apply.con commit Merge branch 'jc/pack-reuse' (416b3cb)
   1/*
   2 * apply.c
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 *
   6 * This applies patches on top of some (arbitrary) version of the SCM.
   7 *
   8 */
   9#include <fnmatch.h>
  10#include "cache.h"
  11#include "quote.h"
  12
  13//  --check turns on checking that the working tree matches the
  14//    files that are being modified, but doesn't apply the patch
  15//  --stat does just a diffstat, and doesn't actually apply
  16//  --numstat does numeric diffstat, and doesn't actually apply
  17//  --index-info shows the old and new index info for paths if available.
  18//
  19static const char *prefix;
  20static int prefix_length = -1;
  21
  22static int p_value = 1;
  23static int allow_binary_replacement = 0;
  24static int check_index = 0;
  25static int write_index = 0;
  26static int diffstat = 0;
  27static int numstat = 0;
  28static int summary = 0;
  29static int check = 0;
  30static int apply = 1;
  31static int no_add = 0;
  32static int show_index_info = 0;
  33static int line_termination = '\n';
  34static const char apply_usage[] =
  35"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] <patch>...";
  36
  37/*
  38 * For "diff-stat" like behaviour, we keep track of the biggest change
  39 * we've seen, and the longest filename. That allows us to do simple
  40 * scaling.
  41 */
  42static int max_change, max_len;
  43
  44/*
  45 * Various "current state", notably line numbers and what
  46 * file (and how) we're patching right now.. The "is_xxxx"
  47 * things are flags, where -1 means "don't know yet".
  48 */
  49static int linenr = 1;
  50
  51struct fragment {
  52        unsigned long oldpos, oldlines;
  53        unsigned long newpos, newlines;
  54        const char *patch;
  55        int size;
  56        struct fragment *next;
  57};
  58
  59struct patch {
  60        char *new_name, *old_name, *def_name;
  61        unsigned int old_mode, new_mode;
  62        int is_rename, is_copy, is_new, is_delete, is_binary;
  63        int lines_added, lines_deleted;
  64        int score;
  65        struct fragment *fragments;
  66        char *result;
  67        unsigned long resultsize;
  68        char old_sha1_prefix[41];
  69        char new_sha1_prefix[41];
  70        struct patch *next;
  71};
  72
  73#define CHUNKSIZE (8192)
  74#define SLOP (16)
  75
  76static void *read_patch_file(int fd, unsigned long *sizep)
  77{
  78        unsigned long size = 0, alloc = CHUNKSIZE;
  79        void *buffer = xmalloc(alloc);
  80
  81        for (;;) {
  82                int nr = alloc - size;
  83                if (nr < 1024) {
  84                        alloc += CHUNKSIZE;
  85                        buffer = xrealloc(buffer, alloc);
  86                        nr = alloc - size;
  87                }
  88                nr = xread(fd, buffer + size, nr);
  89                if (!nr)
  90                        break;
  91                if (nr < 0)
  92                        die("git-apply: read returned %s", strerror(errno));
  93                size += nr;
  94        }
  95        *sizep = size;
  96
  97        /*
  98         * Make sure that we have some slop in the buffer
  99         * so that we can do speculative "memcmp" etc, and
 100         * see to it that it is NUL-filled.
 101         */
 102        if (alloc < size + SLOP)
 103                buffer = xrealloc(buffer, size + SLOP);
 104        memset(buffer + size, 0, SLOP);
 105        return buffer;
 106}
 107
 108static unsigned long linelen(const char *buffer, unsigned long size)
 109{
 110        unsigned long len = 0;
 111        while (size--) {
 112                len++;
 113                if (*buffer++ == '\n')
 114                        break;
 115        }
 116        return len;
 117}
 118
 119static int is_dev_null(const char *str)
 120{
 121        return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 122}
 123
 124#define TERM_SPACE      1
 125#define TERM_TAB        2
 126
 127static int name_terminate(const char *name, int namelen, int c, int terminate)
 128{
 129        if (c == ' ' && !(terminate & TERM_SPACE))
 130                return 0;
 131        if (c == '\t' && !(terminate & TERM_TAB))
 132                return 0;
 133
 134        return 1;
 135}
 136
 137static char * find_name(const char *line, char *def, int p_value, int terminate)
 138{
 139        int len;
 140        const char *start = line;
 141        char *name;
 142
 143        if (*line == '"') {
 144                /* Proposed "new-style" GNU patch/diff format; see
 145                 * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
 146                 */
 147                name = unquote_c_style(line, NULL);
 148                if (name) {
 149                        char *cp = name;
 150                        while (p_value) {
 151                                cp = strchr(name, '/');
 152                                if (!cp)
 153                                        break;
 154                                cp++;
 155                                p_value--;
 156                        }
 157                        if (cp) {
 158                                /* name can later be freed, so we need
 159                                 * to memmove, not just return cp
 160                                 */
 161                                memmove(name, cp, strlen(cp) + 1);
 162                                free(def);
 163                                return name;
 164                        }
 165                        else {
 166                                free(name);
 167                                name = NULL;
 168                        }
 169                }
 170        }
 171
 172        for (;;) {
 173                char c = *line;
 174
 175                if (isspace(c)) {
 176                        if (c == '\n')
 177                                break;
 178                        if (name_terminate(start, line-start, c, terminate))
 179                                break;
 180                }
 181                line++;
 182                if (c == '/' && !--p_value)
 183                        start = line;
 184        }
 185        if (!start)
 186                return def;
 187        len = line - start;
 188        if (!len)
 189                return def;
 190
 191        /*
 192         * Generally we prefer the shorter name, especially
 193         * if the other one is just a variation of that with
 194         * something else tacked on to the end (ie "file.orig"
 195         * or "file~").
 196         */
 197        if (def) {
 198                int deflen = strlen(def);
 199                if (deflen < len && !strncmp(start, def, deflen))
 200                        return def;
 201        }
 202
 203        name = xmalloc(len + 1);
 204        memcpy(name, start, len);
 205        name[len] = 0;
 206        free(def);
 207        return name;
 208}
 209
 210/*
 211 * Get the name etc info from the --/+++ lines of a traditional patch header
 212 *
 213 * NOTE! This hardcodes "-p1" behaviour in filename detection.
 214 *
 215 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 216 * files, we can happily check the index for a match, but for creating a
 217 * new file we should try to match whatever "patch" does. I have no idea.
 218 */
 219static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 220{
 221        char *name;
 222
 223        first += 4;     // skip "--- "
 224        second += 4;    // skip "+++ "
 225        if (is_dev_null(first)) {
 226                patch->is_new = 1;
 227                patch->is_delete = 0;
 228                name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 229                patch->new_name = name;
 230        } else if (is_dev_null(second)) {
 231                patch->is_new = 0;
 232                patch->is_delete = 1;
 233                name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 234                patch->old_name = name;
 235        } else {
 236                name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 237                name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 238                patch->old_name = patch->new_name = name;
 239        }
 240        if (!name)
 241                die("unable to find filename in patch at line %d", linenr);
 242}
 243
 244static int gitdiff_hdrend(const char *line, struct patch *patch)
 245{
 246        return -1;
 247}
 248
 249/*
 250 * We're anal about diff header consistency, to make
 251 * sure that we don't end up having strange ambiguous
 252 * patches floating around.
