792ecea36a95a4055745bd7484a52d9307aa697e
   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 "config.h"
  12#include "object-store.h"
  13#include "blob.h"
  14#include "delta.h"
  15#include "diff.h"
  16#include "dir.h"
  17#include "xdiff-interface.h"
  18#include "ll-merge.h"
  19#include "lockfile.h"
  20#include "parse-options.h"
  21#include "quote.h"
  22#include "rerere.h"
  23#include "apply.h"
  24
  25static void git_apply_config(void)
  26{
  27        git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
  28        git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
  29        git_config(git_default_config, NULL);
  30}
  31
  32static int parse_whitespace_option(struct apply_state *state, const char *option)
  33{
  34        if (!option) {
  35                state->ws_error_action = warn_on_ws_error;
  36                return 0;
  37        }
  38        if (!strcmp(option, "warn")) {
  39                state->ws_error_action = warn_on_ws_error;
  40                return 0;
  41        }
  42        if (!strcmp(option, "nowarn")) {
  43                state->ws_error_action = nowarn_ws_error;
  44                return 0;
  45        }
  46        if (!strcmp(option, "error")) {
  47                state->ws_error_action = die_on_ws_error;
  48                return 0;
  49        }
  50        if (!strcmp(option, "error-all")) {
  51                state->ws_error_action = die_on_ws_error;
  52                state->squelch_whitespace_errors = 0;
  53                return 0;
  54        }
  55        if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
  56                state->ws_error_action = correct_ws_error;
  57                return 0;
  58        }
  59        return error(_("unrecognized whitespace option '%s'"), option);
  60}
  61
  62static int parse_ignorewhitespace_option(struct apply_state *state,
  63                                                 const char *option)
  64{
  65        if (!option || !strcmp(option, "no") ||
  66            !strcmp(option, "false") || !strcmp(option, "never") ||
  67            !strcmp(option, "none")) {
  68                state->ws_ignore_action = ignore_ws_none;
  69                return 0;
  70        }
  71        if (!strcmp(option, "change")) {
  72                state->ws_ignore_action = ignore_ws_change;
  73                return 0;
  74        }
  75        return error(_("unrecognized whitespace ignore option '%s'"), option);
  76}
  77
  78int init_apply_state(struct apply_state *state,
  79                     struct repository *repo,
  80                     const char *prefix)
  81{
  82        memset(state, 0, sizeof(*state));
  83        state->prefix = prefix;
  84        state->repo = repo;
  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->ita_only && (state->check_index || is_not_gitdir))
 148                state->ita_only = 0;
 149        if (state->check_index)
 150                state->unsafe_paths = 0;
 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        int extension_linenr; /* first line specifying delete/new/rename/copy */
 214        unsigned int is_toplevel_relative:1;
 215        unsigned int inaccurate_eof:1;
 216        unsigned int is_binary:1;
 217        unsigned int is_copy:1;
 218        unsigned int is_rename:1;
 219        unsigned int recount:1;
 220        unsigned int conflicted_threeway:1;
 221        unsigned int direct_to_threeway:1;
 222        unsigned int crlf_in_old:1;
 223        struct fragment *fragments;
 224        char *result;
 225        size_t resultsize;
 226        char old_sha1_prefix[GIT_MAX_HEXSZ + 1];
 227        char new_sha1_prefix[GIT_MAX_HEXSZ + 1];
 228        struct patch *next;
 229
 230        /* three-way fallback result */
 231        struct object_id threeway_stage[3];
 232};
 233
 234static void free_fragment_list(struct fragment *list)
 235{
 236        while (list) {
 237                struct fragment *next = list->next;
 238                if (list->free_patch)
 239                        free((char *)list->patch);
 240                free(list);
 241                list = next;
 242        }
 243}
 244
 245static void free_patch(struct patch *patch)
 246{
 247        free_fragment_list(patch->fragments);
 248        free(patch->def_name);
 249        free(patch->old_name);
 250        free(patch->new_name);
 251        free(patch->result);
 252        free(patch);
 253}
 254
 255static void free_patch_list(struct patch *list)
 256{
 257        while (list) {
 258                struct patch *next = list->next;
 259                free_patch(list);
 260                list = next;
 261        }
 262}
 263
 264/*
 265 * A line in a file, len-bytes long (includes the terminating LF,
 266 * except for an incomplete line at the end if the file ends with
 267 * one), and its contents hashes to 'hash'.
 268 */
 269struct line {
 270        size_t len;
 271        unsigned hash : 24;
 272        unsigned flag : 8;
 273#define LINE_COMMON     1
 274#define LINE_PATCHED    2
 275};
 276
 277/*
 278 * This represents a "file", which is an array of "lines".
 279 */
 280struct image {
 281        char *buf;
 282        size_t len;
 283        size_t nr;
 284        size_t alloc;
 285        struct line *line_allocated;
 286        struct line *line;
 287};
 288
 289static uint32_t hash_line(const char *cp, size_t len)
 290{
 291        size_t i;
 292        uint32_t h;
 293        for (i = 0, h = 0; i < len; i++) {
 294                if (!isspace(cp[i])) {
 295                        h = h * 3 + (cp[i] & 0xff);
 296                }
 297        }
 298        return h;
 299}
 300
 301/*
 302 * Compare lines s1 of length n1 and s2 of length n2, ignoring
 303 * whitespace difference. Returns 1 if they match, 0 otherwise
 304 */
 305static int fuzzy_matchlines(const char *s1, size_t n1,
 306                            const char *s2, size_t n2)
 307{
 308        const char *end1 = s1 + n1;
 309        const char *end2 = s2 + n2;
 310
 311        /* ignore line endings */
 312        while (s1 < end1 && (end1[-1] == '\r' || end1[-1] == '\n'))
 313                end1--;
 314        while (s2 < end2 && (end2[-1] == '\r' || end2[-1] == '\n'))
 315                end2--;
 316
 317        while (s1 < end1 && s2 < end2) {
 318                if (isspace(*s1)) {
 319                        /*
 320                         * Skip whitespace. We check on both buffers
 321                         * because we don't want "a b" to match "ab".
 322                         */
 323                        if (!isspace(*s2))
 324                                return 0;
 325                        while (s1 < end1 && isspace(*s1))
 326                                s1++;
 327                        while (s2 < end2 && isspace(*s2))
 328                                s2++;
 329                } else if (*s1++ != *s2++)
 330                        return 0;
 331        }
 332
 333        /* If we reached the end on one side only, lines don't match. */
 334        return s1 == end1 && s2 == end2;
 335}
 336
 337static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
 338{
 339        ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
 340        img->line_allocated[img->nr].len = len;
 341        img->line_allocated[img->nr].hash = hash_line(bol, len);
 342        img->line_allocated[img->nr].flag = flag;
 343        img->nr++;
 344}
 345
 346/*
 347 * "buf" has the file contents to be patched (read from various sources).
 348 * attach it to "image" and add line-based index to it.
 349 * "image" now owns the "buf".
 350 */
 351static void prepare_image(struct image *image, char *buf, size_t len,
 352                          int prepare_linetable)
 353{
 354        const char *cp, *ep;
 355
 356        memset(image, 0, sizeof(*image));
 357        image->buf = buf;
 358        image->len = len;
 359
 360        if (!prepare_linetable)
 361                return;
 362
 363        ep = image->buf + image->len;
 364        cp = image->buf;
 365        while (cp < ep) {
 366                const char *next;
 367                for (next = cp; next < ep && *next != '\n'; next++)
 368                        ;
 369                if (next < ep)
 370                        next++;
 371                add_line_info(image, cp, next - cp, 0);
 372                cp = next;
 373        }
 374        image->line = image->line_allocated;
 375}
 376
 377static void clear_image(struct image *image)
 378{
 379        free(image->buf);
 380        free(image->line_allocated);
 381        memset(image, 0, sizeof(*image));
 382}
 383
 384/* fmt must contain _one_ %s and no other substitution */
 385static void say_patch_name(FILE *output, const char *fmt, struct patch *patch)
 386{
 387        struct strbuf sb = STRBUF_INIT;
 388
 389        if (patch->old_name && patch->new_name &&
 390            strcmp(patch->old_name, patch->new_name)) {
 391                quote_c_style(patch->old_name, &sb, NULL, 0);
 392                strbuf_addstr(&sb, " => ");
 393                quote_c_style(patch->new_name, &sb, NULL, 0);
 394        } else {
 395                const char *n = patch->new_name;
 396                if (!n)
 397                        n = patch->old_name;
 398                quote_c_style(n, &sb, NULL, 0);
 399        }
 400        fprintf(output, fmt, sb.buf);
 401        fputc('\n', output);
 402        strbuf_release(&sb);
 403}
 404
 405#define SLOP (16)
 406
 407static int read_patch_file(struct strbuf *sb, int fd)
 408{
 409        if (strbuf_read(sb, fd, 0) < 0)
 410                return error_errno("git apply: failed to read");
 411
 412        /*
 413         * Make sure that we have some slop in the buffer
 414         * so that we can do speculative "memcmp" etc, and
 415         * see to it that it is NUL-filled.
 416         */
 417        strbuf_grow(sb, SLOP);
 418        memset(sb->buf + sb->len, 0, SLOP);
 419        return 0;
 420}
 421
 422static unsigned long linelen(const char *buffer, unsigned long size)
 423{
 424        unsigned long len = 0;
 425        while (size--) {
 426                len++;
 427                if (*buffer++ == '\n')
 428                        break;
 429        }
 430        return len;
 431}
 432
 433static int is_dev_null(const char *str)
 434{
 435        return skip_prefix(str, "/dev/null", &str) && isspace(*str);
 436}
 437
 438#define TERM_SPACE      1
 439#define TERM_TAB        2
 440
 441static int name_terminate(int c, int terminate)
 442{
 443        if (c == ' ' && !(terminate & TERM_SPACE))
 444                return 0;
 445        if (c == '\t' && !(terminate & TERM_TAB))
 446                return 0;
 447
 448        return 1;
 449}
 450
 451/* remove double slashes to make --index work with such filenames */
 452static char *squash_slash(char *name)
 453{
 454        int i = 0, j = 0;
 455
 456        if (!name)
 457                return NULL;
 458
 459        while (name[i]) {
 460                if ((name[j++] = name[i++]) == '/')
 461                        while (name[i] == '/')
 462                                i++;
 463        }
 464        name[j] = '\0';
 465        return name;
 466}
 467
 468static char *find_name_gnu(struct apply_state *state,
 469                           const char *line,
 470                           const char *def,
 471                           int p_value)
 472{
 473        struct strbuf name = STRBUF_INIT;
 474        char *cp;
 475
 476        /*
 477         * Proposed "new-style" GNU patch/diff format; see
 478         * http://marc.info/?l=git&m=112927316408690&w=2
 479         */
 480        if (unquote_c_style(&name, line, NULL)) {
 481                strbuf_release(&name);
 482                return NULL;
 483        }
 484
 485        for (cp = name.buf; p_value; p_value--) {
 486                cp = strchr(cp, '/');
 487                if (!cp) {
 488                        strbuf_release(&name);
 489                        return NULL;
 490                }
 491                cp++;
 492        }
 493
 494        strbuf_remove(&name, 0, cp - name.buf);
 495        if (state->root.len)
 496                strbuf_insert(&name, 0, state->root.buf, state->root.len);
 497        return squash_slash(strbuf_detach(&name, NULL));
 498}
 499
 500static size_t sane_tz_len(const char *line, size_t len)
 501{
 502        const char *tz, *p;
 503
 504        if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
 505                return 0;
 506        tz = line + len - strlen(" +0500");
 507
 508        if (tz[1] != '+' && tz[1] != '-')
 509                return 0;
 510
 511        for (p = tz + 2; p != line + len; p++)
 512                if (!isdigit(*p))
 513                        return 0;
 514
 515        return line + len - tz;
 516}
 517
 518static size_t tz_with_colon_len(const char *line, size_t len)
 519{
 520        const char *tz, *p;
 521
 522        if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
 523                return 0;
 524        tz = line + len - strlen(" +08:00");
 525
 526        if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
 527                return 0;
 528        p = tz + 2;
 529        if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 530            !isdigit(*p++) || !isdigit(*p++))
 531                return 0;
 532
 533        return line + len - tz;
 534}
 535
 536static size_t date_len(const char *line, size_t len)
 537{
 538        const char *date, *p;
 539
 540        if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
 541                return 0;
 542        p = date = line + len - strlen("72-02-05");
 543
 544        if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
 545            !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
 546            !isdigit(*p++) || !isdigit(*p++))   /* Not a date. */
 547                return 0;
 548
 549        if (date - line >= strlen("19") &&
 550            isdigit(date[-1]) && isdigit(date[-2]))     /* 4-digit year */
 551                date -= strlen("19");
 552
 553        return line + len - date;
 554}
 555
 556static size_t short_time_len(const char *line, size_t len)
 557{
 558        const char *time, *p;
 559
 560        if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
 561                return 0;
 562        p = time = line + len - strlen(" 07:01:32");
 563
 564        /* Permit 1-digit hours? */
 565        if (*p++ != ' ' ||
 566            !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 567            !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
 568            !isdigit(*p++) || !isdigit(*p++))   /* Not a time. */
 569                return 0;
 570
 571        return line + len - time;
 572}
 573
 574static size_t fractional_time_len(const char *line, size_t len)
 575{
 576        const char *p;
 577        size_t n;
 578
 579        /* Expected format: 19:41:17.620000023 */
 580        if (!len || !isdigit(line[len - 1]))
 581                return 0;
 582        p = line + len - 1;
 583
 584        /* Fractional seconds. */
 585        while (p > line && isdigit(*p))
 586                p--;
 587        if (*p != '.')
 588                return 0;
 589
 590        /* Hours, minutes, and whole seconds. */
 591        n = short_time_len(line, p - line);
 592        if (!n)
 593                return 0;
 594
 595        return line + len - p + n;
 596}
 597
 598static size_t trailing_spaces_len(const char *line, size_t len)
 599{
 600        const char *p;
 601
 602        /* Expected format: ' ' x (1 or more)  */
 603        if (!len || line[len - 1] != ' ')
 604                return 0;
 605
 606        p = line + len;
 607        while (p != line) {
 608                p--;
 609                if (*p != ' ')
 610                        return line + len - (p + 1);
 611        }
 612
 613        /* All spaces! */
 614        return len;
 615}
 616
 617static size_t diff_timestamp_len(const char *line, size_t len)
 618{
 619        const char *end = line + len;
 620        size_t n;
 621
 622        /*
 623         * Posix: 2010-07-05 19:41:17
 624         * GNU: 2010-07-05 19:41:17.620000023 -0500
 625         */
 626
 627        if (!isdigit(end[-1]))
 628                return 0;
 629
 630        n = sane_tz_len(line, end - line);
 631        if (!n)
 632                n = tz_with_colon_len(line, end - line);
 633        end -= n;
 634
 635        n = short_time_len(line, end - line);
 636        if (!n)
 637                n = fractional_time_len(line, end - line);
 638        end -= n;
 639
 640        n = date_len(line, end - line);
 641        if (!n) /* No date.  Too bad. */
 642                return 0;
 643        end -= n;
 644
 645        if (end == line)        /* No space before date. */
 646                return 0;
 647        if (end[-1] == '\t') {  /* Success! */
 648                end--;
 649                return line + len - end;
 650        }
 651        if (end[-1] != ' ')     /* No space before date. */
 652                return 0;
 653
 654        /* Whitespace damage. */
 655        end -= trailing_spaces_len(line, end - line);
 656        return line + len - end;
 657}
 658
 659static char *find_name_common(struct apply_state *state,
 660                              const char *line,
 661                              const char *def,
 662                              int p_value,
 663                              const char *end,
 664                              int terminate)
 665{
 666        int len;
 667        const char *start = NULL;
 668
 669        if (p_value == 0)
 670                start = line;
 671        while (line != end) {
 672                char c = *line;
 673
 674                if (!end && isspace(c)) {
 675                        if (c == '\n')
 676                                break;
 677                        if (name_terminate(c, terminate))
 678                                break;
 679                }
 680                line++;
 681                if (c == '/' && !--p_value)
 682                        start = line;
 683        }
 684        if (!start)
 685                return squash_slash(xstrdup_or_null(def));
 686        len = line - start;
 687        if (!len)
 688                return squash_slash(xstrdup_or_null(def));
 689
 690        /*
 691         * Generally we prefer the shorter name, especially
 692         * if the other one is just a variation of that with
 693         * something else tacked on to the end (ie "file.orig"
 694         * or "file~").
