;
  32 static const char apply_usage[] = "git-apply [--stat] [--check] [--show-files] <patch>";
  33
  34 /*
  35  * For "diff-stat" like behaviour, we keep track of the biggest change
  36  * we've seen, and the longest filename. That allows us to do simple
  37  * scaling.
  38  */
  39 static int max_change, max_len;
  40
  41 /*
  42  * Various "current state", notably line numbers and what
  43  * file (and how) we're patching right now.. The "is_xxxx"
  44  * things are flags, where -1 means "don't know yet".
  45  */
  46 static int linenr = 1;
  47
  48 struct fragment {
  49         unsigned long oldpos, oldlines;
  50         unsigned long newpos, newlines;
  51         const char *patch;
  52         int size;
  53         struct fragment *next;
  54 };
  55
  56 struct patch {
  57         char *new_name, *old_name, *def_name;
  58         unsigned int old_mode, new_mode;
  59         int is_rename, is_copy, is_new, is_delete;
  60         int lines_added, lines_deleted;
  61         struct fragment *fragments;
  62         struct patch *next;
  63 };
  64
  65 #define CHUNKSIZE (8192)
  66 #define SLOP (16)
  67
  68 static void *read_patch_file(int fd, unsigned long *sizep)
  69 {
  70         unsigned long size = 0, alloc = CHUNKSIZE;
  71         void *buffer = xmalloc(alloc);
  72
  73         for (;;) {
  74                 int nr = alloc - size;
  75                 if (nr < 1024) {
  76                         alloc += CHUNKSIZE;
  77                         buffer = xrealloc(buffer, alloc);
  78                         nr = alloc - size;
  79                 }
  80                 nr = read(fd, buffer + size, nr);
  81                 if (!nr)
  82                         break;
  83                 if (nr < 0) {
  84                         if (errno == EAGAIN)
  85                                 continue;
  86                         die("git-apply: read returned %s", strerror(errno));
  87                 }
  88                 size += nr;
  89         }
  90         *sizep = size;
  91
  92         /*
  93          * Make sure that we have some slop in the buffer
  94          * so that we can do speculative "memcmp" etc, and
  95          * see to it that it is NUL-filled.
  96          */
  97         if (alloc < size + SLOP)
  98                 buffer = xrealloc(buffer, size + SLOP);
  99         memset(buffer + size, 0, SLOP);
 100         return buffer;
 101 }
 102
 103 static unsigned long linelen(char *buffer, unsigned long size)
 104 {
 105         unsigned long len = 0;
 106         while (size--) {
 107                 len++;
 108                 if (*buffer++ == '\n')
 109                         break;
 110         }
 111         return len;
 112 }
 113
 114 static int is_dev_null(const char *str)
 115 {
 116         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 117 }
 118
 119 #define TERM_EXIST      1
 120 #define TERM_SPACE      2
 121 #define TERM_TAB        4
 122
 123 static int name_terminate(const char *name, int namelen, int c, int terminate)
 124 {
 125         if (c == ' ' && !(terminate & TERM_SPACE))
 126                 return 0;
 127         if (c == '\t' && !(terminate & TERM_TAB))
 128                 return 0;
 129
 130         /*
 131          * Do we want an existing name? Return false and
 132          * continue if it's not there.
 133          */
 134         if (terminate & TERM_EXIST)
 135                 return cache_name_pos(name, namelen) >= 0;
 136
 137         return 1;
 138 }
 139
 140 static char * find_name(const char *line, char *def, int p_value, int terminate)
 141 {
 142         int len;
 143         const char *start = line;
 144         char *name;
 145
 146         for (;;) {
 147                 char c = *line;
 148
 149                 if (isspace(c)) {
 150                         if (c == '\n')
 151                                 break;
 152                         if (name_terminate(start, line-start, c, terminate))
 153                                 break;
 154                 }
 155                 line++;
 156                 if (c == '/' && !--p_value)
 157                         start = line;
 158         }
 159         if (!start)
 160                 return def;
 161         len = line - start;
 162         if (!len)
 163                 return def;
 164
 165         /*
 166          * Generally we prefer the shorter name, especially
 167          * if the other one is just a variation of that with
 168          * something else tacked on to the end (ie "file.orig"
 169          * or "file~").