 253 *
 254 * As a result, gitdiff_{old|new}name() will check
 255 * their names against any previous information, just
 256 * to make sure..
 257 */
 258static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 259{
 260        if (!orig_name && !isnull)
 261                return find_name(line, NULL, 1, 0);
 262
 263        if (orig_name) {
 264                int len;
 265                const char *name;
 266                char *another;
 267                name = orig_name;
 268                len = strlen(name);
 269                if (isnull)
 270                        die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 271                another = find_name(line, NULL, 1, 0);
 272                if (!another || memcmp(another, name, len))
 273                        die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 274                free(another);
 275                return orig_name;
 276        }
 277        else {
 278                /* expect "/dev/null" */
 279                if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 280                        die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
 281                return NULL;
 282        }
 283}
 284
 285static int gitdiff_oldname(const char *line, struct patch *patch)
 286{
 287        patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 288        return 0;
 289}
 290
 291static int gitdiff_newname(const char *line, struct patch *patch)
 292{
 293        patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 294        return 0;
 295}
 296
 297static int gitdiff_oldmode(const char *line, struct patch *patch)
 298{
 299        patch->old_mode = strtoul(line, NULL, 8);
 300        return 0;
 301}
 302
 303static int gitdiff_newmode(const char *line, struct patch *patch)
 304{
 305        patch->new_mode = strtoul(line, NULL, 8);
 306        return 0;
 307}
 308
 309static int gitdiff_delete(const char *line, struct patch *patch)
 310{
 311        patch->is_delete = 1;
 312        patch->old_name = patch->def_name;
 313        return gitdiff_oldmode(line, patch);
 314}
 315
 316static int gitdiff_newfile(const char *line, struct patch *patch)
 317{
 318        patch->is_new = 1;
 319        patch->new_name = patch->def_name;
 320        return gitdiff_newmode(line, patch);
 321}
 322
 323static int gitdiff_copysrc(const char *line, struct patch *patch)
 324{
 325        patch->is_copy = 1;
 326        patch->old_name = find_name(line, NULL, 0, 0);
 327        return 0;
 328}
 329
 330static int gitdiff_copydst(const char *line, struct patch *patch)
 331{
 332        patch->is_copy = 1;
 333        patch->new_name = find_name(line, NULL, 0, 0);
 334        return 0;
 335}
 336
 337static int gitdiff_renamesrc(const char *line, struct patch *patch)
 338{
 339        patch->is_rename = 1;
 340        patch->old_name = find_name(line, NULL, 0, 0);
 341        return 0;
 342}
 343
 344static int gitdiff_renamedst(const char *line, struct patch *patch)
 345{
 346        patch->is_rename = 1;
 347        patch->new_name = find_name(line, NULL, 0, 0);
 348        return 0;
 349}
 350
 351static int gitdiff_similarity(const char *line, struct patch *patch)
 352{
 353        if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 354                patch->score = 0;
 355        return 0;
 356}
 357
 358static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 359{
 360        if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 361                patch->score = 0;
 362        return 0;
 363}
 364
 365static int gitdiff_index(const char *line, struct patch *patch)
 366{
 367        /* index line is N hexadecimal, "..", N hexadecimal,
 368         * and optional space with octal mode.
 369         */
 370        const char *ptr, *eol;
 371        int len;
 372
 373        ptr = strchr(line, '.');
 374        if (!ptr || ptr[1] != '.' || 40 < ptr - line)
 375                return 0;
 376        len = ptr - line;
 377        memcpy(patch->old_sha1_prefix, line, len);
 378        patch->old_sha1_prefix[len] = 0;
 379
 380        line = ptr + 2;
 381        ptr = strchr(line, ' ');
 382        eol = strchr(line, '\n');
 383
 384        if (!ptr || eol < ptr)
 385                ptr = eol;
 386        len = ptr - line;
 387
 388        if (40 < len)
 389                return 0;
 390        memcpy(patch->new_sha1_prefix, line, len);
 391        patch->new_sha1_prefix[len] = 0;
 392        if (*ptr == ' ')
 393                patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
 394        return 0;
 395}
 396
 397/*
 398 * This is normal for a diff that doesn't change anything: we'll fall through
 399 * into the next diff. Tell the parser to break out.
 400 */
 401static int gitdiff_unrecognized(const char *line, struct patch *patch)
 402{
 403        return -1;
 404}
 405
 406static const char *stop_at_slash(const char *line, int llen)
 407{
 408        int i;
 409
 410        for (i = 0; i < llen; i++) {
 411                int ch = line[i];
 412                if (ch == '/')
 413                        return line + i;
 414        }
 415        return NULL;
 416}
 417
 418/* This is to extract the same name that appears on "diff --git"
 419 * line.  We do not find and return anything if it is a rename
 420 * patch, and it is OK because we will find the name elsewhere.
 421 * We need to reliably find name only when it is mode-change only,
 422 * creation or deletion of an empty file.  In any of these cases,
 423 * both sides are the same name under a/ and b/ respectively.
 424 */
 425static char *git_header_name(char *line, int llen)
 426{
 427        int len;
 428        const char *name;
 429        const char *second = NULL;
 430
 431        line += strlen("diff --git ");
 432        llen -= strlen("diff --git ");
 433
 434        if (*line == '"') {
 435                const char *cp;
 436                char *first = unquote_c_style(line, &second);
 437                if (!first)
 438                        return NULL;
 439
 440                /* advance to the first slash */
 441                cp = stop_at_slash(first, strlen(first));
 442                if (!cp || cp == first) {
 443                        /* we do not accept absolute paths */
 444                free_first_and_fail:
 445                        free(first);
 446                        return NULL;
 447                }
 448                len = strlen(cp+1);
 449                memmove(first, cp+1, len+1); /* including NUL */
 450
 451                /* second points at one past closing dq of name.
 452                 * find the second name.
