apply.con commit diff-lib: allow ita entries treated as "not yet exist in index" (425a28e)
   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
  10#include "cache.h"
  11#include "blob.h"
  12#include "delta.h"
  13#include "diff.h"
  14#include "dir.h"
  15#include "xdiff-interface.h"
  16#include "ll-merge.h"
  17#include "lockfile.h"
  18#include "parse-options.h"
  19#include "quote.h"
  20#include "rerere.h"
  21#include "apply.h"
  22
  23static void git_apply_config(void)
  24{
  25        git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
  26        git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
  27        git_config(git_default_config, NULL);
  28}
  29
  30static int parse_whitespace_option(struct apply_state *state, const char *option)
  31{
  32        if (!option) {
  33                state->ws_error_action = warn_on_ws_error;
  34                return 0;
  35        }
  36        if (!strcmp(option, "warn")) {
  37                state->ws_error_action = warn_on_ws_error;
  38                return 0;
  39        }
  40        if (!strcmp(option, "nowarn")) {
  41                state->ws_error_action = nowarn_ws_error;
  42                return 0;
  43        }
  44        if (!strcmp(option, "error")) {
  45                state->ws_error_action = die_on_ws_error;
  46                return 0;
  47        }
  48        if (!strcmp(option, "error-all")) {
  49                state->ws_error_action = die_on_ws_error;
  50                state->squelch_whitespace_errors = 0;
  51                return 0;
  52        }
  53        if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
  54                state->ws_error_action = correct_ws_error;
  55                return 0;
  56        }
  57        return error(_("unrecognized whitespace option '%s'"), option);
  58}
  59
  60static int parse_ignorewhitespace_option(struct apply_state *state,
  61                                                 const char *option)
  62{
  63        if (!option || !strcmp(option, "no") ||
  64            !strcmp(option, "false") || !strcmp(option, "never") ||
  65            !strcmp(option, "none")) {
  66                state->ws_ignore_action = ignore_ws_none;
  67                return 0;
  68        }
  69        if (!strcmp(option, "change")) {
  70                state->ws_ignore_action = ignore_ws_change;
  71                return 0;
  72        }
  73        return error(_("unrecognized whitespace ignore option '%s'"), option);
  74}
  75
  76int init_apply_state(struct apply_state *state,
  77                     const char *prefix,
  78                     struct lock_file *lock_file)
  79{
  80        memset(state, 0, sizeof(*state));
  81        state->prefix = prefix;
  82        state->prefix_length = state->prefix ? strlen(state->prefix) : 0;
  83        state->lock_file = lock_file;
  84        state->newfd = -1;
  85        state->apply = 1;
  86        state->line_termination = '\n';
  87        state->p_value = 1;
  88        state->p_context = UINT_MAX;
  89        state->squelch_whitespace_errors = 5;
  90        state->ws_error_action = warn_on_ws_error;
  91        state->ws_ignore_action = ignore_ws_none;
  92        state->linenr = 1;
  93        string_list_init(&state->fn_table, 0);
  94        string_list_init(&state->limit_by_name, 0);
  95        string_list_init(&state->symlink_changes, 0);
  96        strbuf_init(&state->root, 0);
  97
  98        git_apply_config();
  99        if (apply_default_whitespace && parse_whitespace_option(state, apply_default_whitespace))
 100                return -1;
 101        if (apply_default_ignorewhitespace && parse_ignorewhitespace_option(state, apply_default_ignorewhitespace))
 102                return -1;
 103        return 0;
 104}
 105
 106void clear_apply_state(struct apply_state *state)
 107{
 108        string_list_clear(&state->limit_by_name, 0);
 109        string_list_clear(&state->symlink_changes, 0);
 110        strbuf_release(&state->root);
 111
 112        /* &state->fn_table is cleared at the end of apply_patch() */
 113}
 114
 115static void mute_routine(const char *msg, va_list params)
 116{
 117        /* do nothing */
 118}
 119
 120int check_apply_state(struct apply_state *state, int force_apply)
 121{
 122        int is_not_gitdir = !startup_info->have_repository;
 123
 124        if (state->apply_with_reject && state->threeway)
 125                return error("--reject and --3way cannot be used together.");
 126        if (state->cached && state->threeway)
 127                return error("--cached and --3way cannot be used together.");
 128        if (state->threeway) {
 129                if (is_not_gitdir)
 130                        return error(_("--3way outside a repository"));
 131                state->check_index = 1;
 132        }
 133        if (state->apply_with_reject) {
 134                state->apply = 1;
 135                if (state->apply_verbosity == verbosity_normal)
 136                        state->apply_verbosity = verbosity_verbose;
 137        }
 138        if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
 139                state->apply = 0;
 140        if (state->check_index && is_not_gitdir)
 141                return error(_("--index outside a repository"));
 142        if (state->cached) {
 143                if (is_not_gitdir)
 144                        return error(_("--cached outside a repository"));
 145                state->check_index = 1;
 146        }
 147        if (state->check_index)
 148                state->unsafe_paths = 0;
 149        if (!state->lock_file)
 150                return error("BUG: state->lock_file should not be NULL");
 151
 152        if (state->apply_verbosity <= verbosity_silent) {
 153                state->saved_error_routine = get_error_routine();
 154                state->saved_warn_routine = get_warn_routine();
 155                set_error_routine(mute_routine);
 156                set_warn_routine(mute_routine);
 157        }
 158
 159        return 0;
 160}
 161
 162static void set_default_whitespace_mode(struct apply_state *state)
 163{
 164        if (!state->whitespace_option && !apply_default_whitespace)
 165                state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
 166}
 167
 168/*
 169 * This represents one "hunk" from a patch, starting with
 170 * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
 171 * patch text is pointed at by patch, and its byte length
 172 * is stored in size.  leading and trailing are the number
 173 * of context lines.
 174 */
 175struct fragment {
 176        unsigned long leading, trailing;
 177        unsigned long oldpos, oldlines;
 178        unsigned long newpos, newlines;
 179        /*
 180         * 'patch' is usually borrowed from buf in apply_patch(),
 181         * but some codepaths store an allocated buffer.
 182         */
 183        const char *patch;
 184        unsigned free_patch:1,
 185                rejected:1;
 186        int size;
 187        int linenr;
 188        struct fragment *next;
 189};
 190
 191/*
 192 * When dealing with a binary patch, we reuse "leading" field
 193 * to store the type of the binary hunk, either deflated "delta"
 194 * or deflated "literal".
 195 */
 196#define binary_patch_method leading
 197#define BINARY_DELTA_DEFLATED   1
 198#define BINARY_LITERAL_DEFLATED 2
 199
 200/*
 201 * This represents a "patch" to a file, both metainfo changes
 202 * such as creation/deletion, filemode and content changes represented
 203 * as a series of fragments.
 204 */
 205struct patch {
 206        char *new_name, *old_name, *def_name;
 207        unsigned int old_mode, new_mode;
 208        int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
 209        int rejected;
 210        unsigned ws_rule;
 211        int lines_added, lines_deleted;
 212        int score;
 213        unsigned int is_toplevel_relative:1;
 214        unsigned int inaccurate_eof:1;
 215        unsigned int is_binary:1;
 216        unsigned int is_copy:1;
 217        unsigned int is_rename:1;
 218        unsigned int recount:1;
 219        unsigned int conflicted_threeway:1;
 220        unsigned int direct_to_threeway:1;
 221        struct fragment *fragments;
 222        char *result;
 223        size_t resultsize;
 224        char old_sha1_prefix[41];
 225        char new_sha1_prefix[41];
 226        struct patch *next;
 227
 228        /* three-way fallback result */
 229        struct object_id threeway_stage[3];
 230};
 231
 232static void free_fragment_list(struct fragment *list)
 233{
 234        while (list) {
 235                struct fragment *next = list->next;
 236                if (list->free_patch)
 237                        free((char *)list->patch);
 238                free(list);
 239                list = next;
 240        }
 241}
 242
 243static void free_patch(struct patch *patch)
 244{
 245        free_fragment_list(patch->fragments);
 246        free(patch->def_name);
 247        free(patch->old_name);
 248        free(patch->new_name);
 249        free(patch->result);
 250        free(patch);
 251}
 252
 253static void free_patch_list(struct patch *list)
 254{
 255        while (list) {
 256                struct patch *next = list->next;
 257                free_patch(list);
 258                list = next;
 259        }
 260}
 261
 262/*
 263 * A line in a file, len-bytes long (includes the terminating LF,
 264 * except for an incomplete line at the end if the file ends with
 265 * one), and its contents hashes to 'hash'.
 266 */
 267struct line {
 268        size_t len;
 269        unsigned hash : 24;
 270        unsigned flag : 8;
 271#define LINE_COMMON     1
 272#define LINE_PATCHED    2
 273};
 274
 275/*
 276 * This represents a "file", which is an array of "lines".
 277 */
 278struct image {
 279        char *buf;
 280        size_t len;
 281        size_t nr;
 282        size_t alloc;
 283        struct line *line_allocated;
 284        struct line *line;
 285};
 286
 287static uint32_t hash_line(const char *cp, size_t len)
 288{
 289        size_t i;
 290        uint32_t h;
 291        for (i = 0, h = 0; i < len; i++) {
 292                if (!isspace(cp[i])) {
 293                        h = h * 3 + (cp[i] & 0xff);
 294                }
 295        }
 296        return h;
 297}
 298
 299/*
 300 * Compare lines s1 of length n1 and s2 of length n2, ignoring
 301 * whitespace difference. Returns 1 if they match, 0 otherwise
 302 */
 303static int fuzzy_matchlines(const char *s1, size_t n1,
 304                            const char *s2, size_t n2)
 305{
 306        const char *last1 = s1 + n1 - 1;
 307        const char *last2 = s2 + n2 - 1;
 308        int result = 0;
 309
 310        /* ignore line endings */
 311        while ((*last1 == '\r') || (*last1 == '\n'))
 312                last1--;
 313        while ((*last2 == '\r') || (*last2 == '\n'))
 314                last2--;
 315
 316        /* skip leading whitespaces, if both begin with whitespace */
 317        if (s1 <= last1 && s2 <= last2 && isspace(*s1) && isspace(*s2)) {
 318                while (isspace(*s1) && (s1 <= last1))
 319                        s1++;
 320                while (isspace(*s2) && (s2 <= last2))
 321                        s2++;
 322        }
 323        /* early return if both lines are empty */
 324        if ((s1 > last1) && (s2 > last2))
 325                return 1;
 326        while (!result) {
 327                result = *s1++ - *s2++;
 328                /*
 329                 * Skip whitespace inside. We check for whitespace on
 330                 * both buffers because we don't want "a b" to match
 331                 * "ab"
 332                 */
 333                if (isspace(*s1) && isspace(*s2)) {
 334                        while (isspace(*s1) && s1 <= last1)
 335                                s1++;
 336                        while (isspace(*s2) && s2 <= last2)
 337                                s2++;
 338                }
 339                /*
 340                 * If we reached the end on one side only,
 341                 * lines don't match
 342                 */
 343                if (
 344                    ((s2 > last2) && (s1 <= last1)) ||
 345                    ((s1 > last1) && (s2 <= last2)))
 346                        return 0;
 347                if ((s1 > last1) && (s2 > last2))
 348                        break;
 349        }
 350
 351        return !result;
 352}
 353
 354static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
 355{
 356        ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
 357        img->line_allocated[img->nr].len = len;
 358        img->line_allocated[img->nr].hash = hash_line(bol, len);
 359        img->line_allocated[img->nr].flag = flag;
 360        img->nr++;
 361}
 362
 363/*
 364 * "buf" has the file contents to be patched (read from various sources).
 365 * attach it to "image" and add line-based index to it.
 366 * "image" now owns the "buf".
 367 */
 368static void prepare_image(struct image *image, char *buf, size_t len,
 369                          int prepare_linetable)
 370{
 371        const char *cp, *ep;
 372
 373        memset(image, 0, sizeof(*image));
 374        image->buf = buf;
 375        image->len = len;
 376
 377        if (!prepare_linetable)
 378                return;
 379
 380        ep = image->buf + image->len;
 381        cp = image->buf;
 382        while (cp < ep) {
 383                const char *next;
 384                for (next = cp; next < ep && *next != '\n'; next++)
 385                        ;
 386                if (next < ep)
 387                        next++;
 388                add_line_info(image, cp, next - cp, 0);
 389                cp = next;
 390        }
 391        image->line = image->line_allocated;
 392}
 393
 394static void clear_image(struct image *image)
 395{
 396        free(image->buf);
 397        free(image->line_allocated);
 398        memset(image, 0, sizeof(*image));
 399}
 400
 401/* fmt must contain _one_ %s and no other substitution */
 402static void say_patch_name(FILE *output, const char *fmt, struct patch *patch)
 403{
 404        struct strbuf sb = STRBUF_INIT;
 405
 406        if (patch->old_name && patch->new_name &&
 407            strcmp(patch->old_name, patch->new_name)) {
 408                quote_c_style(patch->old_name, &sb, NULL, 0);
 409                strbuf_addstr(&sb, " => ");
 410                quote_c_style(patch->new_name, &sb, NULL, 0);
 411        } else {
 412                const char *n = patch->new_name;
 413                if (!n)
 414                        n = patch->old_name;
 415                quote_c_style(n, &sb, NULL, 0);
 416        }
 417        fprintf(output, fmt, sb.buf);
 418        fputc('\n', output);
 419        strbuf_release(&sb);
 420}
 421
 422#define SLOP (16)
 423
 424static int read_patch_file(struct strbuf *sb, int fd)
 425{
 426        if (strbuf_read(sb, fd, 0) < 0)
 427                return error_errno("git apply: failed to read");
 428
 429        /*
 430         * Make sure that we have some slop in the buffer
 431         * so that we can do speculative "memcmp" etc, and
 432         * see to it that it is NUL-filled.
 433         */
 434        strbuf_grow(sb, SLOP);
 435        memset(sb->buf + sb->len, 0, SLOP);
 436        return 0;
 437}
 438
 439static unsigned long linelen(const char *buffer, unsigned long size)
 440{
 441        unsigned long len = 0;
 442        while (size--) {
 443                len++;
 444                if (*buffer++ == '\n')
 445                        break;
 446        }
 447        return len;
 448}
 449
 450static int is_dev_null(const char *str)
 451{
 452        return skip_prefix(str, "/dev/null", &str) && isspace(*str);
 453}
 454
 455#define TERM_SPACE      1
 456#define TERM_TAB        2
 457
 458static int name_terminate(int c, int terminate)
 459{
 460        if (c == ' ' && !(terminate & TERM_SPACE))
 461                return 0;
 462        if (c == '\t' && !(terminate & TERM_TAB))
 463                return 0;
 464
 465        return 1;
 466}
 467
 468/* remove double slashes to make --index work with such filenames */
 469static char *squash_slash(char *name)
 470{
 471        int i = 0, j = 0;
 472
 473        if (!name)
 474                return NULL;
 475
 476        while (name[i]) {
 477                if ((name[j++] = name[i++]) == '/')
 478                        while (name[i] == '/')
 479                                i++;
 480        }
 481        name[j] = '\0';
 482        return name;
 483}
 484
 485static char *find_name_gnu(struct apply_state *state,
 486                           const char *line,
 487                           const char *def,
 488                           int p_value)
 489{
 490        struct strbuf name = STRBUF_INIT;
 491        char *cp;
 492
 493        /*
 494         * Proposed "new-style" GNU patch/diff format; see
 495         * http://marc.info/?l=git&m=112927316408690&w=2
 496         */
 497        if (unquote_c_style(&name, line, NULL)) {
 498                strbuf_release(&name);
 499                return NULL;
 500        }
 501
 502        for (cp = name.buf; p_value; p_value--) {
 503                cp = strchr(cp, '/');
 504                if (!cp) {
 505                        strbuf_release(&name);
 506                        return NULL;
 507                }
 508                cp++;
 509        }
 510
 511        strbuf_remove(&name, 0, cp - name.buf);
 512        if (state->root.len)
 513                strbuf_insert(&name, 0, state->root.buf, state->root.len);
 514        return squash_slash(strbuf_detach(&name, NULL));
 515}
 516
 517static size_t sane_tz_len(const char *line, size_t len)
 518{
 519        const char *tz, *p;
 520
 521        if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
 522                return 0;
 523        tz = line + len - strlen(" +0500");
 524
 525        if (tz[1] != '+' && tz[1] != '-')
 526                return 0;
 527
 528        for (p = tz + 2; p != line + len; p++)
 529                if (!isdigit(*p))
 530                        return 0;
 531
 532        return line + len - tz;
 533}
 534
 535static size_t tz_with_colon_len(const char *line, size_t len)
 536{
 537        const char *tz, *p;
 538
 539        if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
 540                return 0;
 541        tz = line + len - strlen(" +08:00");
 542
 543        if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
 544                return 0;
 545        p = tz + 2;
 546        if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 547            !isdigit(*p++) || !isdigit(*p++))
 548                return 0;
 549
 550        return line + len - tz;
 551}
 552
 553static size_t date_len(const char *line, size_t len)
 554{
 555        const char *date, *p;
 556
 557        if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
 558                return 0;
 559        p = date = line + len - strlen("72-02-05");
 560
 561        if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
 562            !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
 563            !isdigit(*p++) || !isdigit(*p++))   /* Not a date. */
 564                return 0;
 565
 566        if (date - line >= strlen("19") &&
 567            isdigit(date[-1]) && isdigit(date[-2]))     /* 4-digit year */
 568                date -= strlen("19");
 569
 570        return line + len - date;
 571}
 572
 573static size_t short_time_len(const char *line, size_t len)
 574{
 575        const char *time, *p;
 576
 577        if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
 578                return 0;
 579        p = time = line + len - strlen(" 07:01:32");
 580
 581        /* Permit 1-digit hours? */
 582        if (*p++ != ' ' ||
 583            !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 584            !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 585            !isdigit(*p++) || !isdigit(*p++))   /* Not a time. */
 586                return 0;
 587
 588        return line + len - time;
 589}
 590
 591static size_t fractional_time_len(const char *line, size_t len)
 592{
 593        const char *p;
 594        size_t n;
 595
 596        /* Expected format: 19:41:17.620000023 */
 597        if (!len || !isdigit(line[len - 1]))
 598                return 0;
 599        p = line + len - 1;
 600
 601        /* Fractional seconds. */
 602        while (p > line && isdigit(*p))
 603                p--;
 604        if (*p != '.')
 605                return 0;
 606
 607        /* Hours, minutes, and whole seconds. */
 608        n = short_time_len(line, p - line);
 609        if (!n)
 610                return 0;
 611
 612        return line + len - p + n;
 613}
 614
 615static size_t trailing_spaces_len(const char *line, size_t len)
 616{
 617        const char *p;
 618
 619        /* Expected format: ' ' x (1 or more)  */
 620        if (!len || line[len - 1] != ' ')
 621                return 0;
 622
 623        p = line + len;
 624        while (p != line) {
 625                p--;
 626                if (*p != ' ')
 627                        return line + len - (p + 1);
 628        }
 629
 630        /* All spaces! */
 631        return len;
 632}
 633
 634static size_t diff_timestamp_len(const char *line, size_t len)
 635{
 636        const char *end = line + len;
 637        size_t n;
 638
 639        /*
 640         * Posix: 2010-07-05 19:41:17
 641         * GNU: 2010-07-05 19:41:17.620000023 -0500
 642         */
 643
 644        if (!isdigit(end[-1]))
 645                return 0;
 646
 647        n = sane_tz_len(line, end - line);
 648        if (!n)
 649                n = tz_with_colon_len(line, end - line);
 650        end -= n;
 651
 652        n = short_time_len(line, end - line);
 653        if (!n)
 654                n = fractional_time_len(line, end - line);
 655        end -= n;
 656
 657        n = date_len(line, end - line);
 658        if (!n) /* No date.  Too bad. */
 659                return 0;
 660        end -= n;
 661
 662        if (end == line)        /* No space before date. */
 663                return 0;
 664        if (end[-1] == '\t') {  /* Success! */
 665                end--;
 666                return line + len - end;
 667        }
 668        if (end[-1] != ' ')     /* No space before date. */
 669                return 0;
 670
 671        /* Whitespace damage. */
 672        end -= trailing_spaces_len(line, end - line);
 673        return line + len - end;
 674}
 675
 676static char *find_name_common(struct apply_state *state,
 677                              const char *line,
 678                              const char *def,
 679                              int p_value,
 680                              const char *end,
 681                              int terminate)
 682{
 683        int len;
 684        const char *start = NULL;
 685
 686        if (p_value == 0)
 687                start = line;
 688        while (line != end) {
 689                char c = *line;
 690
 691                if (!end && isspace(c)) {
 692                        if (c == '\n')
 693                                break;
 694                        if (name_terminate(c, terminate))
 695                                break;
 696                }
 697                line++;
 698                if (c == '/' && !--p_value)
 699                        start = line;
 700        }
 701        if (!start)
 702                return squash_slash(xstrdup_or_null(def));
 703        len = line - start;
 704        if (!len)
 705                return squash_slash(xstrdup_or_null(def));
 706
 707        /*
 708         * Generally we prefer the shorter name, especially
 709         * if the other one is just a variation of that with
 710         * something else tacked on to the end (ie "file.orig"
 711         * or "file~").