 695         */
 696        if (def) {
 697                int deflen = strlen(def);
 698                if (deflen < len && !strncmp(start, def, deflen))
 699                        return squash_slash(xstrdup(def));
 700        }
 701
 702        if (state->root.len) {
 703                char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
 704                return squash_slash(ret);
 705        }
 706
 707        return squash_slash(xmemdupz(start, len));
 708}
 709
 710static char *find_name(struct apply_state *state,
 711                       const char *line,
 712                       char *def,
 713                       int p_value,
 714                       int terminate)
 715{
 716        if (*line == '"') {
 717                char *name = find_name_gnu(state, line, def, p_value);
 718                if (name)
 719                        return name;
 720        }
 721
 722        return find_name_common(state, line, def, p_value, NULL, terminate);
 723}
 724
 725static char *find_name_traditional(struct apply_state *state,
 726                                   const char *line,
 727                                   char *def,
 728                                   int p_value)
 729{
 730        size_t len;
 731        size_t date_len;
 732
 733        if (*line == '"') {
 734                char *name = find_name_gnu(state, line, def, p_value);
 735                if (name)
 736                        return name;
 737        }
 738
 739        len = strchrnul(line, '\n') - line;
 740        date_len = diff_timestamp_len(line, len);
 741        if (!date_len)
 742                return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
 743        len -= date_len;
 744
 745        return find_name_common(state, line, def, p_value, line + len, 0);
 746}
 747
 748/*
 749 * Given the string after "--- " or "+++ ", guess the appropriate
 750 * p_value for the given patch.
 751 */
 752static int guess_p_value(struct apply_state *state, const char *nameline)
 753{
 754        char *name, *cp;
 755        int val = -1;
 756
 757        if (is_dev_null(nameline))
 758                return -1;
 759        name = find_name_traditional(state, nameline, NULL, 0);
 760        if (!name)
 761                return -1;
 762        cp = strchr(name, '/');
 763        if (!cp)
 764                val = 0;
 765        else if (state->prefix) {
 766                /*
 767                 * Does it begin with "a/$our-prefix" and such?  Then this is
 768                 * very likely to apply to our directory.
 769                 */
 770                if (starts_with(name, state->prefix))
 771                        val = count_slashes(state->prefix);
 772                else {
 773                        cp++;
 774                        if (starts_with(cp, state->prefix))
 775                                val = count_slashes(state->prefix) + 1;
 776                }
 777        }
 778        free(name);
 779        return val;
 780}
 781
 782/*
 783 * Does the ---/+++ line have the POSIX timestamp after the last HT?
 784 * GNU diff puts epoch there to signal a creation/deletion event.  Is
 785 * this such a timestamp?
 786 */
 787static int has_epoch_timestamp(const char *nameline)
 788{
 789        /*
 790         * We are only interested in epoch timestamp; any non-zero
 791         * fraction cannot be one, hence "(\.0+)?" in the regexp below.
 792         * For the same reason, the date must be either 1969-12-31 or
 793         * 1970-01-01, and the seconds part must be "00".
 794         */
 795        const char stamp_regexp[] =
 796                "^[0-2][0-9]:([0-5][0-9]):00(\\.0+)?"
 797                " "
 798                "([-+][0-2][0-9]:?[0-5][0-9])\n";
 799        const char *timestamp = NULL, *cp, *colon;
 800        static regex_t *stamp;
 801        regmatch_t m[10];
 802        int zoneoffset, epoch_hour, hour, minute;
 803        int status;
 804
 805        for (cp = nameline; *cp != '\n'; cp++) {
 806                if (*cp == '\t')
 807                        timestamp = cp + 1;
 808        }
 809        if (!timestamp)
 810                return 0;
 811
 812        /*
 813         * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
 814         * (west of GMT) or 1970-01-01 (east of GMT)
 815         */
 816        if (skip_prefix(timestamp, "1969-12-31 ", &timestamp))
 817                epoch_hour = 24;
 818        else if (skip_prefix(timestamp, "1970-01-01 ", &timestamp))
 819                epoch_hour = 0;
 820        else
 821                return 0;
 822
 823        if (!stamp) {
 824                stamp = xmalloc(sizeof(*stamp));
 825                if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
 826                        warning(_("Cannot prepare timestamp regexp %s"),
 827                                stamp_regexp);
 828                        return 0;
 829                }
 830        }
 831
 832        status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
 833        if (status) {
 834                if (status != REG_NOMATCH)
 835                        warning(_("regexec returned %d for input: %s"),
 836                                status, timestamp);
 837                return 0;
 838        }
 839
 840        hour = strtol(timestamp, NULL, 10);
 841        minute = strtol(timestamp + m[1].rm_so, NULL, 10);
 842
 843        zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
 844        if (*colon == ':')
 845                zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
 846        else
 847                zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
 848        if (timestamp[m[3].rm_so] == '-')
 849                zoneoffset = -zoneoffset;
 850
 851        return hour * 60 + minute - zoneoffset == epoch_hour * 60;
 852}
 853
 854/*
 855 * Get the name etc info from the ---/+++ lines of a traditional patch header
 856 *
 857 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 858 * files, we can happily check the index for a match, but for creating a
 859 * new file we should try to match whatever "patch" does. I have no idea.
 860 */
 861static int parse_traditional_patch(struct apply_state *state,
 862                                   const char *first,
 863                                   const char *second,
 864                                   struct patch *patch)
 865{
 866        char *name;
 867
 868        first += 4;     /* skip "--- " */
 869        second += 4;    /* skip "+++ " */
 870        if (!state->p_value_known) {
 871                int p, q;
 872                p = guess_p_value(state, first);
 873                q = guess_p_value(state, second);
 874                if (p < 0) p = q;
 875                if (0 <= p && p == q) {
 876                        state->p_value = p;
 877                        state->p_value_known = 1;
 878                }
 879        }
 880        if (is_dev_null(first)) {
 881                patch->is_new = 1;
 882                patch->is_delete = 0;
 883                name = find_name_traditional(state, second, NULL, state->p_value);
 884                patch->new_name = name;
 885        } else if (is_dev_null(second)) {
 886                patch->is_new = 0;
 887                patch->is_delete = 1;
 888                name = find_name_traditional(state, first, NULL, state->p_value);
 889                patch->old_name = name;
 890        } else {
 891                char *first_name;
 892                first_name = find_name_traditional(state, first, NULL, state->p_value);
 893                name = find_name_traditional(state, second, first_name, state->p_value);
 894                free(first_name);
 895                if (has_epoch_timestamp(first)) {
 896                        patch->is_new = 1;
 897                        patch->is_delete = 0;
 898                        patch->new_name = name;
 899                } else if (has_epoch_timestamp(second)) {
 900                        patch->is_new = 0;
 901                        patch->is_delete = 1;
 902                        patch->old_name = name;
 903                } else {
 904                        patch->old_name = name;
 905                        patch->new_name = xstrdup_or_null(name);
 906                }
 907        }
 908        if (!name)
 909                return error(_("unable to find filename in patch at line %d"), state->linenr);
 910
 911        return 0;
 912}
 913
 914static int gitdiff_hdrend(struct apply_state *state,
 915                          const char *line,
 916                          struct patch *patch)
 917{
 918        return 1;
 919}
 920
 921/*
 922 * We're anal about diff header consistency, to make
 923 * sure that we don't end up having strange ambiguous
 924 * patches floating around.
 925 *
 926 * As a result, gitdiff_{old|new}name() will check
 927 * their names against any previous information, just
 928 * to make sure..
 929 */
 930#define DIFF_OLD_NAME 0
 931#define DIFF_NEW_NAME 1
 932
 933static int gitdiff_verify_name(struct apply_state *state,
 934                               const char *line,
 935                               int isnull,
 936                               char **name,
 937                               int side)
 938{
 939        if (!*name && !isnull) {
 940                *name = find_name(state, line, NULL, state->p_value, TERM_TAB);
 941                return 0;
 942        }
 943
 944        if (*name) {
 945                char *another;
 946                if (isnull)
 947                        return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
 948                                     *name, state->linenr);
 949                another = find_name(state, line, NULL, state->p_value, TERM_TAB);
 950                if (!another || strcmp(another, *name)) {
 951                        free(another);
 952                        return error((side == DIFF_NEW_NAME) ?
 953                            _("git apply: bad git-diff - inconsistent new filename on line %d") :
 954                            _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
 955                }
 956                free(another);
 957        } else {
 958                if (!is_dev_null(line))
 959                        return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
 960        }
 961
 962        return 0;
 963}
 964
 965static int gitdiff_oldname(struct apply_state *state,
 966                           const char *line,
 967                           struct patch *patch)
 968{
 969        return gitdiff_verify_name(state, line,
 970                                   patch->is_new, &patch->old_name,
 971                                   DIFF_OLD_NAME);
 972}
 973
 974static int gitdiff_newname(struct apply_state *state,
 975                           const char *line,
 976                           struct patch *patch)
 977{
 978        return gitdiff_verify_name(state, line,
 979                                   patch->is_delete, &patch->new_name,
 980                                   DIFF_NEW_NAME);
 981}
 982
 983static int parse_mode_line(const char *line, int linenr, unsigned int *mode)
 984{
 985        char *end;
 986        *mode = strtoul(line, &end, 8);
 987        if (end == line || !isspace(*end))
 988                return error(_("invalid mode on line %d: %s"), linenr, line);
 989        return 0;
 990}
 991
 992static int gitdiff_oldmode(struct apply_state *state,
 993                           const char *line,
 994                           struct patch *patch)
 995{
 996        return parse_mode_line(line, state->linenr, &patch->old_mode);
 997}
 998
 999static int gitdiff_newmode(struct apply_state *state,
1000                           const char *line,
1001                           struct patch *patch)
1002{
1003        return parse_mode_line(line, state->linenr, &patch->new_mode);
1004}
1005
1006static int gitdiff_delete(struct apply_state *state,
1007                          const char *line,
1008                          struct patch *patch)
1009{
1010        patch->is_delete = 1;
1011        free(patch->old_name);
1012        patch->old_name = xstrdup_or_null(patch->def_name);
1013        return gitdiff_oldmode(state, line, patch);
1014}
1015
1016static int gitdiff_newfile(struct apply_state *state,
1017                           const char *line,
1018                           struct patch *patch)
1019{
1020        patch->is_new = 1;
1021        free(patch->new_name);
1022        patch->new_name = xstrdup_or_null(patch->def_name);
1023        return gitdiff_newmode(state, line, patch);
1024}
1025
1026static int gitdiff_copysrc(struct apply_state *state,
1027                           const char *line,
1028                           struct patch *patch)
1029{
1030        patch->is_copy = 1;
1031        free(patch->old_name);
1032        patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1033        return 0;
1034}
1035
1036static int gitdiff_copydst(struct apply_state *state,
1037                           const char *line,
1038                           struct patch *patch)
1039{
1040        patch->is_copy = 1;
1041        free(patch->new_name);
1042        patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1043        return 0;
1044}
1045
1046static int gitdiff_renamesrc(struct apply_state *state,
1047                             const char *line,
1048                             struct patch *patch)
1049{
1050        patch->is_rename = 1;
1051        free(patch->old_name);
1052        patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1053        return 0;
1054}
1055
1056static int gitdiff_renamedst(struct apply_state *state,
1057                             const char *line,
1058                             struct patch *patch)
1059{
1060        patch->is_rename = 1;
1061        free(patch->new_name);
1062        patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
1063        return 0;
1064}
1065
1066static int gitdiff_similarity(struct apply_state *state,
1067                              const char *line,
1068                              struct patch *patch)
1069{
1070        unsigned long val = strtoul(line, NULL, 10);
1071        if (val <= 100)
1072                patch->score = val;
1073        return 0;
1074}
1075
1076static int gitdiff_dissimilarity(struct apply_state *state,
1077                                 const char *line,
1078                                 struct patch *patch)
1079{
1080        unsigned long val = strtoul(line, NULL, 10);
1081        if (val <= 100)
1082                patch->score = val;
1083        return 0;
1084}
1085
1086static int gitdiff_index(struct apply_state *state,
1087                         const char *line,
1088                         struct patch *patch)
1089{
1090        /*
1091         * index line is N hexadecimal, "..", N hexadecimal,
1092         * and optional space with octal mode.
1093         */
1094        const char *ptr, *eol;
1095        int len;
1096        const unsigned hexsz = the_hash_algo->hexsz;
1097
1098        ptr = strchr(line, '.');
1099        if (!ptr || ptr[1] != '.' || hexsz < ptr - line)
1100                return 0;
1101        len = ptr - line;
1102        memcpy(patch->old_sha1_prefix, line, len);
1103        patch->old_sha1_prefix[len] = 0;
1104
1105        line = ptr + 2;
1106        ptr = strchr(line, ' ');
1107        eol = strchrnul(line, '\n');
1108
1109        if (!ptr || eol < ptr)
1110                ptr = eol;
1111        len = ptr - line;
1112
1113        if (hexsz < len)
1114                return 0;
1115        memcpy(patch->new_sha1_prefix, line, len);
1116        patch->new_sha1_prefix[len] = 0;
1117        if (*ptr == ' ')
1118                return gitdiff_oldmode(state, ptr + 1, patch);
1119        return 0;
1120}
1121
1122/*
1123 * This is normal for a diff that doesn't change anything: we'll fall through
1124 * into the next diff. Tell the parser to break out.
1125 */
1126static int gitdiff_unrecognized(struct apply_state *state,
1127                                const char *line,
1128                                struct patch *patch)
1129{
1130        return 1;
1131}
1132
1133/*
1134 * Skip p_value leading components from "line"; as we do not accept
1135 * absolute paths, return NULL in that case.
1136 */
1137static const char *skip_tree_prefix(struct apply_state *state,
1138                                    const char *line,
1139                                    int llen)
1140{
1141        int nslash;
1142        int i;
1143
1144        if (!state->p_value)
1145                return (llen && line[0] == '/') ? NULL : line;
1146
1147        nslash = state->p_value;
1148        for (i = 0; i < llen; i++) {
1149                int ch = line[i];
1150                if (ch == '/' && --nslash <= 0)
1151                        return (i == 0) ? NULL : &line[i + 1];
1152        }
1153        return NULL;
1154}
1155
1156/*
1157 * This is to extract the same name that appears on "diff --git"
1158 * line.  We do not find and return anything if it is a rename
1159 * patch, and it is OK because we will find the name elsewhere.