 170          */
 171         if (def) {
 172                 int deflen = strlen(def);
 173                 if (deflen < len && !strncmp(start, def, deflen))
 174                         return def;
 175         }
 176
 177         name = xmalloc(len + 1);
 178         memcpy(name, start, len);
 179         name[len] = 0;
 180         free(def);
 181         return name;
 182 }
 183
 184 /*
 185  * Get the name etc info from the --/+++ lines of a traditional patch header
 186  *
 187  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 188  *
 189  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 190  * files, we can happily check the index for a match, but for creating a
 191  * new file we should try to match whatever "patch" does. I have no idea.
 192  */
 193 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 194 {
 195         int p_value = 1;
 196         char *name;
 197
 198         first += 4;     // skip "--- "
 199         second += 4;    // skip "+++ "
 200         if (is_dev_null(first)) {
 201                 patch->is_new = 1;
 202                 patch->is_delete = 0;
 203                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 204                 patch->new_name = name;
 205         } else if (is_dev_null(second)) {
 206                 patch->is_new = 0;
 207                 patch->is_delete = 1;
 208                 name = find_name(first, NULL, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
 209                 patch->old_name = name;
 210         } else {
 211                 name = find_name(first, NULL, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
 212                 name = find_name(second, name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
 213                 patch->old_name = patch->new_name = name;
 214         }
 215         if (!name)
 216                 die("unable to find filename in patch at line %d", linenr);
 217 }
 218
 219 static int gitdiff_hdrend(const char *line, struct patch *patch)
 220 {
 221         return -1;
 222 }
 223
 224 /*
 225  * We're anal about diff header consistency, to make
 226  * sure that we don't end up having strange ambiguous
 227  * patches floating around.
 228  *
 229  * As a result, gitdiff_{old|new}name() will check
 230  * their names against any previous information, just
 231  * to make sure..
 232  */
 233 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 234 {
 235         int len;
 236         const char *name;
 237
 238         if (!orig_name && !isnull)
 239                 return find_name(line, NULL, 1, 0);
 240
 241         name = "/dev/null";
 242         len = 9;
 243         if (orig_name) {
 244                 name = orig_name;
 245                 len = strlen(name);
 246                 if (isnull)
 247                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 248         }
 249
 250         if (*name == '/')
 251                 goto absolute_path;
 252
 253         for (;;) {
 254                 char c = *line++;
 255                 if (c == '\n')
 256                         break;
 257                 if (c != '/')
 258                         continue;
 259 absolute_path:
 260                 if (memcmp(line, name, len) || line[len] != '\n')
 261                         break;
 262                 return orig_name;
 263         }
 264         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 265         return NULL;
 266 }
 267
 268 static int gitdiff_oldname(const char *line, struct patch *patch)
 269 {
 270         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 271         return 0;
 272 }
 273
 274 static int gitdiff_newname(const char *line, struct patch *patch)
 275 {
 276         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 277         return 0;
 278 }
 279
 280 static int gitdiff_oldmode(const char *line, struct patch *patch)
 281 {
 282         patch->old_mode = strtoul(line, NULL, 8);
 283         return 0;
 284 }
 285
 286 static int gitdiff_newmode(const char *line, struct patch *patch)
 287 {
 288         patch->new_mode = strtoul(line, NULL, 8);
 289         return 0;
 290 }
 291
 292 static int gitdiff_delete(const char *line, struct patch *patch)
 293 {
 294         patch->is_delete = 1;
 295         patch->old_name = patch->def_name;
 296         return gitdiff_oldmode(line, patch);
 297 }
 298
 299 static int gitdiff_newfile(const char *line, struct patch *patch)
 300 {
 301         patch->is_new = 1;
 302         patch->new_name = patch->def_name;
 303         return gitdiff_newmode(line, patch);
 304 }
 305
 306 static int gitdiff_copysrc(const char *line, struct patch *patch)
 307 {
 308         patch->is_copy = 1;
 309         patch->old_name = find_name(line, NULL, 0, 0);
 310         return 0;
 311 }
 312
 313 static int gitdiff_copydst(const char *line, struct patch *patch)
 314 {
 315         patch->is_copy = 1;
 316         patch->new_name = find_name(line, NULL, 0, 0);
 317         return 0;
 318 }
 319
 320 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 321 {
 322         patch->is_rename = 1;
 323         patch->old_name = find_name(line, NULL, 0, 0);
 324         return 0;
 325 }
 326
 327 static int gitdiff_renamedst(const char *line, struct patch *patch)
 328 {
 329         patch->is_rename = 1;
 330         patch->new_name = find_name(line, NULL, 0, 0);
 331         return 0;
 332 }
 333
 334 static int gitdiff_similarity(const char *line, struct patch *patch)
 335 {
 336         return 0;
 337 }
 338
 339 /*
 340  * This is normal for a diff that doesn't change anything: we'll fall through
 341  * into the next diff. Tell the parser to break out.