 453                 */
 454                while ((second < line + llen) && isspace(*second))
 455                        second++;
 456
 457                if (line + llen <= second)
 458                        goto free_first_and_fail;
 459                if (*second == '"') {
 460                        char *sp = unquote_c_style(second, NULL);
 461                        if (!sp)
 462                                goto free_first_and_fail;
 463                        cp = stop_at_slash(sp, strlen(sp));
 464                        if (!cp || cp == sp) {
 465                        free_both_and_fail:
 466                                free(sp);
 467                                goto free_first_and_fail;
 468                        }
 469                        /* They must match, otherwise ignore */
 470                        if (strcmp(cp+1, first))
 471                                goto free_both_and_fail;
 472                        free(sp);
 473                        return first;
 474                }
 475
 476                /* unquoted second */
 477                cp = stop_at_slash(second, line + llen - second);
 478                if (!cp || cp == second)
 479                        goto free_first_and_fail;
 480                cp++;
 481                if (line + llen - cp != len + 1 ||
 482                    memcmp(first, cp, len))
 483                        goto free_first_and_fail;
 484                return first;
 485        }
 486
 487        /* unquoted first name */
 488        name = stop_at_slash(line, llen);
 489        if (!name || name == line)
 490                return NULL;
 491
 492        name++;
 493
 494        /* since the first name is unquoted, a dq if exists must be
 495         * the beginning of the second name.
 496         */
 497        for (second = name; second < line + llen; second++) {
 498                if (*second == '"') {
 499                        const char *cp = second;
 500                        const char *np;
 501                        char *sp = unquote_c_style(second, NULL);
 502
 503                        if (!sp)
 504                                return NULL;
 505                        np = stop_at_slash(sp, strlen(sp));
 506                        if (!np || np == sp) {
 507                        free_second_and_fail:
 508                                free(sp);
 509                                return NULL;
 510                        }
 511                        np++;
 512                        len = strlen(np);
 513                        if (len < cp - name &&
 514                            !strncmp(np, name, len) &&
 515                            isspace(name[len])) {
 516                                /* Good */
 517                                memmove(sp, np, len + 1);
 518                                return sp;
 519                        }
 520                        goto free_second_and_fail;
 521                }
 522        }
 523
 524        /*
 525         * Accept a name only if it shows up twice, exactly the same
 526         * form.
 527         */
 528        for (len = 0 ; ; len++) {
 529                char c = name[len];
 530
 531                switch (c) {
 532                default:
 533                        continue;
 534                case '\n':
 535                        return NULL;
 536                case '\t': case ' ':
 537                        second = name+len;
 538                        for (;;) {
 539                                char c = *second++;
 540                                if (c == '\n')
 541                                        return NULL;
 542                                if (c == '/')
 543                                        break;
 544                        }
 545                        if (second[len] == '\n' && !memcmp(name, second, len)) {
 546                                char *ret = xmalloc(len + 1);
 547                                memcpy(ret, name, len);
 548                                ret[len] = 0;
 549                                return ret;
 550                        }
 551                }
 552        }
 553        return NULL;
 554}
 555
 556/* Verify that we recognize the lines following a git header */
 557static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 558{
 559        unsigned long offset;
 560
 561        /* A git diff has explicit new/delete information, so we don't guess */
 562        patch->is_new = 0;
 563        patch->is_delete = 0;
 564
 565        /*
 566         * Some things may not have the old name in the
 567         * rest of the headers anywhere (pure mode changes,
 568         * or removing or adding empty files), so we get
 569         * the default name from the header.
 570         */
 571        patch->def_name = git_header_name(line, len);
 572
 573        line += len;
 574        size -= len;
 575        linenr++;
 576        for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 577                static const struct opentry {
 578                        const char *str;
 579                        int (*fn)(const char *, struct patch *);
 580                } optable[] = {
 581                        { "@@ -", gitdiff_hdrend },
 582                        { "--- ", gitdiff_oldname },
 583                        { "+++ ", gitdiff_newname },
 584                        { "old mode ", gitdiff_oldmode },
 585                        { "new mode ", gitdiff_newmode },
 586                        { "deleted file mode ", gitdiff_delete },
 587                        { "new file mode ", gitdiff_newfile },
 588                        { "copy from ", gitdiff_copysrc },
 589                        { "copy to ", gitdiff_copydst },
 590                        { "rename old ", gitdiff_renamesrc },
 591                        { "rename new ", gitdiff_renamedst },
 592                        { "rename from ", gitdiff_renamesrc },
 593                        { "rename to ", gitdiff_renamedst },
 594                        { "similarity index ", gitdiff_similarity },
 595                        { "dissimilarity index ", gitdiff_dissimilarity },
 596                        { "index ", gitdiff_index },
 597                        { "", gitdiff_unrecognized },
 598                };
 599                int i;
 600
 601                len = linelen(line, size);
 602                if (!len || line[len-1] != '\n')
 603                        break;
 604                for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
 605                        const struct opentry *p = optable + i;
 606                        int oplen = strlen(p->str);
 607                        if (len < oplen || memcmp(p->str, line, oplen))
 608                                continue;
 609                        if (p->fn(line + oplen, patch) < 0)
 610                                return offset;
 611                        break;
 612                }
 613        }
 614
 615        return offset;
 616}
 617
 618static int parse_num(const char *line, unsigned long *p)
 619{
 620        char *ptr;
 621
 622        if (!isdigit(*line))
 623                return 0;
 624        *p = strtoul(line, &ptr, 10);
 625        return ptr - line;
 626}
 627
 628static int parse_range(const char *line, int len, int offset, const char *expect,
 629                        unsigned long *p1, unsigned long *p2)
 630{
 631        int digits, ex;
 632
 633        if (offset < 0 || offset >= len)
 634                return -1;
 635        line += offset;
 636        len -= offset;
 637
 638        digits = parse_num(line, p1);
 639        if (!digits)
 640                return -1;
 641
 642        offset += digits;
 643        line += digits;
 644        len -= digits;
 645
 646        *p2 = *p1;
 647        if (*line == ',') {
 648                digits = parse_num(line+1, p2);
 649                if (!digits)
 650                        return -1;
 651
 652                offset += digits+1;
 653                line += digits+1;
 654                len -= digits+1;
 655        }
 656
 657        ex = strlen(expect);
 658        if (ex > len)
 659                return -1;
 660        if (memcmp(line, expect, ex))
 661                return -1;
 662
 663        return offset + ex;
 664}
 665
 666/*
 667 * Parse a unified diff fragment header of the
 668 * form "@@ -a,b +c,d @@"
 669 */
 670static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 671{
 672        int offset;
 673
 674        if (!len || line[len-1] != '\n')
 675                return -1;
 676
 677        /* Figure out the number of lines in a fragment */
 678        offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 679        offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 680
 681        return offset;
 682}
 683
 684static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 685{
 686        unsigned long offset, len;
 687
 688        patch->is_rename = patch->is_copy = 0;
 689        patch->is_new = patch->is_delete = -1;
 690        patch->old_mode = patch->new_mode = 0;
 691        patch->old_name = patch->new_name = NULL;
 692        for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 693                unsigned long nextlen;
 694
 695                len = linelen(line, size);
 696                if (!len)
 697                        break;
 698
 699                /* Testing this early allows us to take a few shortcuts.. */
 700                if (len < 6)
 701                        continue;
 702
 703                /*
 704                 * Make sure we don't find any unconnected patch fragmants.
 705                 * That's a sign that we didn't find a header, and that a
 706                 * patch has become corrupted/broken up.
