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_SPACE      1
 120 #define TERM_TAB        2
 121
 122 static int name_terminate(const char *name, int namelen, int c, int terminate)
 123 {
 124         if (c == ' ' && !(terminate & TERM_SPACE))
 125                 return 0;
 126         if (c == '\t' && !(terminate & TERM_TAB))
 127                 return 0;
 128
 129         return 1;
 130 }
 131
 132 static char * find_name(const char *line, char *def, int p_value, int terminate)
 133 {
 134         int len;
 135         const char *start = line;
 136         char *name;
 137
 138         for (;;) {
 139                 char c = *line;
 140
 141                 if (isspace(c)) {
 142                         if (c == '\n')
 143                                 break;
 144                         if (name_terminate(start, line-start, c, terminate))
 145                                 break;
 146                 }
 147                 line++;
 148                 if (c == '/' && !--p_value)
 149                         start = line;
 150         }
 151         if (!start)
 152                 return def;
 153         len = line - start;
 154         if (!len)
 155                 return def;
 156
 157         /*
 158          * Generally we prefer the shorter name, especially
 159          * if the other one is just a variation of that with
 160          * something else tacked on to the end (ie "file.orig"
 161          * or "file~").
 162          */
 163         if (def) {
 164                 int deflen = strlen(def);
 165                 if (deflen < len && !strncmp(start, def, deflen))
 166                         return def;
 167         }
 168
 169         name = xmalloc(len + 1);
 170         memcpy(name, start, len);
 171         name[len] = 0;
 172         free(def);
 173         return name;
 174 }
 175
 176 /*
 177  * Get the name etc info from the --/+++ lines of a traditional patch header
 178  *
 179  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 180  *
 181  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 182  * files, we can happily check the index for a match, but for creating a
 183  * new file we should try to match whatever "patch" does. I have no idea.
 184  */
 185 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 186 {
 187         int p_value = 1;
 188         char *name;
 189
 190         first += 4;     // skip "--- "
 191         second += 4;    // skip "+++ "
 192         if (is_dev_null(first)) {
 193                 patch->is_new = 1;
 194                 patch->is_delete = 0;
 195                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 196                 patch->new_name = name;
 197         } else if (is_dev_null(second)) {
 198                 patch->is_new = 0;
 199                 patch->is_delete = 1;
 200                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 201                 patch->old_name = name;
 202         } else {
 203                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 204                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 205                 patch->old_name = patch->new_name = name;
 206         }
 207         if (!name)
 208                 die("unable to find filename in patch at line %d", linenr);
 209 }
 210
 211 static int gitdiff_hdrend(const char *line, struct patch *patch)
 212 {
 213         return -1;
 214 }
 215
 216 /*
 217  * We're anal about diff header consistency, to make
 218  * sure that we don't end up having strange ambiguous
 219  * patches floating around.
 220  *
 221  * As a result, gitdiff_{old|new}name() will check
 222  * their names against any previous information, just
 223  * to make sure..