 712         */
 713        if (def) {
 714                int deflen = strlen(def);
 715                if (deflen < len && !strncmp(start, def, deflen))
 716                        return squash_slash(xstrdup(def));
 717        }
 718
 719        if (state->root.len) {
 720                char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
 721                return squash_slash(ret);
 722        }
 723
 724        return squash_slash(xmemdupz(start, len));
 725}
 726
 727static char *find_name(struct apply_state *state,
 728                       const char *line,
 729                       char *def,
 730                       int p_value,
 731                       int terminate)
 732{
 733        if (*line == '"') {
 734                char *name = find_name_gnu(state, line, def, p_value);
 735                if (name)
 736                        return name;
 737        }
 738
 739        return find_name_common(state, line, def, p_value, NULL, terminate);
 740}
 741
 742static char *find_name_traditional(struct apply_state *state,
 743                                   const char *line,
 744                                   char *def,
 745                                   int p_value)
 746{
 747        size_t len;
 748        size_t date_len;
 749
 750        if (*line == '"') {
 751                char *name = find_name_gnu(state, line, def, p_value);
 752                if (name)
 753                        return name;
 754        }
 755
 756        len = strchrnul(line, '\n') - line;
 757        date_len = diff_timestamp_len(line, len);
 758        if (!date_len)
 759                return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
 760        len -= date_len;
 761
 762        return find_name_common(state, line, def, p_value, line + len, 0);
 763}
 764
 765static int count_slashes(const char *cp)
 766{
 767        int cnt = 0;
 768        char ch;
 769
 770        while ((ch = *cp++))
 771                if (ch == '/')
 772                        cnt++;
 773        return cnt;
 774}
 775
 776/*
 777 * Given the string after "--- " or "+++ ", guess the appropriate
 778 * p_value for the given patch.
 779 */
 780static int guess_p_value(struct apply_state *state, const char *nameline)
 781{
 782        char *name, *cp;
 783        int val = -1;
 784
 785        if (is_dev_null(nameline))
 786                return -1;
 787        name = find_name_traditional(state, nameline, NULL, 0);
 788        if (!name)
 789                return -1;
 790        cp = strchr(name, '/');
 791        if (!cp)
 792                val = 0;
 793        else if (state->prefix) {
 794                /*
 795                 * Does it begin with "a/$our-prefix" and such?  Then this is
 796                 * very likely to apply to our directory.
 797                 */
 798                if (!strncmp(name, state->prefix, state->prefix_length))
 799                        val = count_slashes(state->prefix);
 800                else {
 801                        cp++;
 802                        if (!strncmp(cp, state->prefix, state->prefix_length))
 803                                val = count_slashes(state->prefix) + 1;
 804                }
 805        }
 806        free(name);
 807        return val;
 808}
 809
 810/*
 811 * Does the ---/+++ line have the POSIX timestamp after the last HT?
 812 * GNU diff puts epoch there to signal a creation/deletion event.  Is
 813 * this such a timestamp?
 814 */
 815static int has_epoch_timestamp(const char *nameline)
 816{
 817        /*
 818         * We are only interested in epoch timestamp; any non-zero
 819         * fraction cannot be one, hence "(\.0+)?" in the regexp below.
 820         * For the same reason, the date must be either 1969-12-31 or
 821         * 1970-01-01, and the seconds part must be "00".
 822         */
 823        const char stamp_regexp[] =
 824                "^(1969-12-31|1970-01-01)"
 825                " "
 826                "[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
 827                " "
 828                "([-+][0-2][0-9]:?[0-5][0-9])\n";
 829        const char *timestamp = NULL, *cp, *colon;
 830        static regex_t *stamp;
 831        regmatch_t m[10];
 832        int zoneoffset;
 833        int hourminute;
 834        int status;
 835
 836        for (cp = nameline; *cp != '\n'; cp++) {
 837                if (*cp == '\t')
 838                        timestamp = cp + 1;
 839        }
 840        if (!timestamp)
 841                return 0;
 842        if (!stamp) {
 843                stamp = xmalloc(sizeof(*stamp));
 844                if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
 845                        warning(_("Cannot prepare timestamp regexp %s"),
 846                                stamp_regexp);
 847                        return 0;
 848                }
 849        }
 850
 851        status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
 852        if (status) {
 853                if (status != REG_NOMATCH)
 854                        warning(_("regexec returned %d for input: %s"),
 855                                status, timestamp);
 856                return 0;
 857        }
 858
 859        zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
 860        if (*colon == ':')
 861                zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
 862        else
 863                zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
 864        if (timestamp[m[3].rm_so] == '-')
 865                zoneoffset = -zoneoffset;
 866
 867        /*
 868         * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
 869         * (west of GMT) or 1970-01-01 (east of GMT)
 870         */
 871        if ((zoneoffset < 0 && memcmp(timestamp, "1969-12-31", 10)) ||
 872            (0 <= zoneoffset && memcmp(timestamp, "1970-01-01", 10)))
 873                return 0;
 874
 875        hourminute = (strtol(timestamp + 11, NULL, 10) * 60 +
 876                      strtol(timestamp + 14, NULL, 10) -
 877                      zoneoffset);
 878
 879        return ((zoneoffset < 0 && hourminute == 1440) ||
 880                (0 <= zoneoffset && !hourminute));
 881}
 882
 883/*
 884 * Get the name etc info from the ---/+++ lines of a traditional patch header
 885 *
 886 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 887 * files, we can happily check the index for a match, but for creating a
 888 * new file we should try to match whatever "patch" does. I have no idea.
 889 */
 890static int parse_traditional_patch(struct apply_state *state,
 891                                   const char *first,
 892                                   const char *second,
 893                                   struct patch *patch)
 894{
 895        char *name;
 896
 897        first += 4;     /* skip "--- " */
 898        second += 4;    /* skip "+++ " */
 899        if (!state->p_value_known) {
 900                int p, q;
 901                p = guess_p_value(state, first);
 902                q = guess_p_value(state, second);
 903                if (p < 0) p = q;
 904                if (0 <= p && p == q) {
 905                        state->p_value = p;
 906                        state->p_value_known = 1;
 907                }
 908        }
 909        if (is_dev_null(first)) {
 910                patch->is_new = 1;
 911                patch->is_delete = 0;
 912                name = find_name_traditional(state, second, NULL, state->p_value);
 913                patch->new_name = name;
 914        } else if (is_dev_null(second)) {
 915                patch->is_new = 0;
 916                patch->is_delete = 1;
 917                name = find_name_traditional(state, first, NULL, state->p_value);
 918                patch->old_name = name;
 919        } else {
 920                char *first_name;
 921                first_name = find_name_traditional(state, first, NULL, state->p_value);
 922                name = find_name_traditional(state, second, first_name, state->p_value);
 923                free(first_name);
 924                if (has_epoch_timestamp(first)) {
 925                        patch->is_new = 1;
 926                        patch->is_delete = 0;
 927                        patch->new_name = name;
 928                } else if (has_epoch_timestamp(second)) {
 929                        patch->is_new = 0;
 930                        patch->is_delete = 1;
 931                        patch->old_name = name;
 932                } else {
 933                        patch->old_name = name;
 934                        patch->new_name = xstrdup_or_null(name);
 935                }
 936        }
 937        if (!name)
 938                return error(_("unable to find filename in patch at line %d"), state->linenr);
 939
 940        return 0;
 941}
 942
 943static int gitdiff_hdrend(struct apply_state *state,
 944                          const char *line,
 945                          struct patch *patch)
 946{
 947        return 1;
 948}
 949
 950/*
 951 * We're anal about diff header consistency, to make
 952 * sure that we don't end up having strange ambiguous
 953 * patches floating around.
 954 *
 955 * As a result, gitdiff_{old|new}name() will check
 956 * their names against any previous information, just
 957 * to make sure..
 958 */
 959#define DIFF_OLD_NAME 0
 960#define DIFF_NEW_NAME 1
 961
 962static int gitdiff_verify_name(struct apply_state *state,
 963                               const char *line,
 964                               int isnull,
 965                               char **name,
 966                               int side)
 967{
 968        if (!*name && !isnull) {
 969                *name = find_name(state, line, NULL, state->p_value, TERM_TAB);
 970                return 0;
 971        }
 972
 973        if (*name) {
 974                int len = strlen(*name);
 975                char *another;
 976                if (isnull)
 977                        return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
 978                                     *name, state->linenr);
 979                another = find_name(state, line, NULL, state->p_value, TERM_TAB);
 980                if (!another || memcmp(another, *name, len + 1)) {
 981                        free(another);
 982                        return error((side == DIFF_NEW_NAME) ?
 983                            _("git apply: bad git-diff - inconsistent new filename on line %d") :
 984                            _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
 985                }
 986                free(another);
 987        } else {
 988                /* expect "/dev/null" */
 989                if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 990                        return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
 991        }
 992
 993        return 0;
 994}
 995
 996static int gitdiff_oldname(struct apply_state *state,
 997                           const char *line,
 998                           struct patch *patch)
 999{
1000        return gitdiff_verify_name(state, line,
1001                                   patch->is_new, &patch->old_name,
1002                                   DIFF_OLD_NAME);
1003}
1004
1005static int gitdiff_newname(struct apply_state *state,
1006                           const char *line,
1007                           struct patch *patch)
1008{
1009        return gitdiff_verify_name(state, line,
1010                                   patch->is_delete, &patch->new_name,
1011                                   DIFF_NEW_NAME);
1012}
1013
1014static int gitdiff_oldmode(struct apply_state *state,
1015                           const char *line,
1016                           struct patch *patch)
1017{
1018        patch->old_mode = strtoul(line, NULL, 8);
1019        return 0;
1020}
1021
1022static int gitdiff_newmode(struct apply_state *state,
1023                           const char *line,
1024                           struct patch *patch)
1025{
1026        patch->new_mode = strtoul(line, NULL, 8);
1027        return 0;
1028}
1029
1030static int gitdiff_delete(struct apply_state *state,
1031                          const char *line,
1032                          struct patch *patch)
1033{
1034        patch->is_delete = 1;
1035        free(patch->old_name);
1036        patch->old_name = xstrdup_or_null(patch->def_name);
1037        return gitdiff_oldmode(state, line, patch);
1038}
1039
1040static int gitdiff_newfile(struct apply_state *state,
1041                           const char *line,
1042                           struct patch *patch)
1043{
1044        patch->is_new = 1;
1045        free(patch->new_name);
1046        patch->new_name = xstrdup_or_null(patch->def_name);
1047        return gitdiff_newmode(state, line, patch);
1048}
1049
1050static int gitdiff_copysrc(struct apply_state *state,
1051                           const char *line,
1052                           struct patch *patch)
1053{
1054        patch->is_copy = 1;
1055        free(patch->old_name);
1056        patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1057        return 0;
1058}
1059
1060static int gitdiff_copydst(struct apply_state *state,
1061                           const char *line,
1062                           struct patch *patch)
1063{
1064        patch->is_copy = 1;
1065        free(patch->new_name);
1066        patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1067        return 0;
1068}
1069
1070static int gitdiff_renamesrc(struct apply_state *state,
1071                             const char *line,
1072                             struct patch *patch)
1073{
1074        patch->is_rename = 1;
1075        free(patch->old_name);
1076        patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1077        return 0;
1078}
1079
1080static int gitdiff_renamedst(struct apply_state *state,
1081                             const char *line,
1082                             struct patch *patch)
1083{
1084        patch->is_rename = 1;
1085        free(patch->new_name);
1086        patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1087        return 0;
1088}
1089
1090static int gitdiff_similarity(struct apply_state *state,
1091                              const char *line,
1092                              struct patch *patch)
1093{
1094        unsigned long val = strtoul(line, NULL, 10);
1095        if (val <= 100)
1096                patch->score = val;
1097        return 0;
1098}
1099
1100static int gitdiff_dissimilarity(struct apply_state *state,
1101                                 const char *line,
1102                                 struct patch *patch)
1103{
1104        unsigned long val = strtoul(line, NULL, 10);
1105        if (val <= 100)
1106                patch->score = val;
1107        return 0;
1108}
1109
1110static int gitdiff_index(struct apply_state *state,
1111                         const char *line,
1112                         struct patch *patch)
1113{
1114        /*
1115         * index line is N hexadecimal, "..", N hexadecimal,
1116         * and optional space with octal mode.
1117         */
1118        const char *ptr, *eol;
1119        int len;
1120
1121        ptr = strchr(line, '.');
1122        if (!ptr || ptr[1] != '.' || 40 < ptr - line)
1123                return 0;
1124        len = ptr - line;
1125        memcpy(patch->old_sha1_prefix, line, len);
1126        patch->old_sha1_prefix[len] = 0;
1127
1128        line = ptr + 2;
1129        ptr = strchr(line, ' ');
1130        eol = strchrnul(line, '\n');
1131
1132        if (!ptr || eol < ptr)
1133                ptr = eol;
1134        len = ptr - line;
1135
1136        if (40 < len)
1137                return 0;
1138        memcpy(patch->new_sha1_prefix, line, len);
1139        patch->new_sha1_prefix[len] = 0;
1140        if (*ptr == ' ')
1141                patch->old_mode = strtoul(ptr+1, NULL, 8);
1142        return 0;
1143}
1144
1145/*
1146 * This is normal for a diff that doesn't change anything: we'll fall through
1147 * into the next diff. Tell the parser to break out.
1148 */
1149static int gitdiff_unrecognized(struct apply_state *state,
1150                                const char *line,
1151                                struct patch *patch)
1152{
1153        return 1;
1154}
1155
1156/*
1157 * Skip p_value leading components from "line"; as we do not accept
1158 * absolute paths, return NULL in that case.
1159 */
1160static const char *skip_tree_prefix(struct apply_state *state,
1161                                    const char *line,
1162                                    int llen)
1163{
1164        int nslash;
1165        int i;
1166
1167        if (!state->p_value)
1168                return (llen && line[0] == '/') ? NULL : line;
1169
1170        nslash = state->p_value;
1171        for (i = 0; i < llen; i++) {
1172                int ch = line[i];
1173                if (ch == '/' && --nslash <= 0)
1174                        return (i == 0) ? NULL : &line[i + 1];
1175        }
1176        return NULL;
1177}
1178
1179/*
1180 * This is to extract the same name that appears on "diff --git"
1181 * line.  We do not find and return anything if it is a rename
1182 * patch, and it is OK because we will find the name elsewhere.
1183 * We need to reliably find name only when it is mode-change only,
1184 * creation or deletion of an empty file.  In any of these cases,
1185 * both sides are the same name under a/ and b/ respectively.
1186 */
1187static char *git_header_name(struct apply_state *state,
1188                             const char *line,
1189                             int llen)
1190{
1191        const char *name;
1192        const char *second = NULL;
1193        size_t len, line_len;
1194
1195        line += strlen("diff --git ");
1196        llen -= strlen("diff --git ");
1197
1198        if (*line == '"') {
1199                const char *cp;
1200                struct strbuf first = STRBUF_INIT;
1201                struct strbuf sp = STRBUF_INIT;
1202
1203                if (unquote_c_style(&first, line, &second))
1204                        goto free_and_fail1;
1205
1206                /* strip the a/b prefix including trailing slash */
1207                cp = skip_tree_prefix(state, first.buf, first.len);
1208                if (!cp)
1209                        goto free_and_fail1;
1210                strbuf_remove(&first, 0, cp - first.buf);
1211
1212                /*
1213                 * second points at one past closing dq of name.
1214                 * find the second name.
1215                 */
1216                while ((second < line + llen) && isspace(*second))
1217                        second++;
1218
1219                if (line + llen <= second)
1220                        goto free_and_fail1;
1221                if (*second == '"') {
1222                        if (unquote_c_style(&sp, second, NULL))
1223                                goto free_and_fail1;
1224                        cp = skip_tree_prefix(state, sp.buf, sp.len);
1225                        if (!cp)
1226                                goto free_and_fail1;
1227                        /* They must match, otherwise ignore */
1228                        if (strcmp(cp, first.buf))
1229                                goto free_and_fail1;
1230                        strbuf_release(&sp);
1231                        return strbuf_detach(&first, NULL);
1232                }
1233
1234                /* unquoted second */
1235                cp = skip_tree_prefix(state, second, line + llen - second);
1236                if (!cp)
1237                        goto free_and_fail1;
1238                if (line + llen - cp != first.len ||
1239                    memcmp(first.buf, cp, first.len))
1240                        goto free_and_fail1;
1241                return strbuf_detach(&first, NULL);
1242
1243        free_and_fail1:
1244                strbuf_release(&first);
1245                strbuf_release(&sp);
1246                return NULL;
1247        }
1248
1249        /* unquoted first name */
1250        name = skip_tree_prefix(state, line, llen);
1251        if (!name)
1252                return NULL;
1253
1254        /*
1255         * since the first name is unquoted, a dq if exists must be
1256         * the beginning of the second name.
1257         */
1258        for (second = name; second < line + llen; second++) {
1259                if (*second == '"') {
1260                        struct strbuf sp = STRBUF_INIT;
1261                        const char *np;
1262
1263                        if (unquote_c_style(&sp, second, NULL))
1264                                goto free_and_fail2;
1265
1266                        np = skip_tree_prefix(state, sp.buf, sp.len);
1267                        if (!np)
1268                                goto free_and_fail2;
1269
1270                        len = sp.buf + sp.len - np;
1271                        if (len < second - name &&
1272                            !strncmp(np, name, len) &&
1273                            isspace(name[len])) {
1274                                /* Good */
1275                                strbuf_remove(&sp, 0, np - sp.buf);
1276                                return strbuf_detach(&sp, NULL);
1277                        }
1278
1279                free_and_fail2:
1280                        strbuf_release(&sp);
1281                        return NULL;
1282                }
1283        }
1284
1285        /*
1286         * Accept a name only if it shows up twice, exactly the same
1287         * form.
1288         */
1289        second = strchr(name, '\n');
1290        if (!second)
1291                return NULL;
1292        line_len = second - name;
1293        for (len = 0 ; ; len++) {
1294                switch (name[len]) {
1295                default:
1296                        continue;
1297                case '\n':
1298                        return NULL;
1299                case '\t': case ' ':
1300                        /*
1301                         * Is this the separator between the preimage
1302                         * and the postimage pathname?  Again, we are
1303                         * only interested in the case where there is
1304                         * no rename, as this is only to set def_name
1305                         * and a rename patch has the names elsewhere
1306                         * in an unambiguous form.
1307                         */
1308                        if (!name[len + 1])
1309                                return NULL; /* no postimage name */
1310                        second = skip_tree_prefix(state, name + len + 1,
1311                                                  line_len - (len + 1));
1312                        if (!second)
1313                                return NULL;
1314                        /*
1315                         * Does len bytes starting at "name" and "second"
1316                         * (that are separated by one HT or SP we just
1317                         * found) exactly match?
1318                         */
1319                        if (second[len] == '\n' && !strncmp(name, second, len))
1320                                return xmemdupz(name, len);
1321                }
1322        }
1323}
1324
1325/* Verify that we recognize the lines following a git header */
1326static int parse_git_header(struct apply_state *state,
1327                            const char *line,
1328                            int len,
1329                            unsigned int size,
1330                            struct patch *patch)
1331{
1332        unsigned long offset;
1333
1334        /* A git diff has explicit new/delete information, so we don't guess */
1335        patch->is_new = 0;
1336        patch->is_delete = 0;
1337
1338        /*
1339         * Some things may not have the old name in the
1340         * rest of the headers anywhere (pure mode changes,
1341         * or removing or adding empty files), so we get
1342         * the default name from the header.