1160 * We need to reliably find name only when it is mode-change only,
1161 * creation or deletion of an empty file.  In any of these cases,
1162 * both sides are the same name under a/ and b/ respectively.
1163 */
1164static char *git_header_name(struct apply_state *state,
1165                             const char *line,
1166                             int llen)
1167{
1168        const char *name;
1169        const char *second = NULL;
1170        size_t len, line_len;
1171
1172        line += strlen("diff --git ");
1173        llen -= strlen("diff --git ");
1174
1175        if (*line == '"') {
1176                const char *cp;
1177                struct strbuf first = STRBUF_INIT;
1178                struct strbuf sp = STRBUF_INIT;
1179
1180                if (unquote_c_style(&first, line, &second))
1181                        goto free_and_fail1;
1182
1183                /* strip the a/b prefix including trailing slash */
1184                cp = skip_tree_prefix(state, first.buf, first.len);
1185                if (!cp)
1186                        goto free_and_fail1;
1187                strbuf_remove(&first, 0, cp - first.buf);
1188
1189                /*
1190                 * second points at one past closing dq of name.
1191                 * find the second name.
1192                 */
1193                while ((second < line + llen) && isspace(*second))
1194                        second++;
1195
1196                if (line + llen <= second)
1197                        goto free_and_fail1;
1198                if (*second == '"') {
1199                        if (unquote_c_style(&sp, second, NULL))
1200                                goto free_and_fail1;
1201                        cp = skip_tree_prefix(state, sp.buf, sp.len);
1202                        if (!cp)
1203                                goto free_and_fail1;
1204                        /* They must match, otherwise ignore */
1205                        if (strcmp(cp, first.buf))
1206                                goto free_and_fail1;
1207                        strbuf_release(&sp);
1208                        return strbuf_detach(&first, NULL);
1209                }
1210
1211                /* unquoted second */
1212                cp = skip_tree_prefix(state, second, line + llen - second);
1213                if (!cp)
1214                        goto free_and_fail1;
1215                if (line + llen - cp != first.len ||
1216                    memcmp(first.buf, cp, first.len))
1217                        goto free_and_fail1;
1218                return strbuf_detach(&first, NULL);
1219
1220        free_and_fail1:
1221                strbuf_release(&first);
1222                strbuf_release(&sp);
1223                return NULL;
1224        }
1225
1226        /* unquoted first name */
1227        name = skip_tree_prefix(state, line, llen);
1228        if (!name)
1229                return NULL;
1230
1231        /*
1232         * since the first name is unquoted, a dq if exists must be
1233         * the beginning of the second name.
1234         */
1235        for (second = name; second < line + llen; second++) {
1236                if (*second == '"') {
1237                        struct strbuf sp = STRBUF_INIT;
1238                        const char *np;
1239
1240                        if (unquote_c_style(&sp, second, NULL))
1241                                goto free_and_fail2;
1242
1243                        np = skip_tree_prefix(state, sp.buf, sp.len);
1244                        if (!np)
1245                                goto free_and_fail2;
1246
1247                        len = sp.buf + sp.len - np;
1248                        if (len < second - name &&
1249                            !strncmp(np, name, len) &&
1250                            isspace(name[len])) {
1251                                /* Good */
1252                                strbuf_remove(&sp, 0, np - sp.buf);
1253                                return strbuf_detach(&sp, NULL);
1254                        }
1255
1256                free_and_fail2:
1257                        strbuf_release(&sp);
1258                        return NULL;
1259                }
1260        }
1261
1262        /*
1263         * Accept a name only if it shows up twice, exactly the same
1264         * form.
1265         */
1266        second = strchr(name, '\n');
1267        if (!second)
1268                return NULL;
1269        line_len = second - name;
1270        for (len = 0 ; ; len++) {
1271                switch (name[len]) {
1272                default:
1273                        continue;
1274                case '\n':
1275                        return NULL;
1276                case '\t': case ' ':
1277                        /*
1278                         * Is this the separator between the preimage
1279                         * and the postimage pathname?  Again, we are
1280                         * only interested in the case where there is
1281                         * no rename, as this is only to set def_name
1282                         * and a rename patch has the names elsewhere
1283                         * in an unambiguous form.
1284                         */
1285                        if (!name[len + 1])
1286                                return NULL; /* no postimage name */
1287                        second = skip_tree_prefix(state, name + len + 1,
1288                                                  line_len - (len + 1));
1289                        if (!second)
1290                                return NULL;
1291                        /*
1292                         * Does len bytes starting at "name" and "second"
1293                         * (that are separated by one HT or SP we just
1294                         * found) exactly match?
1295                         */
1296                        if (second[len] == '\n' && !strncmp(name, second, len))
1297                                return xmemdupz(name, len);
1298                }
1299        }
1300}
1301
1302static int check_header_line(struct apply_state *state, struct patch *patch)
1303{
1304        int extensions = (patch->is_delete == 1) + (patch->is_new == 1) +
1305                         (patch->is_rename == 1) + (patch->is_copy == 1);
1306        if (extensions > 1)
1307                return error(_("inconsistent header lines %d and %d"),
1308                             patch->extension_linenr, state->linenr);
1309        if (extensions && !patch->extension_linenr)
1310                patch->extension_linenr = state->linenr;
1311        return 0;
1312}
1313
1314/* Verify that we recognize the lines following a git header */
1315static int parse_git_header(struct apply_state *state,
1316                            const char *line,
1317                            int len,
1318                            unsigned int size,
1319                            struct patch *patch)
1320{
1321        unsigned long offset;
1322
1323        /* A git diff has explicit new/delete information, so we don't guess */
1324        patch->is_new = 0;
1325        patch->is_delete = 0;
1326
1327        /*
1328         * Some things may not have the old name in the
1329         * rest of the headers anywhere (pure mode changes,
1330         * or removing or adding empty files), so we get
1331         * the default name from the header.
1332         */
1333        patch->def_name = git_header_name(state, line, len);
1334        if (patch->def_name && state->root.len) {
1335                char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
1336                free(patch->def_name);
1337                patch->def_name = s;
1338        }
1339
1340        line += len;
1341        size -= len;
1342        state->linenr++;
1343        for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
1344                static const struct opentry {
1345                        const char *str;
1346                        int (*fn)(struct apply_state *, const char *, struct patch *);
1347                } optable[] = {
1348                        { "@@ -", gitdiff_hdrend },
1349                        { "--- ", gitdiff_oldname },
1350                        { "+++ ", gitdiff_newname },
1351                        { "old mode ", gitdiff_oldmode },
1352                        { "new mode ", gitdiff_newmode },
1353                        { "deleted file mode ", gitdiff_delete },
1354                        { "new file mode ", gitdiff_newfile },
1355                        { "copy from ", gitdiff_copysrc },
1356                        { "copy to ", gitdiff_copydst },
1357                        { "rename old ", gitdiff_renamesrc },
1358                        { "rename new ", gitdiff_renamedst },
1359                        { "rename from ", gitdiff_renamesrc },
1360                        { "rename to ", gitdiff_renamedst },
1361                        { "similarity index ", gitdiff_similarity },
1362                        { "dissimilarity index ", gitdiff_dissimilarity },
1363                        { "index ", gitdiff_index },
1364                        { "", gitdiff_unrecognized },
1365                };
1366                int i;
1367
1368                len = linelen(line, size);
1369                if (!len || line[len-1] != '\n')
1370                        break;
1371                for (i = 0; i < ARRAY_SIZE(optable); i++) {
1372                        const struct opentry *p = optable + i;
1373                        int oplen = strlen(p->str);
1374                        int res;
1375                        if (len < oplen || memcmp(p->str, line, oplen))
1376                                continue;
1377                        res = p->fn(state, line + oplen, patch);
1378                        if (res < 0)
1379                                return -1;
1380                        if (check_header_line(state, patch))
1381                                return -1;
1382                        if (res > 0)
1383                                return offset;
1384                        break;
1385                }
1386        }
1387
1388        return offset;
1389}
1390
1391static int parse_num(const char *line, unsigned long *p)
1392{
1393        char *ptr;
1394
1395        if (!isdigit(*line))
1396                return 0;
1397        *p = strtoul(line, &ptr, 10);
1398        return ptr - line;
1399}
1400
1401static int parse_range(const char *line, int len, int offset, const char *expect,
1402                       unsigned long *p1, unsigned long *p2)
1403{
1404        int digits, ex;
1405
1406        if (offset < 0 || offset >= len)
1407                return -1;
1408        line += offset;
1409        len -= offset;
1410
1411        digits = parse_num(line, p1);
1412        if (!digits)
1413                return -1;
1414
1415        offset += digits;
1416        line += digits;
1417        len -= digits;
1418
1419        *p2 = 1;
1420        if (*line == ',') {
1421                digits = parse_num(line+1, p2);
1422                if (!digits)
1423                        return -1;
1424
1425                offset += digits+1;
1426                line += digits+1;
1427                len -= digits+1;
1428        }
1429
1430        ex = strlen(expect);
1431        if (ex > len)
1432                return -1;
1433        if (memcmp(line, expect, ex))
1434                return -1;
1435
1436        return offset + ex;
1437}
1438
1439static void recount_diff(const char *line, int size, struct fragment *fragment)
1440{
1441        int oldlines = 0, newlines = 0, ret = 0;
1442
1443        if (size < 1) {
1444                warning("recount: ignore empty hunk");
1445                return;
1446        }
1447
1448        for (;;) {
1449                int len = linelen(line, size);
1450                size -= len;
1451                line += len;
1452
1453                if (size < 1)
1454                        break;
1455
1456                switch (*line) {
1457                case ' ': case '\n':
1458                        newlines++;
1459                        /* fall through */
1460                case '-':
1461                        oldlines++;
1462                        continue;
1463                case '+':
1464                        newlines++;
1465                        continue;
1466                case '\\':
1467                        continue;
1468                case '@':
1469                        ret = size < 3 || !starts_with(line, "@@ ");
1470                        break;
1471                case 'd':
1472                        ret = size < 5 || !starts_with(line, "diff ");
1473                        break;
1474                default:
1475                        ret = -1;
1476                        break;
1477                }
1478                if (ret) {
1479                        warning(_("recount: unexpected line: %.*s"),
1480                                (int)linelen(line, size), line);
1481                        return;
1482                }
1483                break;
1484        }
1485        fragment->oldlines = oldlines;
1486        fragment->newlines = newlines;
1487}
1488
1489/*
1490 * Parse a unified diff fragment header of the
1491 * form "@@ -a,b +c,d @@"
1492 */
1493static int parse_fragment_header(const char *line, int len, struct fragment *fragment)
1494{
1495        int offset;
1496
1497        if (!len || line[len-1] != '\n')
1498                return -1;
1499
1500        /* Figure out the number of lines in a fragment */
1501        offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
1502        offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
1503
1504        return offset;
1505}
1506
1507/*
1508 * Find file diff header
1509 *
1510 * Returns:
1511 *  -1 if no header was found
1512 *  -128 in case of error
1513 *   the size of the header in bytes (called "offset") otherwise
1514 */
1515static int find_header(struct apply_state *state,
1516                       const char *line,
1517                       unsigned long size,
1518                       int *hdrsize,
1519                       struct patch *patch)
1520{
1521        unsigned long offset, len;
1522
1523        patch->is_toplevel_relative = 0;
1524        patch->is_rename = patch->is_copy = 0;
1525        patch->is_new = patch->is_delete = -1;
1526        patch->old_mode = patch->new_mode = 0;
1527        patch->old_name = patch->new_name = NULL;
1528        for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
1529                unsigned long nextlen;
1530
1531                len = linelen(line, size);
1532                if (!len)
1533                        break;
1534
1535                /* Testing this early allows us to take a few shortcuts.. */
1536                if (len < 6)
1537                        continue;
1538
1539                /*
1540                 * Make sure we don't find any unconnected patch fragments.
1541                 * That's a sign that we didn't find a header, and that a
1542                 * patch has become corrupted/broken up.
1543                 */
1544                if (!memcmp("@@ -", line, 4)) {
1545                        struct fragment dummy;
1546                        if (parse_fragment_header(line, len, &dummy) < 0)
1547                                continue;
1548                        error(_("patch fragment without header at line %d: %.*s"),
1549                                     state->linenr, (int)len-1, line);
1550                        return -128;
1551                }
1552
1553                if (size < len + 6)
1554                        break;
1555
1556                /*
1557                 * Git patch? It might not have a real patch, just a rename
1558                 * or mode change, so we handle that specially
1559                 */
1560                if (!memcmp("diff --git ", line, 11)) {
1561                        int git_hdr_len = parse_git_header(state, line, len, size, patch);
1562                        if (git_hdr_len < 0)
1563                                return -128;
1564                        if (git_hdr_len <= len)
1565                                continue;
1566                        if (!patch->old_name && !patch->new_name) {
1567                                if (!patch->def_name) {
1568                                        error(Q_("git diff header lacks filename information when removing "
1569                                                        "%d leading pathname component (line %d)",
1570                                                        "git diff header lacks filename information when removing "
1571                                                        "%d leading pathname components (line %d)",
1572                                                        state->p_value),
1573                                                     state->p_value, state->linenr);
1574                                        return -128;
1575                                }
1576                                patch->old_name = xstrdup(patch->def_name);
1577                                patch->new_name = xstrdup(patch->def_name);
1578                        }
1579                        if ((!patch->new_name && !patch->is_delete) ||
1580                            (!patch->old_name && !patch->is_new)) {
1581                                error(_("git diff header lacks filename information "
1582                                             "(line %d)"), state->linenr);
1583                                return -128;
1584                        }
1585                        patch->is_toplevel_relative = 1;
1586                        *hdrsize = git_hdr_len;
1587                        return offset;
1588                }
1589
1590                /* --- followed by +++ ? */
1591                if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
1592                        continue;
1593
1594                /*
1595                 * We only accept unified patches, so we want it to
1596                 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
1597                 * minimum ("@@ -0,0 +1 @@\n" is the shortest).
1598                 */
1599                nextlen = linelen(line + len, size - len);
1600                if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
1601                        continue;
1602
1603                /* Ok, we'll consider it a patch */
1604                if (parse_traditional_patch(state, line, line+len, patch))
1605                        return -128;
1606                *hdrsize = len + nextlen;
1607                state->linenr += 2;
1608                return offset;
1609        }
1610        return -1;
1611}
1612
1613static void record_ws_error(struct apply_state *state,
1614                            unsigned result,
1615                            const char *line,
1616                            int len,
1617                            int linenr)
1618{
1619        char *err;
1620
1621        if (!result)
1622                return;
1623
1624        state->whitespace_error++;
1625        if (state->squelch_whitespace_errors &&
1626            state->squelch_whitespace_errors < state->whitespace_error)
1627                return;
1628
1629        err = whitespace_error_string(result);
1630        if (state->apply_verbosity > verbosity_silent)
1631                fprintf(stderr, "%s:%d: %s.\n%.*s\n",
1632                        state->patch_input_file, linenr, err, len, line);
1633        free(err);
1634}
1635
1636static void check_whitespace(struct apply_state *state,
1637                             const char *line,
1638                             int len,
1639                             unsigned ws_rule)
1640{
1641        unsigned result = ws_check(line + 1, len - 1, ws_rule);
1642
1643        record_ws_error(state, result, line + 1, len - 2, state->linenr);
1644}
1645
1646/*
1647 * Check if the patch has context lines with CRLF or
1648 * the patch wants to remove lines with CRLF.