 224  */
 225 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 226 {
 227         int len;
 228         const char *name;
 229
 230         if (!orig_name && !isnull)
 231                 return find_name(line, NULL, 1, 0);
 232
 233         name = "/dev/null";
 234         len = 9;
 235         if (orig_name) {
 236                 name = orig_name;
 237                 len = strlen(name);
 238                 if (isnull)
 239                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 240         }
 241
 242         if (*name == '/')
 243                 goto absolute_path;
 244
 245         for (;;) {
 246                 char c = *line++;
 247                 if (c == '\n')
 248                         break;
 249                 if (c != '/')
 250                         continue;
 251 absolute_path:
 252                 if (memcmp(line, name, len) || line[len] != '\n')
 253                         break;
 254                 return orig_name;
 255         }
 256         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 257         return NULL;
 258 }
 259
 260 static int gitdiff_oldname(const char *line, struct patch *patch)
 261 {
 262         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 263         return 0;
 264 }
 265
 266 static int gitdiff_newname(const char *line, struct patch *patch)
 267 {
 268         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 269         return 0;
 270 }
 271
 272 static int gitdiff_oldmode(const char *line, struct patch *patch)
 273 {
 274         patch->old_mode = strtoul(line, NULL, 8);
 275         return 0;
 276 }
 277
 278 static int gitdiff_newmode(const char *line, struct patch *patch)
 279 {
 280         patch->new_mode = strtoul(line, NULL, 8);
 281         return 0;
 282 }
 283
 284 static int gitdiff_delete(const char *line, struct patch *patch)
 285 {
 286         patch->is_delete = 1;
 287         patch->old_name = patch->def_name;
 288         return gitdiff_oldmode(line, patch);
 289 }
 290
 291 static int gitdiff_newfile(const char *line, struct patch *patch)
 292 {
 293         patch->is_new = 1;
 294         patch->new_name = patch->def_name;
 295         return gitdiff_newmode(line, patch);
 296 }
 297
 298 static int gitdiff_copysrc(const char *line, struct patch *patch)
 299 {
 300         patch->is_copy = 1;
 301         patch->old_name = find_name(line, NULL, 0, 0);
 302         return 0;
 303 }
 304
 305 static int gitdiff_copydst(const char *line, struct patch *patch)
 306 {
 307         patch->is_copy = 1;
 308         patch->new_name = find_name(line, NULL, 0, 0);
 309         return 0;
 310 }
 311
 312 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 313 {
 314         patch->is_rename = 1;
 315         patch->old_name = find_name(line, NULL, 0, 0);
 316         return 0;
 317 }
 318
 319 static int gitdiff_renamedst(const char *line, struct patch *patch)
 320 {
 321         patch->is_rename = 1;
 322         patch->new_name = find_name(line, NULL, 0, 0);
 323         return 0;
 324 }
 325
 326 static int gitdiff_similarity(const char *line, struct patch *patch)
 327 {
 328         return 0;
 329 }
 330
 331 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 332 {
 333         return 0;
 334 }
 335
 336 /*
 337  * This is normal for a diff that doesn't change anything: we'll fall through
 338  * into the next diff. Tell the parser to break out.
 339  */
 340 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 341 {
 342         return -1;
 343 }
 344
 345 static char *git_header_name(char *line)
 346 {
 347         int len;
 348         char *name, *second;
 349
 350         /*
 351          * Find the first '/'
 352          */
 353         name = line;
 354         for (;;) {
 355                 char c = *name++;
 356                 if (c == '\n')
 357                         return NULL;
 358                 if (c == '/')
 359                         break;
 360         }
 361
 362         /*
 363          * We don't accept absolute paths (/dev/null) as possibly valid
 364          */
 365         if (name == line+1)
 366                 return NULL;
 367
 368         /*
 369          * Accept a name only if it shows up twice, exactly the same
 370          * form.
 371          */
 372         for (len = 0 ; ; len++) {
 373                 char c = name[len];
 374
 375                 switch (c) {
 376                 default:
 377                         continue;
 378                 case '\n':
 379                         break;
 380                 case '\t': case ' ':
 381                         second = name+len;
 382                         for (;;) {
 383                                 char c = *second++;
 384                                 if (c == '\n')
 385                                         return NULL;
 386                                 if (c == '/')
 387                                         break;
 388                         }
 389                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 390                                 char *ret = xmalloc(len + 1);
 391                                 memcpy(ret, name, len);
 392                                 ret[len] = 0;
 393                                 return ret;
 394                         }
 395                 }
 396         }
 397         return NULL;
 398 }
 399
 400 /* Verify that we recognize the lines following a git header */
 401 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 402 {
 403         unsigned long offset;
 404
 405         /* A git diff has explicit new/delete information, so we don't guess */
 406         patch->is_new = 0;
 407         patch->is_delete = 0;
 408
 409         /*
 410          * Some things may not have the old name in the
 411          * rest of the headers anywhere (pure mode changes,
 412          * or removing or adding empty files), so we get
 413          * the default name from the header.