1343         */
1344        patch->def_name = git_header_name(state, line, len);
1345        if (patch->def_name && state->root.len) {
1346                char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
1347                free(patch->def_name);
1348                patch->def_name = s;
1349        }
1350
1351        line += len;
1352        size -= len;
1353        state->linenr++;
1354        for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
1355                static const struct opentry {
1356                        const char *str;
1357                        int (*fn)(struct apply_state *, const char *, struct patch *);
1358                } optable[] = {
1359                        { "@@ -", gitdiff_hdrend },
1360                        { "--- ", gitdiff_oldname },
1361                        { "+++ ", gitdiff_newname },
1362                        { "old mode ", gitdiff_oldmode },
1363                        { "new mode ", gitdiff_newmode },
1364                        { "deleted file mode ", gitdiff_delete },
1365                        { "new file mode ", gitdiff_newfile },
1366                        { "copy from ", gitdiff_copysrc },
1367                        { "copy to ", gitdiff_copydst },
1368                        { "rename old ", gitdiff_renamesrc },
1369                        { "rename new ", gitdiff_renamedst },
1370                        { "rename from ", gitdiff_renamesrc },
1371                        { "rename to ", gitdiff_renamedst },
1372                        { "similarity index ", gitdiff_similarity },
1373                        { "dissimilarity index ", gitdiff_dissimilarity },
1374                        { "index ", gitdiff_index },
1375                        { "", gitdiff_unrecognized },
1376                };
1377                int i;
1378
1379                len = linelen(line, size);
1380                if (!len || line[len-1] != '\n')
1381                        break;
1382                for (i = 0; i < ARRAY_SIZE(optable); i++) {
1383                        const struct opentry *p = optable + i;
1384                        int oplen = strlen(p->str);
1385                        int res;
1386                        if (len < oplen || memcmp(p->str, line, oplen))
1387                                continue;
1388                        res = p->fn(state, line + oplen, patch);
1389                        if (res < 0)
1390                                return -1;
1391                        if (res > 0)
1392                                return offset;
1393                        break;
1394                }
1395        }
1396
1397        return offset;
1398}
1399
1400static int parse_num(const char *line, unsigned long *p)
1401{
1402        char *ptr;
1403
1404        if (!isdigit(*line))
1405                return 0;
1406        *p = strtoul(line, &ptr, 10);
1407        return ptr - line;
1408}
1409
1410static int parse_range(const char *line, int len, int offset, const char *expect,
1411                       unsigned long *p1, unsigned long *p2)
1412{
1413        int digits, ex;
1414
1415        if (offset < 0 || offset >= len)
1416                return -1;
1417        line += offset;
1418        len -= offset;
1419
1420        digits = parse_num(line, p1);
1421        if (!digits)
1422                return -1;
1423
1424        offset += digits;
1425        line += digits;
1426        len -= digits;
1427
1428        *p2 = 1;
1429        if (*line == ',') {
1430                digits = parse_num(line+1, p2);
1431                if (!digits)
1432                        return -1;
1433
1434                offset += digits+1;
1435                line += digits+1;
1436                len -= digits+1;
1437        }
1438
1439        ex = strlen(expect);
1440        if (ex > len)
1441                return -1;
1442        if (memcmp(line, expect, ex))
1443                return -1;
1444
1445        return offset + ex;
1446}
1447
1448static void recount_diff(const char *line, int size, struct fragment *fragment)
1449{
1450        int oldlines = 0, newlines = 0, ret = 0;
1451
1452        if (size < 1) {
1453                warning("recount: ignore empty hunk");
1454                return;
1455        }
1456
1457        for (;;) {
1458                int len = linelen(line, size);
1459                size -= len;
1460                line += len;
1461
1462                if (size < 1)
1463                        break;
1464
1465                switch (*line) {
1466                case ' ': case '\n':
1467                        newlines++;
1468                        /* fall through */
1469                case '-':
1470                        oldlines++;
1471                        continue;
1472                case '+':
1473                        newlines++;
1474                        continue;
1475                case '\\':
1476                        continue;
1477                case '@':
1478                        ret = size < 3 || !starts_with(line, "@@ ");
1479                        break;
1480                case 'd':
1481                        ret = size < 5 || !starts_with(line, "diff ");
1482                        break;
1483                default:
1484                        ret = -1;
1485                        break;
1486                }
1487                if (ret) {
1488                        warning(_("recount: unexpected line: %.*s"),
1489                                (int)linelen(line, size), line);
1490                        return;
1491                }
1492                break;
1493        }
1494        fragment->oldlines = oldlines;
1495        fragment->newlines = newlines;
1496}
1497
1498/*
1499 * Parse a unified diff fragment header of the
1500 * form "@@ -a,b +c,d @@"
1501 */
1502static int parse_fragment_header(const char *line, int len, struct fragment *fragment)
1503{
1504        int offset;
1505
1506        if (!len || line[len-1] != '\n')
1507                return -1;
1508
1509        /* Figure out the number of lines in a fragment */
1510        offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
1511        offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
1512
1513        return offset;
1514}
1515
1516/*
1517 * Find file diff header
1518 *
1519 * Returns:
1520 *  -1 if no header was found
1521 *  -128 in case of error
1522 *   the size of the header in bytes (called "offset") otherwise
1523 */
1524static int find_header(struct apply_state *state,
1525                       const char *line,
1526                       unsigned long size,
1527                       int *hdrsize,
1528                       struct patch *patch)
1529{
1530        unsigned long offset, len;
1531
1532        patch->is_toplevel_relative = 0;
1533        patch->is_rename = patch->is_copy = 0;
1534        patch->is_new = patch->is_delete = -1;
1535        patch->old_mode = patch->new_mode = 0;
1536        patch->old_name = patch->new_name = NULL;
1537        for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
1538                unsigned long nextlen;
1539
1540                len = linelen(line, size);
1541                if (!len)
1542                        break;
1543
1544                /* Testing this early allows us to take a few shortcuts.. */
1545                if (len < 6)
1546                        continue;
1547
1548                /*
1549                 * Make sure we don't find any unconnected patch fragments.
1550                 * That's a sign that we didn't find a header, and that a
1551                 * patch has become corrupted/broken up.
1552                 */
1553                if (!memcmp("@@ -", line, 4)) {
1554                        struct fragment dummy;
1555                        if (parse_fragment_header(line, len, &dummy) < 0)
1556                                continue;
1557                        error(_("patch fragment without header at line %d: %.*s"),
1558                                     state->linenr, (int)len-1, line);
1559                        return -128;
1560                }
1561
1562                if (size < len + 6)
1563                        break;
1564
1565                /*
1566                 * Git patch? It might not have a real patch, just a rename
1567                 * or mode change, so we handle that specially
1568                 */
1569                if (!memcmp("diff --git ", line, 11)) {
1570                        int git_hdr_len = parse_git_header(state, line, len, size, patch);
1571                        if (git_hdr_len < 0)
1572                                return -128;
1573                        if (git_hdr_len <= len)
1574                                continue;
1575                        if (!patch->old_name && !patch->new_name) {
1576                                if (!patch->def_name) {
1577                                        error(Q_("git diff header lacks filename information when removing "
1578                                                        "%d leading pathname component (line %d)",
1579                                                        "git diff header lacks filename information when removing "
1580                                                        "%d leading pathname components (line %d)",
1581                                                        state->p_value),
1582                                                     state->p_value, state->linenr);
1583                                        return -128;
1584                                }
1585                                patch->old_name = xstrdup(patch->def_name);
1586                                patch->new_name = xstrdup(patch->def_name);
1587                        }
1588                        if (!patch->is_delete && !patch->new_name) {
1589                                error("git diff header lacks filename information "
1590                                             "(line %d)", state->linenr);
1591                                return -128;
1592                        }
1593                        patch->is_toplevel_relative = 1;
1594                        *hdrsize = git_hdr_len;
1595                        return offset;
1596                }
1597
1598                /* --- followed by +++ ? */
1599                if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
1600                        continue;
1601
1602                /*
1603                 * We only accept unified patches, so we want it to
1604                 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
1605                 * minimum ("@@ -0,0 +1 @@\n" is the shortest).
1606                 */
1607                nextlen = linelen(line + len, size - len);
1608                if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
1609                        continue;
1610
1611                /* Ok, we'll consider it a patch */
1612                if (parse_traditional_patch(state, line, line+len, patch))
1613                        return -128;
1614                *hdrsize = len + nextlen;
1615                state->linenr += 2;
1616                return offset;
1617        }
1618        return -1;
1619}
1620
1621static void record_ws_error(struct apply_state *state,
1622                            unsigned result,
1623                            const char *line,
1624                            int len,
1625                            int linenr)
1626{
1627        char *err;
1628
1629        if (!result)
1630                return;
1631
1632        state->whitespace_error++;
1633        if (state->squelch_whitespace_errors &&
1634            state->squelch_whitespace_errors < state->whitespace_error)
1635                return;
1636
1637        err = whitespace_error_string(result);
1638        if (state->apply_verbosity > verbosity_silent)
1639                fprintf(stderr, "%s:%d: %s.\n%.*s\n",
1640                        state->patch_input_file, linenr, err, len, line);
1641        free(err);
1642}
1643
1644static void check_whitespace(struct apply_state *state,
1645                             const char *line,
1646                             int len,
1647                             unsigned ws_rule)
1648{
1649        unsigned result = ws_check(line + 1, len - 1, ws_rule);
1650
1651        record_ws_error(state, result, line + 1, len - 2, state->linenr);
1652}
1653
1654/*
1655 * Parse a unified diff. Note that this really needs to parse each
1656 * fragment separately, since the only way to know the difference
1657 * between a "---" that is part of a patch, and a "---" that starts
1658 * the next patch is to look at the line counts..
1659 */
1660static int parse_fragment(struct apply_state *state,
1661                          const char *line,
1662                          unsigned long size,
1663                          struct patch *patch,
1664                          struct fragment *fragment)
1665{
1666        int added, deleted;
1667        int len = linelen(line, size), offset;
1668        unsigned long oldlines, newlines;
1669        unsigned long leading, trailing;
1670
1671        offset = parse_fragment_header(line, len, fragment);
1672        if (offset < 0)
1673                return -1;
1674        if (offset > 0 && patch->recount)
1675                recount_diff(line + offset, size - offset, fragment);
1676        oldlines = fragment->oldlines;
1677        newlines = fragment->newlines;
1678        leading = 0;
1679        trailing = 0;
1680
1681        /* Parse the thing.. */
1682        line += len;
1683        size -= len;
1684        state->linenr++;
1685        added = deleted = 0;
1686        for (offset = len;
1687             0 < size;
1688             offset += len, size -= len, line += len, state->linenr++) {
1689                if (!oldlines && !newlines)
1690                        break;
1691                len = linelen(line, size);
1692                if (!len || line[len-1] != '\n')
1693                        return -1;
1694                switch (*line) {
1695                default:
1696                        return -1;
1697                case '\n': /* newer GNU diff, an empty context line */
1698                case ' ':
1699                        oldlines--;
1700                        newlines--;
1701                        if (!deleted && !added)
1702                                leading++;
1703                        trailing++;
1704                        if (!state->apply_in_reverse &&
1705                            state->ws_error_action == correct_ws_error)
1706                                check_whitespace(state, line, len, patch->ws_rule);
1707                        break;
1708                case '-':
1709                        if (state->apply_in_reverse &&
1710                            state->ws_error_action != nowarn_ws_error)
1711                                check_whitespace(state, line, len, patch->ws_rule);
1712                        deleted++;
1713                        oldlines--;
1714                        trailing = 0;
1715                        break;
1716                case '+':
1717                        if (!state->apply_in_reverse &&
1718                            state->ws_error_action != nowarn_ws_error)
1719                                check_whitespace(state, line, len, patch->ws_rule);
1720                        added++;
1721                        newlines--;
1722                        trailing = 0;
1723                        break;
1724
1725                /*
1726                 * We allow "\ No newline at end of file". Depending
1727                 * on locale settings when the patch was produced we
1728                 * don't know what this line looks like. The only
1729                 * thing we do know is that it begins with "\ ".
1730                 * Checking for 12 is just for sanity check -- any
1731                 * l10n of "\ No newline..." is at least that long.
1732                 */
1733                case '\\':
1734                        if (len < 12 || memcmp(line, "\\ ", 2))
1735                                return -1;
1736                        break;
1737                }
1738        }
1739        if (oldlines || newlines)
1740                return -1;
1741        if (!deleted && !added)
1742                return -1;
1743
1744        fragment->leading = leading;
1745        fragment->trailing = trailing;
1746
1747        /*
1748         * If a fragment ends with an incomplete line, we failed to include
1749         * it in the above loop because we hit oldlines == newlines == 0
1750         * before seeing it.
1751         */
1752        if (12 < size && !memcmp(line, "\\ ", 2))
1753                offset += linelen(line, size);
1754
1755        patch->lines_added += added;
1756        patch->lines_deleted += deleted;
1757
1758        if (0 < patch->is_new && oldlines)
1759                return error(_("new file depends on old contents"));
1760        if (0 < patch->is_delete && newlines)
1761                return error(_("deleted file still has contents"));
1762        return offset;
1763}
1764
1765/*
1766 * We have seen "diff --git a/... b/..." header (or a traditional patch
1767 * header).  Read hunks that belong to this patch into fragments and hang
1768 * them to the given patch structure.
1769 *
1770 * The (fragment->patch, fragment->size) pair points into the memory given
1771 * by the caller, not a copy, when we return.
1772 *
1773 * Returns:
1774 *   -1 in case of error,
1775 *   the number of bytes in the patch otherwise.
1776 */
1777static int parse_single_patch(struct apply_state *state,
1778                              const char *line,
1779                              unsigned long size,
1780                              struct patch *patch)
1781{
1782        unsigned long offset = 0;
1783        unsigned long oldlines = 0, newlines = 0, context = 0;
1784        struct fragment **fragp = &patch->fragments;
1785
1786        while (size > 4 && !memcmp(line, "@@ -", 4)) {
1787                struct fragment *fragment;
1788                int len;
1789
1790                fragment = xcalloc(1, sizeof(*fragment));
1791                fragment->linenr = state->linenr;
1792                len = parse_fragment(state, line, size, patch, fragment);
1793                if (len <= 0) {
1794                        free(fragment);
1795                        return error(_("corrupt patch at line %d"), state->linenr);
1796                }
1797                fragment->patch = line;
1798                fragment->size = len;
1799                oldlines += fragment->oldlines;
1800                newlines += fragment->newlines;
1801                context += fragment->leading + fragment->trailing;
1802
1803                *fragp = fragment;
1804                fragp = &fragment->next;
1805
1806                offset += len;
1807                line += len;
1808                size -= len;
1809        }
1810
1811        /*
1812         * If something was removed (i.e. we have old-lines) it cannot
1813         * be creation, and if something was added it cannot be
1814         * deletion.  However, the reverse is not true; --unified=0
1815         * patches that only add are not necessarily creation even
1816         * though they do not have any old lines, and ones that only
1817         * delete are not necessarily deletion.
1818         *
1819         * Unfortunately, a real creation/deletion patch do _not_ have
1820         * any context line by definition, so we cannot safely tell it
1821         * apart with --unified=0 insanity.  At least if the patch has
1822         * more than one hunk it is not creation or deletion.
1823         */
1824        if (patch->is_new < 0 &&
1825            (oldlines || (patch->fragments && patch->fragments->next)))
1826                patch->is_new = 0;
1827        if (patch->is_delete < 0 &&
1828            (newlines || (patch->fragments && patch->fragments->next)))
1829                patch->is_delete = 0;
1830
1831        if (0 < patch->is_new && oldlines)
1832                return error(_("new file %s depends on old contents"), patch->new_name);
1833        if (0 < patch->is_delete && newlines)
1834                return error(_("deleted file %s still has contents"), patch->old_name);
1835        if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
1836                fprintf_ln(stderr,
1837                           _("** warning: "
1838                             "file %s becomes empty but is not deleted"),
1839                           patch->new_name);
1840
1841        return offset;
1842}
1843
1844static inline int metadata_changes(struct patch *patch)
1845{
1846        return  patch->is_rename > 0 ||
1847                patch->is_copy > 0 ||
1848                patch->is_new > 0 ||
1849                patch->is_delete ||
1850                (patch->old_mode && patch->new_mode &&
1851                 patch->old_mode != patch->new_mode);
1852}
1853
1854static char *inflate_it(const void *data, unsigned long size,
1855                        unsigned long inflated_size)
1856{
1857        git_zstream stream;
1858        void *out;
1859        int st;
1860
1861        memset(&stream, 0, sizeof(stream));
1862
1863        stream.next_in = (unsigned char *)data;
1864        stream.avail_in = size;
1865        stream.next_out = out = xmalloc(inflated_size);
1866        stream.avail_out = inflated_size;
1867        git_inflate_init(&stream);
1868        st = git_inflate(&stream, Z_FINISH);
1869        git_inflate_end(&stream);
1870        if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1871                free(out);
1872                return NULL;
1873        }
1874        return out;
1875}
1876
1877/*
1878 * Read a binary hunk and return a new fragment; fragment->patch
1879 * points at an allocated memory that the caller must free, so
1880 * it is marked as "->free_patch = 1".
1881 */
1882static struct fragment *parse_binary_hunk(struct apply_state *state,
1883                                          char **buf_p,
1884                                          unsigned long *sz_p,
1885                                          int *status_p,
1886                                          int *used_p)
1887{
1888        /*
1889         * Expect a line that begins with binary patch method ("literal"
1890         * or "delta"), followed by the length of data before deflating.
1891         * a sequence of 'length-byte' followed by base-85 encoded data
1892         * should follow, terminated by a newline.
1893         *
1894         * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1895         * and we would limit the patch line to 66 characters,
1896         * so one line can fit up to 13 groups that would decode
1897         * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1898         * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1899         */
1900        int llen, used;
1901        unsigned long size = *sz_p;
1902        char *buffer = *buf_p;
1903        int patch_method;
1904        unsigned long origlen;
1905        char *data = NULL;
1906        int hunk_size = 0;
1907        struct fragment *frag;
1908
1909        llen = linelen(buffer, size);
1910        used = llen;
1911
1912        *status_p = 0;
1913
1914        if (starts_with(buffer, "delta ")) {
1915                patch_method = BINARY_DELTA_DEFLATED;
1916                origlen = strtoul(buffer + 6, NULL, 10);
1917        }
1918        else if (starts_with(buffer, "literal ")) {
1919                patch_method = BINARY_LITERAL_DEFLATED;
1920                origlen = strtoul(buffer + 8, NULL, 10);
1921        }
1922        else
1923                return NULL;
1924
1925        state->linenr++;
1926        buffer += llen;
1927        while (1) {
1928                int byte_length, max_byte_length, newsize;
1929                llen = linelen(buffer, size);
1930                used += llen;
1931                state->linenr++;
1932                if (llen == 1) {
1933                        /* consume the blank line */
1934                        buffer++;
1935                        size--;
1936                        break;
1937                }
1938                /*
1939                 * Minimum line is "A00000\n" which is 7-byte long,
1940                 * and the line length must be multiple of 5 plus 2.
1941                 */
1942                if ((llen < 7) || (llen-2) % 5)
1943                        goto corrupt;
1944                max_byte_length = (llen - 2) / 5 * 4;
1945                byte_length = *buffer;
1946                if ('A' <= byte_length && byte_length <= 'Z')
1947                        byte_length = byte_length - 'A' + 1;
1948                else if ('a' <= byte_length && byte_length <= 'z')
1949                        byte_length = byte_length - 'a' + 27;
1950                else
1951                        goto corrupt;
1952                /* if the input length was not multiple of 4, we would
1953                 * have filler at the end but the filler should never
1954                 * exceed 3 bytes
1955                 */
1956                if (max_byte_length < byte_length ||
1957                    byte_length <= max_byte_length - 4)
1958                        goto corrupt;
1959                newsize = hunk_size + byte_length;
1960                data = xrealloc(data, newsize);
1961                if (decode_85(data + hunk_size, buffer + 1, byte_length))
1962                        goto corrupt;
1963                hunk_size = newsize;
1964                buffer += llen;
1965                size -= llen;
1966        }
1967
1968        frag = xcalloc(1, sizeof(*frag));
1969        frag->patch = inflate_it(data, hunk_size, origlen);
1970        frag->free_patch = 1;
1971        if (!frag->patch)
1972                goto corrupt;
1973        free(data);
1974        frag->size = origlen;
1975        *buf_p = buffer;
1976        *sz_p = size;
1977        *used_p = used;
1978        frag->binary_patch_method = patch_method;
1979        return frag;
1980
1981 corrupt:
1982        free(data);
1983        *status_p = -1;
1984        error(_("corrupt binary patch at line %d: %.*s"),
1985              state->linenr-1, llen-1, buffer);
1986        return NULL;
1987}
1988
1989/*
1990 * Returns:
1991 *   -1 in case of error,
1992 *   the length of the parsed binary patch otherwise
1993 */
1994static int parse_binary(struct apply_state *state,
1995                        char *buffer,
1996                        unsigned long size,
1997                        struct patch *patch)
1998{
1999        /*
2000         * We have read "GIT binary patch\n"; what follows is a line
2001         * that says the patch method (currently, either "literal" or
2002         * "delta") and the length of data before deflating; a
2003         * sequence of 'length-byte' followed by base-85 encoded data
2004         * follows.