 342  */
 343 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 344 {
 345         return -1;
 346 }
 347
 348 static char *git_header_name(char *line)
 349 {
 350         int len;
 351         char *name, *second;
 352
 353         /*
 354          * Find the first '/'
 355          */
 356         name = line;
 357         for (;;) {
 358                 char c = *name++;
 359                 if (c == '\n')
 360                         return NULL;
 361                 if (c == '/')
 362                         break;
 363         }
 364
 365         /*
 366          * We don't accept absolute paths (/dev/null) as possibly valid
 367          */
 368         if (name == line+1)
 369                 return NULL;
 370
 371         /*
 372          * Accept a name only if it shows up twice, exactly the same
 373          * form.
 374          */
 375         for (len = 0 ; ; len++) {
 376                 char c = name[len];
 377
 378                 switch (c) {
 379                 default:
 380                         continue;
 381                 case '\n':
 382                         break;
 383                 case '\t': case ' ':
 384                         second = name+len;
 385                         for (;;) {
 386                                 char c = *second++;
 387                                 if (c == '\n')
 388                                         return NULL;
 389                                 if (c == '/')
 390                                         break;
 391                         }
 392                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 393                                 char *ret = xmalloc(len + 1);
 394                                 memcpy(ret, name, len);
 395                                 ret[len] = 0;
 396                                 return ret;
 397                         }
 398                 }
 399         }
 400         return NULL;
 401 }
 402
 403 /* Verify that we recognize the lines following a git header */
 404 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 405 {
 406         unsigned long offset;
 407
 408         /* A git diff has explicit new/delete information, so we don't guess */
 409         patch->is_new = 0;
 410         patch->is_delete = 0;
 411
 412         /*
 413          * Some things may not have the old name in the
 414          * rest of the headers anywhere (pure mode changes,
 415          * or removing or adding empty files), so we get
 416          * the default name from the header.
 417          */
 418         patch->def_name = git_header_name(line + strlen("diff --git "));
 419
 420         line += len;
 421         size -= len;
 422         linenr++;
 423         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 424                 static const struct opentry {
 425                         const char *str;
 426                         int (*fn)(const char *, struct patch *);
 427                 } optable[] = {
 428                         { "@@ -", gitdiff_hdrend },
 429                         { "--- ", gitdiff_oldname },
 430                         { "+++ ", gitdiff_newname },
 431                         { "old mode ", gitdiff_oldmode },
 432                         { "new mode ", gitdiff_newmode },
 433                         { "deleted file mode ", gitdiff_delete },
 434                         { "new file mode ", gitdiff_newfile },
 435                         { "copy from ", gitdiff_copysrc },
 436                         { "copy to ", gitdiff_copydst },
 437                         { "rename from ", gitdiff_renamesrc },
 438                         { "rename to ", gitdiff_renamedst },
 439                         { "similarity index ", gitdiff_similarity },
 440                         { "", gitdiff_unrecognized },
 441                 };
 442                 int i;
 443
 444                 len = linelen(line, size);
 445                 if (!len || line[len-1] != '\n')
 446                         break;
 447                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 448                         const struct opentry *p = optable + i;
 449                         int oplen = strlen(p->str);
 450                         if (len < oplen || memcmp(p->str, line, oplen))
 451                                 continue;
 452                         if (p->fn(line + oplen, patch) < 0)
 453                                 return offset;
 454                         break;
 455                 }
 456         }
 457
 458         return offset;
 459 }
 460
 461 static int parse_num(const char *line, unsigned long *p)
 462 {
 463         char *ptr;
 464
 465         if (!isdigit(*line))
 466                 return 0;
 467         *p = strtoul(line, &ptr, 10);
 468         return ptr - line;
 469 }
 470