 414          */
 415         patch->def_name = git_header_name(line + strlen("diff --git "));
 416
 417         line += len;
 418         size -= len;
 419         linenr++;
 420         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 421                 static const struct opentry {
 422                         const char *str;
 423                         int (*fn)(const char *, struct patch *);
 424                 } optable[] = {
 425                         { "@@ -", gitdiff_hdrend },
 426                         { "--- ", gitdiff_oldname },
 427                         { "+++ ", gitdiff_newname },
 428                         { "old mode ", gitdiff_oldmode },
 429                         { "new mode ", gitdiff_newmode },
 430                         { "deleted file mode ", gitdiff_delete },
 431                         { "new file mode ", gitdiff_newfile },
 432                         { "copy from ", gitdiff_copysrc },
 433                         { "copy to ", gitdiff_copydst },
 434                         { "rename from ", gitdiff_renamesrc },
 435                         { "rename to ", gitdiff_renamedst },
 436                         { "similarity index ", gitdiff_similarity },
 437                         { "dissimilarity index ", gitdiff_dissimilarity },
 438                         { "", gitdiff_unrecognized },
 439                 };
 440                 int i;
 441
 442                 len = linelen(line, size);
 443                 if (!len || line[len-1] != '\n')
 444                         break;
 445                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 446                         const struct opentry *p = optable + i;
 447                         int oplen = strlen(p->str);
 448                         if (len < oplen || memcmp(p->str, line, oplen))
 449                                 continue;
 450                         if (p->fn(line + oplen, patch) < 0)
 451                                 return offset;
 452                         break;
 453                 }
 454         }
 455
 456         return offset;
 457 }
 458
 459 static int parse_num(const char *line, unsigned long *p)
 460 {
 461         char *ptr;
 462
 463         if (!isdigit(*line))
 464                 return 0;
 465         *p = strtoul(line, &ptr, 10);
 466         return ptr - line;
 467 }
 468
 469 static int parse_range(const char *line, int len, int offset, const char *expect,
 470                         unsigned long *p1, unsigned long *p2)
 471 {
 472         int digits, ex;
 473
 474         if (offset < 0 || offset >= len)
 475                 return -1;
 476         line += offset;
 477         len -= offset;
 478
 479         digits = parse_num(line, p1);
 480         if (!digits)
 481                 return -1;
 482
 483         offset += digits;
 484         line += digits;
 485         len -= digits;
 486
 487         *p2 = *p1;
 488         if (*line == ',') {
 489                 digits = parse_num(line+1, p2);
 490                 if (!digits)
 491                         return -1;
 492
 493                 offset += digits+1;
 494                 line += digits+1;
 495                 len -= digits+1;
 496         }
 497
 498         ex = strlen(expect);
 499         if (ex > len)
 500                 return -1;
 501         if (memcmp(line, expect, ex))
 502                 return -1;
 503
 504         return offset + ex;
 505 }
 506
 507 /*
 508  * Parse a unified diff fragment header of the
 509  * form "@@ -a,b +c,d @@"
 510  */
 511 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 512 {
 513         int offset;
 514
 515         if (!len || line[len-1] != '\n')
 516                 return -1;
 517
 518         /* Figure out the number of lines in a fragment */
 519         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 520         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 521
 522         return offset;
 523 }
 524
 525 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 526 {
 527         unsigned long offset, len;
 528
 529         patch->is_rename = patch->is_copy = 0;
 530         patch->is_new = patch->is_delete = -1;
 531         patch->old_mode = patch->new_mode = 0;
 532         patch->old_name = patch->new_name = NULL;
 533         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 534                 unsigned long nextlen;
 535
 536                 len = linelen(line, size);
 537                 if (!len)
 538                         break;
 539
 540                 /* Testing this early allows us to take a few shortcuts.. */
 541                 if (len < 6)
 542                         continue;
 543
 544                 /*
 545                  * Make sure we don't find any unconnected patch fragmants.