2005         *
2006         * When a binary patch is reversible, there is another binary
2007         * hunk in the same format, starting with patch method (either
2008         * "literal" or "delta") with the length of data, and a sequence
2009         * of length-byte + base-85 encoded data, terminated with another
2010         * empty line.  This data, when applied to the postimage, produces
2011         * the preimage.
2012         */
2013        struct fragment *forward;
2014        struct fragment *reverse;
2015        int status;
2016        int used, used_1;
2017
2018        forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
2019        if (!forward && !status)
2020                /* there has to be one hunk (forward hunk) */
2021                return error(_("unrecognized binary patch at line %d"), state->linenr-1);
2022        if (status)
2023                /* otherwise we already gave an error message */
2024                return status;
2025
2026        reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
2027        if (reverse)
2028                used += used_1;
2029        else if (status) {
2030                /*
2031                 * Not having reverse hunk is not an error, but having
2032                 * a corrupt reverse hunk is.
2033                 */
2034                free((void*) forward->patch);
2035                free(forward);
2036                return status;
2037        }
2038        forward->next = reverse;
2039        patch->fragments = forward;
2040        patch->is_binary = 1;
2041        return used;
2042}
2043
2044static void prefix_one(struct apply_state *state, char **name)
2045{
2046        char *old_name = *name;
2047        if (!old_name)
2048                return;
2049        *name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
2050        free(old_name);
2051}
2052
2053static void prefix_patch(struct apply_state *state, struct patch *p)
2054{
2055        if (!state->prefix || p->is_toplevel_relative)
2056                return;
2057        prefix_one(state, &p->new_name);
2058        prefix_one(state, &p->old_name);
2059}
2060
2061/*
2062 * include/exclude
2063 */
2064
2065static void add_name_limit(struct apply_state *state,
2066                           const char *name,
2067                           int exclude)
2068{
2069        struct string_list_item *it;
2070
2071        it = string_list_append(&state->limit_by_name, name);
2072        it->util = exclude ? NULL : (void *) 1;
2073}
2074
2075static int use_patch(struct apply_state *state, struct patch *p)
2076{
2077        const char *pathname = p->new_name ? p->new_name : p->old_name;
2078        int i;
2079
2080        /* Paths outside are not touched regardless of "--include" */
2081        if (0 < state->prefix_length) {
2082                int pathlen = strlen(pathname);
2083                if (pathlen <= state->prefix_length ||
2084                    memcmp(state->prefix, pathname, state->prefix_length))
2085                        return 0;
2086        }
2087
2088        /* See if it matches any of exclude/include rule */
2089        for (i = 0; i < state->limit_by_name.nr; i++) {
2090                struct string_list_item *it = &state->limit_by_name.items[i];
2091                if (!wildmatch(it->string, pathname, 0, NULL))
2092                        return (it->util != NULL);
2093        }
2094
2095        /*
2096         * If we had any include, a path that does not match any rule is
2097         * not used.  Otherwise, we saw bunch of exclude rules (or none)
2098         * and such a path is used.
2099         */
2100        return !state->has_include;
2101}
2102
2103/*
2104 * Read the patch text in "buffer" that extends for "size" bytes; stop
2105 * reading after seeing a single patch (i.e. changes to a single file).
2106 * Create fragments (i.e. patch hunks) and hang them to the given patch.
2107 *
2108 * Returns:
2109 *   -1 if no header was found or parse_binary() failed,
2110 *   -128 on another error,
2111 *   the number of bytes consumed otherwise,
2112 *     so that the caller can call us again for the next patch.
2113 */
2114static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
2115{
2116        int hdrsize, patchsize;
2117        int offset = find_header(state, buffer, size, &hdrsize, patch);
2118
2119        if (offset < 0)
2120                return offset;
2121
2122        prefix_patch(state, patch);
2123
2124        if (!use_patch(state, patch))
2125                patch->ws_rule = 0;
2126        else
2127                patch->ws_rule = whitespace_rule(patch->new_name
2128                                                 ? patch->new_name
2129                                                 : patch->old_name);
2130
2131        patchsize = parse_single_patch(state,
2132                                       buffer + offset + hdrsize,
2133                                       size - offset - hdrsize,
2134                                       patch);
2135
2136        if (patchsize < 0)
2137                return -128;
2138
2139        if (!patchsize) {
2140                static const char git_binary[] = "GIT binary patch\n";
2141                int hd = hdrsize + offset;
2142                unsigned long llen = linelen(buffer + hd, size - hd);
2143
2144                if (llen == sizeof(git_binary) - 1 &&
2145                    !memcmp(git_binary, buffer + hd, llen)) {
2146                        int used;
2147                        state->linenr++;
2148                        used = parse_binary(state, buffer + hd + llen,
2149                                            size - hd - llen, patch);
2150                        if (used < 0)
2151                                return -1;
2152                        if (used)
2153                                patchsize = used + llen;
2154                        else
2155                                patchsize = 0;
2156                }
2157                else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
2158                        static const char *binhdr[] = {
2159                                "Binary files ",
2160                                "Files ",
2161                                NULL,
2162                        };
2163                        int i;
2164                        for (i = 0; binhdr[i]; i++) {
2165                                int len = strlen(binhdr[i]);
2166                                if (len < size - hd &&
2167                                    !memcmp(binhdr[i], buffer + hd, len)) {
2168                                        state->linenr++;
2169                                        patch->is_binary = 1;
2170                                        patchsize = llen;
2171                                        break;
2172                                }
2173                        }
2174                }
2175
2176                /* Empty patch cannot be applied if it is a text patch
2177                 * without metadata change.  A binary patch appears
2178                 * empty to us here.
2179                 */
2180                if ((state->apply || state->check) &&
2181                    (!patch->is_binary && !metadata_changes(patch))) {
2182                        error(_("patch with only garbage at line %d"), state->linenr);
2183                        return -128;
2184                }
2185        }
2186
2187        return offset + hdrsize + patchsize;
2188}
2189
2190#define swap(a,b) myswap((a),(b),sizeof(a))
2191
2192#define myswap(a, b, size) do {         \
2193        unsigned char mytmp[size];      \
2194        memcpy(mytmp, &a, size);                \
2195        memcpy(&a, &b, size);           \
2196        memcpy(&b, mytmp, size);                \
2197} while (0)
2198
2199static void reverse_patches(struct patch *p)
2200{
2201        for (; p; p = p->next) {
2202                struct fragment *frag = p->fragments;
2203
2204                swap(p->new_name, p->old_name);
2205                swap(p->new_mode, p->old_mode);
2206                swap(p->is_new, p->is_delete);
2207                swap(p->lines_added, p->lines_deleted);
2208                swap(p->old_sha1_prefix, p->new_sha1_prefix);
2209
2210                for (; frag; frag = frag->next) {
2211                        swap(frag->newpos, frag->oldpos);
2212                        swap(frag->newlines, frag->oldlines);
2213                }
2214        }
2215}
2216
2217static const char pluses[] =
2218"++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
2219static const char minuses[]=
2220"----------------------------------------------------------------------";
2221
2222static void show_stats(struct apply_state *state, struct patch *patch)
2223{
2224        struct strbuf qname = STRBUF_INIT;
2225        char *cp = patch->new_name ? patch->new_name : patch->old_name;
2226        int max, add, del;
2227
2228        quote_c_style(cp, &qname, NULL, 0);
2229
2230        /*
2231         * "scale" the filename
2232         */
2233        max = state->max_len;
2234        if (max > 50)
2235                max = 50;
2236
2237        if (qname.len > max) {
2238                cp = strchr(qname.buf + qname.len + 3 - max, '/');
2239                if (!cp)
2240                        cp = qname.buf + qname.len + 3 - max;
2241                strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
2242        }
2243
2244        if (patch->is_binary) {
2245                printf(" %-*s |  Bin\n", max, qname.buf);
2246                strbuf_release(&qname);
2247                return;
2248        }
2249
2250        printf(" %-*s |", max, qname.buf);
2251        strbuf_release(&qname);
2252
2253        /*
2254         * scale the add/delete
2255         */
2256        max = max + state->max_change > 70 ? 70 - max : state->max_change;
2257        add = patch->lines_added;
2258        del = patch->lines_deleted;
2259
2260        if (state->max_change > 0) {
2261                int total = ((add + del) * max + state->max_change / 2) / state->max_change;
2262                add = (add * max + state->max_change / 2) / state->max_change;
2263                del = total - add;
2264        }
2265        printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
2266                add, pluses, del, minuses);
2267}
2268
2269static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
2270{
2271        switch (st->st_mode & S_IFMT) {
2272        case S_IFLNK:
2273                if (strbuf_readlink(buf, path, st->st_size) < 0)
2274                        return error(_("unable to read symlink %s"), path);
2275                return 0;
2276        case S_IFREG:
2277                if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
2278                        return error(_("unable to open or read %s"), path);
2279                convert_to_git(path, buf->buf, buf->len, buf, 0);
2280                return 0;
2281        default:
2282                return -1;
2283        }
2284}
2285
2286/*
2287 * Update the preimage, and the common lines in postimage,
2288 * from buffer buf of length len. If postlen is 0 the postimage
2289 * is updated in place, otherwise it's updated on a new buffer
2290 * of length postlen
2291 */
2292
2293static void update_pre_post_images(struct image *preimage,
2294                                   struct image *postimage,
2295                                   char *buf,
2296                                   size_t len, size_t postlen)
2297{
2298        int i, ctx, reduced;
2299        char *new, *old, *fixed;
2300        struct image fixed_preimage;
2301
2302        /*
2303         * Update the preimage with whitespace fixes.  Note that we
2304         * are not losing preimage->buf -- apply_one_fragment() will
2305         * free "oldlines".
2306         */
2307        prepare_image(&fixed_preimage, buf, len, 1);
2308        assert(postlen
2309               ? fixed_preimage.nr == preimage->nr
2310               : fixed_preimage.nr <= preimage->nr);
2311        for (i = 0; i < fixed_preimage.nr; i++)
2312                fixed_preimage.line[i].flag = preimage->line[i].flag;
2313        free(preimage->line_allocated);
2314        *preimage = fixed_preimage;
2315
2316        /*
2317         * Adjust the common context lines in postimage. This can be
2318         * done in-place when we are shrinking it with whitespace
2319         * fixing, but needs a new buffer when ignoring whitespace or
2320         * expanding leading tabs to spaces.
2321         *
2322         * We trust the caller to tell us if the update can be done
2323         * in place (postlen==0) or not.
2324         */
2325        old = postimage->buf;
2326        if (postlen)
2327                new = postimage->buf = xmalloc(postlen);
2328        else
2329                new = old;
2330        fixed = preimage->buf;
2331
2332        for (i = reduced = ctx = 0; i < postimage->nr; i++) {
2333                size_t l_len = postimage->line[i].len;
2334                if (!(postimage->line[i].flag & LINE_COMMON)) {
2335                        /* an added line -- no counterparts in preimage */
2336                        memmove(new, old, l_len);
2337                        old += l_len;
2338                        new += l_len;
2339                        continue;
2340                }
2341
2342                /* a common context -- skip it in the original postimage */
2343                old += l_len;
2344
2345                /* and find the corresponding one in the fixed preimage */
2346                while (ctx < preimage->nr &&
2347                       !(preimage->line[ctx].flag & LINE_COMMON)) {
2348                        fixed += preimage->line[ctx].len;
2349                        ctx++;
2350                }
2351
2352                /*
2353                 * preimage is expected to run out, if the caller
2354                 * fixed addition of trailing blank lines.
2355                 */
2356                if (preimage->nr <= ctx) {
2357                        reduced++;
2358                        continue;
2359                }
2360
2361                /* and copy it in, while fixing the line length */
2362                l_len = preimage->line[ctx].len;
2363                memcpy(new, fixed, l_len);
2364                new += l_len;
2365                fixed += l_len;
2366                postimage->line[i].len = l_len;
2367                ctx++;
2368        }
2369
2370        if (postlen
2371            ? postlen < new - postimage->buf
2372            : postimage->len < new - postimage->buf)
2373                die("BUG: caller miscounted postlen: asked %d, orig = %d, used = %d",
2374                    (int)postlen, (int) postimage->len, (int)(new - postimage->buf));
2375
2376        /* Fix the length of the whole thing */
2377        postimage->len = new - postimage->buf;
2378        postimage->nr -= reduced;
2379}
2380
2381static int line_by_line_fuzzy_match(struct image *img,
2382                                    struct image *preimage,
2383                                    struct image *postimage,
2384                                    unsigned long try,
2385                                    int try_lno,
2386                                    int preimage_limit)
2387{
2388        int i;
2389        size_t imgoff = 0;
2390        size_t preoff = 0;
2391        size_t postlen = postimage->len;
2392        size_t extra_chars;
2393        char *buf;
2394        char *preimage_eof;
2395        char *preimage_end;
2396        struct strbuf fixed;
2397        char *fixed_buf;
2398        size_t fixed_len;
2399
2400        for (i = 0; i < preimage_limit; i++) {
2401                size_t prelen = preimage->line[i].len;
2402                size_t imglen = img->line[try_lno+i].len;
2403
2404                if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
2405                                      preimage->buf + preoff, prelen))
2406                        return 0;
2407                if (preimage->line[i].flag & LINE_COMMON)
2408                        postlen += imglen - prelen;
2409                imgoff += imglen;
2410                preoff += prelen;
2411        }
2412
2413        /*
2414         * Ok, the preimage matches with whitespace fuzz.
2415         *
2416         * imgoff now holds the true length of the target that
2417         * matches the preimage before the end of the file.
2418         *
2419         * Count the number of characters in the preimage that fall
2420         * beyond the end of the file and make sure that all of them
2421         * are whitespace characters. (This can only happen if
2422         * we are removing blank lines at the end of the file.)
2423         */
2424        buf = preimage_eof = preimage->buf + preoff;
2425        for ( ; i < preimage->nr; i++)
2426                preoff += preimage->line[i].len;
2427        preimage_end = preimage->buf + preoff;
2428        for ( ; buf < preimage_end; buf++)
2429                if (!isspace(*buf))
2430                        return 0;
2431
2432        /*
2433         * Update the preimage and the common postimage context
2434         * lines to use the same whitespace as the target.
2435         * If whitespace is missing in the target (i.e.
2436         * if the preimage extends beyond the end of the file),
2437         * use the whitespace from the preimage.
2438         */
2439        extra_chars = preimage_end - preimage_eof;
2440        strbuf_init(&fixed, imgoff + extra_chars);
2441        strbuf_add(&fixed, img->buf + try, imgoff);
2442        strbuf_add(&fixed, preimage_eof, extra_chars);
2443        fixed_buf = strbuf_detach(&fixed, &fixed_len);
2444        update_pre_post_images(preimage, postimage,
2445                               fixed_buf, fixed_len, postlen);
2446        return 1;
2447}
2448
2449static int match_fragment(struct apply_state *state,
2450                          struct image *img,
2451                          struct image *preimage,
2452                          struct image *postimage,
2453                          unsigned long try,
2454                          int try_lno,
2455                          unsigned ws_rule,
2456                          int match_beginning, int match_end)
2457{
2458        int i;
2459        char *fixed_buf, *buf, *orig, *target;
2460        struct strbuf fixed;
2461        size_t fixed_len, postlen;
2462        int preimage_limit;
2463
2464        if (preimage->nr + try_lno <= img->nr) {
2465                /*
2466                 * The hunk falls within the boundaries of img.
2467                 */
2468                preimage_limit = preimage->nr;
2469                if (match_end && (preimage->nr + try_lno != img->nr))
2470                        return 0;
2471        } else if (state->ws_error_action == correct_ws_error &&
2472                   (ws_rule & WS_BLANK_AT_EOF)) {
2473                /*
2474                 * This hunk extends beyond the end of img, and we are
2475                 * removing blank lines at the end of the file.  This
2476                 * many lines from the beginning of the preimage must
2477                 * match with img, and the remainder of the preimage
2478                 * must be blank.
2479                 */
2480                preimage_limit = img->nr - try_lno;
2481        } else {
2482                /*
2483                 * The hunk extends beyond the end of the img and
2484                 * we are not removing blanks at the end, so we
2485                 * should reject the hunk at this position.
2486                 */
2487                return 0;
2488        }
2489
2490        if (match_beginning && try_lno)
2491                return 0;
2492
2493        /* Quick hash check */
2494        for (i = 0; i < preimage_limit; i++)
2495                if ((img->line[try_lno + i].flag & LINE_PATCHED) ||
2496                    (preimage->line[i].hash != img->line[try_lno + i].hash))
2497                        return 0;
2498
2499        if (preimage_limit == preimage->nr) {
2500                /*
2501                 * Do we have an exact match?  If we were told to match
2502                 * at the end, size must be exactly at try+fragsize,
2503                 * otherwise try+fragsize must be still within the preimage,
2504                 * and either case, the old piece should match the preimage
2505                 * exactly.
2506                 */
2507                if ((match_end
2508                     ? (try + preimage->len == img->len)
2509                     : (try + preimage->len <= img->len)) &&
2510                    !memcmp(img->buf + try, preimage->buf, preimage->len))
2511                        return 1;
2512        } else {
2513                /*
2514                 * The preimage extends beyond the end of img, so
2515                 * there cannot be an exact match.
2516                 *
2517                 * There must be one non-blank context line that match
2518                 * a line before the end of img.
2519                 */
2520                char *buf_end;
2521
2522                buf = preimage->buf;
2523                buf_end = buf;
2524                for (i = 0; i < preimage_limit; i++)
2525                        buf_end += preimage->line[i].len;
2526
2527                for ( ; buf < buf_end; buf++)
2528                        if (!isspace(*buf))
2529                                break;
2530                if (buf == buf_end)
2531                        return 0;
2532        }
2533
2534        /*
2535         * No exact match. If we are ignoring whitespace, run a line-by-line
2536         * fuzzy matching. We collect all the line length information because
2537         * we need it to adjust whitespace if we match.
2538         */
2539        if (state->ws_ignore_action == ignore_ws_change)
2540                return line_by_line_fuzzy_match(img, preimage, postimage,
2541                                                try, try_lno, preimage_limit);
2542
2543        if (state->ws_error_action != correct_ws_error)
2544                return 0;
2545
2546        /*
2547         * The hunk does not apply byte-by-byte, but the hash says
2548         * it might with whitespace fuzz. We weren't asked to
2549         * ignore whitespace, we were asked to correct whitespace
2550         * errors, so let's try matching after whitespace correction.
2551         *
2552         * While checking the preimage against the target, whitespace
2553         * errors in both fixed, we count how large the corresponding
2554         * postimage needs to be.  The postimage prepared by
2555         * apply_one_fragment() has whitespace errors fixed on added
2556         * lines already, but the common lines were propagated as-is,
2557         * which may become longer when their whitespace errors are
2558         * fixed.
2559         */
2560
2561        /* First count added lines in postimage */
2562        postlen = 0;
2563        for (i = 0; i < postimage->nr; i++) {
2564                if (!(postimage->line[i].flag & LINE_COMMON))
2565                        postlen += postimage->line[i].len;
2566        }
2567
2568        /*
2569         * The preimage may extend beyond the end of the file,
2570         * but in this loop we will only handle the part of the
2571         * preimage that falls within the file.