1649 */
1650static void check_old_for_crlf(struct patch *patch, const char *line, int len)
1651{
1652        if (len >= 2 && line[len-1] == '\n' && line[len-2] == '\r') {
1653                patch->ws_rule |= WS_CR_AT_EOL;
1654                patch->crlf_in_old = 1;
1655        }
1656}
1657
1658
1659/*
1660 * Parse a unified diff. Note that this really needs to parse each
1661 * fragment separately, since the only way to know the difference
1662 * between a "---" that is part of a patch, and a "---" that starts
1663 * the next patch is to look at the line counts..
1664 */
1665static int parse_fragment(struct apply_state *state,
1666                          const char *line,
1667                          unsigned long size,
1668                          struct patch *patch,
1669                          struct fragment *fragment)
1670{
1671        int added, deleted;
1672        int len = linelen(line, size), offset;
1673        unsigned long oldlines, newlines;
1674        unsigned long leading, trailing;
1675
1676        offset = parse_fragment_header(line, len, fragment);
1677        if (offset < 0)
1678                return -1;
1679        if (offset > 0 && patch->recount)
1680                recount_diff(line + offset, size - offset, fragment);
1681        oldlines = fragment->oldlines;
1682        newlines = fragment->newlines;
1683        leading = 0;
1684        trailing = 0;
1685
1686        /* Parse the thing.. */
1687        line += len;
1688        size -= len;
1689        state->linenr++;
1690        added = deleted = 0;
1691        for (offset = len;
1692             0 < size;
1693             offset += len, size -= len, line += len, state->linenr++) {
1694                if (!oldlines && !newlines)
1695                        break;
1696                len = linelen(line, size);
1697                if (!len || line[len-1] != '\n')
1698                        return -1;
1699                switch (*line) {
1700                default:
1701                        return -1;
1702                case '\n': /* newer GNU diff, an empty context line */
1703                case ' ':
1704                        oldlines--;
1705                        newlines--;
1706                        if (!deleted && !added)
1707                                leading++;
1708                        trailing++;
1709                        check_old_for_crlf(patch, line, len);
1710                        if (!state->apply_in_reverse &&
1711                            state->ws_error_action == correct_ws_error)
1712                                check_whitespace(state, line, len, patch->ws_rule);
1713                        break;
1714                case '-':
1715                        if (!state->apply_in_reverse)
1716                                check_old_for_crlf(patch, line, len);
1717                        if (state->apply_in_reverse &&
1718                            state->ws_error_action != nowarn_ws_error)
1719                                check_whitespace(state, line, len, patch->ws_rule);
1720                        deleted++;
1721                        oldlines--;
1722                        trailing = 0;
1723                        break;
1724                case '+':
1725                        if (state->apply_in_reverse)
1726                                check_old_for_crlf(patch, line, len);
1727                        if (!state->apply_in_reverse &&
1728                            state->ws_error_action != nowarn_ws_error)
1729                                check_whitespace(state, line, len, patch->ws_rule);
1730                        added++;
1731                        newlines--;
1732                        trailing = 0;
1733                        break;
1734
1735                /*
1736                 * We allow "\ No newline at end of file". Depending
1737                 * on locale settings when the patch was produced we
1738                 * don't know what this line looks like. The only
1739                 * thing we do know is that it begins with "\ ".
1740                 * Checking for 12 is just for sanity check -- any
1741                 * l10n of "\ No newline..." is at least that long.
1742                 */
1743                case '\\':
1744                        if (len < 12 || memcmp(line, "\\ ", 2))
1745                                return -1;
1746                        break;
1747                }
1748        }
1749        if (oldlines || newlines)
1750                return -1;
1751        if (!deleted && !added)
1752                return -1;
1753
1754        fragment->leading = leading;
1755        fragment->trailing = trailing;
1756
1757        /*
1758         * If a fragment ends with an incomplete line, we failed to include
1759         * it in the above loop because we hit oldlines == newlines == 0
1760         * before seeing it.
1761         */
1762        if (12 < size && !memcmp(line, "\\ ", 2))
1763                offset += linelen(line, size);
1764
1765        patch->lines_added += added;
1766        patch->lines_deleted += deleted;
1767
1768        if (0 < patch->is_new && oldlines)
1769                return error(_("new file depends on old contents"));
1770        if (0 < patch->is_delete && newlines)
1771                return error(_("deleted file still has contents"));
1772        return offset;
1773}
1774
1775/*
1776 * We have seen "diff --git a/... b/..." header (or a traditional patch
1777 * header).  Read hunks that belong to this patch into fragments and hang
1778 * them to the given patch structure.
1779 *
1780 * The (fragment->patch, fragment->size) pair points into the memory given
1781 * by the caller, not a copy, when we return.
1782 *
1783 * Returns:
1784 *   -1 in case of error,
1785 *   the number of bytes in the patch otherwise.
1786 */
1787static int parse_single_patch(struct apply_state *state,
1788                              const char *line,
1789                              unsigned long size,
1790                              struct patch *patch)
1791{
1792        unsigned long offset = 0;
1793        unsigned long oldlines = 0, newlines = 0, context = 0;
1794        struct fragment **fragp = &patch->fragments;
1795
1796        while (size > 4 && !memcmp(line, "@@ -", 4)) {
1797                struct fragment *fragment;
1798                int len;
1799
1800                fragment = xcalloc(1, sizeof(*fragment));
1801                fragment->linenr = state->linenr;
1802                len = parse_fragment(state, line, size, patch, fragment);
1803                if (len <= 0) {
1804                        free(fragment);
1805                        return error(_("corrupt patch at line %d"), state->linenr);
1806                }
1807                fragment->patch = line;
1808                fragment->size = len;
1809                oldlines += fragment->oldlines;
1810                newlines += fragment->newlines;
1811                context += fragment->leading + fragment->trailing;
1812
1813                *fragp = fragment;
1814                fragp = &fragment->next;
1815
1816                offset += len;
1817                line += len;
1818                size -= len;
1819        }
1820
1821        /*
1822         * If something was removed (i.e. we have old-lines) it cannot
1823         * be creation, and if something was added it cannot be
1824         * deletion.  However, the reverse is not true; --unified=0
1825         * patches that only add are not necessarily creation even
1826         * though they do not have any old lines, and ones that only
1827         * delete are not necessarily deletion.
1828         *
1829         * Unfortunately, a real creation/deletion patch do _not_ have
1830         * any context line by definition, so we cannot safely tell it
1831         * apart with --unified=0 insanity.  At least if the patch has
1832         * more than one hunk it is not creation or deletion.
1833         */
1834        if (patch->is_new < 0 &&
1835            (oldlines || (patch->fragments && patch->fragments->next)))
1836                patch->is_new = 0;
1837        if (patch->is_delete < 0 &&
1838            (newlines || (patch->fragments && patch->fragments->next)))
1839                patch->is_delete = 0;
1840
1841        if (0 < patch->is_new && oldlines)
1842                return error(_("new file %s depends on old contents"), patch->new_name);
1843        if (0 < patch->is_delete && newlines)
1844                return error(_("deleted file %s still has contents"), patch->old_name);
1845        if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
1846                fprintf_ln(stderr,
1847                           _("** warning: "
1848                             "file %s becomes empty but is not deleted"),
1849                           patch->new_name);
1850
1851        return offset;
1852}
1853
1854static inline int metadata_changes(struct patch *patch)
1855{
1856        return  patch->is_rename > 0 ||
1857                patch->is_copy > 0 ||
1858                patch->is_new > 0 ||
1859                patch->is_delete ||
1860                (patch->old_mode && patch->new_mode &&
1861                 patch->old_mode != patch->new_mode);
1862}
1863
1864static char *inflate_it(const void *data, unsigned long size,
1865                        unsigned long inflated_size)
1866{
1867        git_zstream stream;
1868        void *out;
1869        int st;
1870
1871        memset(&stream, 0, sizeof(stream));
1872
1873        stream.next_in = (unsigned char *)data;
1874        stream.avail_in = size;
1875        stream.next_out = out = xmalloc(inflated_size);
1876        stream.avail_out = inflated_size;
1877        git_inflate_init(&stream);
1878        st = git_inflate(&stream, Z_FINISH);
1879        git_inflate_end(&stream);
1880        if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1881                free(out);
1882                return NULL;
1883        }
1884        return out;
1885}
1886
1887/*
1888 * Read a binary hunk and return a new fragment; fragment->patch
1889 * points at an allocated memory that the caller must free, so
1890 * it is marked as "->free_patch = 1".
1891 */
1892static struct fragment *parse_binary_hunk(struct apply_state *state,
1893                                          char **buf_p,
1894                                          unsigned long *sz_p,
1895                                          int *status_p,
1896                                          int *used_p)
1897{
1898        /*
1899         * Expect a line that begins with binary patch method ("literal"
1900         * or "delta"), followed by the length of data before deflating.
1901         * a sequence of 'length-byte' followed by base-85 encoded data
1902         * should follow, terminated by a newline.
1903         *
1904         * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1905         * and we would limit the patch line to 66 characters,
1906         * so one line can fit up to 13 groups that would decode
1907         * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1908         * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1909         */
1910        int llen, used;
1911        unsigned long size = *sz_p;
1912        char *buffer = *buf_p;
1913        int patch_method;
1914        unsigned long origlen;
1915        char *data = NULL;
1916        int hunk_size = 0;
1917        struct fragment *frag;
1918
1919        llen = linelen(buffer, size);
1920        used = llen;
1921
1922        *status_p = 0;
1923
1924        if (starts_with(buffer, "delta ")) {
1925                patch_method = BINARY_DELTA_DEFLATED;
1926                origlen = strtoul(buffer + 6, NULL, 10);
1927        }
1928        else if (starts_with(buffer, "literal ")) {
1929                patch_method = BINARY_LITERAL_DEFLATED;
1930                origlen = strtoul(buffer + 8, NULL, 10);
1931        }
1932        else
1933                return NULL;
1934
1935        state->linenr++;
1936        buffer += llen;
1937        while (1) {
1938                int byte_length, max_byte_length, newsize;
1939                llen = linelen(buffer, size);
1940                used += llen;
1941                state->linenr++;
1942                if (llen == 1) {
1943                        /* consume the blank line */
1944                        buffer++;
1945                        size--;
1946                        break;
1947                }
1948                /*
1949                 * Minimum line is "A00000\n" which is 7-byte long,
1950                 * and the line length must be multiple of 5 plus 2.
1951                 */
1952                if ((llen < 7) || (llen-2) % 5)
1953                        goto corrupt;
1954                max_byte_length = (llen - 2) / 5 * 4;
1955                byte_length = *buffer;
1956                if ('A' <= byte_length && byte_length <= 'Z')
1957                        byte_length = byte_length - 'A' + 1;
1958                else if ('a' <= byte_length && byte_length <= 'z')
1959                        byte_length = byte_length - 'a' + 27;
1960                else
1961                        goto corrupt;
1962                /* if the input length was not multiple of 4, we would
1963                 * have filler at the end but the filler should never
1964                 * exceed 3 bytes
1965                 */
1966                if (max_byte_length < byte_length ||
1967                    byte_length <= max_byte_length - 4)
1968                        goto corrupt;
1969                newsize = hunk_size + byte_length;
1970                data = xrealloc(data, newsize);
1971                if (decode_85(data + hunk_size, buffer + 1, byte_length))
1972                        goto corrupt;
1973                hunk_size = newsize;
1974                buffer += llen;
1975                size -= llen;
1976        }
1977
1978        frag = xcalloc(1, sizeof(*frag));
1979        frag->patch = inflate_it(data, hunk_size, origlen);
1980        frag->free_patch = 1;
1981        if (!frag->patch)
1982                goto corrupt;
1983        free(data);
1984        frag->size = origlen;
1985        *buf_p = buffer;
1986        *sz_p = size;
1987        *used_p = used;
1988        frag->binary_patch_method = patch_method;
1989        return frag;
1990
1991 corrupt:
1992        free(data);
1993        *status_p = -1;
1994        error(_("corrupt binary patch at line %d: %.*s"),
1995              state->linenr-1, llen-1, buffer);
1996        return NULL;
1997}
1998
1999/*
2000 * Returns:
2001 *   -1 in case of error,
2002 *   the length of the parsed binary patch otherwise
2003 */
2004static int parse_binary(struct apply_state *state,
2005                        char *buffer,
2006                        unsigned long size,
2007                        struct patch *patch)
2008{
2009        /*
2010         * We have read "GIT binary patch\n"; what follows is a line
2011         * that says the patch method (currently, either "literal" or
2012         * "delta") and the length of data before deflating; a
2013         * sequence of 'length-byte' followed by base-85 encoded data
2014         * follows.
2015         *
2016         * When a binary patch is reversible, there is another binary
2017         * hunk in the same format, starting with patch method (either
2018         * "literal" or "delta") with the length of data, and a sequence
2019         * of length-byte + base-85 encoded data, terminated with another
2020         * empty line.  This data, when applied to the postimage, produces
2021         * the preimage.
2022         */
2023        struct fragment *forward;
2024        struct fragment *reverse;
2025        int status;
2026        int used, used_1;
2027
2028        forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
2029        if (!forward && !status)
2030                /* there has to be one hunk (forward hunk) */
2031                return error(_("unrecognized binary patch at line %d"), state->linenr-1);
2032        if (status)
2033                /* otherwise we already gave an error message */
2034                return status;
2035
2036        reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
2037        if (reverse)
2038                used += used_1;
2039        else if (status) {
2040                /*
2041                 * Not having reverse hunk is not an error, but having
2042                 * a corrupt reverse hunk is.
2043                 */
2044                free((void*) forward->patch);
2045                free(forward);
2046                return status;
2047        }
2048        forward->next = reverse;
2049        patch->fragments = forward;
2050        patch->is_binary = 1;
2051        return used;
2052}
2053
2054static void prefix_one(struct apply_state *state, char **name)
2055{
2056        char *old_name = *name;
2057        if (!old_name)
2058                return;
2059        *name = prefix_filename(state->prefix, *name);
2060        free(old_name);
2061}
2062
2063static void prefix_patch(struct apply_state *state, struct patch *p)
2064{
2065        if (!state->prefix || p->is_toplevel_relative)
2066                return;
2067        prefix_one(state, &p->new_name);
2068        prefix_one(state, &p->old_name);
2069}
2070
2071/*
2072 * include/exclude
2073 */
2074
2075static void add_name_limit(struct apply_state *state,
2076                           const char *name,
2077                           int exclude)
2078{
2079        struct string_list_item *it;
2080
2081        it = string_list_append(&state->limit_by_name, name);
2082        it->util = exclude ? NULL : (void *) 1;
2083}
2084
2085static int use_patch(struct apply_state *state, struct patch *p)
2086{
2087        const char *pathname = p->new_name ? p->new_name : p->old_name;
2088        int i;
2089
2090        /* Paths outside are not touched regardless of "--include" */
2091        if (state->prefix && *state->prefix) {
2092                const char *rest;
2093                if (!skip_prefix(pathname, state->prefix, &rest) || !*rest)
2094                        return 0;
2095        }
2096
2097        /* See if it matches any of exclude/include rule */
2098        for (i = 0; i < state->limit_by_name.nr; i++) {
2099                struct string_list_item *it = &state->limit_by_name.items[i];
2100                if (!wildmatch(it->string, pathname, 0))
2101                        return (it->util != NULL);
2102        }
2103
2104        /*
2105         * If we had any include, a path that does not match any rule is
2106         * not used.  Otherwise, we saw bunch of exclude rules (or none)
2107         * and such a path is used.