 546                  * That's a sign that we didn't find a header, and that a
 547                  * patch has become corrupted/broken up.
 548                  */
 549                 if (!memcmp("@@ -", line, 4)) {
 550                         struct fragment dummy;
 551                         if (parse_fragment_header(line, len, &dummy) < 0)
 552                                 continue;
 553                         error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
 554                 }
 555
 556                 if (size < len + 6)
 557                         break;
 558
 559                 /*
 560                  * Git patch? It might not have a real patch, just a rename
 561                  * or mode change, so we handle that specially
 562                  */
 563                 if (!memcmp("diff --git ", line, 11)) {
 564                         int git_hdr_len = parse_git_header(line, len, size, patch);
 565                         if (git_hdr_len < 0)
 566                                 continue;
 567                         if (!patch->old_name && !patch->new_name)
 568                                 die("git diff header lacks filename information");
 569                         *hdrsize = git_hdr_len;
 570                         return offset;
 571                 }
 572
 573                 /** --- followed by +++ ? */
 574                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 575                         continue;
 576
 577                 /*
 578                  * We only accept unified patches, so we want it to
 579                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 580                  * minimum
 581                  */
 582                 nextlen = linelen(line + len, size - len);
 583                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 584                         continue;
 585
 586                 /* Ok, we'll consider it a patch */
 587                 parse_traditional_patch(line, line+len, patch);
 588                 *hdrsize = len + nextlen;
 589                 linenr += 2;
 590                 return offset;
 591         }
 592         return -1;
 593 }
 594
 595 /*
 596  * Parse a unified diff. Note that this really needs
 597  * to parse each fragment separately, since the only
 598  * way to know the difference between a "---" that is
 599  * part of a patch, and a "---" that starts the next
 600  * patch is to look at the line counts..
 601  */
 602 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 603 {
 604         int added, deleted;
 605         int len = linelen(line, size), offset;
 606         unsigned long pos[4], oldlines, newlines;
 607
 608         offset = parse_fragment_header(line, len, fragment);
 609         if (offset < 0)
 610                 return -1;
 611         oldlines = fragment->oldlines;
 612         newlines = fragment->newlines;
 613
 614         if (patch->is_new < 0 && (pos[0] || oldlines))
 615                 patch->is_new = 0;
 616         if (patch->is_delete < 0 && (pos[1] || newlines))
 617                 patch->is_delete = 0;
 618
 619         /* Parse the thing.. */
 620         line += len;
 621         size -= len;
 622         linenr++;
 623         added = deleted = 0;
 624         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 625                 if (!oldlines && !newlines)
 626                         break;
 627                 len = linelen(line, size);
 628                 if (!len || line[len-1] != '\n')
 629                         return -1;
 630                 switch (*line) {
 631                 default:
 632                         return -1;
 633                 case ' ':
 634                         oldlines--;
 635                         newlines--;
 636                         break;
 637                 case '-':
 638                         deleted++;
 639                         oldlines--;
 640                         break;
 641                 case '+':
 642                         added++;
 643                         newlines--;
 644                         break;
 645                 /* We allow "\ No newline at end of file" */
 646                 case '\\':
 647                         break;
 648                 }
 649         }
 650         patch->lines_added += added;
 651         patch->lines_deleted += deleted;
 652         return offset;
 653 }
 654
 655 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 656 {
 657         unsigned long offset = 0;
 658         struct fragment **fragp = &patch->fragments;
 659