2572         */
2573        strbuf_init(&fixed, preimage->len + 1);
2574        orig = preimage->buf;
2575        target = img->buf + try;
2576        for (i = 0; i < preimage_limit; i++) {
2577                size_t oldlen = preimage->line[i].len;
2578                size_t tgtlen = img->line[try_lno + i].len;
2579                size_t fixstart = fixed.len;
2580                struct strbuf tgtfix;
2581                int match;
2582
2583                /* Try fixing the line in the preimage */
2584                ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2585
2586                /* Try fixing the line in the target */
2587                strbuf_init(&tgtfix, tgtlen);
2588                ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
2589
2590                /*
2591                 * If they match, either the preimage was based on
2592                 * a version before our tree fixed whitespace breakage,
2593                 * or we are lacking a whitespace-fix patch the tree
2594                 * the preimage was based on already had (i.e. target
2595                 * has whitespace breakage, the preimage doesn't).
2596                 * In either case, we are fixing the whitespace breakages
2597                 * so we might as well take the fix together with their
2598                 * real change.
2599                 */
2600                match = (tgtfix.len == fixed.len - fixstart &&
2601                         !memcmp(tgtfix.buf, fixed.buf + fixstart,
2602                                             fixed.len - fixstart));
2603
2604                /* Add the length if this is common with the postimage */
2605                if (preimage->line[i].flag & LINE_COMMON)
2606                        postlen += tgtfix.len;
2607
2608                strbuf_release(&tgtfix);
2609                if (!match)
2610                        goto unmatch_exit;
2611
2612                orig += oldlen;
2613                target += tgtlen;
2614        }
2615
2616
2617        /*
2618         * Now handle the lines in the preimage that falls beyond the
2619         * end of the file (if any). They will only match if they are
2620         * empty or only contain whitespace (if WS_BLANK_AT_EOL is
2621         * false).
2622         */
2623        for ( ; i < preimage->nr; i++) {
2624                size_t fixstart = fixed.len; /* start of the fixed preimage */
2625                size_t oldlen = preimage->line[i].len;
2626                int j;
2627
2628                /* Try fixing the line in the preimage */
2629                ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2630
2631                for (j = fixstart; j < fixed.len; j++)
2632                        if (!isspace(fixed.buf[j]))
2633                                goto unmatch_exit;
2634
2635                orig += oldlen;
2636        }
2637
2638        /*
2639         * Yes, the preimage is based on an older version that still
2640         * has whitespace breakages unfixed, and fixing them makes the
2641         * hunk match.  Update the context lines in the postimage.
2642         */
2643        fixed_buf = strbuf_detach(&fixed, &fixed_len);
2644        if (postlen < postimage->len)
2645                postlen = 0;
2646        update_pre_post_images(preimage, postimage,
2647                               fixed_buf, fixed_len, postlen);
2648        return 1;
2649
2650 unmatch_exit:
2651        strbuf_release(&fixed);
2652        return 0;
2653}
2654
2655static int find_pos(struct apply_state *state,
2656                    struct image *img,
2657                    struct image *preimage,
2658                    struct image *postimage,
2659                    int line,
2660                    unsigned ws_rule,
2661                    int match_beginning, int match_end)
2662{
2663        int i;
2664        unsigned long backwards, forwards, try;
2665        int backwards_lno, forwards_lno, try_lno;
2666
2667        /*
2668         * If match_beginning or match_end is specified, there is no
2669         * point starting from a wrong line that will never match and
2670         * wander around and wait for a match at the specified end.
2671         */
2672        if (match_beginning)
2673                line = 0;
2674        else if (match_end)
2675                line = img->nr - preimage->nr;
2676
2677        /*
2678         * Because the comparison is unsigned, the following test
2679         * will also take care of a negative line number that can
2680         * result when match_end and preimage is larger than the target.
2681         */
2682        if ((size_t) line > img->nr)
2683                line = img->nr;
2684
2685        try = 0;
2686        for (i = 0; i < line; i++)
2687                try += img->line[i].len;
2688
2689        /*
2690         * There's probably some smart way to do this, but I'll leave
2691         * that to the smart and beautiful people. I'm simple and stupid.
2692         */
2693        backwards = try;
2694        backwards_lno = line;
2695        forwards = try;
2696        forwards_lno = line;
2697        try_lno = line;
2698
2699        for (i = 0; ; i++) {
2700                if (match_fragment(state, img, preimage, postimage,
2701                                   try, try_lno, ws_rule,
2702                                   match_beginning, match_end))
2703                        return try_lno;
2704
2705        again:
2706                if (backwards_lno == 0 && forwards_lno == img->nr)
2707                        break;
2708
2709                if (i & 1) {
2710                        if (backwards_lno == 0) {
2711                                i++;
2712                                goto again;
2713                        }
2714                        backwards_lno--;
2715                        backwards -= img->line[backwards_lno].len;
2716                        try = backwards;
2717                        try_lno = backwards_lno;
2718                } else {
2719                        if (forwards_lno == img->nr) {
2720                                i++;
2721                                goto again;
2722                        }
2723                        forwards += img->line[forwards_lno].len;
2724                        forwards_lno++;
2725                        try = forwards;
2726                        try_lno = forwards_lno;
2727                }
2728
2729        }
2730        return -1;
2731}
2732
2733static void remove_first_line(struct image *img)
2734{
2735        img->buf += img->line[0].len;
2736        img->len -= img->line[0].len;
2737        img->line++;
2738        img->nr--;
2739}
2740
2741static void remove_last_line(struct image *img)
2742{
2743        img->len -= img->line[--img->nr].len;
2744}
2745
2746/*
2747 * The change from "preimage" and "postimage" has been found to
2748 * apply at applied_pos (counts in line numbers) in "img".
2749 * Update "img" to remove "preimage" and replace it with "postimage".
2750 */
2751static void update_image(struct apply_state *state,
2752                         struct image *img,
2753                         int applied_pos,
2754                         struct image *preimage,
2755                         struct image *postimage)
2756{
2757        /*
2758         * remove the copy of preimage at offset in img
2759         * and replace it with postimage
2760         */
2761        int i, nr;
2762        size_t remove_count, insert_count, applied_at = 0;
2763        char *result;
2764        int preimage_limit;
2765
2766        /*
2767         * If we are removing blank lines at the end of img,
2768         * the preimage may extend beyond the end.
2769         * If that is the case, we must be careful only to
2770         * remove the part of the preimage that falls within
2771         * the boundaries of img. Initialize preimage_limit
2772         * to the number of lines in the preimage that falls
2773         * within the boundaries.
2774         */
2775        preimage_limit = preimage->nr;
2776        if (preimage_limit > img->nr - applied_pos)
2777                preimage_limit = img->nr - applied_pos;
2778
2779        for (i = 0; i < applied_pos; i++)
2780                applied_at += img->line[i].len;
2781
2782        remove_count = 0;
2783        for (i = 0; i < preimage_limit; i++)
2784                remove_count += img->line[applied_pos + i].len;
2785        insert_count = postimage->len;
2786
2787        /* Adjust the contents */
2788        result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1));
2789        memcpy(result, img->buf, applied_at);
2790        memcpy(result + applied_at, postimage->buf, postimage->len);
2791        memcpy(result + applied_at + postimage->len,
2792               img->buf + (applied_at + remove_count),
2793               img->len - (applied_at + remove_count));
2794        free(img->buf);
2795        img->buf = result;
2796        img->len += insert_count - remove_count;
2797        result[img->len] = '\0';
2798
2799        /* Adjust the line table */
2800        nr = img->nr + postimage->nr - preimage_limit;
2801        if (preimage_limit < postimage->nr) {
2802                /*
2803                 * NOTE: this knows that we never call remove_first_line()
2804                 * on anything other than pre/post image.
2805                 */
2806                REALLOC_ARRAY(img->line, nr);
2807                img->line_allocated = img->line;
2808        }
2809        if (preimage_limit != postimage->nr)
2810                memmove(img->line + applied_pos + postimage->nr,
2811                        img->line + applied_pos + preimage_limit,
2812                        (img->nr - (applied_pos + preimage_limit)) *
2813                        sizeof(*img->line));
2814        memcpy(img->line + applied_pos,
2815               postimage->line,
2816               postimage->nr * sizeof(*img->line));
2817        if (!state->allow_overlap)
2818                for (i = 0; i < postimage->nr; i++)
2819                        img->line[applied_pos + i].flag |= LINE_PATCHED;
2820        img->nr = nr;
2821}
2822
2823/*
2824 * Use the patch-hunk text in "frag" to prepare two images (preimage and
2825 * postimage) for the hunk.  Find lines that match "preimage" in "img" and
2826 * replace the part of "img" with "postimage" text.
2827 */
2828static int apply_one_fragment(struct apply_state *state,
2829                              struct image *img, struct fragment *frag,
2830                              int inaccurate_eof, unsigned ws_rule,
2831                              int nth_fragment)
2832{
2833        int match_beginning, match_end;
2834        const char *patch = frag->patch;
2835        int size = frag->size;
2836        char *old, *oldlines;
2837        struct strbuf newlines;
2838        int new_blank_lines_at_end = 0;
2839        int found_new_blank_lines_at_end = 0;
2840        int hunk_linenr = frag->linenr;
2841        unsigned long leading, trailing;
2842        int pos, applied_pos;
2843        struct image preimage;
2844        struct image postimage;
2845
2846        memset(&preimage, 0, sizeof(preimage));
2847        memset(&postimage, 0, sizeof(postimage));
2848        oldlines = xmalloc(size);
2849        strbuf_init(&newlines, size);
2850
2851        old = oldlines;
2852        while (size > 0) {
2853                char first;
2854                int len = linelen(patch, size);
2855                int plen;
2856                int added_blank_line = 0;
2857                int is_blank_context = 0;
2858                size_t start;
2859
2860                if (!len)
2861                        break;
2862
2863                /*
2864                 * "plen" is how much of the line we should use for
2865                 * the actual patch data. Normally we just remove the
2866                 * first character on the line, but if the line is
2867                 * followed by "\ No newline", then we also remove the
2868                 * last one (which is the newline, of course).
2869                 */
2870                plen = len - 1;
2871                if (len < size && patch[len] == '\\')
2872                        plen--;
2873                first = *patch;
2874                if (state->apply_in_reverse) {
2875                        if (first == '-')
2876                                first = '+';
2877                        else if (first == '+')
2878                                first = '-';
2879                }
2880
2881                switch (first) {
2882                case '\n':
2883                        /* Newer GNU diff, empty context line */
2884                        if (plen < 0)
2885                                /* ... followed by '\No newline'; nothing */
2886                                break;
2887                        *old++ = '\n';
2888                        strbuf_addch(&newlines, '\n');
2889                        add_line_info(&preimage, "\n", 1, LINE_COMMON);
2890                        add_line_info(&postimage, "\n", 1, LINE_COMMON);
2891                        is_blank_context = 1;
2892                        break;
2893                case ' ':
2894                        if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
2895                            ws_blank_line(patch + 1, plen, ws_rule))
2896                                is_blank_context = 1;
2897                case '-':
2898                        memcpy(old, patch + 1, plen);
2899                        add_line_info(&preimage, old, plen,
2900                                      (first == ' ' ? LINE_COMMON : 0));
2901                        old += plen;
2902                        if (first == '-')
2903                                break;
2904                /* Fall-through for ' ' */
2905                case '+':
2906                        /* --no-add does not add new lines */
2907                        if (first == '+' && state->no_add)
2908                                break;
2909
2910                        start = newlines.len;
2911                        if (first != '+' ||
2912                            !state->whitespace_error ||
2913                            state->ws_error_action != correct_ws_error) {
2914                                strbuf_add(&newlines, patch + 1, plen);
2915                        }
2916                        else {
2917                                ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
2918                        }
2919                        add_line_info(&postimage, newlines.buf + start, newlines.len - start,
2920                                      (first == '+' ? 0 : LINE_COMMON));
2921                        if (first == '+' &&
2922                            (ws_rule & WS_BLANK_AT_EOF) &&
2923                            ws_blank_line(patch + 1, plen, ws_rule))
2924                                added_blank_line = 1;
2925                        break;
2926                case '@': case '\\':
2927                        /* Ignore it, we already handled it */
2928                        break;
2929                default:
2930                        if (state->apply_verbosity > verbosity_normal)
2931                                error(_("invalid start of line: '%c'"), first);
2932                        applied_pos = -1;
2933                        goto out;
2934                }
2935                if (added_blank_line) {
2936                        if (!new_blank_lines_at_end)
2937                                found_new_blank_lines_at_end = hunk_linenr;
2938                        new_blank_lines_at_end++;
2939                }
2940                else if (is_blank_context)
2941                        ;
2942                else
2943                        new_blank_lines_at_end = 0;
2944                patch += len;
2945                size -= len;
2946                hunk_linenr++;
2947        }
2948        if (inaccurate_eof &&
2949            old > oldlines && old[-1] == '\n' &&
2950            newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
2951                old--;
2952                strbuf_setlen(&newlines, newlines.len - 1);
2953        }
2954
2955        leading = frag->leading;
2956        trailing = frag->trailing;
2957
2958        /*
2959         * A hunk to change lines at the beginning would begin with
2960         * @@ -1,L +N,M @@
2961         * but we need to be careful.  -U0 that inserts before the second
2962         * line also has this pattern.
2963         *
2964         * And a hunk to add to an empty file would begin with
2965         * @@ -0,0 +N,M @@
2966         *
2967         * In other words, a hunk that is (frag->oldpos <= 1) with or
2968         * without leading context must match at the beginning.
2969         */
2970        match_beginning = (!frag->oldpos ||
2971                           (frag->oldpos == 1 && !state->unidiff_zero));
2972
2973        /*
2974         * A hunk without trailing lines must match at the end.
2975         * However, we simply cannot tell if a hunk must match end
2976         * from the lack of trailing lines if the patch was generated
2977         * with unidiff without any context.
2978         */
2979        match_end = !state->unidiff_zero && !trailing;
2980
2981        pos = frag->newpos ? (frag->newpos - 1) : 0;
2982        preimage.buf = oldlines;
2983        preimage.len = old - oldlines;
2984        postimage.buf = newlines.buf;
2985        postimage.len = newlines.len;
2986        preimage.line = preimage.line_allocated;
2987        postimage.line = postimage.line_allocated;
2988
2989        for (;;) {
2990
2991                applied_pos = find_pos(state, img, &preimage, &postimage, pos,
2992                                       ws_rule, match_beginning, match_end);
2993
2994                if (applied_pos >= 0)
2995                        break;
2996
2997                /* Am I at my context limits? */
2998                if ((leading <= state->p_context) && (trailing <= state->p_context))
2999                        break;
3000                if (match_beginning || match_end) {
3001                        match_beginning = match_end = 0;
3002                        continue;
3003                }
3004
3005                /*
3006                 * Reduce the number of context lines; reduce both
3007                 * leading and trailing if they are equal otherwise
3008                 * just reduce the larger context.
3009                 */
3010                if (leading >= trailing) {
3011                        remove_first_line(&preimage);
3012                        remove_first_line(&postimage);
3013                        pos--;
3014                        leading--;
3015                }
3016                if (trailing > leading) {
3017                        remove_last_line(&preimage);
3018                        remove_last_line(&postimage);
3019                        trailing--;
3020                }
3021        }
3022
3023        if (applied_pos >= 0) {
3024                if (new_blank_lines_at_end &&
3025                    preimage.nr + applied_pos >= img->nr &&
3026                    (ws_rule & WS_BLANK_AT_EOF) &&
3027                    state->ws_error_action != nowarn_ws_error) {
3028                        record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
3029                                        found_new_blank_lines_at_end);
3030                        if (state->ws_error_action == correct_ws_error) {
3031                                while (new_blank_lines_at_end--)
3032                                        remove_last_line(&postimage);
3033                        }
3034                        /*
3035                         * We would want to prevent write_out_results()
3036                         * from taking place in apply_patch() that follows
3037                         * the callchain led us here, which is:
3038                         * apply_patch->check_patch_list->check_patch->
3039                         * apply_data->apply_fragments->apply_one_fragment
3040                         */
3041                        if (state->ws_error_action == die_on_ws_error)
3042                                state->apply = 0;
3043                }
3044
3045                if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
3046                        int offset = applied_pos - pos;
3047                        if (state->apply_in_reverse)
3048                                offset = 0 - offset;
3049                        fprintf_ln(stderr,
3050                                   Q_("Hunk #%d succeeded at %d (offset %d line).",
3051                                      "Hunk #%d succeeded at %d (offset %d lines).",
3052                                      offset),
3053                                   nth_fragment, applied_pos + 1, offset);
3054                }
3055
3056                /*
3057                 * Warn if it was necessary to reduce the number
3058                 * of context lines.
3059                 */
3060                if ((leading != frag->leading ||
3061                     trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
3062                        fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
3063                                             " to apply fragment at %d"),
3064                                   leading, trailing, applied_pos+1);
3065                update_image(state, img, applied_pos, &preimage, &postimage);
3066        } else {
3067                if (state->apply_verbosity > verbosity_normal)
3068                        error(_("while searching for:\n%.*s"),
3069                              (int)(old - oldlines), oldlines);
3070        }
3071
3072out:
3073        free(oldlines);
3074        strbuf_release(&newlines);
3075        free(preimage.line_allocated);
3076        free(postimage.line_allocated);
3077
3078        return (applied_pos < 0);
3079}
3080
3081static int apply_binary_fragment(struct apply_state *state,
3082                                 struct image *img,
3083                                 struct patch *patch)
3084{
3085        struct fragment *fragment = patch->fragments;
3086        unsigned long len;
3087        void *dst;
3088
3089        if (!fragment)
3090                return error(_("missing binary patch data for '%s'"),
3091                             patch->new_name ?
3092                             patch->new_name :
3093                             patch->old_name);
3094
3095        /* Binary patch is irreversible without the optional second hunk */
3096        if (state->apply_in_reverse) {
3097                if (!fragment->next)
3098                        return error("cannot reverse-apply a binary patch "
3099                                     "without the reverse hunk to '%s'",
3100                                     patch->new_name
3101                                     ? patch->new_name : patch->old_name);
3102                fragment = fragment->next;
3103        }
3104        switch (fragment->binary_patch_method) {
3105        case BINARY_DELTA_DEFLATED:
3106                dst = patch_delta(img->buf, img->len, fragment->patch,
3107                                  fragment->size, &len);
3108                if (!dst)
3109                        return -1;
3110                clear_image(img);
3111                img->buf = dst;
3112                img->len = len;
3113                return 0;
3114        case BINARY_LITERAL_DEFLATED:
3115                clear_image(img);
3116                img->len = fragment->size;
3117                img->buf = xmemdupz(fragment->patch, img->len);
3118                return 0;
3119        }
3120        return -1;
3121}
3122
3123/*
3124 * Replace "img" with the result of applying the binary patch.
3125 * The binary patch data itself in patch->fragment is still kept
3126 * but the preimage prepared by the caller in "img" is freed here
3127 * or in the helper function apply_binary_fragment() this calls.
3128 */
3129static int apply_binary(struct apply_state *state,
3130                        struct image *img,
3131                        struct patch *patch)
3132{
3133        const char *name = patch->old_name ? patch->old_name : patch->new_name;
3134        struct object_id oid;
3135
3136        /*
3137         * For safety, we require patch index line to contain
3138         * full 40-byte textual SHA1 for old and new, at least for now.
3139         */
3140        if (strlen(patch->old_sha1_prefix) != 40 ||
3141            strlen(patch->new_sha1_prefix) != 40 ||
3142            get_oid_hex(patch->old_sha1_prefix, &oid) ||
3143            get_oid_hex(patch->new_sha1_prefix, &oid))
3144                return error("cannot apply binary patch to '%s' "
3145                             "without full index line", name);
3146
3147        if (patch->old_name) {
3148                /*
3149                 * See if the old one matches what the patch
3150                 * applies to.
3151                 */
3152                hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
3153                if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
3154                        return error("the patch applies to '%s' (%s), "
3155                                     "which does not match the "
3156                                     "current contents.",
3157                                     name, oid_to_hex(&oid));
3158        }
3159        else {
3160                /* Otherwise, the old one must be empty. */
3161                if (img->len)
3162                        return error("the patch applies to an empty "
3163                                     "'%s' but it is not empty", name);
3164        }
3165
3166        get_oid_hex(patch->new_sha1_prefix, &oid);
3167        if (is_null_oid(&oid)) {
3168                clear_image(img);
3169                return 0; /* deletion patch */
3170        }
3171
3172        if (has_sha1_file(oid.hash)) {
3173                /* We already have the postimage */
3174                enum object_type type;
3175                unsigned long size;
3176                char *result;
3177
3178                result = read_sha1_file(oid.hash, &type, &size);
3179                if (!result)
3180                        return error("the necessary postimage %s for "
3181                                     "'%s' cannot be read",
3182                                     patch->new_sha1_prefix, name);
3183                clear_image(img);
3184                img->buf = result;
3185                img->len = size;
3186        } else {
3187                /*
3188                 * We have verified buf matches the preimage;
3189                 * apply the patch data to it, which is stored
3190                 * in the patch->fragments->{patch,size}.