2108         */
2109        return !state->has_include;
2110}
2111
2112/*
2113 * Read the patch text in "buffer" that extends for "size" bytes; stop
2114 * reading after seeing a single patch (i.e. changes to a single file).
2115 * Create fragments (i.e. patch hunks) and hang them to the given patch.
2116 *
2117 * Returns:
2118 *   -1 if no header was found or parse_binary() failed,
2119 *   -128 on another error,
2120 *   the number of bytes consumed otherwise,
2121 *     so that the caller can call us again for the next patch.
2122 */
2123static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
2124{
2125        int hdrsize, patchsize;
2126        int offset = find_header(state, buffer, size, &hdrsize, patch);
2127
2128        if (offset < 0)
2129                return offset;
2130
2131        prefix_patch(state, patch);
2132
2133        if (!use_patch(state, patch))
2134                patch->ws_rule = 0;
2135        else
2136                patch->ws_rule = whitespace_rule(patch->new_name
2137                                                 ? patch->new_name
2138                                                 : patch->old_name);
2139
2140        patchsize = parse_single_patch(state,
2141                                       buffer + offset + hdrsize,
2142                                       size - offset - hdrsize,
2143                                       patch);
2144
2145        if (patchsize < 0)
2146                return -128;
2147
2148        if (!patchsize) {
2149                static const char git_binary[] = "GIT binary patch\n";
2150                int hd = hdrsize + offset;
2151                unsigned long llen = linelen(buffer + hd, size - hd);
2152
2153                if (llen == sizeof(git_binary) - 1 &&
2154                    !memcmp(git_binary, buffer + hd, llen)) {
2155                        int used;
2156                        state->linenr++;
2157                        used = parse_binary(state, buffer + hd + llen,
2158                                            size - hd - llen, patch);
2159                        if (used < 0)
2160                                return -1;
2161                        if (used)
2162                                patchsize = used + llen;
2163                        else
2164                                patchsize = 0;
2165                }
2166                else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
2167                        static const char *binhdr[] = {
2168                                "Binary files ",
2169                                "Files ",
2170                                NULL,
2171                        };
2172                        int i;
2173                        for (i = 0; binhdr[i]; i++) {
2174                                int len = strlen(binhdr[i]);
2175                                if (len < size - hd &&
2176                                    !memcmp(binhdr[i], buffer + hd, len)) {
2177                                        state->linenr++;
2178                                        patch->is_binary = 1;
2179                                        patchsize = llen;
2180                                        break;
2181                                }
2182                        }
2183                }
2184
2185                /* Empty patch cannot be applied if it is a text patch
2186                 * without metadata change.  A binary patch appears
2187                 * empty to us here.
2188                 */
2189                if ((state->apply || state->check) &&
2190                    (!patch->is_binary && !metadata_changes(patch))) {
2191                        error(_("patch with only garbage at line %d"), state->linenr);
2192                        return -128;
2193                }
2194        }
2195
2196        return offset + hdrsize + patchsize;
2197}
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, struct patch *patch,
2270                         const char *path, struct strbuf *buf)
2271{
2272        int conv_flags = patch->crlf_in_old ?
2273                CONV_EOL_KEEP_CRLF : CONV_EOL_RENORMALIZE;
2274        switch (st->st_mode & S_IFMT) {
2275        case S_IFLNK:
2276                if (strbuf_readlink(buf, path, st->st_size) < 0)
2277                        return error(_("unable to read symlink %s"), path);
2278                return 0;
2279        case S_IFREG:
2280                if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
2281                        return error(_("unable to open or read %s"), path);
2282                /*
2283                 * "git apply" without "--index/--cached" should never look
2284                 * at the index; the target file may not have been added to
2285                 * the index yet, and we may not even be in any Git repository.
2286                 * Pass NULL to convert_to_git() to stress this; the function
2287                 * should never look at the index when explicit crlf option
2288                 * is given.
2289                 */
2290                convert_to_git(NULL, path, buf->buf, buf->len, buf, conv_flags);
2291                return 0;
2292        default:
2293                return -1;
2294        }
2295}
2296
2297/*
2298 * Update the preimage, and the common lines in postimage,
2299 * from buffer buf of length len. If postlen is 0 the postimage
2300 * is updated in place, otherwise it's updated on a new buffer
2301 * of length postlen
2302 */
2303
2304static void update_pre_post_images(struct image *preimage,
2305                                   struct image *postimage,
2306                                   char *buf,
2307                                   size_t len, size_t postlen)
2308{
2309        int i, ctx, reduced;
2310        char *new_buf, *old_buf, *fixed;
2311        struct image fixed_preimage;
2312
2313        /*
2314         * Update the preimage with whitespace fixes.  Note that we
2315         * are not losing preimage->buf -- apply_one_fragment() will
2316         * free "oldlines".
2317         */
2318        prepare_image(&fixed_preimage, buf, len, 1);
2319        assert(postlen
2320               ? fixed_preimage.nr == preimage->nr
2321               : fixed_preimage.nr <= preimage->nr);
2322        for (i = 0; i < fixed_preimage.nr; i++)
2323                fixed_preimage.line[i].flag = preimage->line[i].flag;
2324        free(preimage->line_allocated);
2325        *preimage = fixed_preimage;
2326
2327        /*
2328         * Adjust the common context lines in postimage. This can be
2329         * done in-place when we are shrinking it with whitespace
2330         * fixing, but needs a new buffer when ignoring whitespace or
2331         * expanding leading tabs to spaces.
2332         *
2333         * We trust the caller to tell us if the update can be done
2334         * in place (postlen==0) or not.
2335         */
2336        old_buf = postimage->buf;
2337        if (postlen)
2338                new_buf = postimage->buf = xmalloc(postlen);
2339        else
2340                new_buf = old_buf;
2341        fixed = preimage->buf;
2342
2343        for (i = reduced = ctx = 0; i < postimage->nr; i++) {
2344                size_t l_len = postimage->line[i].len;
2345                if (!(postimage->line[i].flag & LINE_COMMON)) {
2346                        /* an added line -- no counterparts in preimage */
2347                        memmove(new_buf, old_buf, l_len);
2348                        old_buf += l_len;
2349                        new_buf += l_len;
2350                        continue;
2351                }
2352
2353                /* a common context -- skip it in the original postimage */
2354                old_buf += l_len;
2355
2356                /* and find the corresponding one in the fixed preimage */
2357                while (ctx < preimage->nr &&
2358                       !(preimage->line[ctx].flag & LINE_COMMON)) {
2359                        fixed += preimage->line[ctx].len;
2360                        ctx++;
2361                }
2362
2363                /*
2364                 * preimage is expected to run out, if the caller
2365                 * fixed addition of trailing blank lines.
2366                 */
2367                if (preimage->nr <= ctx) {
2368                        reduced++;
2369                        continue;
2370                }
2371
2372                /* and copy it in, while fixing the line length */
2373                l_len = preimage->line[ctx].len;
2374                memcpy(new_buf, fixed, l_len);
2375                new_buf += l_len;
2376                fixed += l_len;
2377                postimage->line[i].len = l_len;
2378                ctx++;
2379        }
2380
2381        if (postlen
2382            ? postlen < new_buf - postimage->buf
2383            : postimage->len < new_buf - postimage->buf)
2384                BUG("caller miscounted postlen: asked %d, orig = %d, used = %d",
2385                    (int)postlen, (int) postimage->len, (int)(new_buf - postimage->buf));
2386
2387        /* Fix the length of the whole thing */
2388        postimage->len = new_buf - postimage->buf;
2389        postimage->nr -= reduced;
2390}
2391
2392static int line_by_line_fuzzy_match(struct image *img,
2393                                    struct image *preimage,
2394                                    struct image *postimage,
2395                                    unsigned long current,
2396                                    int current_lno,
2397                                    int preimage_limit)
2398{
2399        int i;
2400        size_t imgoff = 0;
2401        size_t preoff = 0;
2402        size_t postlen = postimage->len;
2403        size_t extra_chars;
2404        char *buf;
2405        char *preimage_eof;
2406        char *preimage_end;
2407        struct strbuf fixed;
2408        char *fixed_buf;
2409        size_t fixed_len;
2410
2411        for (i = 0; i < preimage_limit; i++) {
2412                size_t prelen = preimage->line[i].len;
2413                size_t imglen = img->line[current_lno+i].len;
2414
2415                if (!fuzzy_matchlines(img->buf + current + imgoff, imglen,
2416                                      preimage->buf + preoff, prelen))
2417                        return 0;
2418                if (preimage->line[i].flag & LINE_COMMON)
2419                        postlen += imglen - prelen;
2420                imgoff += imglen;
2421                preoff += prelen;
2422        }
2423
2424        /*
2425         * Ok, the preimage matches with whitespace fuzz.
2426         *
2427         * imgoff now holds the true length of the target that
2428         * matches the preimage before the end of the file.
2429         *
2430         * Count the number of characters in the preimage that fall
2431         * beyond the end of the file and make sure that all of them
2432         * are whitespace characters. (This can only happen if
2433         * we are removing blank lines at the end of the file.)
2434         */
2435        buf = preimage_eof = preimage->buf + preoff;
2436        for ( ; i < preimage->nr; i++)
2437                preoff += preimage->line[i].len;
2438        preimage_end = preimage->buf + preoff;
2439        for ( ; buf < preimage_end; buf++)
2440                if (!isspace(*buf))
2441                        return 0;
2442
2443        /*
2444         * Update the preimage and the common postimage context
2445         * lines to use the same whitespace as the target.
2446         * If whitespace is missing in the target (i.e.
2447         * if the preimage extends beyond the end of the file),
2448         * use the whitespace from the preimage.
2449         */
2450        extra_chars = preimage_end - preimage_eof;
2451        strbuf_init(&fixed, imgoff + extra_chars);
2452        strbuf_add(&fixed, img->buf + current, imgoff);
2453        strbuf_add(&fixed, preimage_eof, extra_chars);
2454        fixed_buf = strbuf_detach(&fixed, &fixed_len);
2455        update_pre_post_images(preimage, postimage,
2456                               fixed_buf, fixed_len, postlen);
2457        return 1;
2458}
2459
2460static int match_fragment(struct apply_state *state,
2461                          struct image *img,
2462                          struct image *preimage,
2463                          struct image *postimage,
2464                          unsigned long current,
2465                          int current_lno,
2466                          unsigned ws_rule,
2467                          int match_beginning, int match_end)
2468{
2469        int i;
2470        char *fixed_buf, *buf, *orig, *target;
2471        struct strbuf fixed;
2472        size_t fixed_len, postlen;
2473        int preimage_limit;
2474
2475        if (preimage->nr + current_lno <= img->nr) {
2476                /*
2477                 * The hunk falls within the boundaries of img.
2478                 */
2479                preimage_limit = preimage->nr;
2480                if (match_end && (preimage->nr + current_lno != img->nr))
2481                        return 0;
2482        } else if (state->ws_error_action == correct_ws_error &&
2483                   (ws_rule & WS_BLANK_AT_EOF)) {
2484                /*
2485                 * This hunk extends beyond the end of img, and we are
2486                 * removing blank lines at the end of the file.  This
2487                 * many lines from the beginning of the preimage must
2488                 * match with img, and the remainder of the preimage
2489                 * must be blank.
2490                 */
2491                preimage_limit = img->nr - current_lno;
2492        } else {
2493                /*
2494                 * The hunk extends beyond the end of the img and
2495                 * we are not removing blanks at the end, so we
2496                 * should reject the hunk at this position.
2497                 */
2498                return 0;
2499        }
2500
2501        if (match_beginning && current_lno)
2502                return 0;
2503
2504        /* Quick hash check */
2505        for (i = 0; i < preimage_limit; i++)
2506                if ((img->line[current_lno + i].flag & LINE_PATCHED) ||
2507                    (preimage->line[i].hash != img->line[current_lno + i].hash))
2508                        return 0;
2509
2510        if (preimage_limit == preimage->nr) {
2511                /*
2512                 * Do we have an exact match?  If we were told to match
2513                 * at the end, size must be exactly at current+fragsize,
2514                 * otherwise current+fragsize must be still within the preimage,
2515                 * and either case, the old piece should match the preimage
2516                 * exactly.
2517                 */
2518                if ((match_end
2519                     ? (current + preimage->len == img->len)
2520                     : (current + preimage->len <= img->len)) &&
2521                    !memcmp(img->buf + current, preimage->buf, preimage->len))
2522                        return 1;
2523        } else {
2524                /*
2525                 * The preimage extends beyond the end of img, so
2526                 * there cannot be an exact match.
2527                 *
2528                 * There must be one non-blank context line that match
2529                 * a line before the end of img.
2530                 */
2531                char *buf_end;
2532
2533                buf = preimage->buf;
2534                buf_end = buf;
2535                for (i = 0; i < preimage_limit; i++)
2536                        buf_end += preimage->line[i].len;
2537
2538                for ( ; buf < buf_end; buf++)
2539                        if (!isspace(*buf))
2540                                break;
2541                if (buf == buf_end)
2542                        return 0;
2543        }
2544
2545        /*
2546         * No exact match. If we are ignoring whitespace, run a line-by-line
2547         * fuzzy matching. We collect all the line length information because
2548         * we need it to adjust whitespace if we match.
2549         */
2550        if (state->ws_ignore_action == ignore_ws_change)
2551                return line_by_line_fuzzy_match(img, preimage, postimage,
2552                                                current, current_lno, preimage_limit);
2553
2554        if (state->ws_error_action != correct_ws_error)
2555                return 0;
2556
2557        /*
2558         * The hunk does not apply byte-by-byte, but the hash says
2559         * it might with whitespace fuzz. We weren't asked to
2560         * ignore whitespace, we were asked to correct whitespace
2561         * errors, so let's try matching after whitespace correction.
2562         *
2563         * While checking the preimage against the target, whitespace
2564         * errors in both fixed, we count how large the corresponding
2565         * postimage needs to be.  The postimage prepared by
2566         * apply_one_fragment() has whitespace errors fixed on added
2567         * lines already, but the common lines were propagated as-is,
2568         * which may become longer when their whitespace errors are
2569         * fixed.
2570         */
2571
2572        /* First count added lines in postimage */
2573        postlen = 0;
2574        for (i = 0; i < postimage->nr; i++) {
2575                if (!(postimage->line[i].flag & LINE_COMMON))
2576                        postlen += postimage->line[i].len;
2577        }
2578
2579        /*
2580         * The preimage may extend beyond the end of the file,
2581         * but in this loop we will only handle the part of the
2582         * preimage that falls within the file.
2583         */
2584        strbuf_init(&fixed, preimage->len + 1);
2585        orig = preimage->buf;
2586        target = img->buf + current;
2587        for (i = 0; i < preimage_limit; i++) {
2588                size_t oldlen = preimage->line[i].len;
2589                size_t tgtlen = img->line[current_lno + i].len;
2590                size_t fixstart = fixed.len;
2591                struct strbuf tgtfix;
2592                int match;
2593
2594                /* Try fixing the line in the preimage */
2595                ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2596
2597                /* Try fixing the line in the target */
2598                strbuf_init(&tgtfix, tgtlen);
2599                ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
2600
2601                /*
2602                 * If they match, either the preimage was based on
2603                 * a version before our tree fixed whitespace breakage,
2604                 * or we are lacking a whitespace-fix patch the tree
2605                 * the preimage was based on already had (i.e. target
2606                 * has whitespace breakage, the preimage doesn't).