 660         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 661                 struct fragment *fragment;
 662                 int len;
 663
 664                 fragment = xmalloc(sizeof(*fragment));
 665                 memset(fragment, 0, sizeof(*fragment));
 666                 len = parse_fragment(line, size, patch, fragment);
 667                 if (len <= 0)
 668                         die("corrupt patch at line %d", linenr);
 669
 670                 fragment->patch = line;
 671                 fragment->size = len;
 672
 673                 *fragp = fragment;
 674                 fragp = &fragment->next;
 675
 676                 offset += len;
 677                 line += len;
 678                 size -= len;
 679         }
 680         return offset;
 681 }
 682
 683 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 684 {
 685         int hdrsize, patchsize;
 686         int offset = find_header(buffer, size, &hdrsize, patch);
 687
 688         if (offset < 0)
 689                 return offset;
 690
 691         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 692
 693         return offset + hdrsize + patchsize;
 694 }
 695
 696 const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 697 const char minuses[]= "----------------------------------------------------------------------";
 698
 699 static void show_stats(struct patch *patch)
 700 {
 701         char *name = patch->old_name;
 702         int len, max, add, del, total;
 703
 704         if (!name)
 705                 name = patch->new_name;
 706
 707         /*
 708          * "scale" the filename
 709          */
 710         len = strlen(name);
 711         max = max_len;
 712         if (max > 50)
 713                 max = 50;
 714         if (len > max)
 715                 name += len - max;
 716         len = max;
 717
 718         /*
 719          * scale the add/delete
 720          */
 721         max = max_change;
 722         if (max + len > 70)
 723                 max = 70 - len;
 724
 725         add = patch->lines_added;
 726         del = patch->lines_deleted;
 727         total = add + del;
 728
 729         total = (total * max + max_change / 2) / max_change;
 730         add = (add * max + max_change / 2) / max_change;
 731         del = total - add;
 732         printf(" %-*s |%5d %.*s%.*s\n",
 733                 len, name, patch->lines_added + patch->lines_deleted,
 734                 add, pluses, del, minuses);
 735 }
 736
 737 static int check_patch(struct patch *patch)
 738 {
 739         struct stat st;
 740         const char *old_name = patch->old_name;
 741         const char *new_name = patch->new_name;
 742
 743         if (old_name) {
 744                 int pos = cache_name_pos(old_name, strlen(old_name));
 745                 int changed;
 746
 747                 if (pos < 0)
 748                         return error("%s: does not exist in index", old_name);
 749                 if (patch->is_new < 0)
 750                         patch->is_new = 0;
 751                 if (lstat(old_name, &st) < 0)
 752                         return error("%s: %s\n", strerror(errno));
 753                 changed = ce_match_stat(active_cache[pos], &st);
 754                 if (changed)
 755                         return error("%s: does not match index", old_name);
 756                 if (!patch->old_mode)
 757                         patch->old_mode = st.st_mode;
 758         }
 759
 760         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
 761                 if (cache_name_pos(new_name, strlen(new_name)) >= 0)
 762                         return error("%s: already exists in index", new_name);
 763                 if (!lstat(new_name, &st))
 764                         return error("%s: already exists in working directory", new_name);
 765                 if (errno != ENOENT)
 766                         return error("%s: %s", new_name, strerror(errno));
 767         }
 768         return 0;
 769 }
 770
 771 static int check_patch_list(struct patch *patch)
 772 {
 773         int error = 0;
 774
 775         for (;patch ; patch = patch->next)
 776                 error |= check_patch(patch);
 777         return error;
 778 }
 779
 780 static void show_file(int c, unsigned int mode, const char *name)
 781 {
 782         printf("%c %o %s\n", c, mode, name);
 783 }
 784
 785 static void show_file_list(struct patch *patch)
 786 {
 787         for (;patch ; patch = patch->next) {
 788                 if (patch->is_rename) {
 789                         show_file('-', patch->old_mode, patch->old_name);
 790                         show_file('+', patch->new_mode, patch->new_name);