3191                 */
3192                if (apply_binary_fragment(state, img, patch))
3193                        return error(_("binary patch does not apply to '%s'"),
3194                                     name);
3195
3196                /* verify that the result matches */
3197                hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
3198                if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
3199                        return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
3200                                name, patch->new_sha1_prefix, oid_to_hex(&oid));
3201        }
3202
3203        return 0;
3204}
3205
3206static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
3207{
3208        struct fragment *frag = patch->fragments;
3209        const char *name = patch->old_name ? patch->old_name : patch->new_name;
3210        unsigned ws_rule = patch->ws_rule;
3211        unsigned inaccurate_eof = patch->inaccurate_eof;
3212        int nth = 0;
3213
3214        if (patch->is_binary)
3215                return apply_binary(state, img, patch);
3216
3217        while (frag) {
3218                nth++;
3219                if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
3220                        error(_("patch failed: %s:%ld"), name, frag->oldpos);
3221                        if (!state->apply_with_reject)
3222                                return -1;
3223                        frag->rejected = 1;
3224                }
3225                frag = frag->next;
3226        }
3227        return 0;
3228}
3229
3230static int read_blob_object(struct strbuf *buf, const struct object_id *oid, unsigned mode)
3231{
3232        if (S_ISGITLINK(mode)) {
3233                strbuf_grow(buf, 100);
3234                strbuf_addf(buf, "Subproject commit %s\n", oid_to_hex(oid));
3235        } else {
3236                enum object_type type;
3237                unsigned long sz;
3238                char *result;
3239
3240                result = read_sha1_file(oid->hash, &type, &sz);
3241                if (!result)
3242                        return -1;
3243                /* XXX read_sha1_file NUL-terminates */
3244                strbuf_attach(buf, result, sz, sz + 1);
3245        }
3246        return 0;
3247}
3248
3249static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf)
3250{
3251        if (!ce)
3252                return 0;
3253        return read_blob_object(buf, &ce->oid, ce->ce_mode);
3254}
3255
3256static struct patch *in_fn_table(struct apply_state *state, const char *name)
3257{
3258        struct string_list_item *item;
3259
3260        if (name == NULL)
3261                return NULL;
3262
3263        item = string_list_lookup(&state->fn_table, name);
3264        if (item != NULL)
3265                return (struct patch *)item->util;
3266
3267        return NULL;
3268}
3269
3270/*
3271 * item->util in the filename table records the status of the path.
3272 * Usually it points at a patch (whose result records the contents
3273 * of it after applying it), but it could be PATH_WAS_DELETED for a
3274 * path that a previously applied patch has already removed, or
3275 * PATH_TO_BE_DELETED for a path that a later patch would remove.
3276 *
3277 * The latter is needed to deal with a case where two paths A and B
3278 * are swapped by first renaming A to B and then renaming B to A;
3279 * moving A to B should not be prevented due to presence of B as we
3280 * will remove it in a later patch.
3281 */
3282#define PATH_TO_BE_DELETED ((struct patch *) -2)
3283#define PATH_WAS_DELETED ((struct patch *) -1)
3284
3285static int to_be_deleted(struct patch *patch)
3286{
3287        return patch == PATH_TO_BE_DELETED;
3288}
3289
3290static int was_deleted(struct patch *patch)
3291{
3292        return patch == PATH_WAS_DELETED;
3293}
3294
3295static void add_to_fn_table(struct apply_state *state, struct patch *patch)
3296{
3297        struct string_list_item *item;
3298
3299        /*
3300         * Always add new_name unless patch is a deletion
3301         * This should cover the cases for normal diffs,
3302         * file creations and copies
3303         */
3304        if (patch->new_name != NULL) {
3305                item = string_list_insert(&state->fn_table, patch->new_name);
3306                item->util = patch;
3307        }
3308
3309        /*
3310         * store a failure on rename/deletion cases because
3311         * later chunks shouldn't patch old names
3312         */
3313        if ((patch->new_name == NULL) || (patch->is_rename)) {
3314                item = string_list_insert(&state->fn_table, patch->old_name);
3315                item->util = PATH_WAS_DELETED;
3316        }
3317}
3318
3319static void prepare_fn_table(struct apply_state *state, struct patch *patch)
3320{
3321        /*
3322         * store information about incoming file deletion
3323         */
3324        while (patch) {
3325                if ((patch->new_name == NULL) || (patch->is_rename)) {
3326                        struct string_list_item *item;
3327                        item = string_list_insert(&state->fn_table, patch->old_name);
3328                        item->util = PATH_TO_BE_DELETED;
3329                }
3330                patch = patch->next;
3331        }
3332}
3333
3334static int checkout_target(struct index_state *istate,
3335                           struct cache_entry *ce, struct stat *st)
3336{
3337        struct checkout costate = CHECKOUT_INIT;
3338
3339        costate.refresh_cache = 1;
3340        costate.istate = istate;
3341        if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
3342                return error(_("cannot checkout %s"), ce->name);
3343        return 0;
3344}
3345
3346static struct patch *previous_patch(struct apply_state *state,
3347                                    struct patch *patch,
3348                                    int *gone)
3349{
3350        struct patch *previous;
3351
3352        *gone = 0;
3353        if (patch->is_copy || patch->is_rename)
3354                return NULL; /* "git" patches do not depend on the order */
3355
3356        previous = in_fn_table(state, patch->old_name);
3357        if (!previous)
3358                return NULL;
3359
3360        if (to_be_deleted(previous))
3361                return NULL; /* the deletion hasn't happened yet */
3362
3363        if (was_deleted(previous))
3364                *gone = 1;
3365
3366        return previous;
3367}
3368
3369static int verify_index_match(const struct cache_entry *ce, struct stat *st)
3370{
3371        if (S_ISGITLINK(ce->ce_mode)) {
3372                if (!S_ISDIR(st->st_mode))
3373                        return -1;
3374                return 0;
3375        }
3376        return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
3377}
3378
3379#define SUBMODULE_PATCH_WITHOUT_INDEX 1
3380
3381static int load_patch_target(struct apply_state *state,
3382                             struct strbuf *buf,
3383                             const struct cache_entry *ce,
3384                             struct stat *st,
3385                             const char *name,
3386                             unsigned expected_mode)
3387{
3388        if (state->cached || state->check_index) {
3389                if (read_file_or_gitlink(ce, buf))
3390                        return error(_("failed to read %s"), name);
3391        } else if (name) {
3392                if (S_ISGITLINK(expected_mode)) {
3393                        if (ce)
3394                                return read_file_or_gitlink(ce, buf);
3395                        else
3396                                return SUBMODULE_PATCH_WITHOUT_INDEX;
3397                } else if (has_symlink_leading_path(name, strlen(name))) {
3398                        return error(_("reading from '%s' beyond a symbolic link"), name);
3399                } else {
3400                        if (read_old_data(st, name, buf))
3401                                return error(_("failed to read %s"), name);
3402                }
3403        }
3404        return 0;
3405}
3406
3407/*
3408 * We are about to apply "patch"; populate the "image" with the
3409 * current version we have, from the working tree or from the index,
3410 * depending on the situation e.g. --cached/--index.  If we are
3411 * applying a non-git patch that incrementally updates the tree,
3412 * we read from the result of a previous diff.
3413 */
3414static int load_preimage(struct apply_state *state,
3415                         struct image *image,
3416                         struct patch *patch, struct stat *st,
3417                         const struct cache_entry *ce)
3418{
3419        struct strbuf buf = STRBUF_INIT;
3420        size_t len;
3421        char *img;
3422        struct patch *previous;
3423        int status;
3424
3425        previous = previous_patch(state, patch, &status);
3426        if (status)
3427                return error(_("path %s has been renamed/deleted"),
3428                             patch->old_name);
3429        if (previous) {
3430                /* We have a patched copy in memory; use that. */
3431                strbuf_add(&buf, previous->result, previous->resultsize);
3432        } else {
3433                status = load_patch_target(state, &buf, ce, st,
3434                                           patch->old_name, patch->old_mode);
3435                if (status < 0)
3436                        return status;
3437                else if (status == SUBMODULE_PATCH_WITHOUT_INDEX) {
3438                        /*
3439                         * There is no way to apply subproject
3440                         * patch without looking at the index.
3441                         * NEEDSWORK: shouldn't this be flagged
3442                         * as an error???
3443                         */
3444                        free_fragment_list(patch->fragments);
3445                        patch->fragments = NULL;
3446                } else if (status) {
3447                        return error(_("failed to read %s"), patch->old_name);
3448                }
3449        }
3450
3451        img = strbuf_detach(&buf, &len);
3452        prepare_image(image, img, len, !patch->is_binary);
3453        return 0;
3454}
3455
3456static int three_way_merge(struct image *image,
3457                           char *path,
3458                           const struct object_id *base,
3459                           const struct object_id *ours,
3460                           const struct object_id *theirs)
3461{
3462        mmfile_t base_file, our_file, their_file;
3463        mmbuffer_t result = { NULL };
3464        int status;
3465
3466        read_mmblob(&base_file, base);
3467        read_mmblob(&our_file, ours);
3468        read_mmblob(&their_file, theirs);
3469        status = ll_merge(&result, path,
3470                          &base_file, "base",
3471                          &our_file, "ours",
3472                          &their_file, "theirs", NULL);
3473        free(base_file.ptr);
3474        free(our_file.ptr);
3475        free(their_file.ptr);
3476        if (status < 0 || !result.ptr) {
3477                free(result.ptr);
3478                return -1;
3479        }
3480        clear_image(image);
3481        image->buf = result.ptr;
3482        image->len = result.size;
3483
3484        return status;
3485}
3486
3487/*
3488 * When directly falling back to add/add three-way merge, we read from
3489 * the current contents of the new_name.  In no cases other than that
3490 * this function will be called.
3491 */
3492static int load_current(struct apply_state *state,
3493                        struct image *image,
3494                        struct patch *patch)
3495{
3496        struct strbuf buf = STRBUF_INIT;
3497        int status, pos;
3498        size_t len;
3499        char *img;
3500        struct stat st;
3501        struct cache_entry *ce;
3502        char *name = patch->new_name;
3503        unsigned mode = patch->new_mode;
3504
3505        if (!patch->is_new)
3506                die("BUG: patch to %s is not a creation", patch->old_name);
3507
3508        pos = cache_name_pos(name, strlen(name));
3509        if (pos < 0)
3510                return error(_("%s: does not exist in index"), name);
3511        ce = active_cache[pos];
3512        if (lstat(name, &st)) {
3513                if (errno != ENOENT)
3514                        return error_errno("%s", name);
3515                if (checkout_target(&the_index, ce, &st))
3516                        return -1;
3517        }
3518        if (verify_index_match(ce, &st))
3519                return error(_("%s: does not match index"), name);
3520
3521        status = load_patch_target(state, &buf, ce, &st, name, mode);
3522        if (status < 0)
3523                return status;
3524        else if (status)
3525                return -1;
3526        img = strbuf_detach(&buf, &len);
3527        prepare_image(image, img, len, !patch->is_binary);
3528        return 0;
3529}
3530
3531static int try_threeway(struct apply_state *state,
3532                        struct image *image,
3533                        struct patch *patch,
3534                        struct stat *st,
3535                        const struct cache_entry *ce)
3536{
3537        struct object_id pre_oid, post_oid, our_oid;
3538        struct strbuf buf = STRBUF_INIT;
3539        size_t len;
3540        int status;
3541        char *img;
3542        struct image tmp_image;
3543
3544        /* No point falling back to 3-way merge in these cases */
3545        if (patch->is_delete ||
3546            S_ISGITLINK(patch->old_mode) || S_ISGITLINK(patch->new_mode))
3547                return -1;
3548
3549        /* Preimage the patch was prepared for */
3550        if (patch->is_new)
3551                write_sha1_file("", 0, blob_type, pre_oid.hash);
3552        else if (get_sha1(patch->old_sha1_prefix, pre_oid.hash) ||
3553                 read_blob_object(&buf, &pre_oid, patch->old_mode))
3554                return error("repository lacks the necessary blob to fall back on 3-way merge.");
3555
3556        if (state->apply_verbosity > verbosity_silent)
3557                fprintf(stderr, "Falling back to three-way merge...\n");
3558
3559        img = strbuf_detach(&buf, &len);
3560        prepare_image(&tmp_image, img, len, 1);
3561        /* Apply the patch to get the post image */
3562        if (apply_fragments(state, &tmp_image, patch) < 0) {
3563                clear_image(&tmp_image);
3564                return -1;
3565        }
3566        /* post_oid is theirs */
3567        write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_oid.hash);
3568        clear_image(&tmp_image);
3569
3570        /* our_oid is ours */
3571        if (patch->is_new) {
3572                if (load_current(state, &tmp_image, patch))
3573                        return error("cannot read the current contents of '%s'",
3574                                     patch->new_name);
3575        } else {
3576                if (load_preimage(state, &tmp_image, patch, st, ce))
3577                        return error("cannot read the current contents of '%s'",
3578                                     patch->old_name);
3579        }
3580        write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_oid.hash);
3581        clear_image(&tmp_image);
3582
3583        /* in-core three-way merge between post and our using pre as base */
3584        status = three_way_merge(image, patch->new_name,
3585                                 &pre_oid, &our_oid, &post_oid);
3586        if (status < 0) {
3587                if (state->apply_verbosity > verbosity_silent)
3588                        fprintf(stderr,
3589                                "Failed to fall back on three-way merge...\n");
3590                return status;
3591        }
3592
3593        if (status) {
3594                patch->conflicted_threeway = 1;
3595                if (patch->is_new)
3596                        oidclr(&patch->threeway_stage[0]);
3597                else
3598                        oidcpy(&patch->threeway_stage[0], &pre_oid);
3599                oidcpy(&patch->threeway_stage[1], &our_oid);
3600                oidcpy(&patch->threeway_stage[2], &post_oid);
3601                if (state->apply_verbosity > verbosity_silent)
3602                        fprintf(stderr,
3603                                "Applied patch to '%s' with conflicts.\n",
3604                                patch->new_name);
3605        } else {
3606                if (state->apply_verbosity > verbosity_silent)
3607                        fprintf(stderr,
3608                                "Applied patch to '%s' cleanly.\n",
3609                                patch->new_name);
3610        }
3611        return 0;
3612}
3613
3614static int apply_data(struct apply_state *state, struct patch *patch,
3615                      struct stat *st, const struct cache_entry *ce)
3616{
3617        struct image image;
3618
3619        if (load_preimage(state, &image, patch, st, ce) < 0)
3620                return -1;
3621
3622        if (patch->direct_to_threeway ||
3623            apply_fragments(state, &image, patch) < 0) {
3624                /* Note: with --reject, apply_fragments() returns 0 */
3625                if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
3626                        return -1;
3627        }
3628        patch->result = image.buf;
3629        patch->resultsize = image.len;
3630        add_to_fn_table(state, patch);
3631        free(image.line_allocated);
3632
3633        if (0 < patch->is_delete && patch->resultsize)
3634                return error(_("removal patch leaves file contents"));
3635
3636        return 0;
3637}
3638
3639/*
3640 * If "patch" that we are looking at modifies or deletes what we have,
3641 * we would want it not to lose any local modification we have, either
3642 * in the working tree or in the index.
3643 *
3644 * This also decides if a non-git patch is a creation patch or a
3645 * modification to an existing empty file.  We do not check the state
3646 * of the current tree for a creation patch in this function; the caller
3647 * check_patch() separately makes sure (and errors out otherwise) that
3648 * the path the patch creates does not exist in the current tree.
3649 */
3650static int check_preimage(struct apply_state *state,
3651                          struct patch *patch,
3652                          struct cache_entry **ce,
3653                          struct stat *st)
3654{
3655        const char *old_name = patch->old_name;
3656        struct patch *previous = NULL;
3657        int stat_ret = 0, status;
3658        unsigned st_mode = 0;
3659
3660        if (!old_name)
3661                return 0;
3662
3663        assert(patch->is_new <= 0);
3664        previous = previous_patch(state, patch, &status);
3665
3666        if (status)
3667                return error(_("path %s has been renamed/deleted"), old_name);
3668        if (previous) {
3669                st_mode = previous->new_mode;
3670        } else if (!state->cached) {
3671                stat_ret = lstat(old_name, st);
3672                if (stat_ret && errno != ENOENT)
3673                        return error_errno("%s", old_name);
3674        }
3675
3676        if (state->check_index && !previous) {
3677                int pos = cache_name_pos(old_name, strlen(old_name));
3678                if (pos < 0) {
3679                        if (patch->is_new < 0)
3680                                goto is_new;
3681                        return error(_("%s: does not exist in index"), old_name);
3682                }
3683                *ce = active_cache[pos];
3684                if (stat_ret < 0) {
3685                        if (checkout_target(&the_index, *ce, st))
3686                                return -1;
3687                }
3688                if (!state->cached && verify_index_match(*ce, st))
3689                        return error(_("%s: does not match index"), old_name);
3690                if (state->cached)
3691                        st_mode = (*ce)->ce_mode;
3692        } else if (stat_ret < 0) {
3693                if (patch->is_new < 0)
3694                        goto is_new;
3695                return error_errno("%s", old_name);
3696        }
3697
3698        if (!state->cached && !previous)
3699                st_mode = ce_mode_from_stat(*ce, st->st_mode);
3700
3701        if (patch->is_new < 0)
3702                patch->is_new = 0;
3703        if (!patch->old_mode)
3704                patch->old_mode = st_mode;
3705        if ((st_mode ^ patch->old_mode) & S_IFMT)
3706                return error(_("%s: wrong type"), old_name);
3707        if (st_mode != patch->old_mode)
3708                warning(_("%s has type %o, expected %o"),
3709                        old_name, st_mode, patch->old_mode);
3710        if (!patch->new_mode && !patch->is_delete)
3711                patch->new_mode = st_mode;
3712        return 0;
3713
3714 is_new:
3715        patch->is_new = 1;
3716        patch->is_delete = 0;
3717        free(patch->old_name);
3718        patch->old_name = NULL;
3719        return 0;
3720}
3721
3722
3723#define EXISTS_IN_INDEX 1
3724#define EXISTS_IN_WORKTREE 2
3725
3726static int check_to_create(struct apply_state *state,
3727                           const char *new_name,
3728                           int ok_if_exists)
3729{
3730        struct stat nst;
3731
3732        if (state->check_index &&
3733            cache_name_pos(new_name, strlen(new_name)) >= 0 &&
3734            !ok_if_exists)
3735                return EXISTS_IN_INDEX;
3736        if (state->cached)
3737                return 0;
3738
3739        if (!lstat(new_name, &nst)) {
3740                if (S_ISDIR(nst.st_mode) || ok_if_exists)
3741                        return 0;
3742                /*
3743                 * A leading component of new_name might be a symlink
3744                 * that is going to be removed with this patch, but
3745                 * still pointing at somewhere that has the path.
3746                 * In such a case, path "new_name" does not exist as
3747                 * far as git is concerned.