 471 static int parse_range(const char *line, int len, int offset, const char *expect,
 472                         unsigned long *p1, unsigned long *p2)
 473 {
 474         int digits, ex;
 475
 476         if (offset < 0 || offset >= len)
 477                 return -1;
 478         line += offset;
 479         len -= offset;
 480
 481         digits = parse_num(line, p1);
 482         if (!digits)
 483                 return -1;
 484
 485         offset += digits;
 486         line += digits;
 487         len -= digits;
 488
 489         *p2 = *p1;
 490         if (*line == ',') {
 491                 digits = parse_num(line+1, p2);
 492                 if (!digits)
 493                         return -1;
 494
 495                 offset += digits+1;
 496                 line += digits+1;
 497                 len -= digits+1;
 498         }
 499
 500         ex = strlen(expect);
 501         if (ex > len)
 502                 return -1;
 503         if (memcmp(line, expect, ex))
 504                 return -1;
 505
 506         return offset + ex;
 507 }
 508
 509 /*
 510  * Parse a unified diff fragment header of the
 511  * form "@@ -a,b +c,d @@"
 512  */
 513 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 514 {
 515         int offset;
 516
 517         if (!len || line[len-1] != '\n')
 518                 return -1;
 519
 520         /* Figure out the number of lines in a fragment */
 521         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 522         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 523
 524         return offset;
 525 }
 526
 527 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 528 {
 529         unsigned long offset, len;
 530
 531         patch->is_rename = patch->is_copy = 0;
 532         patch->is_new = patch->is_delete = -1;
 533         patch->old_mode = patch->new_mode = 0;
 534         patch->old_name = patch->new_name = NULL;
 535         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 536                 unsigned long nextlen;
 537
 538                 len = linelen(line, size);
 539                 if (!len)
 540                         break;
 541
 542                 /* Testing this early allows us to take a few shortcuts.. */
 543                 if (len < 6)
 544                         continue;
 545
 546                 /*
 547                  * Make sure we don't find any unconnected patch fragmants.
 548                  * That's a sign that we didn't find a header, and that a
 549                  * patch has become corrupted/broken up.
 550                  */
 551                 if (!memcmp("@@ -", line, 4)) {
 552                         struct fragment dummy;
 553                         if (parse_fragment_header(line, len, &dummy) < 0)
 554                                 continue;
 555                         error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
 556                 }
 557
 558                 if (size < len + 6)
 559                         break;
 560
 561                 /*
 562                  * Git patch? It might not have a real patch, just a rename
 563                  * or mode change, so we handle that specially
 564                  */
 565                 if (!memcmp("diff --git ", line, 11)) {
 566                         int git_hdr_len = parse_git_header(line, len, size, patch);
 567                         if (git_hdr_len < 0)
 568                                 continue;
 569                         if (!patch->old_name && !patch->new_name)
 570                                 die("git diff header lacks filename information");
 571                         *hdrsize = git_hdr_len;
 572                         return offset;
 573                 }
 574
 575                 /** --- followed by +++ ? */
 576                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 577                         continue;
 578
 579                 /*
 580                  * We only accept unified patches, so we want it to
 581                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 582                  * minimum
 583                  */
 584                 nextlen = linelen(line + len, size - len);
 585                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 586                         continue;
 587
 588                 /* Ok, we'll consider it a patch */
 589                 parse_traditional_patch(line, line+len, patch);
 590                 *hdrsize = len + nextlen;
 591                 linenr += 2;
 592                 return offset;
 593         }
 594         return -1;
 595 }
 596
 597 /*
 598  * Parse a unified diff. Note that this really needs
 599  * to parse each fragment separately, since the only
 600  * way to know the difference between a "---" that is
 601  * part of a patch, and a "---" that starts the next
 602  * patch is to look at the line counts..