 707                 */
 708                if (!memcmp("@@ -", line, 4)) {
 709                        struct fragment dummy;
 710                        if (parse_fragment_header(line, len, &dummy) < 0)
 711                                continue;
 712                        error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
 713                }
 714
 715                if (size < len + 6)
 716                        break;
 717
 718                /*
 719                 * Git patch? It might not have a real patch, just a rename
 720                 * or mode change, so we handle that specially
 721                 */
 722                if (!memcmp("diff --git ", line, 11)) {
 723                        int git_hdr_len = parse_git_header(line, len, size, patch);
 724                        if (git_hdr_len <= len)
 725                                continue;
 726                        if (!patch->old_name && !patch->new_name) {
 727                                if (!patch->def_name)
 728                                        die("git diff header lacks filename information (line %d)", linenr);
 729                                patch->old_name = patch->new_name = patch->def_name;
 730                        }
 731                        *hdrsize = git_hdr_len;
 732                        return offset;
 733                }
 734
 735                /** --- followed by +++ ? */
 736                if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 737                        continue;
 738
 739                /*
 740                 * We only accept unified patches, so we want it to
 741                 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 742                 * minimum
 743                 */
 744                nextlen = linelen(line + len, size - len);
 745                if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 746                        continue;
 747
 748                /* Ok, we'll consider it a patch */
 749                parse_traditional_patch(line, line+len, patch);
 750                *hdrsize = len + nextlen;
 751                linenr += 2;
 752                return offset;
 753        }
 754        return -1;
 755}
 756
 757/*
 758 * Parse a unified diff. Note that this really needs
 759 * to parse each fragment separately, since the only
 760 * way to know the difference between a "---" that is
 761 * part of a patch, and a "---" that starts the next
 762 * patch is to look at the line counts..
 763 */
 764static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 765{
 766        int added, deleted;
 767        int len = linelen(line, size), offset;
 768        unsigned long oldlines, newlines;
 769
 770        offset = parse_fragment_header(line, len, fragment);
 771        if (offset < 0)
 772                return -1;
 773        oldlines = fragment->oldlines;
 774        newlines = fragment->newlines;
 775
 776        if (patch->is_new < 0) {
 777                patch->is_new =  !oldlines;
 778                if (!oldlines)
 779                        patch->old_name = NULL;
 780        }
 781        if (patch->is_delete < 0) {
 782                patch->is_delete = !newlines;
 783                if (!newlines)
 784                        patch->new_name = NULL;
 785        }
 786
 787        if (patch->is_new != !oldlines)
 788                return error("new file depends on old contents");
 789        if (patch->is_delete != !newlines) {
 790                if (newlines)
 791                        return error("deleted file still has contents");
 792                fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
 793        }
 794
 795        /* Parse the thing.. */
 796        line += len;
 797        size -= len;
 798        linenr++;
 799        added = deleted = 0;
 800        for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 801                if (!oldlines && !newlines)
 802                        break;
 803                len = linelen(line, size);
 804                if (!len || line[len-1] != '\n')
 805                        return -1;
 806                switch (*line) {
 807                default:
 808                        return -1;
 809                case ' ':
 810                        oldlines--;
 811                        newlines--;
 812                        break;
 813                case '-':
 814                        deleted++;
 815                        oldlines--;
 816                        break;
 817                case '+':
 818                        added++;
 819                        newlines--;
 820                        break;
 821
 822                /* We allow "\ No newline at end of file". Depending
 823                 * on locale settings when the patch was produced we
 824                 * don't know what this line looks like. The only
 825                 * thing we do know is that it begins with "\ ".
 826                 * Checking for 12 is just for sanity check -- any
 827                 * l10n of "\ No newline..." is at least that long.
 828                 */
 829                case '\\':
 830                        if (len < 12 || memcmp(line, "\\ ", 2))
 831                                return -1;
 832                        break;
 833                }
 834        }
 835        /* If a fragment ends with an incomplete line, we failed to include
 836         * it in the above loop because we hit oldlines == newlines == 0
 837         * before seeing it.
 838         */
 839        if (12 < size && !memcmp(line, "\\ ", 2))
 840                offset += linelen(line, size);
 841
 842        patch->lines_added += added;
 843        patch->lines_deleted += deleted;
 844        return offset;
 845}
 846
 847static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 848{
 849        unsigned long offset = 0;
 850        struct fragment **fragp = &patch->fragments;
 851
 852        while (size > 4 && !memcmp(line, "@@ -", 4)) {
 853                struct fragment *fragment;
 854                int len;
 855
 856                fragment = xmalloc(sizeof(*fragment));
 857                memset(fragment, 0, sizeof(*fragment));
 858                len = parse_fragment(line, size, patch, fragment);
 859                if (len <= 0)
 860                        die("corrupt patch at line %d", linenr);
 861
 862                fragment->patch = line;
 863                fragment->size = len;
 864
 865                *fragp = fragment;
 866                fragp = &fragment->next;
 867
 868                offset += len;
 869                line += len;
 870                size -= len;
 871        }
 872        return offset;
 873}
 874
 875static inline int metadata_changes(struct patch *patch)
 876{
 877        return  patch->is_rename > 0 ||
 878                patch->is_copy > 0 ||
 879                patch->is_new > 0 ||
 880                patch->is_delete ||
 881                (patch->old_mode && patch->new_mode &&
 882                 patch->old_mode != patch->new_mode);
 883}
 884
 885static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 886{
 887        int hdrsize, patchsize;
 888        int offset = find_header(buffer, size, &hdrsize, patch);
 889
 890        if (offset < 0)
 891                return offset;
 892
 893        patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
 894
 895        if (!patchsize) {
 896                static const char *binhdr[] = {
 897                        "Binary files ",
 898                        "Files ",
 899                        NULL,
 900                };
 901                int i;
 902                int hd = hdrsize + offset;
 903                unsigned long llen = linelen(buffer + hd, size - hd);
 904
 905                if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
 906                        for (i = 0; binhdr[i]; i++) {
 907                                int len = strlen(binhdr[i]);
 908                                if (len < size - hd &&
 909                                    !memcmp(binhdr[i], buffer + hd, len)) {
 910                                        patch->is_binary = 1;
 911                                        break;
 912                                }
 913                        }
 914
 915                /* Empty patch cannot be applied if:
 916                 * - it is a binary patch and we do not do binary_replace, or
 917                 * - text patch without metadata change
 918                 */
 919                if ((apply || check) &&
 920                    (patch->is_binary
 921                     ? !allow_binary_replacement
 922                     : !metadata_changes(patch)))
 923                        die("patch with only garbage at line %d", linenr);
 924        }
 925
 926        return offset + hdrsize + patchsize;
 927}
 928
 929static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 930static const char minuses[]= "----------------------------------------------------------------------";
 931
 932static void show_stats(struct patch *patch)
 933{
 934        const char *prefix = "";