3748                 */
3749                if (has_symlink_leading_path(new_name, strlen(new_name)))
3750                        return 0;
3751
3752                return EXISTS_IN_WORKTREE;
3753        } else if ((errno != ENOENT) && (errno != ENOTDIR)) {
3754                return error_errno("%s", new_name);
3755        }
3756        return 0;
3757}
3758
3759static uintptr_t register_symlink_changes(struct apply_state *state,
3760                                          const char *path,
3761                                          uintptr_t what)
3762{
3763        struct string_list_item *ent;
3764
3765        ent = string_list_lookup(&state->symlink_changes, path);
3766        if (!ent) {
3767                ent = string_list_insert(&state->symlink_changes, path);
3768                ent->util = (void *)0;
3769        }
3770        ent->util = (void *)(what | ((uintptr_t)ent->util));
3771        return (uintptr_t)ent->util;
3772}
3773
3774static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
3775{
3776        struct string_list_item *ent;
3777
3778        ent = string_list_lookup(&state->symlink_changes, path);
3779        if (!ent)
3780                return 0;
3781        return (uintptr_t)ent->util;
3782}
3783
3784static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
3785{
3786        for ( ; patch; patch = patch->next) {
3787                if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
3788                    (patch->is_rename || patch->is_delete))
3789                        /* the symlink at patch->old_name is removed */
3790                        register_symlink_changes(state, patch->old_name, APPLY_SYMLINK_GOES_AWAY);
3791
3792                if (patch->new_name && S_ISLNK(patch->new_mode))
3793                        /* the symlink at patch->new_name is created or remains */
3794                        register_symlink_changes(state, patch->new_name, APPLY_SYMLINK_IN_RESULT);
3795        }
3796}
3797
3798static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
3799{
3800        do {
3801                unsigned int change;
3802
3803                while (--name->len && name->buf[name->len] != '/')
3804                        ; /* scan backwards */
3805                if (!name->len)
3806                        break;
3807                name->buf[name->len] = '\0';
3808                change = check_symlink_changes(state, name->buf);
3809                if (change & APPLY_SYMLINK_IN_RESULT)
3810                        return 1;
3811                if (change & APPLY_SYMLINK_GOES_AWAY)
3812                        /*
3813                         * This cannot be "return 0", because we may
3814                         * see a new one created at a higher level.
3815                         */
3816                        continue;
3817
3818                /* otherwise, check the preimage */
3819                if (state->check_index) {
3820                        struct cache_entry *ce;
3821
3822                        ce = cache_file_exists(name->buf, name->len, ignore_case);
3823                        if (ce && S_ISLNK(ce->ce_mode))
3824                                return 1;
3825                } else {
3826                        struct stat st;
3827                        if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
3828                                return 1;
3829                }
3830        } while (1);
3831        return 0;
3832}
3833
3834static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
3835{
3836        int ret;
3837        struct strbuf name = STRBUF_INIT;
3838
3839        assert(*name_ != '\0');
3840        strbuf_addstr(&name, name_);
3841        ret = path_is_beyond_symlink_1(state, &name);
3842        strbuf_release(&name);
3843
3844        return ret;
3845}
3846
3847static int check_unsafe_path(struct patch *patch)
3848{
3849        const char *old_name = NULL;
3850        const char *new_name = NULL;
3851        if (patch->is_delete)
3852                old_name = patch->old_name;
3853        else if (!patch->is_new && !patch->is_copy)
3854                old_name = patch->old_name;
3855        if (!patch->is_delete)
3856                new_name = patch->new_name;
3857
3858        if (old_name && !verify_path(old_name))
3859                return error(_("invalid path '%s'"), old_name);
3860        if (new_name && !verify_path(new_name))
3861                return error(_("invalid path '%s'"), new_name);
3862        return 0;
3863}
3864
3865/*
3866 * Check and apply the patch in-core; leave the result in patch->result
3867 * for the caller to write it out to the final destination.
3868 */
3869static int check_patch(struct apply_state *state, struct patch *patch)
3870{
3871        struct stat st;
3872        const char *old_name = patch->old_name;
3873        const char *new_name = patch->new_name;
3874        const char *name = old_name ? old_name : new_name;
3875        struct cache_entry *ce = NULL;
3876        struct patch *tpatch;
3877        int ok_if_exists;
3878        int status;
3879
3880        patch->rejected = 1; /* we will drop this after we succeed */
3881
3882        status = check_preimage(state, patch, &ce, &st);
3883        if (status)
3884                return status;
3885        old_name = patch->old_name;
3886
3887        /*
3888         * A type-change diff is always split into a patch to delete
3889         * old, immediately followed by a patch to create new (see
3890         * diff.c::run_diff()); in such a case it is Ok that the entry
3891         * to be deleted by the previous patch is still in the working
3892         * tree and in the index.
3893         *
3894         * A patch to swap-rename between A and B would first rename A
3895         * to B and then rename B to A.  While applying the first one,
3896         * the presence of B should not stop A from getting renamed to
3897         * B; ask to_be_deleted() about the later rename.  Removal of
3898         * B and rename from A to B is handled the same way by asking
3899         * was_deleted().
3900         */
3901        if ((tpatch = in_fn_table(state, new_name)) &&
3902            (was_deleted(tpatch) || to_be_deleted(tpatch)))
3903                ok_if_exists = 1;
3904        else
3905                ok_if_exists = 0;
3906
3907        if (new_name &&
3908            ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
3909                int err = check_to_create(state, new_name, ok_if_exists);
3910
3911                if (err && state->threeway) {
3912                        patch->direct_to_threeway = 1;
3913                } else switch (err) {
3914                case 0:
3915                        break; /* happy */
3916                case EXISTS_IN_INDEX:
3917                        return error(_("%s: already exists in index"), new_name);
3918                        break;
3919                case EXISTS_IN_WORKTREE:
3920                        return error(_("%s: already exists in working directory"),
3921                                     new_name);
3922                default:
3923                        return err;
3924                }
3925
3926                if (!patch->new_mode) {
3927                        if (0 < patch->is_new)
3928                                patch->new_mode = S_IFREG | 0644;
3929                        else
3930                                patch->new_mode = patch->old_mode;
3931                }
3932        }
3933
3934        if (new_name && old_name) {
3935                int same = !strcmp(old_name, new_name);
3936                if (!patch->new_mode)
3937                        patch->new_mode = patch->old_mode;
3938                if ((patch->old_mode ^ patch->new_mode) & S_IFMT) {
3939                        if (same)
3940                                return error(_("new mode (%o) of %s does not "
3941                                               "match old mode (%o)"),
3942                                        patch->new_mode, new_name,
3943                                        patch->old_mode);
3944                        else
3945                                return error(_("new mode (%o) of %s does not "
3946                                               "match old mode (%o) of %s"),
3947                                        patch->new_mode, new_name,
3948                                        patch->old_mode, old_name);
3949                }
3950        }
3951
3952        if (!state->unsafe_paths && check_unsafe_path(patch))
3953                return -128;
3954
3955        /*
3956         * An attempt to read from or delete a path that is beyond a
3957         * symbolic link will be prevented by load_patch_target() that
3958         * is called at the beginning of apply_data() so we do not
3959         * have to worry about a patch marked with "is_delete" bit
3960         * here.  We however need to make sure that the patch result
3961         * is not deposited to a path that is beyond a symbolic link
3962         * here.
3963         */
3964        if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
3965                return error(_("affected file '%s' is beyond a symbolic link"),
3966                             patch->new_name);
3967
3968        if (apply_data(state, patch, &st, ce) < 0)
3969                return error(_("%s: patch does not apply"), name);
3970        patch->rejected = 0;
3971        return 0;
3972}
3973
3974static int check_patch_list(struct apply_state *state, struct patch *patch)
3975{
3976        int err = 0;
3977
3978        prepare_symlink_changes(state, patch);
3979        prepare_fn_table(state, patch);
3980        while (patch) {
3981                int res;
3982                if (state->apply_verbosity > verbosity_normal)
3983                        say_patch_name(stderr,
3984                                       _("Checking patch %s..."), patch);
3985                res = check_patch(state, patch);
3986                if (res == -128)
3987                        return -128;
3988                err |= res;
3989                patch = patch->next;
3990        }
3991        return err;
3992}
3993
3994static int read_apply_cache(struct apply_state *state)
3995{
3996        if (state->index_file)
3997                return read_cache_from(state->index_file);
3998        else
3999                return read_cache();
4000}
4001
4002/* This function tries to read the object name from the current index */
4003static int get_current_oid(struct apply_state *state, const char *path,
4004                           struct object_id *oid)
4005{
4006        int pos;
4007
4008        if (read_apply_cache(state) < 0)
4009                return -1;
4010        pos = cache_name_pos(path, strlen(path));
4011        if (pos < 0)
4012                return -1;
4013        oidcpy(oid, &active_cache[pos]->oid);
4014        return 0;
4015}
4016
4017static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
4018{
4019        /*
4020         * A usable gitlink patch has only one fragment (hunk) that looks like:
4021         * @@ -1 +1 @@
4022         * -Subproject commit <old sha1>
4023         * +Subproject commit <new sha1>
4024         * or
4025         * @@ -1 +0,0 @@
4026         * -Subproject commit <old sha1>
4027         * for a removal patch.
4028         */
4029        struct fragment *hunk = p->fragments;
4030        static const char heading[] = "-Subproject commit ";
4031        char *preimage;
4032
4033        if (/* does the patch have only one hunk? */
4034            hunk && !hunk->next &&
4035            /* is its preimage one line? */
4036            hunk->oldpos == 1 && hunk->oldlines == 1 &&
4037            /* does preimage begin with the heading? */
4038            (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
4039            starts_with(++preimage, heading) &&
4040            /* does it record full SHA-1? */
4041            !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
4042            preimage[sizeof(heading) + GIT_SHA1_HEXSZ - 1] == '\n' &&
4043            /* does the abbreviated name on the index line agree with it? */
4044            starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
4045                return 0; /* it all looks fine */
4046
4047        /* we may have full object name on the index line */
4048        return get_oid_hex(p->old_sha1_prefix, oid);
4049}
4050
4051/* Build an index that contains the just the files needed for a 3way merge */
4052static int build_fake_ancestor(struct apply_state *state, struct patch *list)
4053{
4054        struct patch *patch;
4055        struct index_state result = { NULL };
4056        static struct lock_file lock;
4057        int res;
4058
4059        /* Once we start supporting the reverse patch, it may be
4060         * worth showing the new sha1 prefix, but until then...
4061         */
4062        for (patch = list; patch; patch = patch->next) {
4063                struct object_id oid;
4064                struct cache_entry *ce;
4065                const char *name;
4066
4067                name = patch->old_name ? patch->old_name : patch->new_name;
4068                if (0 < patch->is_new)
4069                        continue;
4070
4071                if (S_ISGITLINK(patch->old_mode)) {
4072                        if (!preimage_oid_in_gitlink_patch(patch, &oid))
4073                                ; /* ok, the textual part looks sane */
4074                        else
4075                                return error("sha1 information is lacking or "
4076                                             "useless for submodule %s", name);
4077                } else if (!get_sha1_blob(patch->old_sha1_prefix, oid.hash)) {
4078                        ; /* ok */
4079                } else if (!patch->lines_added && !patch->lines_deleted) {
4080                        /* mode-only change: update the current */
4081                        if (get_current_oid(state, patch->old_name, &oid))
4082                                return error("mode change for %s, which is not "
4083                                             "in current HEAD", name);
4084                } else
4085                        return error("sha1 information is lacking or useless "
4086                                     "(%s).", name);
4087
4088                ce = make_cache_entry(patch->old_mode, oid.hash, name, 0, 0);
4089                if (!ce)
4090                        return error(_("make_cache_entry failed for path '%s'"),
4091                                     name);
4092                if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD)) {
4093                        free(ce);
4094                        return error("Could not add %s to temporary index",
4095                                     name);
4096                }
4097        }
4098
4099        hold_lock_file_for_update(&lock, state->fake_ancestor, LOCK_DIE_ON_ERROR);
4100        res = write_locked_index(&result, &lock, COMMIT_LOCK);
4101        discard_index(&result);
4102
4103         if (res)
4104                 return error("Could not write temporary index to %s",
4105                              state->fake_ancestor);
4106
4107         return 0;
4108 }
4109
4110 static void stat_patch_list(struct apply_state *state, struct patch *patch)
4111 {
4112         int files, adds, dels;
4113
4114         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
4115                 files++;
4116                 adds += patch->lines_added;
4117                 dels += patch->lines_deleted;
4118                 show_stats(state, patch);
4119         }
4120
4121         print_stat_summary(stdout, files, adds, dels);
4122 }
4123
4124 static void numstat_patch_list(struct apply_state *state,
4125                                struct patch *patch)
4126 {
4127         for ( ; patch; patch = patch->next) {
4128                 const char *name;
4129                 name = patch->new_name ? patch->new_name : patch->old_name;
4130                 if (patch->is_binary)
4131                         printf("-\t-\t");
4132                 else
4133                         printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
4134                 write_name_quoted(name, stdout, state->line_termination);
4135         }
4136 }
4137
4138 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
4139 {
4140         if (mode)
4141                 printf(" %s mode %06o %s\n", newdelete, mode, name);
4142         else
4143                 printf(" %s %s\n", newdelete, name);
4144 }
4145
4146 static void show_mode_change(struct patch *p, int show_name)
4147 {
4148         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
4149                 if (show_name)
4150                         printf(" mode change %06o => %06o %s\n",
4151                                p->old_mode, p->new_mode, p->new_name);
4152                 else
4153                         printf(" mode change %06o => %06o\n",
4154                                p->old_mode, p->new_mode);
4155         }
4156 }
4157
4158 static void show_rename_copy(struct patch *p)
4159 {
4160         const char *renamecopy = p->is_rename ? "rename" : "copy";
4161         const char *old, *new;
4162
4163         /* Find common prefix */
4164         old = p->old_name;
4165         new = p->new_name;
4166         while (1) {
4167                 const char *slash_old, *slash_new;
4168                 slash_old = strchr(old, '/');
4169                 slash_new = strchr(new, '/');
4170                 if (!slash_old ||
4171                     !slash_new ||
4172                     slash_old - old != slash_new - new ||
4173                     memcmp(old, new, slash_new - new))
4174                         break;
4175                 old = slash_old + 1;
4176                 new = slash_new + 1;
4177         }
4178         /* p->old_name thru old is the common prefix, and old and new
4179          * through the end of names are renames
4180          */
4181         if (old != p->old_name)
4182                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
4183                        (int)(old - p->old_name), p->old_name,
4184                        old, new, p->score);
4185         else
4186                 printf(" %s %s => %s (%d%%)\n", renamecopy,
4187                        p->old_name, p->new_name, p->score);
4188         show_mode_change(p, 0);
4189 }
4190
4191 static void summary_patch_list(struct patch *patch)
4192 {
4193         struct patch *p;
4194
4195         for (p = patch; p; p = p->next) {
4196                 if (p->is_new)
4197                         show_file_mode_name("create", p->new_mode, p->new_name);
4198                 else if (p->is_delete)
4199                         show_file_mode_name("delete", p->old_mode, p->old_name);
4200                 else {
4201                         if (p->is_rename || p->is_copy)
4202                                 show_rename_copy(p);
4203                         else {
4204                                 if (p->score) {
4205                                         printf(" rewrite %s (%d%%)\n",
4206                                                p->new_name, p->score);
4207                                         show_mode_change(p, 0);
4208                                 }
4209                                 else
4210                                         show_mode_change(p, 1);
4211                         }
4212                 }
4213         }
4214 }
4215
4216 static void patch_stats(struct apply_state *state, struct patch *patch)
4217 {
4218         int lines = patch->lines_added + patch->lines_deleted;
4219
4220         if (lines > state->max_change)
4221                 state->max_change = lines;
4222         if (patch->old_name) {
4223                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
4224                 if (!len)
4225                         len = strlen(patch->old_name);
4226                 if (len > state->max_len)
4227                         state->max_len = len;
4228         }
4229         if (patch->new_name) {
4230                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
4231                 if (!len)
4232                         len = strlen(patch->new_name);
4233                 if (len > state->max_len)
4234                         state->max_len = len;
4235         }
4236 }
4237
4238 static int remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
4239 {
4240         if (state->update_index) {
4241                 if (remove_file_from_cache(patch->old_name) < 0)
4242                         return error(_("unable to remove %s from index"), patch->old_name);
4243         }
4244         if (!state->cached) {
4245                 if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
4246                         remove_path(patch->old_name);
4247                 }
4248         }
4249         return 0;
4250 }
4251
4252 static int add_index_file(struct apply_state *state,
4253                           const char *path,
4254                           unsigned mode,
4255                           void *buf,
4256                           unsigned long size)
4257 {
4258         struct stat st;
4259         struct cache_entry *ce;
4260         int namelen = strlen(path);
4261         unsigned ce_size = cache_entry_size(namelen);
4262
4263         if (!state->update_index)
4264                 return 0;
4265
4266         ce = xcalloc(1, ce_size);
4267         memcpy(ce->name, path, namelen);
4268         ce->ce_mode = create_ce_mode(mode);
4269         ce->ce_flags = create_ce_flags(0);
4270         ce->ce_namelen = namelen;
4271         if (S_ISGITLINK(mode)) {
4272                 const char *s;
4273
4274                 if (!skip_prefix(buf, "Subproject commit ", &s) ||
4275                     get_oid_hex(s, &ce->oid)) {
4276                        free(ce);
4277                        return error(_("corrupt patch for submodule %s"), path);
4278                }
4279        } else {
4280                if (!state->cached) {
4281                        if (lstat(path, &st) < 0) {
4282                                free(ce);
4283                                return error_errno(_("unable to stat newly "
4284                                                     "created file '%s'"),
4285                                                   path);
4286                        }
4287                        fill_stat_cache_info(ce, &st);
4288                }
4289                if (write_sha1_file(buf, size, blob_type, ce->oid.hash) < 0) {
4290                        free(ce);
4291                        return error(_("unable to create backing store "
4292                                       "for newly created file %s"), path);
4293                }
4294        }
4295        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
4296                free(ce);
4297                return error(_("unable to add cache entry for %s"), path);
4298        }
4299
4300        return 0;
4301}
4302
4303/*
4304 * Returns:
4305 *  -1 if an unrecoverable error happened
4306 *   0 if everything went well
4307 *   1 if a recoverable error happened
4308 */
4309static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
4310{
4311        int fd, res;
4312        struct strbuf nbuf = STRBUF_INIT;
4313
4314        if (S_ISGITLINK(mode)) {
4315                struct stat st;
4316                if (!lstat(path, &st) && S_ISDIR(st.st_mode))
4317                        return 0;
4318                return !!mkdir(path, 0777);
4319        }
4320
4321        if (has_symlinks && S_ISLNK(mode))
4322                /* Although buf:size is counted string, it also is NUL
4323                 * terminated.
4324                 */
4325                return !!symlink(buf, path);
4326
4327        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
4328        if (fd < 0)
4329                return 1;
4330
4331        if (convert_to_working_tree(path, buf, size, &nbuf)) {
4332                size = nbuf.len;
4333                buf  = nbuf.buf;
4334        }
4335
4336        res = write_in_full(fd, buf, size) < 0;
4337        if (res)
4338                error_errno(_("failed to write to '%s'"), path);
4339        strbuf_release(&nbuf);
4340
4341        if (close(fd) < 0 && !res)
4342                return error_errno(_("closing file '%s'"), path);
4343
4344        return res ? -1 : 0;
4345}
4346
4347/*
4348 * We optimistically assume that the directories exist,
4349 * which is true 99% of the time anyway. If they don't,
4350 * we create them and try again.
4351 *
4352 * Returns:
4353 *   -1 on error
4354 *   0 otherwise
4355 */
4356static int create_one_file(struct apply_state *state,
4357                           char *path,
4358                           unsigned mode,
4359                           const char *buf,
4360                           unsigned long size)
4361{
4362        int res;
4363
4364        if (state->cached)
4365                return 0;
4366
4367        res = try_create_file(path, mode, buf, size);
4368        if (res < 0)
4369                return -1;
4370        if (!res)
4371                return 0;
4372
4373        if (errno == ENOENT) {
4374                if (safe_create_leading_directories(path))
4375                        return 0;
4376                res = try_create_file(path, mode, buf, size);
4377                if (res < 0)
4378                        return -1;
4379                if (!res)
4380                        return 0;
4381        }
4382
4383        if (errno == EEXIST || errno == EACCES) {
4384                /* We may be trying to create a file where a directory
4385                 * used to be.