 791                         continue;
 792                 }
 793                 if (patch->is_copy || patch->is_new) {
 794                         show_file('+', patch->new_mode, patch->new_name);
 795                         continue;
 796                 }
 797                 if (patch->is_delete) {
 798                         show_file('-', patch->old_mode, patch->old_name);
 799                         continue;
 800                 }
 801                 if (patch->old_mode && patch->new_mode && patch->old_mode != patch->new_mode) {
 802                         printf("M %o:%o %s\n", patch->old_mode, patch->new_mode, patch->old_name);
 803                         continue;
 804                 }
 805                 printf("M %o %s\n", patch->old_mode, patch->old_name);
 806         }
 807 }
 808
 809 static void stat_patch_list(struct patch *patch)
 810 {
 811         int files, adds, dels;
 812
 813         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
 814                 files++;
 815                 adds += patch->lines_added;
 816                 dels += patch->lines_deleted;
 817                 show_stats(patch);
 818         }
 819
 820         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
 821 }
 822
 823 static void patch_stats(struct patch *patch)
 824 {
 825         int lines = patch->lines_added + patch->lines_deleted;
 826
 827         if (lines > max_change)
 828                 max_change = lines;
 829         if (patch->old_name) {
 830                 int len = strlen(patch->old_name);
 831                 if (len > max_len)
 832                         max_len = len;
 833         }
 834         if (patch->new_name) {
 835                 int len = strlen(patch->new_name);
 836                 if (len > max_len)
 837                         max_len = len;
 838         }
 839 }
 840
 841 static int apply_patch(int fd)
 842 {
 843         unsigned long offset, size;
 844         char *buffer = read_patch_file(fd, &size);
 845         struct patch *list = NULL, **listp = &list;
 846
 847         if (!buffer)
 848                 return -1;
 849         offset = 0;
 850         while (size > 0) {
 851                 struct patch *patch;
 852                 int nr;
 853
 854                 patch = xmalloc(sizeof(*patch));
 855                 memset(patch, 0, sizeof(*patch));
 856                 nr = parse_chunk(buffer + offset, size, patch);
 857                 if (nr < 0)
 858                         break;
 859                 patch_stats(patch);
 860                 *listp = patch;
 861                 listp = &patch->next;
 862                 offset += nr;
 863                 size -= nr;
 864         }
 865
 866         if ((check || apply) && check_patch_list(list) < 0)
 867                 exit(1);
 868
 869         if (show_files)
 870                 show_file_list(list);
 871
 872         if (diffstat)
 873                 stat_patch_list(list);
 874
 875         free(buffer);
 876         return 0;
 877 }
 878
 879 int main(int argc, char **argv)
 880 {
 881         int i;
 882         int read_stdin = 1;
 883
 884         if (read_cache() < 0)
 885                 die("unable to read index file");
 886
 887         for (i = 1; i < argc; i++) {
 888                 const char *arg = argv[i];
 889                 int fd;
 890
 891                 if (!strcmp(arg, "-")) {
 892                         apply_patch(0);
 893                         read_stdin = 0;
 894                         continue;
 895                 }
 896                 if (!strcmp(arg, "--no-merge")) {
 897                         merge_patch = 0;
 898                         continue;
 899                 }
 900                 if (!strcmp(arg, "--stat")) {
 901                         apply = 0;
 902                         diffstat = 1;
 903                         continue;
 904                 }
 905                 if (!strcmp(arg, "--check")) {
 906                         apply = 0;
 907                         check = 1;
 908                         continue;
 909                 }
 910                 if (!strcmp(arg, "--show-files")) {
 911                         show_files = 1;
 912                         continue;
 913                 }
 914                 fd = open(arg, O_RDONLY);
 915                 if (fd < 0)
 916                         usage(apply_usage);
 917                 read_stdin = 0;
 918                 apply_patch(fd);
 919                 close(fd);
 920         }
 921         if (read_stdin)
 922                 apply_patch(0);
 923         return 0;
 924 }