2607                 * In either case, we are fixing the whitespace breakages
2608                 * so we might as well take the fix together with their
2609                 * real change.
2610                 */
2611                match = (tgtfix.len == fixed.len - fixstart &&
2612                         !memcmp(tgtfix.buf, fixed.buf + fixstart,
2613                                             fixed.len - fixstart));
2614
2615                /* Add the length if this is common with the postimage */
2616                if (preimage->line[i].flag & LINE_COMMON)
2617                        postlen += tgtfix.len;
2618
2619                strbuf_release(&tgtfix);
2620                if (!match)
2621                        goto unmatch_exit;
2622
2623                orig += oldlen;
2624                target += tgtlen;
2625        }
2626
2627
2628        /*
2629         * Now handle the lines in the preimage that falls beyond the
2630         * end of the file (if any). They will only match if they are
2631         * empty or only contain whitespace (if WS_BLANK_AT_EOL is
2632         * false).
2633         */
2634        for ( ; i < preimage->nr; i++) {
2635                size_t fixstart = fixed.len; /* start of the fixed preimage */
2636                size_t oldlen = preimage->line[i].len;
2637                int j;
2638
2639                /* Try fixing the line in the preimage */
2640                ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
2641
2642                for (j = fixstart; j < fixed.len; j++)
2643                        if (!isspace(fixed.buf[j]))
2644                                goto unmatch_exit;
2645
2646                orig += oldlen;
2647        }
2648
2649        /*
2650         * Yes, the preimage is based on an older version that still
2651         * has whitespace breakages unfixed, and fixing them makes the
2652         * hunk match.  Update the context lines in the postimage.
2653         */
2654        fixed_buf = strbuf_detach(&fixed, &fixed_len);
2655        if (postlen < postimage->len)
2656                postlen = 0;
2657        update_pre_post_images(preimage, postimage,
2658                               fixed_buf, fixed_len, postlen);
2659        return 1;
2660
2661 unmatch_exit:
2662        strbuf_release(&fixed);
2663        return 0;
2664}
2665
2666static int find_pos(struct apply_state *state,
2667                    struct image *img,
2668                    struct image *preimage,
2669                    struct image *postimage,
2670                    int line,
2671                    unsigned ws_rule,
2672                    int match_beginning, int match_end)
2673{
2674        int i;
2675        unsigned long backwards, forwards, current;
2676        int backwards_lno, forwards_lno, current_lno;
2677
2678        /*
2679         * If match_beginning or match_end is specified, there is no
2680         * point starting from a wrong line that will never match and
2681         * wander around and wait for a match at the specified end.
2682         */
2683        if (match_beginning)
2684                line = 0;
2685        else if (match_end)
2686                line = img->nr - preimage->nr;
2687
2688        /*
2689         * Because the comparison is unsigned, the following test
2690         * will also take care of a negative line number that can
2691         * result when match_end and preimage is larger than the target.
2692         */
2693        if ((size_t) line > img->nr)
2694                line = img->nr;
2695
2696        current = 0;
2697        for (i = 0; i < line; i++)
2698                current += img->line[i].len;
2699
2700        /*
2701         * There's probably some smart way to do this, but I'll leave
2702         * that to the smart and beautiful people. I'm simple and stupid.
2703         */
2704        backwards = current;
2705        backwards_lno = line;
2706        forwards = current;
2707        forwards_lno = line;
2708        current_lno = line;
2709
2710        for (i = 0; ; i++) {
2711                if (match_fragment(state, img, preimage, postimage,
2712                                   current, current_lno, ws_rule,
2713                                   match_beginning, match_end))
2714                        return current_lno;
2715
2716        again:
2717                if (backwards_lno == 0 && forwards_lno == img->nr)
2718                        break;
2719
2720                if (i & 1) {
2721                        if (backwards_lno == 0) {
2722                                i++;
2723                                goto again;
2724                        }
2725                        backwards_lno--;
2726                        backwards -= img->line[backwards_lno].len;
2727                        current = backwards;
2728                        current_lno = backwards_lno;
2729                } else {
2730                        if (forwards_lno == img->nr) {
2731                                i++;
2732                                goto again;
2733                        }
2734                        forwards += img->line[forwards_lno].len;
2735                        forwards_lno++;
2736                        current = forwards;
2737                        current_lno = forwards_lno;
2738                }
2739
2740        }
2741        return -1;
2742}
2743
2744static void remove_first_line(struct image *img)
2745{
2746        img->buf += img->line[0].len;
2747        img->len -= img->line[0].len;
2748        img->line++;
2749        img->nr--;
2750}
2751
2752static void remove_last_line(struct image *img)
2753{
2754        img->len -= img->line[--img->nr].len;
2755}
2756
2757/*
2758 * The change from "preimage" and "postimage" has been found to
2759 * apply at applied_pos (counts in line numbers) in "img".
2760 * Update "img" to remove "preimage" and replace it with "postimage".
2761 */
2762static void update_image(struct apply_state *state,
2763                         struct image *img,
2764                         int applied_pos,
2765                         struct image *preimage,
2766                         struct image *postimage)
2767{
2768        /*
2769         * remove the copy of preimage at offset in img
2770         * and replace it with postimage
2771         */
2772        int i, nr;
2773        size_t remove_count, insert_count, applied_at = 0;
2774        char *result;
2775        int preimage_limit;
2776
2777        /*
2778         * If we are removing blank lines at the end of img,
2779         * the preimage may extend beyond the end.
2780         * If that is the case, we must be careful only to
2781         * remove the part of the preimage that falls within
2782         * the boundaries of img. Initialize preimage_limit
2783         * to the number of lines in the preimage that falls
2784         * within the boundaries.
2785         */
2786        preimage_limit = preimage->nr;
2787        if (preimage_limit > img->nr - applied_pos)
2788                preimage_limit = img->nr - applied_pos;
2789
2790        for (i = 0; i < applied_pos; i++)
2791                applied_at += img->line[i].len;
2792
2793        remove_count = 0;
2794        for (i = 0; i < preimage_limit; i++)
2795                remove_count += img->line[applied_pos + i].len;
2796        insert_count = postimage->len;
2797
2798        /* Adjust the contents */
2799        result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1));
2800        memcpy(result, img->buf, applied_at);
2801        memcpy(result + applied_at, postimage->buf, postimage->len);
2802        memcpy(result + applied_at + postimage->len,
2803               img->buf + (applied_at + remove_count),
2804               img->len - (applied_at + remove_count));
2805        free(img->buf);
2806        img->buf = result;
2807        img->len += insert_count - remove_count;
2808        result[img->len] = '\0';
2809
2810        /* Adjust the line table */
2811        nr = img->nr + postimage->nr - preimage_limit;
2812        if (preimage_limit < postimage->nr) {
2813                /*
2814                 * NOTE: this knows that we never call remove_first_line()
2815                 * on anything other than pre/post image.
2816                 */
2817                REALLOC_ARRAY(img->line, nr);
2818                img->line_allocated = img->line;
2819        }
2820        if (preimage_limit != postimage->nr)
2821                MOVE_ARRAY(img->line + applied_pos + postimage->nr,
2822                           img->line + applied_pos + preimage_limit,
2823                           img->nr - (applied_pos + preimage_limit));
2824        COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr);
2825        if (!state->allow_overlap)
2826                for (i = 0; i < postimage->nr; i++)
2827                        img->line[applied_pos + i].flag |= LINE_PATCHED;
2828        img->nr = nr;
2829}
2830
2831/*
2832 * Use the patch-hunk text in "frag" to prepare two images (preimage and
2833 * postimage) for the hunk.  Find lines that match "preimage" in "img" and
2834 * replace the part of "img" with "postimage" text.
2835 */
2836static int apply_one_fragment(struct apply_state *state,
2837                              struct image *img, struct fragment *frag,
2838                              int inaccurate_eof, unsigned ws_rule,
2839                              int nth_fragment)
2840{
2841        int match_beginning, match_end;
2842        const char *patch = frag->patch;
2843        int size = frag->size;
2844        char *old, *oldlines;
2845        struct strbuf newlines;
2846        int new_blank_lines_at_end = 0;
2847        int found_new_blank_lines_at_end = 0;
2848        int hunk_linenr = frag->linenr;
2849        unsigned long leading, trailing;
2850        int pos, applied_pos;
2851        struct image preimage;
2852        struct image postimage;
2853
2854        memset(&preimage, 0, sizeof(preimage));
2855        memset(&postimage, 0, sizeof(postimage));
2856        oldlines = xmalloc(size);
2857        strbuf_init(&newlines, size);
2858
2859        old = oldlines;
2860        while (size > 0) {
2861                char first;
2862                int len = linelen(patch, size);
2863                int plen;
2864                int added_blank_line = 0;
2865                int is_blank_context = 0;
2866                size_t start;
2867
2868                if (!len)
2869                        break;
2870
2871                /*
2872                 * "plen" is how much of the line we should use for
2873                 * the actual patch data. Normally we just remove the
2874                 * first character on the line, but if the line is
2875                 * followed by "\ No newline", then we also remove the
2876                 * last one (which is the newline, of course).
2877                 */
2878                plen = len - 1;
2879                if (len < size && patch[len] == '\\')
2880                        plen--;
2881                first = *patch;
2882                if (state->apply_in_reverse) {
2883                        if (first == '-')
2884                                first = '+';
2885                        else if (first == '+')
2886                                first = '-';
2887                }
2888
2889                switch (first) {
2890                case '\n':
2891                        /* Newer GNU diff, empty context line */
2892                        if (plen < 0)
2893                                /* ... followed by '\No newline'; nothing */
2894                                break;
2895                        *old++ = '\n';
2896                        strbuf_addch(&newlines, '\n');
2897                        add_line_info(&preimage, "\n", 1, LINE_COMMON);
2898                        add_line_info(&postimage, "\n", 1, LINE_COMMON);
2899                        is_blank_context = 1;
2900                        break;
2901                case ' ':
2902                        if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
2903                            ws_blank_line(patch + 1, plen, ws_rule))
2904                                is_blank_context = 1;
2905                        /* fallthrough */
2906                case '-':
2907                        memcpy(old, patch + 1, plen);
2908                        add_line_info(&preimage, old, plen,
2909                                      (first == ' ' ? LINE_COMMON : 0));
2910                        old += plen;
2911                        if (first == '-')
2912                                break;
2913                        /* fallthrough */
2914                case '+':
2915                        /* --no-add does not add new lines */
2916                        if (first == '+' && state->no_add)
2917                                break;
2918
2919                        start = newlines.len;
2920                        if (first != '+' ||
2921                            !state->whitespace_error ||
2922                            state->ws_error_action != correct_ws_error) {
2923                                strbuf_add(&newlines, patch + 1, plen);
2924                        }
2925                        else {
2926                                ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
2927                        }
2928                        add_line_info(&postimage, newlines.buf + start, newlines.len - start,
2929                                      (first == '+' ? 0 : LINE_COMMON));
2930                        if (first == '+' &&
2931                            (ws_rule & WS_BLANK_AT_EOF) &&
2932                            ws_blank_line(patch + 1, plen, ws_rule))
2933                                added_blank_line = 1;
2934                        break;
2935                case '@': case '\\':
2936                        /* Ignore it, we already handled it */
2937                        break;
2938                default:
2939                        if (state->apply_verbosity > verbosity_normal)
2940                                error(_("invalid start of line: '%c'"), first);
2941                        applied_pos = -1;
2942                        goto out;
2943                }
2944                if (added_blank_line) {
2945                        if (!new_blank_lines_at_end)
2946                                found_new_blank_lines_at_end = hunk_linenr;
2947                        new_blank_lines_at_end++;
2948                }
2949                else if (is_blank_context)
2950                        ;
2951                else
2952                        new_blank_lines_at_end = 0;
2953                patch += len;
2954                size -= len;
2955                hunk_linenr++;
2956        }
2957        if (inaccurate_eof &&
2958            old > oldlines && old[-1] == '\n' &&
2959            newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
2960                old--;
2961                strbuf_setlen(&newlines, newlines.len - 1);
2962                preimage.line_allocated[preimage.nr - 1].len--;
2963                postimage.line_allocated[postimage.nr - 1].len--;
2964        }
2965
2966        leading = frag->leading;
2967        trailing = frag->trailing;
2968
2969        /*
2970         * A hunk to change lines at the beginning would begin with
2971         * @@ -1,L +N,M @@
2972         * but we need to be careful.  -U0 that inserts before the second
2973         * line also has this pattern.
2974         *
2975         * And a hunk to add to an empty file would begin with
2976         * @@ -0,0 +N,M @@
2977         *
2978         * In other words, a hunk that is (frag->oldpos <= 1) with or
2979         * without leading context must match at the beginning.
2980         */
2981        match_beginning = (!frag->oldpos ||
2982                           (frag->oldpos == 1 && !state->unidiff_zero));
2983
2984        /*
2985         * A hunk without trailing lines must match at the end.
2986         * However, we simply cannot tell if a hunk must match end
2987         * from the lack of trailing lines if the patch was generated
2988         * with unidiff without any context.
2989         */
2990        match_end = !state->unidiff_zero && !trailing;
2991
2992        pos = frag->newpos ? (frag->newpos - 1) : 0;
2993        preimage.buf = oldlines;
2994        preimage.len = old - oldlines;
2995        postimage.buf = newlines.buf;
2996        postimage.len = newlines.len;
2997        preimage.line = preimage.line_allocated;
2998        postimage.line = postimage.line_allocated;
2999
3000        for (;;) {
3001
3002                applied_pos = find_pos(state, img, &preimage, &postimage, pos,
3003                                       ws_rule, match_beginning, match_end);
3004
3005                if (applied_pos >= 0)
3006                        break;
3007
3008                /* Am I at my context limits? */
3009                if ((leading <= state->p_context) && (trailing <= state->p_context))
3010                        break;
3011                if (match_beginning || match_end) {
3012                        match_beginning = match_end = 0;
3013                        continue;
3014                }
3015
3016                /*
3017                 * Reduce the number of context lines; reduce both
3018                 * leading and trailing if they are equal otherwise
3019                 * just reduce the larger context.
3020                 */
3021                if (leading >= trailing) {
3022                        remove_first_line(&preimage);
3023                        remove_first_line(&postimage);
3024                        pos--;
3025                        leading--;
3026                }
3027                if (trailing > leading) {
3028                        remove_last_line(&preimage);
3029                        remove_last_line(&postimage);
3030                        trailing--;
3031                }
3032        }
3033
3034        if (applied_pos >= 0) {
3035                if (new_blank_lines_at_end &&
3036                    preimage.nr + applied_pos >= img->nr &&
3037                    (ws_rule & WS_BLANK_AT_EOF) &&
3038                    state->ws_error_action != nowarn_ws_error) {
3039                        record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
3040                                        found_new_blank_lines_at_end);
3041                        if (state->ws_error_action == correct_ws_error) {
3042                                while (new_blank_lines_at_end--)
3043                                        remove_last_line(&postimage);
3044                        }
3045                        /*
3046                         * We would want to prevent write_out_results()
3047                         * from taking place in apply_patch() that follows
3048                         * the callchain led us here, which is:
3049                         * apply_patch->check_patch_list->check_patch->
3050                         * apply_data->apply_fragments->apply_one_fragment
3051                         */
3052                        if (state->ws_error_action == die_on_ws_error)
3053                                state->apply = 0;
3054                }
3055
3056                if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
3057                        int offset = applied_pos - pos;
3058                        if (state->apply_in_reverse)
3059                                offset = 0 - offset;
3060                        fprintf_ln(stderr,
3061                                   Q_("Hunk #%d succeeded at %d (offset %d line).",
3062                                      "Hunk #%d succeeded at %d (offset %d lines).",
3063                                      offset),
3064                                   nth_fragment, applied_pos + 1, offset);
3065                }
3066
3067                /*
3068                 * Warn if it was necessary to reduce the number
3069                 * of context lines.