 935        char *name = patch->new_name;
 936        char *qname = NULL;
 937        int len, max, add, del, total;
 938
 939        if (!name)
 940                name = patch->old_name;
 941
 942        if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 943                qname = xmalloc(len + 1);
 944                quote_c_style(name, qname, NULL, 0);
 945                name = qname;
 946        }
 947
 948        /*
 949         * "scale" the filename
 950         */
 951        len = strlen(name);
 952        max = max_len;
 953        if (max > 50)
 954                max = 50;
 955        if (len > max) {
 956                char *slash;
 957                prefix = "...";
 958                max -= 3;
 959                name += len - max;
 960                slash = strchr(name, '/');
 961                if (slash)
 962                        name = slash;
 963        }
 964        len = max;
 965
 966        /*
 967         * scale the add/delete
 968         */
 969        max = max_change;
 970        if (max + len > 70)
 971                max = 70 - len;
 972
 973        add = patch->lines_added;
 974        del = patch->lines_deleted;
 975        total = add + del;
 976
 977        if (max_change > 0) {
 978                total = (total * max + max_change / 2) / max_change;
 979                add = (add * max + max_change / 2) / max_change;
 980                del = total - add;
 981        }
 982        if (patch->is_binary)
 983                printf(" %s%-*s |  Bin\n", prefix, len, name);
 984        else
 985                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 986                       len, name, patch->lines_added + patch->lines_deleted,
 987                       add, pluses, del, minuses);
 988        if (qname)
 989                free(qname);
 990}
 991
 992static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
 993{
 994        int fd;
 995        unsigned long got;
 996
 997        switch (st->st_mode & S_IFMT) {
 998        case S_IFLNK:
 999                return readlink(path, buf, size);
1000        case S_IFREG:
1001                fd = open(path, O_RDONLY);
1002                if (fd < 0)
1003                        return error("unable to open %s", path);
1004                got = 0;
1005                for (;;) {
1006                        int ret = xread(fd, buf + got, size - got);
1007                        if (ret <= 0)
1008                                break;
1009                        got += ret;
1010                }
1011                close(fd);
1012                return got;
1013
1014        default:
1015                return -1;
1016        }
1017}
1018
1019static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1020{
1021        int i;
1022        unsigned long start, backwards, forwards;
1023
1024        if (fragsize > size)
1025                return -1;
1026
1027        start = 0;
1028        if (line > 1) {
1029                unsigned long offset = 0;
1030                i = line-1;
1031                while (offset + fragsize <= size) {
1032                        if (buf[offset++] == '\n') {
1033                                start = offset;
1034                                if (!--i)
1035                                        break;
1036                        }
1037                }
1038        }
1039
1040        /* Exact line number? */
1041        if (!memcmp(buf + start, fragment, fragsize))
1042                return start;
1043
1044        /*
1045         * There's probably some smart way to do this, but I'll leave
1046         * that to the smart and beautiful people. I'm simple and stupid.
1047         */
1048        backwards = start;
1049        forwards = start;
1050        for (i = 0; ; i++) {
1051                unsigned long try;
1052                int n;
1053
1054                /* "backward" */
1055                if (i & 1) {
1056                        if (!backwards) {
1057                                if (forwards + fragsize > size)
1058                                        break;
1059                                continue;
1060                        }
1061                        do {
1062                                --backwards;
1063                        } while (backwards && buf[backwards-1] != '\n');
1064                        try = backwards;
1065                } else {
1066                        while (forwards + fragsize <= size) {
1067                                if (buf[forwards++] == '\n')
1068                                        break;
1069                        }
1070                        try = forwards;
1071                }
1072
1073                if (try + fragsize > size)
1074                        continue;
1075                if (memcmp(buf + try, fragment, fragsize))
1076                        continue;
1077                n = (i >> 1)+1;
1078                if (i & 1)
1079                        n = -n;
1080                return try;
1081        }
1082
1083        /*
1084         * We should start searching forward and backward.
1085         */
1086        return -1;
1087}
1088
1089struct buffer_desc {
1090        char *buffer;
1091        unsigned long size;
1092        unsigned long alloc;
1093};
1094
1095static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1096{
1097        char *buf = desc->buffer;
1098        const char *patch = frag->patch;
1099        int offset, size = frag->size;
1100        char *old = xmalloc(size);
1101        char *new = xmalloc(size);
1102        int oldsize = 0, newsize = 0;
1103
1104        while (size > 0) {
1105                int len = linelen(patch, size);
1106                int plen;
1107
1108                if (!len)
1109                        break;
1110
1111                /*
1112                 * "plen" is how much of the line we should use for
1113                 * the actual patch data. Normally we just remove the
1114                 * first character on the line, but if the line is
1115                 * followed by "\ No newline", then we also remove the
1116                 * last one (which is the newline, of course).
1117                 */
1118                plen = len-1;
1119                if (len < size && patch[len] == '\\')
1120                        plen--;
1121                switch (*patch) {
1122                case ' ':
1123                case '-':
1124                        memcpy(old + oldsize, patch + 1, plen);
1125                        oldsize += plen;
1126                        if (*patch == '-')
1127                                break;
1128                /* Fall-through for ' ' */
1129                case '+':
1130                        if (*patch != '+' || !no_add) {
1131                                memcpy(new + newsize, patch + 1, plen);
1132                                newsize += plen;
1133                        }
1134                        break;
1135                case '@': case '\\':
1136                        /* Ignore it, we already handled it */
1137                        break;
1138                default:
1139                        return -1;
1140                }
1141                patch += len;
1142                size -= len;
1143        }
1144
1145#ifdef NO_ACCURATE_DIFF
1146        if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1147                        newsize > 0 && new[newsize - 1] == '\n') {
1148                oldsize--;
1149                newsize--;
1150        }
1151#endif
1152                        
1153        offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1154        if (offset >= 0) {
1155                int diff = newsize - oldsize;
1156                unsigned long size = desc->size + diff;
1157                unsigned long alloc = desc->alloc;
1158
1159                if (size > alloc) {
1160                        alloc = size + 8192;
1161                        desc->alloc = alloc;
1162                        buf = xrealloc(buf, alloc);
1163                        desc->buffer = buf;
1164                }
1165                desc->size = size;
1166                memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1167                memcpy(buf + offset, new, newsize);
1168                offset = 0;
1169        }
1170
1171        free(old);
1172        free(new);
1173        return offset;
1174}
1175
1176static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1177{
1178        struct fragment *frag = patch->fragments;
1179        const char *name = patch->old_name ? patch->old_name : patch->new_name;
1180
1181        if (patch->is_binary) {
1182                unsigned char sha1[20];
1183
1184                if (!allow_binary_replacement)
1185                        return error("cannot apply binary patch to '%s' "
1186                                     "without --allow-binary-replacement",
1187                                     name);
1188
1189                /* For safety, we require patch index line to contain
1190                 * full 40-byte textual SHA1 for old and new, at least for now.
