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 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 340 {
 341         return 0;
 342 }
 343
 344 /*
 345  * This is normal for a diff that doesn't change anything: we'll fall through
 346  * into the next diff. Tell the parser to break out.
 347  */
 348 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 349 {
 350         return -1;
 351 }
 352
 353 static char *git_header_name(char *line)
 354 {
 355         int len;
 356         char *name, *second;
 357
 358         /*
 359          * Find the first '/'
 360          */
 361         name = line;
 362         for (;;) {
 363                 char c = *name++;
 364                 if (c == '\n')
 365                         return NULL;
 366                 if (c == '/')
 367                         break;
 368         }
 369
 370         /*
 371          * We don't accept absolute paths (/dev/null) as possibly valid
 372          */
 373         if (name == line+1)
 374                 return NULL;
 375
 376         /*
 377          * Accept a name only if it shows up twice, exactly the same
 378          * form.
 379          */
 380         for (len = 0 ; ; len++) {
 381                 char c = name[len];
 382
 383                 switch (c) {
 384                 default:
 385                         continue;
 386                 case '\n':
 387                         break;
 388                 case '\t': case ' ':
 389                         second = name+len;
 390                         for (;;) {
 391                                 char c = *second++;
 392                                 if (c == '\n')
 393                                         return NULL;
 394                                 if (c == '/')
 395                                         break;
 396                         }
 397                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 398                                 char *ret = xmalloc(len + 1);
 399                                 memcpy(ret, name, len);
 400                                 ret[len] = 0;
 401                                 return ret;
 402                         }
 403                 }
 404         }
 405         return NULL;
 406 }
 407
 408 /* Verify that we recognize the lines following a git header */
 409 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 410 {
 411         unsigned long offset;
 412
 413         /* A git diff has explicit new/delete information, so we don't guess */
 414         patch->is_new = 0;
 415         patch->is_delete = 0;
 416
 417         /*
 418          * Some things may not have the old name in the
 419          * rest of the headers anywhere (pure mode changes,
 420          * or removing or adding empty files), so we get
 421          * the default name from the header.
 422          */
 423         patch->def_name = git_header_name(line + strlen("diff --git "));
 424
 425         line += len;
 426         size -= len;
 427         linenr++;
 428         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 429                 static const struct opentry {
 430                         const char *str;
 431                         int (*fn)(const char *, struct patch *);
 432                 } optable[] = {
 433                         { "@@ -", gitdiff_hdrend },
 434                         { "--- ", gitdiff_oldname },
 435                         { "+++ ", gitdiff_newname },
 436                         { "old mode ", gitdiff_oldmode },
 437                         { "new mode ", gitdiff_newmode },
 438                         { "deleted file mode ", gitdiff_delete },
 439                         { "new file mode ", gitdiff_newfile },
 440                         { "copy from ", gitdiff_copysrc },
 441                         { "copy to ", gitdiff_copydst },
 442                         { "rename from ", gitdiff_renamesrc },
 443                         { "rename to ", gitdiff_renamedst },
 444                         { "similarity index ", gitdiff_similarity },
 445                         { "dissimilarity index ", gitdiff_dissimilarity },
 446                         { "", gitdiff_unrecognized },
 447                 };
 448                 int i;
 449
 450                 len = linelen(line, size);
 451                 if (!len || line[len-1] != '\n')
 452                         break;
 453                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 454                         const struct opentry *p = optable + i;
 455                         int oplen = strlen(p->str);
 456                         if (len < oplen || memcmp(p->str, line, oplen))
 457                                 continue;
 458                         if (p->fn(line + oplen, patch) < 0)
 459                                 return offset;
 460                         break;
 461                 }
 462         }
 463
 464         return offset;
 465 }
 466
 467 static int parse_num(const char *line, unsigned long *p)
 468 {
 469         char *ptr;
 470