3070                 */
3071                if ((leading != frag->leading ||
3072                     trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
3073                        fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
3074                                             " to apply fragment at %d"),
3075                                   leading, trailing, applied_pos+1);
3076                update_image(state, img, applied_pos, &preimage, &postimage);
3077        } else {
3078                if (state->apply_verbosity > verbosity_normal)
3079                        error(_("while searching for:\n%.*s"),
3080                              (int)(old - oldlines), oldlines);
3081        }
3082
3083out:
3084        free(oldlines);
3085        strbuf_release(&newlines);
3086        free(preimage.line_allocated);
3087        free(postimage.line_allocated);
3088
3089        return (applied_pos < 0);
3090}
3091
3092static int apply_binary_fragment(struct apply_state *state,
3093                                 struct image *img,
3094                                 struct patch *patch)
3095{
3096        struct fragment *fragment = patch->fragments;
3097        unsigned long len;
3098        void *dst;
3099
3100        if (!fragment)
3101                return error(_("missing binary patch data for '%s'"),
3102                             patch->new_name ?
3103                             patch->new_name :
3104                             patch->old_name);
3105
3106        /* Binary patch is irreversible without the optional second hunk */
3107        if (state->apply_in_reverse) {
3108                if (!fragment->next)
3109                        return error(_("cannot reverse-apply a binary patch "
3110                                       "without the reverse hunk to '%s'"),
3111                                     patch->new_name
3112                                     ? patch->new_name : patch->old_name);
3113                fragment = fragment->next;
3114        }
3115        switch (fragment->binary_patch_method) {
3116        case BINARY_DELTA_DEFLATED:
3117                dst = patch_delta(img->buf, img->len, fragment->patch,
3118                                  fragment->size, &len);
3119                if (!dst)
3120                        return -1;
3121                clear_image(img);
3122                img->buf = dst;
3123                img->len = len;
3124                return 0;
3125        case BINARY_LITERAL_DEFLATED:
3126                clear_image(img);
3127                img->len = fragment->size;
3128                img->buf = xmemdupz(fragment->patch, img->len);
3129                return 0;
3130        }
3131        return -1;
3132}
3133
3134/*
3135 * Replace "img" with the result of applying the binary patch.
3136 * The binary patch data itself in patch->fragment is still kept
3137 * but the preimage prepared by the caller in "img" is freed here
3138 * or in the helper function apply_binary_fragment() this calls.
3139 */
3140static int apply_binary(struct apply_state *state,
3141                        struct image *img,
3142                        struct patch *patch)
3143{
3144        const char *name = patch->old_name ? patch->old_name : patch->new_name;
3145        struct object_id oid;
3146        const unsigned hexsz = the_hash_algo->hexsz;
3147
3148        /*
3149         * For safety, we require patch index line to contain
3150         * full hex textual object ID for old and new, at least for now.
3151         */
3152        if (strlen(patch->old_sha1_prefix) != hexsz ||
3153            strlen(patch->new_sha1_prefix) != hexsz ||
3154            get_oid_hex(patch->old_sha1_prefix, &oid) ||
3155            get_oid_hex(patch->new_sha1_prefix, &oid))
3156                return error(_("cannot apply binary patch to '%s' "
3157                               "without full index line"), name);
3158
3159        if (patch->old_name) {
3160                /*
3161                 * See if the old one matches what the patch
3162                 * applies to.
3163                 */
3164                hash_object_file(img->buf, img->len, blob_type, &oid);
3165                if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
3166                        return error(_("the patch applies to '%s' (%s), "
3167                                       "which does not match the "
3168                                       "current contents."),
3169                                     name, oid_to_hex(&oid));
3170        }
3171        else {
3172                /* Otherwise, the old one must be empty. */
3173                if (img->len)
3174                        return error(_("the patch applies to an empty "
3175                                       "'%s' but it is not empty"), name);
3176        }
3177
3178        get_oid_hex(patch->new_sha1_prefix, &oid);
3179        if (is_null_oid(&oid)) {
3180                clear_image(img);
3181                return 0; /* deletion patch */
3182        }
3183
3184        if (has_sha1_file(oid.hash)) {
3185                /* We already have the postimage */
3186                enum object_type type;
3187                unsigned long size;
3188                char *result;
3189
3190                result = read_object_file(&oid, &type, &size);
3191                if (!result)
3192                        return error(_("the necessary postimage %s for "
3193                                       "'%s' cannot be read"),
3194                                     patch->new_sha1_prefix, name);
3195                clear_image(img);
3196                img->buf = result;
3197                img->len = size;
3198        } else {
3199                /*
3200                 * We have verified buf matches the preimage;
3201                 * apply the patch data to it, which is stored
3202                 * in the patch->fragments->{patch,size}.
3203                 */
3204                if (apply_binary_fragment(state, img, patch))
3205                        return error(_("binary patch does not apply to '%s'"),
3206                                     name);
3207
3208                /* verify that the result matches */
3209                hash_object_file(img->buf, img->len, blob_type, &oid);
3210                if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
3211                        return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
3212                                name, patch->new_sha1_prefix, oid_to_hex(&oid));
3213        }
3214
3215        return 0;
3216}
3217
3218static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
3219{
3220        struct fragment *frag = patch->fragments;
3221        const char *name = patch->old_name ? patch->old_name : patch->new_name;
3222        unsigned ws_rule = patch->ws_rule;
3223        unsigned inaccurate_eof = patch->inaccurate_eof;
3224        int nth = 0;
3225
3226        if (patch->is_binary)
3227                return apply_binary(state, img, patch);
3228
3229        while (frag) {
3230                nth++;
3231                if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
3232                        error(_("patch failed: %s:%ld"), name, frag->oldpos);
3233                        if (!state->apply_with_reject)
3234                                return -1;
3235                        frag->rejected = 1;
3236                }
3237                frag = frag->next;
3238        }
3239        return 0;
3240}
3241
3242static int read_blob_object(struct strbuf *buf, const struct object_id *oid, unsigned mode)
3243{
3244        if (S_ISGITLINK(mode)) {
3245                strbuf_grow(buf, 100);
3246                strbuf_addf(buf, "Subproject commit %s\n", oid_to_hex(oid));
3247        } else {
3248                enum object_type type;
3249                unsigned long sz;
3250                char *result;
3251
3252                result = read_object_file(oid, &type, &sz);
3253                if (!result)
3254                        return -1;
3255                /* XXX read_sha1_file NUL-terminates */
3256                strbuf_attach(buf, result, sz, sz + 1);
3257        }
3258        return 0;
3259}
3260
3261static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf)
3262{
3263        if (!ce)
3264                return 0;
3265        return read_blob_object(buf, &ce->oid, ce->ce_mode);
3266}
3267
3268static struct patch *in_fn_table(struct apply_state *state, const char *name)
3269{
3270        struct string_list_item *item;
3271
3272        if (name == NULL)
3273                return NULL;
3274
3275        item = string_list_lookup(&state->fn_table, name);
3276        if (item != NULL)
3277                return (struct patch *)item->util;
3278
3279        return NULL;
3280}
3281
3282/*
3283 * item->util in the filename table records the status of the path.
3284 * Usually it points at a patch (whose result records the contents
3285 * of it after applying it), but it could be PATH_WAS_DELETED for a
3286 * path that a previously applied patch has already removed, or
3287 * PATH_TO_BE_DELETED for a path that a later patch would remove.
3288 *
3289 * The latter is needed to deal with a case where two paths A and B
3290 * are swapped by first renaming A to B and then renaming B to A;
3291 * moving A to B should not be prevented due to presence of B as we
3292 * will remove it in a later patch.
3293 */
3294#define PATH_TO_BE_DELETED ((struct patch *) -2)
3295#define PATH_WAS_DELETED ((struct patch *) -1)
3296
3297static int to_be_deleted(struct patch *patch)
3298{
3299        return patch == PATH_TO_BE_DELETED;
3300}
3301
3302static int was_deleted(struct patch *patch)
3303{
3304        return patch == PATH_WAS_DELETED;
3305}
3306
3307static void add_to_fn_table(struct apply_state *state, struct patch *patch)
3308{
3309        struct string_list_item *item;
3310
3311        /*
3312         * Always add new_name unless patch is a deletion
3313         * This should cover the cases for normal diffs,
3314         * file creations and copies
3315         */
3316        if (patch->new_name != NULL) {
3317                item = string_list_insert(&state->fn_table, patch->new_name);
3318                item->util = patch;
3319        }
3320
3321        /*
3322         * store a failure on rename/deletion cases because
3323         * later chunks shouldn't patch old names
3324         */
3325        if ((patch->new_name == NULL) || (patch->is_rename)) {
3326                item = string_list_insert(&state->fn_table, patch->old_name);
3327                item->util = PATH_WAS_DELETED;
3328        }
3329}
3330
3331static void prepare_fn_table(struct apply_state *state, struct patch *patch)
3332{
3333        /*
3334         * store information about incoming file deletion
3335         */
3336        while (patch) {
3337                if ((patch->new_name == NULL) || (patch->is_rename)) {
3338                        struct string_list_item *item;
3339                        item = string_list_insert(&state->fn_table, patch->old_name);
3340                        item->util = PATH_TO_BE_DELETED;
3341                }
3342                patch = patch->next;
3343        }
3344}
3345
3346static int checkout_target(struct index_state *istate,
3347                           struct cache_entry *ce, struct stat *st)
3348{
3349        struct checkout costate = CHECKOUT_INIT;
3350
3351        costate.refresh_cache = 1;
3352        costate.istate = istate;
3353        if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
3354                return error(_("cannot checkout %s"), ce->name);
3355        return 0;
3356}
3357
3358static struct patch *previous_patch(struct apply_state *state,
3359                                    struct patch *patch,
3360                                    int *gone)
3361{
3362        struct patch *previous;
3363
3364        *gone = 0;
3365        if (patch->is_copy || patch->is_rename)
3366                return NULL; /* "git" patches do not depend on the order */
3367
3368        previous = in_fn_table(state, patch->old_name);
3369        if (!previous)
3370                return NULL;
3371
3372        if (to_be_deleted(previous))
3373                return NULL; /* the deletion hasn't happened yet */
3374
3375        if (was_deleted(previous))
3376                *gone = 1;
3377
3378        return previous;
3379}
3380
3381static int verify_index_match(struct apply_state *state,
3382                              const struct cache_entry *ce,
3383                              struct stat *st)
3384{
3385        if (S_ISGITLINK(ce->ce_mode)) {
3386                if (!S_ISDIR(st->st_mode))
3387                        return -1;
3388                return 0;
3389        }
3390        return ie_match_stat(state->repo->index, ce, st,
3391                             CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
3392}
3393
3394#define SUBMODULE_PATCH_WITHOUT_INDEX 1
3395
3396static int load_patch_target(struct apply_state *state,
3397                             struct strbuf *buf,
3398                             const struct cache_entry *ce,
3399                             struct stat *st,
3400                             struct patch *patch,
3401                             const char *name,
3402                             unsigned expected_mode)
3403{
3404        if (state->cached || state->check_index) {
3405                if (read_file_or_gitlink(ce, buf))
3406                        return error(_("failed to read %s"), name);
3407        } else if (name) {
3408                if (S_ISGITLINK(expected_mode)) {
3409                        if (ce)
3410                                return read_file_or_gitlink(ce, buf);
3411                        else
3412                                return SUBMODULE_PATCH_WITHOUT_INDEX;
3413                } else if (has_symlink_leading_path(name, strlen(name))) {
3414                        return error(_("reading from '%s' beyond a symbolic link"), name);
3415                } else {
3416                        if (read_old_data(st, patch, name, buf))
3417                                return error(_("failed to read %s"), name);
3418                }
3419        }
3420        return 0;
3421}
3422
3423/*
3424 * We are about to apply "patch"; populate the "image" with the
3425 * current version we have, from the working tree or from the index,
3426 * depending on the situation e.g. --cached/--index.  If we are
3427 * applying a non-git patch that incrementally updates the tree,
3428 * we read from the result of a previous diff.
3429 */
3430static int load_preimage(struct apply_state *state,
3431                         struct image *image,
3432                         struct patch *patch, struct stat *st,
3433                         const struct cache_entry *ce)
3434{
3435        struct strbuf buf = STRBUF_INIT;
3436        size_t len;
3437        char *img;
3438        struct patch *previous;
3439        int status;
3440
3441        previous = previous_patch(state, patch, &status);
3442        if (status)
3443                return error(_("path %s has been renamed/deleted"),
3444                             patch->old_name);
3445        if (previous) {
3446                /* We have a patched copy in memory; use that. */
3447                strbuf_add(&buf, previous->result, previous->resultsize);
3448        } else {
3449                status = load_patch_target(state, &buf, ce, st, patch,
3450                                           patch->old_name, patch->old_mode);
3451                if (status < 0)
3452                        return status;
3453                else if (status == SUBMODULE_PATCH_WITHOUT_INDEX) {
3454                        /*
3455                         * There is no way to apply subproject
3456                         * patch without looking at the index.
3457                         * NEEDSWORK: shouldn't this be flagged
3458                         * as an error???
3459                         */
3460                        free_fragment_list(patch->fragments);
3461                        patch->fragments = NULL;
3462                } else if (status) {
3463                        return error(_("failed to read %s"), patch->old_name);
3464                }
3465        }
3466
3467        img = strbuf_detach(&buf, &len);
3468        prepare_image(image, img, len, !patch->is_binary);
3469        return 0;
3470}
3471
3472static int three_way_merge(struct image *image,
3473                           char *path,
3474                           const struct object_id *base,
3475                           const struct object_id *ours,
3476                           const struct object_id *theirs)
3477{
3478        mmfile_t base_file, our_file, their_file;
3479        mmbuffer_t result = { NULL };
3480        int status;
3481
3482        read_mmblob(&base_file, base);
3483        read_mmblob(&our_file, ours);
3484        read_mmblob(&their_file, theirs);
3485        status = ll_merge(&result, path,
3486                          &base_file, "base",
3487                          &our_file, "ours",
3488                          &their_file, "theirs", NULL);
3489        free(base_file.ptr);
3490        free(our_file.ptr);
3491        free(their_file.ptr);
3492        if (status < 0 || !result.ptr) {
3493                free(result.ptr);
3494                return -1;
3495        }
3496        clear_image(image);
3497        image->buf = result.ptr;
3498        image->len = result.size;
3499
3500        return status;
3501}
3502
3503/*
3504 * When directly falling back to add/add three-way merge, we read from
3505 * the current contents of the new_name.  In no cases other than that
3506 * this function will be called.