1191                 */
1192                if (strlen(patch->old_sha1_prefix) != 40 ||
1193                    strlen(patch->new_sha1_prefix) != 40 ||
1194                    get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1195                    get_sha1_hex(patch->new_sha1_prefix, sha1))
1196                        return error("cannot apply binary patch to '%s' "
1197                                     "without full index line", name);
1198
1199                if (patch->old_name) {
1200                        unsigned char hdr[50];
1201                        int hdrlen;
1202
1203                        /* See if the old one matches what the patch
1204                         * applies to.
1205                         */
1206                        write_sha1_file_prepare(desc->buffer, desc->size,
1207                                                "blob", sha1, hdr, &hdrlen);
1208                        if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1209                                return error("the patch applies to '%s' (%s), "
1210                                             "which does not match the "
1211                                             "current contents.",
1212                                             name, sha1_to_hex(sha1));
1213                }
1214                else {
1215                        /* Otherwise, the old one must be empty. */
1216                        if (desc->size)
1217                                return error("the patch applies to an empty "
1218                                             "'%s' but it is not empty", name);
1219                }
1220
1221                /* For now, we do not record post-image data in the patch,
1222                 * and require the object already present in the recipient's
1223                 * object database.
1224                 */
1225                if (desc->buffer) {
1226                        free(desc->buffer);
1227                        desc->alloc = desc->size = 0;
1228                }
1229                get_sha1_hex(patch->new_sha1_prefix, sha1);
1230
1231                if (memcmp(sha1, null_sha1, 20)) {
1232                        char type[10];
1233                        unsigned long size;
1234
1235                        desc->buffer = read_sha1_file(sha1, type, &size);
1236                        if (!desc->buffer)
1237                                return error("the necessary postimage %s for "
1238                                             "'%s' does not exist",
1239                                             patch->new_sha1_prefix, name);
1240                        desc->alloc = desc->size = size;
1241                }
1242
1243                return 0;
1244        }
1245
1246        while (frag) {
1247                if (apply_one_fragment(desc, frag) < 0)
1248                        return error("patch failed: %s:%ld",
1249                                     name, frag->oldpos);
1250                frag = frag->next;
1251        }
1252        return 0;
1253}
1254
1255static int apply_data(struct patch *patch, struct stat *st)
1256{
1257        char *buf;
1258        unsigned long size, alloc;
1259        struct buffer_desc desc;
1260
1261        size = 0;
1262        alloc = 0;
1263        buf = NULL;
1264        if (patch->old_name) {
1265                size = st->st_size;
1266                alloc = size + 8192;
1267                buf = xmalloc(alloc);
1268                if (read_old_data(st, patch->old_name, buf, alloc) != size)
1269                        return error("read of %s failed", patch->old_name);
1270        }
1271
1272        desc.size = size;
1273        desc.alloc = alloc;
1274        desc.buffer = buf;
1275        if (apply_fragments(&desc, patch) < 0)
1276                return -1;
1277        patch->result = desc.buffer;
1278        patch->resultsize = desc.size;
1279
1280        if (patch->is_delete && patch->resultsize)
1281                return error("removal patch leaves file contents");
1282
1283        return 0;
1284}
1285
1286static int check_patch(struct patch *patch)
1287{
1288        struct stat st;
1289        const char *old_name = patch->old_name;
1290        const char *new_name = patch->new_name;
1291        const char *name = old_name ? old_name : new_name;
1292
1293        if (old_name) {
1294                int changed;
1295                int stat_ret = lstat(old_name, &st);
1296
1297                if (check_index) {
1298                        int pos = cache_name_pos(old_name, strlen(old_name));
1299                        if (pos < 0)
1300                                return error("%s: does not exist in index",
1301                                             old_name);
1302                        if (stat_ret < 0) {
1303                                struct checkout costate;
1304                                if (errno != ENOENT)
1305                                        return error("%s: %s", old_name,
1306                                                     strerror(errno));
1307                                /* checkout */
1308                                costate.base_dir = "";
1309                                costate.base_dir_len = 0;
1310                                costate.force = 0;
1311                                costate.quiet = 0;
1312                                costate.not_new = 0;
1313                                costate.refresh_cache = 1;
1314                                if (checkout_entry(active_cache[pos],
1315                                                   &costate) ||
1316                                    lstat(old_name, &st))
1317                                        return -1;
1318                        }
1319
1320                        changed = ce_match_stat(active_cache[pos], &st, 1);
1321                        if (changed)
1322                                return error("%s: does not match index",
1323                                             old_name);
1324                }
1325                else if (stat_ret < 0)
1326                        return error("%s: %s", old_name, strerror(errno));
1327
1328                if (patch->is_new < 0)
1329                        patch->is_new = 0;
1330                st.st_mode = ntohl(create_ce_mode(st.st_mode));
1331                if (!patch->old_mode)
1332                        patch->old_mode = st.st_mode;
1333                if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1334                        return error("%s: wrong type", old_name);
1335                if (st.st_mode != patch->old_mode)
1336                        fprintf(stderr, "warning: %s has type %o, expected %o\n",
1337                                old_name, st.st_mode, patch->old_mode);
1338        }
1339
1340        if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1341                if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1342                        return error("%s: already exists in index", new_name);
1343                if (!lstat(new_name, &st))
1344                        return error("%s: already exists in working directory", new_name);
1345                if (errno != ENOENT)
1346                        return error("%s: %s", new_name, strerror(errno));
1347                if (!patch->new_mode) {
1348                        if (patch->is_new)
1349                                patch->new_mode = S_IFREG | 0644;
1350                        else
1351                                patch->new_mode = patch->old_mode;
1352                }
1353        }
1354
1355        if (new_name && old_name) {
1356                int same = !strcmp(old_name, new_name);
1357                if (!patch->new_mode)
1358                        patch->new_mode = patch->old_mode;
1359                if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1360                        return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1361                                patch->new_mode, new_name, patch->old_mode,
1362                                same ? "" : " of ", same ? "" : old_name);
1363        }       
1364
1365        if (apply_data(patch, &st) < 0)
1366                return error("%s: patch does not apply", name);
1367        return 0;
1368}
1369
1370static int check_patch_list(struct patch *patch)
1371{
1372        int error = 0;
1373
1374        for (;patch ; patch = patch->next)
1375                error |= check_patch(patch);
1376        return error;
1377}
1378
1379static inline int is_null_sha1(const unsigned char *sha1)
1380{
1381        return !memcmp(sha1, null_sha1, 20);
1382}
1383
1384static void show_index_list(struct patch *list)
1385{
1386        struct patch *patch;
1387
1388        /* Once we start supporting the reverse patch, it may be
1389         * worth showing the new sha1 prefix, but until then...