 471         if (!isdigit(*line))
 472                 return 0;
 473         *p = strtoul(line, &ptr, 10);
 474         return ptr - line;
 475 }
 476
 477 static int parse_range(const char *line, int len, int offset, const char *expect,
 478                         unsigned long *p1, unsigned long *p2)
 479 {
 480         int digits, ex;
 481
 482         if (offset < 0 || offset >= len)
 483                 return -1;
 484         line += offset;
 485         len -= offset;
 486
 487         digits = parse_num(line, p1);
 488         if (!digits)
 489                 return -1;
 490
 491         offset += digits;
 492         line += digits;
 493         len -= digits;
 494
 495         *p2 = *p1;
 496         if (*line == ',') {
 497                 digits = parse_num(line+1, p2);
 498                 if (!digits)
 499                         return -1;
 500
 501                 offset += digits+1;
 502                 line += digits+1;
 503                 len -= digits+1;
 504         }
 505
 506         ex = strlen(expect);
 507         if (ex > len)
 508                 return -1;
 509         if (memcmp(line, expect, ex))
 510                 return -1;
 511
 512         return offset + ex;
 513 }
 514
 515 /*
 516  * Parse a unified diff fragment header of the
 517  * form "@@ -a,b +c,d @@"
 518  */
 519 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 520 {
 521         int offset;
 522
 523         if (!len || line[len-1] != '\n')
 524                 return -1;
 525
 526         /* Figure out the number of lines in a fragment */
 527         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 528         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 529
 530         return offset;
 531 }
 532
 533 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 534 {
 535         unsigned long offset, len;
 536
 537         patch->is_rename = patch->is_copy = 0;
 538         patch->is_new = patch->is_delete = -1;
 539         patch->old_mode = patch->new_mode = 0;
 540         patch->old_name = patch->new_name = NULL;
 541         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 542                 unsigned long nextlen;
 543
 544                 len = linelen(line, size);
 545                 if (!len)
 546                         break;
 547
 548                 /* Testing this early allows us to take a few shortcuts.. */
 549                 if (len < 6)
 550                         continue;
 551
 552                 /*
 553                  * Make sure we don't find any unconnected patch fragmants.
 554                  * That's a sign that we didn't find a header, and that a
 555                  * patch has become corrupted/broken up.
 556                  */
 557                 if (!memcmp("@@ -", line, 4)) {
 558                         struct fragment dummy;
 559                         if (parse_fragment_header(line, len, &dummy) < 0)
 560                                 continue;
 561                         error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
 562                 }
 563
 564                 if (size < len + 6)
 565                         break;
 566
 567                 /*
 568                  * Git patch? It might not have a real patch, just a rename
 569                  * or mode change, so we handle that specially
 570                  */
 571                 if (!memcmp("diff --git ", line, 11)) {
 572                         int git_hdr_len = parse_git_header(line, len, size, patch);
 573                         if (git_hdr_len < 0)
 574                                 continue;
 575                         if (!patch->old_name && !patch->new_name)
 576                                 die("git diff header lacks filename information");
 577                         *hdrsize = git_hdr_len;
 578                         return offset;
 579                 }
 580
 581                 /** --- followed by +++ ? */
 582                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 583                         continue;
 584
 585                 /*
 586                  * We only accept unified patches, so we want it to
 587                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 588                  * minimum
 589                  */
 590                 nextlen = linelen(line + len, size - len);
 591                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 592                         continue;
 593
 594                 /* Ok, we'll consider it a patch */
 595                 parse_traditional_patch(line, line+len, patch);
 596                 *hdrsize = len + nextlen;
 597                 linenr += 2;
 598                 return offset;
 599         }
 600         return -1;
 601 }
 602
 603 /*
 604  * Parse a unified diff. Note that this really needs
 605  * to parse each fragment separately, since the only
 606  * way to know the difference between a "---" that is
 607  * part of a patch, and a "---" that starts the next
 608  * patch is to look at the line counts..