4386                 */
4387                struct stat st;
4388                if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
4389                        errno = EEXIST;
4390        }
4391
4392        if (errno == EEXIST) {
4393                unsigned int nr = getpid();
4394
4395                for (;;) {
4396                        char newpath[PATH_MAX];
4397                        mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
4398                        res = try_create_file(newpath, mode, buf, size);
4399                        if (res < 0)
4400                                return -1;
4401                        if (!res) {
4402                                if (!rename(newpath, path))
4403                                        return 0;
4404                                unlink_or_warn(newpath);
4405                                break;
4406                        }
4407                        if (errno != EEXIST)
4408                                break;
4409                        ++nr;
4410                }
4411        }
4412        return error_errno(_("unable to write file '%s' mode %o"),
4413                           path, mode);
4414}
4415
4416static int add_conflicted_stages_file(struct apply_state *state,
4417                                       struct patch *patch)
4418{
4419        int stage, namelen;
4420        unsigned ce_size, mode;
4421        struct cache_entry *ce;
4422
4423        if (!state->update_index)
4424                return 0;
4425        namelen = strlen(patch->new_name);
4426        ce_size = cache_entry_size(namelen);
4427        mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
4428
4429        remove_file_from_cache(patch->new_name);
4430        for (stage = 1; stage < 4; stage++) {
4431                if (is_null_oid(&patch->threeway_stage[stage - 1]))
4432                        continue;
4433                ce = xcalloc(1, ce_size);
4434                memcpy(ce->name, patch->new_name, namelen);
4435                ce->ce_mode = create_ce_mode(mode);
4436                ce->ce_flags = create_ce_flags(stage);
4437                ce->ce_namelen = namelen;
4438                oidcpy(&ce->oid, &patch->threeway_stage[stage - 1]);
4439                if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0) {
4440                        free(ce);
4441                        return error(_("unable to add cache entry for %s"),
4442                                     patch->new_name);
4443                }
4444        }
4445
4446        return 0;
4447}
4448
4449static int create_file(struct apply_state *state, struct patch *patch)
4450{
4451        char *path = patch->new_name;
4452        unsigned mode = patch->new_mode;
4453        unsigned long size = patch->resultsize;
4454        char *buf = patch->result;
4455
4456        if (!mode)
4457                mode = S_IFREG | 0644;
4458        if (create_one_file(state, path, mode, buf, size))
4459                return -1;
4460
4461        if (patch->conflicted_threeway)
4462                return add_conflicted_stages_file(state, patch);
4463        else
4464                return add_index_file(state, path, mode, buf, size);
4465}
4466
4467/* phase zero is to remove, phase one is to create */
4468static int write_out_one_result(struct apply_state *state,
4469                                struct patch *patch,
4470                                int phase)
4471{
4472        if (patch->is_delete > 0) {
4473                if (phase == 0)
4474                        return remove_file(state, patch, 1);
4475                return 0;
4476        }
4477        if (patch->is_new > 0 || patch->is_copy) {
4478                if (phase == 1)
4479                        return create_file(state, patch);
4480                return 0;
4481        }
4482        /*
4483         * Rename or modification boils down to the same
4484         * thing: remove the old, write the new
4485         */
4486        if (phase == 0)
4487                return remove_file(state, patch, patch->is_rename);
4488        if (phase == 1)
4489                return create_file(state, patch);
4490        return 0;
4491}
4492
4493static int write_out_one_reject(struct apply_state *state, struct patch *patch)
4494{
4495        FILE *rej;
4496        char namebuf[PATH_MAX];
4497        struct fragment *frag;
4498        int cnt = 0;
4499        struct strbuf sb = STRBUF_INIT;
4500
4501        for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
4502                if (!frag->rejected)
4503                        continue;
4504                cnt++;
4505        }
4506
4507        if (!cnt) {
4508                if (state->apply_verbosity > verbosity_normal)
4509                        say_patch_name(stderr,
4510                                       _("Applied patch %s cleanly."), patch);
4511                return 0;
4512        }
4513
4514        /* This should not happen, because a removal patch that leaves
4515         * contents are marked "rejected" at the patch level.
4516         */
4517        if (!patch->new_name)
4518                die(_("internal error"));
4519
4520        /* Say this even without --verbose */
4521        strbuf_addf(&sb, Q_("Applying patch %%s with %d reject...",
4522                            "Applying patch %%s with %d rejects...",
4523                            cnt),
4524                    cnt);
4525        if (state->apply_verbosity > verbosity_silent)
4526                say_patch_name(stderr, sb.buf, patch);
4527        strbuf_release(&sb);
4528
4529        cnt = strlen(patch->new_name);
4530        if (ARRAY_SIZE(namebuf) <= cnt + 5) {
4531                cnt = ARRAY_SIZE(namebuf) - 5;
4532                warning(_("truncating .rej filename to %.*s.rej"),
4533                        cnt - 1, patch->new_name);
4534        }
4535        memcpy(namebuf, patch->new_name, cnt);
4536        memcpy(namebuf + cnt, ".rej", 5);
4537
4538        rej = fopen(namebuf, "w");
4539        if (!rej)
4540                return error_errno(_("cannot open %s"), namebuf);
4541
4542        /* Normal git tools never deal with .rej, so do not pretend
4543         * this is a git patch by saying --git or giving extended
4544         * headers.  While at it, maybe please "kompare" that wants
4545         * the trailing TAB and some garbage at the end of line ;-).
4546         */
4547        fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
4548                patch->new_name, patch->new_name);
4549        for (cnt = 1, frag = patch->fragments;
4550             frag;
4551             cnt++, frag = frag->next) {
4552                if (!frag->rejected) {
4553                        if (state->apply_verbosity > verbosity_silent)
4554                                fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
4555                        continue;
4556                }
4557                if (state->apply_verbosity > verbosity_silent)
4558                        fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
4559                fprintf(rej, "%.*s", frag->size, frag->patch);
4560                if (frag->patch[frag->size-1] != '\n')
4561                        fputc('\n', rej);
4562        }
4563        fclose(rej);
4564        return -1;
4565}
4566
4567/*
4568 * Returns:
4569 *  -1 if an error happened
4570 *   0 if the patch applied cleanly
4571 *   1 if the patch did not apply cleanly
4572 */
4573static int write_out_results(struct apply_state *state, struct patch *list)
4574{
4575        int phase;
4576        int errs = 0;
4577        struct patch *l;
4578        struct string_list cpath = STRING_LIST_INIT_DUP;
4579
4580        for (phase = 0; phase < 2; phase++) {
4581                l = list;
4582                while (l) {
4583                        if (l->rejected)
4584                                errs = 1;
4585                        else {
4586                                if (write_out_one_result(state, l, phase)) {
4587                                        string_list_clear(&cpath, 0);
4588                                        return -1;
4589                                }
4590                                if (phase == 1) {
4591                                        if (write_out_one_reject(state, l))
4592                                                errs = 1;
4593                                        if (l->conflicted_threeway) {
4594                                                string_list_append(&cpath, l->new_name);
4595                                                errs = 1;
4596                                        }
4597                                }
4598                        }
4599                        l = l->next;
4600                }
4601        }
4602
4603        if (cpath.nr) {
4604                struct string_list_item *item;
4605
4606                string_list_sort(&cpath);
4607                if (state->apply_verbosity > verbosity_silent) {
4608                        for_each_string_list_item(item, &cpath)
4609                                fprintf(stderr, "U %s\n", item->string);
4610                }
4611                string_list_clear(&cpath, 0);
4612
4613                rerere(0);
4614        }
4615
4616        return errs;
4617}
4618
4619/*
4620 * Try to apply a patch.
4621 *
4622 * Returns:
4623 *  -128 if a bad error happened (like patch unreadable)
4624 *  -1 if patch did not apply and user cannot deal with it
4625 *   0 if the patch applied
4626 *   1 if the patch did not apply but user might fix it
4627 */
4628static int apply_patch(struct apply_state *state,
4629                       int fd,
4630                       const char *filename,
4631                       int options)
4632{
4633        size_t offset;
4634        struct strbuf buf = STRBUF_INIT; /* owns the patch text */
4635        struct patch *list = NULL, **listp = &list;
4636        int skipped_patch = 0;
4637        int res = 0;
4638
4639        state->patch_input_file = filename;
4640        if (read_patch_file(&buf, fd) < 0)
4641                return -128;
4642        offset = 0;
4643        while (offset < buf.len) {
4644                struct patch *patch;
4645                int nr;
4646
4647                patch = xcalloc(1, sizeof(*patch));
4648                patch->inaccurate_eof = !!(options & APPLY_OPT_INACCURATE_EOF);
4649                patch->recount =  !!(options & APPLY_OPT_RECOUNT);
4650                nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
4651                if (nr < 0) {
4652                        free_patch(patch);
4653                        if (nr == -128) {
4654                                res = -128;
4655                                goto end;
4656                        }
4657                        break;
4658                }
4659                if (state->apply_in_reverse)
4660                        reverse_patches(patch);
4661                if (use_patch(state, patch)) {
4662                        patch_stats(state, patch);
4663                        *listp = patch;
4664                        listp = &patch->next;
4665                }
4666                else {
4667                        if (state->apply_verbosity > verbosity_normal)
4668                                say_patch_name(stderr, _("Skipped patch '%s'."), patch);
4669                        free_patch(patch);
4670                        skipped_patch++;
4671                }
4672                offset += nr;
4673        }
4674
4675        if (!list && !skipped_patch) {
4676                error(_("unrecognized input"));
4677                res = -128;
4678                goto end;
4679        }
4680
4681        if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
4682                state->apply = 0;
4683
4684        state->update_index = state->check_index && state->apply;
4685        if (state->update_index && state->newfd < 0) {
4686                if (state->index_file)
4687                        state->newfd = hold_lock_file_for_update(state->lock_file,
4688                                                                 state->index_file,
4689                                                                 LOCK_DIE_ON_ERROR);
4690                else
4691                        state->newfd = hold_locked_index(state->lock_file, 1);
4692        }
4693
4694        if (state->check_index && read_apply_cache(state) < 0) {
4695                error(_("unable to read index file"));
4696                res = -128;
4697                goto end;
4698        }
4699
4700        if (state->check || state->apply) {
4701                int r = check_patch_list(state, list);
4702                if (r == -128) {
4703                        res = -128;
4704                        goto end;
4705                }
4706                if (r < 0 && !state->apply_with_reject) {
4707                        res = -1;
4708                        goto end;
4709                }
4710        }
4711
4712        if (state->apply) {
4713                int write_res = write_out_results(state, list);
4714                if (write_res < 0) {
4715                        res = -128;
4716                        goto end;
4717                }
4718                if (write_res > 0) {
4719                        /* with --3way, we still need to write the index out */
4720                        res = state->apply_with_reject ? -1 : 1;
4721                        goto end;
4722                }
4723        }
4724
4725        if (state->fake_ancestor &&
4726            build_fake_ancestor(state, list)) {
4727                res = -128;
4728                goto end;
4729        }
4730
4731        if (state->diffstat && state->apply_verbosity > verbosity_silent)
4732                stat_patch_list(state, list);
4733
4734        if (state->numstat && state->apply_verbosity > verbosity_silent)
4735                numstat_patch_list(state, list);
4736
4737        if (state->summary && state->apply_verbosity > verbosity_silent)
4738                summary_patch_list(list);
4739
4740end:
4741        free_patch_list(list);
4742        strbuf_release(&buf);
4743        string_list_clear(&state->fn_table, 0);
4744        return res;
4745}
4746
4747static int apply_option_parse_exclude(const struct option *opt,
4748                                      const char *arg, int unset)
4749{
4750        struct apply_state *state = opt->value;
4751        add_name_limit(state, arg, 1);
4752        return 0;
4753}
4754
4755static int apply_option_parse_include(const struct option *opt,
4756                                      const char *arg, int unset)
4757{
4758        struct apply_state *state = opt->value;
4759        add_name_limit(state, arg, 0);
4760        state->has_include = 1;
4761        return 0;
4762}
4763
4764static int apply_option_parse_p(const struct option *opt,
4765                                const char *arg,
4766                                int unset)
4767{
4768        struct apply_state *state = opt->value;
4769        state->p_value = atoi(arg);
4770        state->p_value_known = 1;
4771        return 0;
4772}
4773
4774static int apply_option_parse_space_change(const struct option *opt,
4775                                           const char *arg, int unset)
4776{
4777        struct apply_state *state = opt->value;
4778        if (unset)
4779                state->ws_ignore_action = ignore_ws_none;
4780        else
4781                state->ws_ignore_action = ignore_ws_change;
4782        return 0;
4783}
4784
4785static int apply_option_parse_whitespace(const struct option *opt,
4786                                         const char *arg, int unset)
4787{
4788        struct apply_state *state = opt->value;
4789        state->whitespace_option = arg;
4790        if (parse_whitespace_option(state, arg))
4791                exit(1);
4792        return 0;
4793}
4794
4795static int apply_option_parse_directory(const struct option *opt,
4796                                        const char *arg, int unset)
4797{
4798        struct apply_state *state = opt->value;
4799        strbuf_reset(&state->root);
4800        strbuf_addstr(&state->root, arg);
4801        strbuf_complete(&state->root, '/');
4802        return 0;
4803}
4804
4805int apply_all_patches(struct apply_state *state,
4806                      int argc,
4807                      const char **argv,
4808                      int options)
4809{
4810        int i;
4811        int res;
4812        int errs = 0;
4813        int read_stdin = 1;
4814
4815        for (i = 0; i < argc; i++) {
4816                const char *arg = argv[i];
4817                int fd;
4818
4819                if (!strcmp(arg, "-")) {
4820                        res = apply_patch(state, 0, "<stdin>", options);
4821                        if (res < 0)
4822                                goto end;
4823                        errs |= res;
4824                        read_stdin = 0;
4825                        continue;
4826                } else if (0 < state->prefix_length)
4827                        arg = prefix_filename(state->prefix,
4828                                              state->prefix_length,
4829                                              arg);
4830
4831                fd = open(arg, O_RDONLY);
4832                if (fd < 0) {
4833                        error(_("can't open patch '%s': %s"), arg, strerror(errno));
4834                        res = -128;
4835                        goto end;
4836                }
4837                read_stdin = 0;
4838                set_default_whitespace_mode(state);
4839                res = apply_patch(state, fd, arg, options);
4840                close(fd);
4841                if (res < 0)
4842                        goto end;
4843                errs |= res;
4844        }
4845        set_default_whitespace_mode(state);
4846        if (read_stdin) {
4847                res = apply_patch(state, 0, "<stdin>", options);
4848                if (res < 0)
4849                        goto end;
4850                errs |= res;
4851        }
4852
4853        if (state->whitespace_error) {
4854                if (state->squelch_whitespace_errors &&
4855                    state->squelch_whitespace_errors < state->whitespace_error) {
4856                        int squelched =
4857                                state->whitespace_error - state->squelch_whitespace_errors;
4858                        warning(Q_("squelched %d whitespace error",
4859                                   "squelched %d whitespace errors",
4860                                   squelched),
4861                                squelched);
4862                }
4863                if (state->ws_error_action == die_on_ws_error) {
4864                        error(Q_("%d line adds whitespace errors.",
4865                                 "%d lines add whitespace errors.",
4866                                 state->whitespace_error),
4867                              state->whitespace_error);
4868                        res = -128;
4869                        goto end;
4870                }
4871                if (state->applied_after_fixing_ws && state->apply)
4872                        warning("%d line%s applied after"
4873                                " fixing whitespace errors.",
4874                                state->applied_after_fixing_ws,
4875                                state->applied_after_fixing_ws == 1 ? "" : "s");
4876                else if (state->whitespace_error)
4877                        warning(Q_("%d line adds whitespace errors.",
4878                                   "%d lines add whitespace errors.",
4879                                   state->whitespace_error),
4880                                state->whitespace_error);
4881        }
4882
4883        if (state->update_index) {
4884                res = write_locked_index(&the_index, state->lock_file, COMMIT_LOCK);
4885                if (res) {
4886                        error(_("Unable to write new index file"));
4887                        res = -128;
4888                        goto end;
4889                }
4890                state->newfd = -1;
4891        }
4892
4893        res = !!errs;
4894
4895end:
4896        if (state->newfd >= 0) {
4897                rollback_lock_file(state->lock_file);
4898                state->newfd = -1;
4899        }
4900
4901        if (state->apply_verbosity <= verbosity_silent) {
4902                set_error_routine(state->saved_error_routine);
4903                set_warn_routine(state->saved_warn_routine);
4904        }
4905
4906        if (res > -1)
4907                return res;
4908        return (res == -1 ? 1 : 128);
4909}
4910
4911int apply_parse_options(int argc, const char **argv,
4912                        struct apply_state *state,
4913                        int *force_apply, int *options,
4914                        const char * const *apply_usage)
4915{
4916        struct option builtin_apply_options[] = {
4917                { OPTION_CALLBACK, 0, "exclude", state, N_("path"),
4918                        N_("don't apply changes matching the given path"),
4919                        0, apply_option_parse_exclude },
4920                { OPTION_CALLBACK, 0, "include", state, N_("path"),
4921                        N_("apply changes matching the given path"),
4922                        0, apply_option_parse_include },
4923                { OPTION_CALLBACK, 'p', NULL, state, N_("num"),
4924                        N_("remove <num> leading slashes from traditional diff paths"),
4925                        0, apply_option_parse_p },
4926                OPT_BOOL(0, "no-add", &state->no_add,
4927                        N_("ignore additions made by the patch")),
4928                OPT_BOOL(0, "stat", &state->diffstat,
4929                        N_("instead of applying the patch, output diffstat for the input")),
4930                OPT_NOOP_NOARG(0, "allow-binary-replacement"),
4931                OPT_NOOP_NOARG(0, "binary"),
4932                OPT_BOOL(0, "numstat", &state->numstat,
4933                        N_("show number of added and deleted lines in decimal notation")),
4934                OPT_BOOL(0, "summary", &state->summary,
4935                        N_("instead of applying the patch, output a summary for the input")),
4936                OPT_BOOL(0, "check", &state->check,
4937                        N_("instead of applying the patch, see if the patch is applicable")),
4938                OPT_BOOL(0, "index", &state->check_index,
4939                        N_("make sure the patch is applicable to the current index")),
4940                OPT_BOOL(0, "cached", &state->cached,
4941                        N_("apply a patch without touching the working tree")),
4942                OPT_BOOL(0, "unsafe-paths", &state->unsafe_paths,
4943                        N_("accept a patch that touches outside the working area")),
4944                OPT_BOOL(0, "apply", force_apply,
4945                        N_("also apply the patch (use with --stat/--summary/--check)")),
4946                OPT_BOOL('3', "3way", &state->threeway,
4947                         N_( "attempt three-way merge if a patch does not apply")),
4948                OPT_FILENAME(0, "build-fake-ancestor", &state->fake_ancestor,
4949                        N_("build a temporary index based on embedded index information")),
4950                /* Think twice before adding "--nul" synonym to this */
4951                OPT_SET_INT('z', NULL, &state->line_termination,
4952                        N_("paths are separated with NUL character"), '\0'),
4953                OPT_INTEGER('C', NULL, &state->p_context,
4954                                N_("ensure at least <n> lines of context match")),
4955                { OPTION_CALLBACK, 0, "whitespace", state, N_("action"),
4956                        N_("detect new or modified lines that have whitespace errors"),
4957                        0, apply_option_parse_whitespace },
4958                { OPTION_CALLBACK, 0, "ignore-space-change", state, NULL,
4959                        N_("ignore changes in whitespace when finding context"),
4960                        PARSE_OPT_NOARG, apply_option_parse_space_change },
4961                { OPTION_CALLBACK, 0, "ignore-whitespace", state, NULL,
4962                        N_("ignore changes in whitespace when finding context"),
4963                        PARSE_OPT_NOARG, apply_option_parse_space_change },
4964                OPT_BOOL('R', "reverse", &state->apply_in_reverse,
4965                        N_("apply the patch in reverse")),
4966                OPT_BOOL(0, "unidiff-zero", &state->unidiff_zero,
4967                        N_("don't expect at least one line of context")),
4968                OPT_BOOL(0, "reject", &state->apply_with_reject,
4969                        N_("leave the rejected hunks in corresponding *.rej files")),
4970                OPT_BOOL(0, "allow-overlap", &state->allow_overlap,
4971                        N_("allow overlapping hunks")),
4972                OPT__VERBOSE(&state->apply_verbosity, N_("be verbose")),
4973                OPT_BIT(0, "inaccurate-eof", options,
4974                        N_("tolerate incorrectly detected missing new-line at the end of file"),
4975                        APPLY_OPT_INACCURATE_EOF),
4976                OPT_BIT(0, "recount", options,
4977                        N_("do not trust the line counts in the hunk headers"),
4978                        APPLY_OPT_RECOUNT),
4979                { OPTION_CALLBACK, 0, "directory", state, N_("root"),
4980                        N_("prepend <root> to all filenames"),
4981                        0, apply_option_parse_directory },
4982                OPT_END()
4983        };
4984
4985        return parse_options(argc, argv, state->prefix, builtin_apply_options, apply_usage, 0);
4986}