1390         */
1391        for (patch = list; patch; patch = patch->next) {
1392                const unsigned char *sha1_ptr;
1393                unsigned char sha1[20];
1394                const char *name;
1395
1396                name = patch->old_name ? patch->old_name : patch->new_name;
1397                if (patch->is_new)
1398                        sha1_ptr = null_sha1;
1399                else if (get_sha1(patch->old_sha1_prefix, sha1))
1400                        die("sha1 information is lacking or useless (%s).",
1401                            name);
1402                else
1403                        sha1_ptr = sha1;
1404
1405                printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1406                if (line_termination && quote_c_style(name, NULL, NULL, 0))
1407                        quote_c_style(name, NULL, stdout, 0);
1408                else
1409                        fputs(name, stdout);
1410                putchar(line_termination);
1411        }
1412}
1413
1414static void stat_patch_list(struct patch *patch)
1415{
1416        int files, adds, dels;
1417
1418        for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1419                files++;
1420                adds += patch->lines_added;
1421                dels += patch->lines_deleted;
1422                show_stats(patch);
1423        }
1424
1425        printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1426}
1427
1428static void numstat_patch_list(struct patch *patch)
1429{
1430        for ( ; patch; patch = patch->next) {
1431                const char *name;
1432                name = patch->old_name ? patch->old_name : patch->new_name;
1433                printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1434                if (line_termination && quote_c_style(name, NULL, NULL, 0))
1435                        quote_c_style(name, NULL, stdout, 0);
1436                else
1437                        fputs(name, stdout);
1438                putchar('\n');
1439        }
1440}
1441
1442static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1443{
1444        if (mode)
1445                printf(" %s mode %06o %s\n", newdelete, mode, name);
1446        else
1447                printf(" %s %s\n", newdelete, name);
1448}
1449
1450static void show_mode_change(struct patch *p, int show_name)
1451{
1452        if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1453                if (show_name)
1454                        printf(" mode change %06o => %06o %s\n",
1455                               p->old_mode, p->new_mode, p->new_name);
1456                else
1457                        printf(" mode change %06o => %06o\n",
1458                               p->old_mode, p->new_mode);
1459        }
1460}
1461
1462static void show_rename_copy(struct patch *p)
1463{
1464        const char *renamecopy = p->is_rename ? "rename" : "copy";
1465        const char *old, *new;
1466
1467        /* Find common prefix */
1468        old = p->old_name;
1469        new = p->new_name;
1470        while (1) {
1471                const char *slash_old, *slash_new;
1472                slash_old = strchr(old, '/');
1473                slash_new = strchr(new, '/');
1474                if (!slash_old ||
1475                    !slash_new ||
1476                    slash_old - old != slash_new - new ||
1477                    memcmp(old, new, slash_new - new))
1478                        break;
1479                old = slash_old + 1;
1480                new = slash_new + 1;
1481        }
1482        /* p->old_name thru old is the common prefix, and old and new
1483         * through the end of names are renames
1484         */
1485        if (old != p->old_name)
1486                printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1487                       (int)(old - p->old_name), p->old_name,
1488                       old, new, p->score);
1489        else
1490                printf(" %s %s => %s (%d%%)\n", renamecopy,
1491                       p->old_name, p->new_name, p->score);
1492        show_mode_change(p, 0);
1493}
1494
1495static void summary_patch_list(struct patch *patch)
1496{
1497        struct patch *p;
1498
1499        for (p = patch; p; p = p->next) {
1500                if (p->is_new)
1501                        show_file_mode_name("create", p->new_mode, p->new_name);
1502                else if (p->is_delete)
1503                        show_file_mode_name("delete", p->old_mode, p->old_name);
1504                else {
1505                        if (p->is_rename || p->is_copy)
1506                                show_rename_copy(p);
1507                        else {
1508                                if (p->score) {
1509                                        printf(" rewrite %s (%d%%)\n",
1510                                               p->new_name, p->score);
1511                                        show_mode_change(p, 0);
1512                                }
1513                                else
1514                                        show_mode_change(p, 1);
1515                        }
1516                }
1517        }
1518}
1519
1520static void patch_stats(struct patch *patch)
1521{
1522        int lines = patch->lines_added + patch->lines_deleted;
1523
1524        if (lines > max_change)
1525                max_change = lines;
1526        if (patch->old_name) {
1527                int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1528                if (!len)
1529                        len = strlen(patch->old_name);
1530                if (len > max_len)
1531                        max_len = len;
1532        }
1533        if (patch->new_name) {
1534                int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1535                if (!len)
1536                        len = strlen(patch->new_name);
1537                if (len > max_len)
1538                        max_len = len;
1539        }
1540}
1541
1542static void remove_file(struct patch *patch)
1543{
1544        if (write_index) {
1545                if (remove_file_from_cache(patch->old_name) < 0)
1546                        die("unable to remove %s from index", patch->old_name);
1547        }
1548        unlink(patch->old_name);
1549}
1550
1551static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1552{
1553        struct stat st;
1554        struct cache_entry *ce;
1555        int namelen = strlen(path);
1556        unsigned ce_size = cache_entry_size(namelen);
1557
1558        if (!write_index)
1559                return;
1560
1561        ce = xmalloc(ce_size);
1562        memset(ce, 0, ce_size);
1563        memcpy(ce->name, path, namelen);
1564        ce->ce_mode = create_ce_mode(mode);
1565        ce->ce_flags = htons(namelen);
1566        if (lstat(path, &st) < 0)
1567                die("unable to stat newly created file %s", path);
1568        fill_stat_cache_info(ce, &st);
1569        if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1570                die("unable to create backing store for newly created file %s", path);
1571        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1572                die("unable to add cache entry for %s", path);
1573}
1574
1575static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1576{
1577        int fd;
1578
1579        if (S_ISLNK(mode))
1580                return symlink(buf, path);
1581        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1582        if (fd < 0)
1583                return -1;
1584        while (size) {
1585                int written = xwrite(fd, buf, size);
1586                if (written < 0)
1587                        die("writing file %s: %s", path, strerror(errno));
1588                if (!written)
1589                        die("out of space writing file %s", path);
1590                buf += written;
1591                size -= written;
1592        }
1593        if (close(fd) < 0)
1594                die("closing file %s: %s", path, strerror(errno));
1595        return 0;
1596}
1597
1598/*
1599 * We optimistically assume that the directories exist,
1600 * which is true 99% of the time anyway. If they don't,
1601 * we create them and try again.