 609  */
 610 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 611 {
 612         int added, deleted;
 613         int len = linelen(line, size), offset;
 614         unsigned long pos[4], oldlines, newlines;
 615
 616         offset = parse_fragment_header(line, len, fragment);
 617         if (offset < 0)
 618                 return -1;
 619         oldlines = fragment->oldlines;
 620         newlines = fragment->newlines;
 621
 622         if (patch->is_new < 0 && (pos[0] || oldlines))
 623                 patch->is_new = 0;
 624         if (patch->is_delete < 0 && (pos[1] || newlines))
 625                 patch->is_delete = 0;
 626
 627         /* Parse the thing.. */
 628         line += len;
 629         size -= len;
 630         linenr++;
 631         added = deleted = 0;
 632         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 633                 if (!oldlines && !newlines)
 634                         break;
 635                 len = linelen(line, size);
 636                 if (!len || line[len-1] != '\n')
 637                         return -1;
 638                 switch (*line) {
 639                 default:
 640                         return -1;
 641                 case ' ':
 642                         oldlines--;
 643                         newlines--;
 644                         break;
 645                 case '-':
 646                         deleted++;
 647                         oldlines--;
 648                         break;
 649                 case '+':
 650                         added++;
 651                         newlines--;
 652                         break;
 653                 /* We allow "\ No newline at end of file" */
 654                 case '\\':
 655                         break;
 656                 }
 657         }
 658         patch->lines_added += added;
 659         patch->lines_deleted += deleted;
 660         return offset;
 661 }
 662
 663 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 664 {
 665         unsigned long offset = 0;
 666         struct fragment **fragp = &patch->fragments;
 667
 668         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 669                 struct fragment *fragment;
 670                 int len;
 671
 672                 fragment = xmalloc(sizeof(*fragment));
 673                 memset(fragment, 0, sizeof(*fragment));
 674                 len = parse_fragment(line, size, patch, fragment);
 675                 if (len <= 0)
 676                         die("corrupt patch at line %d", linenr);
 677
 678                 fragment->patch = line;
 679                 fragment->size = len;
 680
 681                 *fragp = fragment;
 682                 fragp = &fragment->next;
 683
 684                 offset += len;
 685                 line += len;
 686                 size -= len;
 687         }
 688         return offset;
 689 }
 690
 691 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 692 {
 693         int hdrsize, patchsize;
 694         int offset = find_header(buffer, size, &hdrsize, patch);
 695
 696         if (offset < 0)
 697                 return offset;
 698
 699         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 700
 701         return offset + hdrsize + patchsize;
 702 }
 703
 704 const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 705 const char minuses[]= "----------------------------------------------------------------------";
 706
 707 static void show_stats(struct patch *patch)
 708 {
 709         char *name = patch->old_name;
 710         int len, max, add, del;
 711
 712         if (!name)
 713                 name = patch->new_name;
 714
 715         /*
 716          * "scale" the filename
 717          */
 718         len = strlen(name);
 719         max = max_len;
 720         if (max > 50)
 721                 max = 50;
 722         if (len > max)
 723                 name += len - max;
 724         len = max;
 725
 726         /*
 727          * scale the add/delete
 728          */
 729         max = max_change;
 730         if (max + len > 70)
 731                 max = 70 - len;
 732
 733         add = (patch->lines_added * max + max_change/2) / max_change;
 734         del = (patch->lines_deleted * max + max_change/2) / max_change;
 735         printf(" %-*s |%5d %.*s%.*s\n",
 736                 len, name, patch->lines_added + patch->lines_deleted,
 737                 add, pluses, del, minuses);
 738 }
 739
 740 static int check_patch(struct patch *patch)
 741 {
 742         struct stat st;
 743         const char *old_name = patch->old_name;
 744         const char *new_name = patch->new_name;
 745
 746         if (old_name) {
 747                 int pos = cache_name_pos(old_name, strlen(old_name));
 748                 int changed;
 749
 750                 if (pos < 0)
 751                         return error("%s: does not exist in index", old_name);
 752                 if (patch->is_new < 0)
 753                         patch->is_new = 0;
 754                 if (lstat(old_name, &st) < 0)
 755                         return error("%s: %s\n", strerror(errno));
 756                 changed = ce_match_stat(active_cache[pos], &st);
 757                 if (changed)
 758                         return error("%s: does not match index", old_name);
 759                 if (!patch->old_mode)
 760                         patch->old_mode = st.st_mode;
 761         }
 762
 763         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
 764                 if (cache_name_pos(new_name, strlen(new_name)) >= 0)
 765                         return error("%s: already exists in index", new_name);