 603  */
 604 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 605 {
 606         int added, deleted;
 607         int len = linelen(line, size), offset;
 608         unsigned long pos[4], oldlines, newlines;
 609
 610         offset = parse_fragment_header(line, len, fragment);
 611         if (offset < 0)
 612                 return -1;
 613         oldlines = fragment->oldlines;
 614         newlines = fragment->newlines;
 615
 616         if (patch->is_new < 0 && (pos[0] || oldlines))
 617                 patch->is_new = 0;
 618         if (patch->is_delete < 0 && (pos[1] || newlines))
 619                 patch->is_delete = 0;
 620
 621         /* Parse the thing.. */
 622         line += len;
 623         size -= len;
 624         linenr++;
 625         added = deleted = 0;
 626         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 627                 if (!oldlines && !newlines)
 628                         break;
 629                 len = linelen(line, size);
 630                 if (!len || line[len-1] != '\n')
 631                         return -1;
 632                 switch (*line) {
 633                 default:
 634                         return -1;
 635                 case ' ':
 636                         oldlines--;
 637                         newlines--;
 638                         break;
 639                 case '-':
 640                         deleted++;
 641                         oldlines--;
 642                         break;
 643                 case '+':
 644                         added++;
 645                         newlines--;
 646                         break;
 647                 /* We allow "\ No newline at end of file" */
 648                 case '\\':
 649                         break;
 650                 }
 651         }
 652         patch->lines_added += added;
 653         patch->lines_deleted += deleted;
 654         return offset;
 655 }
 656
 657 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 658 {
 659         unsigned long offset = 0;
 660         struct fragment **fragp = &patch->fragments;
 661
 662         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 663                 struct fragment *fragment;
 664                 int len;
 665
 666                 fragment = xmalloc(sizeof(*fragment));
 667                 memset(fragment, 0, sizeof(*fragment));
 668                 len = parse_fragment(line, size, patch, fragment);
 669                 if (len <= 0)
 670                         die("corrupt patch at line %d", linenr);
 671
 672                 fragment->patch = line;
 673                 fragment->size = len;
 674
 675                 *fragp = fragment;
 676                 fragp = &fragment->next;
 677
 678                 offset += len;
 679                 line += len;
 680                 size -= len;
 681         }
 682         return offset;
 683 }
 684
 685 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 686 {
 687         int hdrsize, patchsize;
 688         int offset = find_header(buffer, size, &hdrsize, patch);
 689
 690         if (offset < 0)
 691                 return offset;
 692
 693         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 694
 695         return offset + hdrsize + patchsize;
 696 }
 697
 698 const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 699 const char minuses[]= "----------------------------------------------------------------------";
 700
 701 static void show_stats(struct patch *patch)
 702 {
 703         char *name = patch->old_name;
 704         int len, max, add, del;
 705
 706         if (!name)
 707                 name = patch->new_name;
 708
 709         /*
 710          * "scale" the filename
 711          */
 712         len = strlen(name);
 713         max = max_len;
 714         if (max > 50)
 715                 max = 50;
 716         if (len > max)
 717                 name += len - max;
 718         len = max;
 719
 720         /*
 721          * scale the add/delete
 722          */
 723         max = max_change;
 724         if (max + len > 70)
 725                 max = 70 - len;
 726
 727         add = (patch->lines_added * max + max_change/2) / max_change;
 728         del = (patch->lines_deleted * max + max_change/2) / max_change;
 729         printf(" %-*s |%5d %.*s%.*s\n",
 730                 len, name, patch->lines_added + patch->lines_deleted,
 731                 add, pluses, del, minuses);
 732 }
 733
 734 static int check_patch(struct patch *patch)
 735 {
 736         struct stat st;
 737         const char *old_name = patch->old_name;
 738         const char *new_name = patch->new_name;
 739
 740         if (old_name) {
 741                 int pos = cache_name_pos(old_name, strlen(old_name));
 742                 int changed;
 743
 744                 if (pos < 0)
 745                         return error("%s: does not exist in index", old_name);
 746                 if (patch->is_new < 0)
 747                         patch->is_new = 0;
 748                 if (lstat(old_name, &st) < 0)
 749                         return error("%s: %s\n", strerror(errno));
 750                 changed = ce_match_stat(active_cache[pos], &st);
 751                 if (changed)
 752                         return error("%s: does not match index", old_name);
 753                 if (!patch->old_mode)
 754                         patch->old_mode = st.st_mode;
 755         }
 756
 757         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
 758                 if (cache_name_pos(new_name, strlen(new_name)) >= 0)
 759                         return error("%s: already exists in index", new_name);