1602 */
1603static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1604{
1605        if (!try_create_file(path, mode, buf, size))
1606                return;
1607
1608        if (errno == ENOENT) {
1609                if (safe_create_leading_directories(path))
1610                        return;
1611                if (!try_create_file(path, mode, buf, size))
1612                        return;
1613        }
1614
1615        if (errno == EEXIST) {
1616                unsigned int nr = getpid();
1617
1618                for (;;) {
1619                        const char *newpath;
1620                        newpath = mkpath("%s~%u", path, nr);
1621                        if (!try_create_file(newpath, mode, buf, size)) {
1622                                if (!rename(newpath, path))
1623                                        return;
1624                                unlink(newpath);
1625                                break;
1626                        }
1627                        if (errno != EEXIST)
1628                                break;
1629                        ++nr;
1630                }
1631        }
1632        die("unable to write file %s mode %o", path, mode);
1633}
1634
1635static void create_file(struct patch *patch)
1636{
1637        char *path = patch->new_name;
1638        unsigned mode = patch->new_mode;
1639        unsigned long size = patch->resultsize;
1640        char *buf = patch->result;
1641
1642        if (!mode)
1643                mode = S_IFREG | 0644;
1644        create_one_file(path, mode, buf, size); 
1645        add_index_file(path, mode, buf, size);
1646}
1647
1648static void write_out_one_result(struct patch *patch)
1649{
1650        if (patch->is_delete > 0) {
1651                remove_file(patch);
1652                return;
1653        }
1654        if (patch->is_new > 0 || patch->is_copy) {
1655                create_file(patch);
1656                return;
1657        }
1658        /*
1659         * Rename or modification boils down to the same
1660         * thing: remove the old, write the new
1661         */
1662        remove_file(patch);
1663        create_file(patch);
1664}
1665
1666static void write_out_results(struct patch *list, int skipped_patch)
1667{
1668        if (!list && !skipped_patch)
1669                die("No changes");
1670
1671        while (list) {
1672                write_out_one_result(list);
1673                list = list->next;
1674        }
1675}
1676
1677static struct cache_file cache_file;
1678
1679static struct excludes {
1680        struct excludes *next;
1681        const char *path;
1682} *excludes;
1683
1684static int use_patch(struct patch *p)
1685{
1686        const char *pathname = p->new_name ? p->new_name : p->old_name;
1687        struct excludes *x = excludes;
1688        while (x) {
1689                if (fnmatch(x->path, pathname, 0) == 0)
1690                        return 0;
1691                x = x->next;
1692        }
1693        if (0 < prefix_length) {
1694                int pathlen = strlen(pathname);
1695                if (pathlen <= prefix_length ||
1696                    memcmp(prefix, pathname, prefix_length))
1697                        return 0;
1698        }
1699        return 1;
1700}
1701
1702static int apply_patch(int fd)
1703{
1704        int newfd;
1705        unsigned long offset, size;
1706        char *buffer = read_patch_file(fd, &size);
1707        struct patch *list = NULL, **listp = &list;
1708        int skipped_patch = 0;
1709
1710        if (!buffer)
1711                return -1;
1712        offset = 0;
1713        while (size > 0) {
1714                struct patch *patch;
1715                int nr;
1716
1717                patch = xmalloc(sizeof(*patch));
1718                memset(patch, 0, sizeof(*patch));
1719                nr = parse_chunk(buffer + offset, size, patch);
1720                if (nr < 0)
1721                        break;
1722                if (use_patch(patch)) {
1723                        patch_stats(patch);
1724                        *listp = patch;
1725                        listp = &patch->next;
1726                } else {
1727                        /* perhaps free it a bit better? */
1728                        free(patch);
1729                        skipped_patch++;
1730                }
1731                offset += nr;
1732                size -= nr;
1733        }
1734
1735        newfd = -1;
1736        write_index = check_index && apply;
1737        if (write_index)
1738                newfd = hold_index_file_for_update(&cache_file, get_index_file());
1739        if (check_index) {
1740                if (read_cache() < 0)
1741                        die("unable to read index file");
1742        }
1743
1744        if ((check || apply) && check_patch_list(list) < 0)
1745                exit(1);
1746
1747        if (apply)
1748                write_out_results(list, skipped_patch);
1749
1750        if (write_index) {
1751                if (write_cache(newfd, active_cache, active_nr) ||
1752                    commit_index_file(&cache_file))
1753                        die("Unable to write new cachefile");
1754        }
1755
1756        if (show_index_info)
1757                show_index_list(list);
1758
1759        if (diffstat)
1760                stat_patch_list(list);
1761
1762        if (numstat)
1763                numstat_patch_list(list);
1764
1765        if (summary)
1766                summary_patch_list(list);
1767
1768        free(buffer);
1769        return 0;
1770}
1771
1772int main(int argc, char **argv)
1773{
1774        int i;
1775        int read_stdin = 1;
1776
1777        for (i = 1; i < argc; i++) {
1778                const char *arg = argv[i];
1779                int fd;
1780
1781                if (!strcmp(arg, "-")) {
1782                        apply_patch(0);
1783                        read_stdin = 0;
1784                        continue;
1785                }
1786                if (!strncmp(arg, "--exclude=", 10)) {
1787                        struct excludes *x = xmalloc(sizeof(*x));
1788                        x->path = arg + 10;
1789                        x->next = excludes;
1790                        excludes = x;
1791                        continue;
1792                }
1793                if (!strncmp(arg, "-p", 2)) {
1794                        p_value = atoi(arg + 2);
1795                        continue;
1796                }
1797                if (!strcmp(arg, "--no-add")) {
1798                        no_add = 1;
1799                        continue;
1800                }
1801                if (!strcmp(arg, "--stat")) {
1802                        apply = 0;
1803                        diffstat = 1;
1804                        continue;
1805                }
1806                if (!strcmp(arg, "--allow-binary-replacement")) {
1807                        allow_binary_replacement = 1;
1808                        continue;
1809                }
1810                if (!strcmp(arg, "--numstat")) {
1811                        apply = 0;
1812                        numstat = 1;
1813                        continue;
1814                }
1815                if (!strcmp(arg, "--summary")) {
1816                        apply = 0;
1817                        summary = 1;
1818                        continue;
1819                }
1820                if (!strcmp(arg, "--check")) {
1821                        apply = 0;
1822                        check = 1;
1823                        continue;
1824                }
1825                if (!strcmp(arg, "--index")) {
1826                        check_index = 1;
1827                        continue;
1828                }
1829                if (!strcmp(arg, "--apply")) {
1830                        apply = 1;
1831                        continue;
1832                }
1833                if (!strcmp(arg, "--index-info")) {
1834                        apply = 0;
1835                        show_index_info = 1;
1836                        continue;
1837                }
1838                if (!strcmp(arg, "-z")) {
1839                        line_termination = 0;
1840                        continue;
1841                }
1842
1843                if (check_index && prefix_length < 0) {
1844                        prefix = setup_git_directory();
1845                        prefix_length = prefix ? strlen(prefix) : 0;
1846                        git_config(git_default_config);
1847                }
1848                if (0 < prefix_length)
1849                        arg = prefix_filename(prefix, prefix_length, arg);
1850
1851                fd = open(arg, O_RDONLY);
1852                if (fd < 0)
1853                        usage(apply_usage);
1854                read_stdin = 0;
1855                apply_patch(fd);
1856                close(fd);
1857        }
1858        if (read_stdin)
1859                apply_patch(0);
1860        return 0;
1861}