 766                 if (!lstat(new_name, &st))
 767                         return error("%s: already exists in working directory", new_name);
 768                 if (errno != ENOENT)
 769                         return error("%s: %s", new_name, strerror(errno));
 770         }
 771         return 0;
 772 }
 773
 774 static int check_patch_list(struct patch *patch)
 775 {
 776         int error = 0;
 777
 778         for (;patch ; patch = patch->next)
 779                 error |= check_patch(patch);
 780         return error;
 781 }
 782
 783 static void show_file(int c, unsigned int mode, const char *name)
 784 {
 785         printf("%c %o %s\n", c, mode, name);
 786 }
 787
 788 static void show_file_list(struct patch *patch)
 789 {
 790         for (;patch ; patch = patch->next) {
 791                 if (patch->is_rename) {
 792                         show_file('-', patch->old_mode, patch->old_name);
 793                         show_file('+', patch->new_mode, patch->new_name);
 794                         continue;
 795                 }
 796                 if (patch->is_copy || patch->is_new) {
 797                         show_file('+', patch->new_mode, patch->new_name);
 798                         continue;
 799                 }
 800                 if (patch->is_delete) {
 801                         show_file('-', patch->old_mode, patch->old_name);
 802                         continue;
 803                 }
 804                 if (patch->old_mode && patch->new_mode && patch->old_mode != patch->new_mode) {
 805                         printf("M %o:%o %s\n", patch->old_mode, patch->new_mode, patch->old_name);
 806                         continue;
 807                 }
 808                 printf("M %o %s\n", patch->old_mode, patch->old_name);
 809         }
 810 }
 811
 812 static void stat_patch_list(struct patch *patch)
 813 {
 814         int files, adds, dels;
 815
 816         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
 817                 files++;
 818                 adds += patch->lines_added;
 819                 dels += patch->lines_deleted;
 820                 show_stats(patch);
 821         }
 822
 823         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
 824 }
 825
 826 static void patch_stats(struct patch *patch)
 827 {
 828         int lines = patch->lines_added + patch->lines_deleted;
 829
 830         if (lines > max_change)
 831                 max_change = lines;
 832         if (patch->old_name) {
 833                 int len = strlen(patch->old_name);
 834                 if (len > max_len)
 835                         max_len = len;
 836         }
 837         if (patch->new_name) {
 838                 int len = strlen(patch->new_name);
 839                 if (len > max_len)
 840                         max_len = len;
 841         }
 842 }
 843
 844 static int apply_patch(int fd)
 845 {
 846         unsigned long offset, size;
 847         char *buffer = read_patch_file(fd, &size);
 848         struct patch *list = NULL, **listp = &list;
 849
 850         if (!buffer)
 851                 return -1;
 852         offset = 0;
 853         while (size > 0) {
 854                 struct patch *patch;
 855                 int nr;
 856
 857                 patch = xmalloc(sizeof(*patch));
 858                 memset(patch, 0, sizeof(*patch));
 859                 nr = parse_chunk(buffer + offset, size, patch);
 860                 if (nr < 0)
 861                         break;
 862                 patch_stats(patch);
 863                 *listp = patch;
 864                 listp = &patch->next;
 865                 offset += nr;
 866                 size -= nr;
 867         }
 868
 869         if ((check || apply) && check_patch_list(list) < 0)
 870                 exit(1);
 871
 872         if (show_files)
 873                 show_file_list(list);
 874
 875         if (diffstat)
 876                 stat_patch_list(list);
 877
 878         free(buffer);
 879         return 0;
 880 }
 881
 882 int main(int argc, char **argv)
 883 {
 884         int i;
 885         int read_stdin = 1;
 886
 887         if (read_cache() < 0)
 888                 die("unable to read index file");
 889
 890         for (i = 1; i < argc; i++) {
 891                 const char *arg = argv[i];
 892                 int fd;
 893
 894                 if (!strcmp(arg, "-")) {
 895                         apply_patch(0);
 896                         read_stdin = 0;
 897                         continue;
 898                 }
 899                 if (!strcmp(arg, "--no-merge")) {
 900                         merge_patch = 0;
 901                         continue;
 902                 }
 903                 if (!strcmp(arg, "--stat")) {
 904                         apply = 0;
 905                         diffstat = 1;
 906                         continue;
 907                 }
 908                 if (!strcmp(arg, "--check")) {
 909                         apply = 0;
 910                         check = 1;
 911                         continue;
 912                 }
 913                 if (!strcmp(arg, "--show-files")) {
 914                         show_files = 1;
 915                         continue;
 916                 }
 917                 fd = open(arg, O_RDONLY);
 918                 if (fd < 0)
 919                         usage(apply_usage);
 920                 read_stdin = 0;
 921                 apply_patch(fd);
 922                 close(fd);
 923         }
 924         if (read_stdin)
 925                 apply_patch(0);
 926         return 0;
 927 }