 760                 if (!lstat(new_name, &st))
 761                         return error("%s: already exists in working directory", new_name);
 762                 if (errno != ENOENT)
 763                         return error("%s: %s", new_name, strerror(errno));
 764         }
 765         return 0;
 766 }
 767
 768 static int check_patch_list(struct patch *patch)
 769 {
 770         int error = 0;
 771
 772         for (;patch ; patch = patch->next)
 773                 error |= check_patch(patch);
 774         return error;
 775 }
 776
 777 static void show_file(int c, unsigned int mode, const char *name)
 778 {
 779         printf("%c %o %s\n", c, mode, name);
 780 }
 781
 782 static void show_file_list(struct patch *patch)
 783 {
 784         for (;patch ; patch = patch->next) {
 785                 if (patch->is_rename) {
 786                         show_file('-', patch->old_mode, patch->old_name);
 787                         show_file('+', patch->new_mode, patch->new_name);
 788                         continue;
 789                 }
 790                 if (patch->is_copy || patch->is_new) {
 791                         show_file('+', patch->new_mode, patch->new_name);
 792                         continue;
 793                 }
 794                 if (patch->is_delete) {
 795                         show_file('-', patch->old_mode, patch->old_name);
 796                         continue;
 797                 }
 798                 if (patch->old_mode && patch->new_mode && patch->old_mode != patch->new_mode) {
 799                         printf("M %o:%o %s\n", patch->old_mode, patch->new_mode, patch->old_name);
 800                         continue;
 801                 }
 802                 printf("M %o %s\n", patch->old_mode, patch->old_name);
 803         }
 804 }
 805
 806 static void stat_patch_list(struct patch *patch)
 807 {
 808         int files, adds, dels;
 809
 810         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
 811                 files++;
 812                 adds += patch->lines_added;
 813                 dels += patch->lines_deleted;
 814                 show_stats(patch);
 815         }
 816
 817         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
 818 }
 819
 820 static void patch_stats(struct patch *patch)
 821 {
 822         int lines = patch->lines_added + patch->lines_deleted;
 823
 824         if (lines > max_change)
 825                 max_change = lines;
 826         if (patch->old_name) {
 827                 int len = strlen(patch->old_name);
 828                 if (len > max_len)
 829                         max_len = len;
 830         }
 831         if (patch->new_name) {
 832                 int len = strlen(patch->new_name);
 833                 if (len > max_len)
 834                         max_len = len;
 835         }
 836 }
 837
 838 static int apply_patch(int fd)
 839 {
 840         unsigned long offset, size;
 841         char *buffer = read_patch_file(fd, &size);
 842         struct patch *list = NULL, **listp = &list;
 843
 844         if (!buffer)
 845                 return -1;
 846         offset = 0;
 847         while (size > 0) {
 848                 struct patch *patch;
 849                 int nr;
 850
 851                 patch = xmalloc(sizeof(*patch));
 852                 memset(patch, 0, sizeof(*patch));
 853                 nr = parse_chunk(buffer + offset, size, patch);
 854                 if (nr < 0)
 855                         break;
 856                 patch_stats(patch);
 857                 *listp = patch;
 858                 listp = &patch->next;
 859                 offset += nr;
 860                 size -= nr;
 861         }
 862
 863         if ((check || apply) && check_patch_list(list) < 0)
 864                 exit(1);
 865
 866         if (show_files)
 867                 show_file_list(list);
 868
 869         if (diffstat)
 870                 stat_patch_list(list);
 871
 872         free(buffer);
 873         return 0;
 874 }
 875
 876 int main(int argc, char **argv)
 877 {
 878         int i;
 879         int read_stdin = 1;
 880
 881         if (read_cache() < 0)
 882                 die("unable to read index file");
 883
 884         for (i = 1; i < argc; i++) {
 885                 const char *arg = argv[i];
 886                 int fd;
 887
 888                 if (!strcmp(arg, "-")) {
 889                         apply_patch(0);
 890                         read_stdin = 0;
 891                         continue;
 892                 }
 893                 if (!strcmp(arg, "--no-merge")) {
 894                         merge_patch = 0;
 895                         continue;
 896                 }
 897                 if (!strcmp(arg, "--stat")) {
 898                         apply = 0;
 899                         diffstat = 1;
 900                         continue;
 901                 }
 902                 if (!strcmp(arg, "--check")) {
 903                         apply = 0;
 904                         check = 1;
 905                         continue;
 906                 }
 907                 if (!strcmp(arg, "--show-files")) {
 908                         show_files = 1;
 909                         continue;
 910                 }
 911                 fd = open(arg, O_RDONLY);
 912                 if (fd < 0)
 913                         usage(apply_usage);
 914                 read_stdin = 0;
 915                 apply_patch(fd);
 916                 close(fd);
 917         }
 918         if (read_stdin)
 919                 apply_patch(0);
 920         return 0;
 921 }