3507 */
3508static int load_current(struct apply_state *state,
3509                        struct image *image,
3510                        struct patch *patch)
3511{
3512        struct strbuf buf = STRBUF_INIT;
3513        int status, pos;
3514        size_t len;
3515        char *img;
3516        struct stat st;
3517        struct cache_entry *ce;
3518        char *name = patch->new_name;
3519        unsigned mode = patch->new_mode;
3520
3521        if (!patch->is_new)
3522                BUG("patch to %s is not a creation", patch->old_name);
3523
3524        pos = index_name_pos(state->repo->index, name, strlen(name));
3525        if (pos < 0)
3526                return error(_("%s: does not exist in index"), name);
3527        ce = state->repo->index->cache[pos];
3528        if (lstat(name, &st)) {
3529                if (errno != ENOENT)
3530                        return error_errno("%s", name);
3531                if (checkout_target(state->repo->index, ce, &st))
3532                        return -1;
3533        }
3534        if (verify_index_match(state, ce, &st))
3535                return error(_("%s: does not match index"), name);
3536
3537        status = load_patch_target(state, &buf, ce, &st, patch, name, mode);
3538        if (status < 0)
3539                return status;
3540        else if (status)
3541                return -1;
3542        img = strbuf_detach(&buf, &len);
3543        prepare_image(image, img, len, !patch->is_binary);
3544        return 0;
3545}
3546
3547static int try_threeway(struct apply_state *state,
3548                        struct image *image,
3549                        struct patch *patch,
3550                        struct stat *st,
3551                        const struct cache_entry *ce)
3552{
3553        struct object_id pre_oid, post_oid, our_oid;
3554        struct strbuf buf = STRBUF_INIT;
3555        size_t len;
3556        int status;
3557        char *img;
3558        struct image tmp_image;
3559
3560        /* No point falling back to 3-way merge in these cases */
3561        if (patch->is_delete ||
3562            S_ISGITLINK(patch->old_mode) || S_ISGITLINK(patch->new_mode))
3563                return -1;
3564
3565        /* Preimage the patch was prepared for */
3566        if (patch->is_new)
3567                write_object_file("", 0, blob_type, &pre_oid);
3568        else if (get_oid(patch->old_sha1_prefix, &pre_oid) ||
3569                 read_blob_object(&buf, &pre_oid, patch->old_mode))
3570                return error(_("repository lacks the necessary blob to fall back on 3-way merge."));
3571
3572        if (state->apply_verbosity > verbosity_silent)
3573                fprintf(stderr, _("Falling back to three-way merge...\n"));
3574
3575        img = strbuf_detach(&buf, &len);
3576        prepare_image(&tmp_image, img, len, 1);
3577        /* Apply the patch to get the post image */
3578        if (apply_fragments(state, &tmp_image, patch) < 0) {
3579                clear_image(&tmp_image);
3580                return -1;
3581        }
3582        /* post_oid is theirs */
3583        write_object_file(tmp_image.buf, tmp_image.len, blob_type, &post_oid);
3584        clear_image(&tmp_image);
3585
3586        /* our_oid is ours */
3587        if (patch->is_new) {
3588                if (load_current(state, &tmp_image, patch))
3589                        return error(_("cannot read the current contents of '%s'"),
3590                                     patch->new_name);
3591        } else {
3592                if (load_preimage(state, &tmp_image, patch, st, ce))
3593                        return error(_("cannot read the current contents of '%s'"),
3594                                     patch->old_name);
3595        }
3596        write_object_file(tmp_image.buf, tmp_image.len, blob_type, &our_oid);
3597        clear_image(&tmp_image);
3598
3599        /* in-core three-way merge between post and our using pre as base */
3600        status = three_way_merge(image, patch->new_name,
3601                                 &pre_oid, &our_oid, &post_oid);
3602        if (status < 0) {
3603                if (state->apply_verbosity > verbosity_silent)
3604                        fprintf(stderr,
3605                                _("Failed to fall back on three-way merge...\n"));
3606                return status;
3607        }
3608
3609        if (status) {
3610                patch->conflicted_threeway = 1;
3611                if (patch->is_new)
3612                        oidclr(&patch->threeway_stage[0]);
3613                else
3614                        oidcpy(&patch->threeway_stage[0], &pre_oid);
3615                oidcpy(&patch->threeway_stage[1], &our_oid);
3616                oidcpy(&patch->threeway_stage[2], &post_oid);
3617                if (state->apply_verbosity > verbosity_silent)
3618                        fprintf(stderr,
3619                                _("Applied patch to '%s' with conflicts.\n"),
3620                                patch->new_name);
3621        } else {
3622                if (state->apply_verbosity > verbosity_silent)
3623                        fprintf(stderr,
3624                                _("Applied patch to '%s' cleanly.\n"),
3625                                patch->new_name);
3626        }
3627        return 0;
3628}
3629
3630static int apply_data(struct apply_state *state, struct patch *patch,
3631                      struct stat *st, const struct cache_entry *ce)
3632{
3633        struct image image;
3634
3635        if (load_preimage(state, &image, patch, st, ce) < 0)
3636                return -1;
3637
3638        if (patch->direct_to_threeway ||
3639            apply_fragments(state, &image, patch) < 0) {
3640                /* Note: with --reject, apply_fragments() returns 0 */
3641                if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
3642                        return -1;
3643        }
3644        patch->result = image.buf;
3645        patch->resultsize = image.len;
3646        add_to_fn_table(state, patch);
3647        free(image.line_allocated);
3648
3649        if (0 < patch->is_delete && patch->resultsize)
3650                return error(_("removal patch leaves file contents"));
3651
3652        return 0;
3653}
3654
3655/*
3656 * If "patch" that we are looking at modifies or deletes what we have,
3657 * we would want it not to lose any local modification we have, either
3658 * in the working tree or in the index.
3659 *
3660 * This also decides if a non-git patch is a creation patch or a
3661 * modification to an existing empty file.  We do not check the state
3662 * of the current tree for a creation patch in this function; the caller
3663 * check_patch() separately makes sure (and errors out otherwise) that
3664 * the path the patch creates does not exist in the current tree.
3665 */
3666static int check_preimage(struct apply_state *state,
3667                          struct patch *patch,
3668                          struct cache_entry **ce,
3669                          struct stat *st)
3670{
3671        const char *old_name = patch->old_name;
3672        struct patch *previous = NULL;
3673        int stat_ret = 0, status;
3674        unsigned st_mode = 0;
3675
3676        if (!old_name)
3677                return 0;
3678
3679        assert(patch->is_new <= 0);
3680        previous = previous_patch(state, patch, &status);
3681
3682        if (status)
3683                return error(_("path %s has been renamed/deleted"), old_name);
3684        if (previous) {
3685                st_mode = previous->new_mode;
3686        } else if (!state->cached) {
3687                stat_ret = lstat(old_name, st);
3688                if (stat_ret && errno != ENOENT)
3689                        return error_errno("%s", old_name);
3690        }
3691
3692        if (state->check_index && !previous) {
3693                int pos = index_name_pos(state->repo->index, old_name,
3694                                         strlen(old_name));
3695                if (pos < 0) {
3696                        if (patch->is_new < 0)
3697                                goto is_new;
3698                        return error(_("%s: does not exist in index"), old_name);
3699                }
3700                *ce = state->repo->index->cache[pos];
3701                if (stat_ret < 0) {
3702                        if (checkout_target(state->repo->index, *ce, st))
3703                                return -1;
3704                }
3705                if (!state->cached && verify_index_match(state, *ce, st))
3706                        return error(_("%s: does not match index"), old_name);
3707                if (state->cached)
3708                        st_mode = (*ce)->ce_mode;
3709        } else if (stat_ret < 0) {
3710                if (patch->is_new < 0)
3711                        goto is_new;
3712                return error_errno("%s", old_name);
3713        }
3714
3715        if (!state->cached && !previous)
3716                st_mode = ce_mode_from_stat(*ce, st->st_mode);
3717
3718        if (patch->is_new < 0)
3719                patch->is_new = 0;
3720        if (!patch->old_mode)
3721                patch->old_mode = st_mode;
3722        if ((st_mode ^ patch->old_mode) & S_IFMT)
3723                return error(_("%s: wrong type"), old_name);
3724        if (st_mode != patch->old_mode)
3725                warning(_("%s has type %o, expected %o"),
3726                        old_name, st_mode, patch->old_mode);
3727        if (!patch->new_mode && !patch->is_delete)
3728                patch->new_mode = st_mode;
3729        return 0;
3730
3731 is_new:
3732        patch->is_new = 1;
3733        patch->is_delete = 0;
3734        FREE_AND_NULL(patch->old_name);
3735        return 0;
3736}
3737
3738
3739#define EXISTS_IN_INDEX 1
3740#define EXISTS_IN_WORKTREE 2
3741
3742static int check_to_create(struct apply_state *state,
3743                           const char *new_name,
3744                           int ok_if_exists)
3745{
3746        struct stat nst;
3747
3748        if (state->check_index &&
3749            index_name_pos(state->repo->index, new_name, strlen(new_name)) >= 0 &&
3750            !ok_if_exists)
3751                return EXISTS_IN_INDEX;
3752        if (state->cached)
3753                return 0;
3754
3755        if (!lstat(new_name, &nst)) {
3756                if (S_ISDIR(nst.st_mode) || ok_if_exists)
3757                        return 0;
3758                /*
3759                 * A leading component of new_name might be a symlink
3760                 * that is going to be removed with this patch, but
3761                 * still pointing at somewhere that has the path.
3762                 * In such a case, path "new_name" does not exist as
3763                 * far as git is concerned.
3764                 */
3765                if (has_symlink_leading_path(new_name, strlen(new_name)))
3766                        return 0;
3767
3768                return EXISTS_IN_WORKTREE;
3769        } else if (!is_missing_file_error(errno)) {
3770                return error_errno("%s", new_name);
3771        }
3772        return 0;
3773}
3774
3775static uintptr_t register_symlink_changes(struct apply_state *state,
3776                                          const char *path,
3777                                          uintptr_t what)
3778{
3779        struct string_list_item *ent;
3780
3781        ent = string_list_lookup(&state->symlink_changes, path);
3782        if (!ent) {
3783                ent = string_list_insert(&state->symlink_changes, path);
3784                ent->util = (void *)0;
3785        }
3786        ent->util = (void *)(what | ((uintptr_t)ent->util));
3787        return (uintptr_t)ent->util;
3788}
3789
3790static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
3791{
3792        struct string_list_item *ent;
3793
3794        ent = string_list_lookup(&state->symlink_changes, path);
3795        if (!ent)
3796                return 0;
3797        return (uintptr_t)ent->util;
3798}
3799
3800static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
3801{
3802        for ( ; patch; patch = patch->next) {
3803                if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
3804                    (patch->is_rename || patch->is_delete))
3805                        /* the symlink at patch->old_name is removed */
3806                        register_symlink_changes(state, patch->old_name, APPLY_SYMLINK_GOES_AWAY);
3807
3808                if (patch->new_name && S_ISLNK(patch->new_mode))
3809                        /* the symlink at patch->new_name is created or remains */
3810                        register_symlink_changes(state, patch->new_name, APPLY_SYMLINK_IN_RESULT);
3811        }
3812}
3813
3814static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
3815{
3816        do {
3817                unsigned int change;
3818
3819                while (--name->len && name->buf[name->len] != '/')
3820                        ; /* scan backwards */
3821                if (!name->len)
3822                        break;
3823                name->buf[name->len] = '\0';
3824                change = check_symlink_changes(state, name->buf);
3825                if (change & APPLY_SYMLINK_IN_RESULT)
3826                        return 1;
3827                if (change & APPLY_SYMLINK_GOES_AWAY)
3828                        /*
3829                         * This cannot be "return 0", because we may
3830                         * see a new one created at a higher level.
3831                         */
3832                        continue;
3833
3834                /* otherwise, check the preimage */
3835                if (state->check_index) {
3836                        struct cache_entry *ce;
3837
3838                        ce = index_file_exists(state->repo->index, name->buf,
3839                                               name->len, ignore_case);
3840                        if (ce && S_ISLNK(ce->ce_mode))
3841                                return 1;
3842                } else {
3843                        struct stat st;
3844                        if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
3845                                return 1;
3846                }
3847        } while (1);
3848        return 0;
3849}
3850
3851static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
3852{
3853        int ret;
3854        struct strbuf name = STRBUF_INIT;
3855
3856        assert(*name_ != '\0');
3857        strbuf_addstr(&name, name_);
3858        ret = path_is_beyond_symlink_1(state, &name);
3859        strbuf_release(&name);
3860
3861        return ret;
3862}
3863
3864static int check_unsafe_path(struct patch *patch)
3865{
3866        const char *old_name = NULL;
3867        const char *new_name = NULL;
3868        if (patch->is_delete)
3869                old_name = patch->old_name;
3870        else if (!patch->is_new && !patch->is_copy)
3871                old_name = patch->old_name;
3872        if (!patch->is_delete)
3873                new_name = patch->new_name;
3874
3875        if (old_name && !verify_path(old_name, patch->old_mode))
3876                return error(_("invalid path '%s'"), old_name);
3877        if (new_name && !verify_path(new_name, patch->new_mode))
3878                return error(_("invalid path '%s'"), new_name);
3879        return 0;
3880}
3881
3882/*
3883 * Check and apply the patch in-core; leave the result in patch->result
3884 * for the caller to write it out to the final destination.
3885 */
3886static int check_patch(struct apply_state *state, struct patch *patch)
3887{
3888        struct stat st;
3889        const char *old_name = patch->old_name;
3890        const char *new_name = patch->new_name;
3891        const char *name = old_name ? old_name : new_name;
3892        struct cache_entry *ce = NULL;
3893        struct patch *tpatch;
3894        int ok_if_exists;
3895        int status;
3896
3897        patch->rejected = 1; /* we will drop this after we succeed */
3898
3899        status = check_preimage(state, patch, &ce, &st);
3900        if (status)
3901                return status;
3902        old_name = patch->old_name;
3903
3904        /*
3905         * A type-change diff is always split into a patch to delete
3906         * old, immediately followed by a patch to create new (see
3907         * diff.c::run_diff()); in such a case it is Ok that the entry
3908         * to be deleted by the previous patch is still in the working
3909         * tree and in the index.
3910         *
3911         * A patch to swap-rename between A and B would first rename A
3912         * to B and then rename B to A.  While applying the first one,
3913         * the presence of B should not stop A from getting renamed to
3914         * B; ask to_be_deleted() about the later rename.  Removal of
3915         * B and rename from A to B is handled the same way by asking
3916         * was_deleted().
3917         */
3918        if ((tpatch = in_fn_table(state, new_name)) &&
3919            (was_deleted(tpatch) || to_be_deleted(tpatch)))
3920                ok_if_exists = 1;
3921        else
3922                ok_if_exists = 0;
3923
3924        if (new_name &&
3925            ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
3926                int err = check_to_create(state, new_name, ok_if_exists);
3927
3928                if (err && state->threeway) {
3929                        patch->direct_to_threeway = 1;
3930                } else switch (err) {
3931                case 0:
3932                        break; /* happy */
3933                case EXISTS_IN_INDEX:
3934                        return error(_("%s: already exists in index"), new_name);
3935                        break;
3936                case EXISTS_IN_WORKTREE:
3937                        return error(_("%s: already exists in working directory"),
3938                                     new_name);
3939                default:
3940                        return err;
3941                }
3942
3943                if (!patch->new_mode) {
3944                        if (0 < patch->is_new)
3945                                patch->new_mode = S_IFREG | 0644;
3946                        else
3947                                patch->new_mode = patch->old_mode;
3948                }
3949        }
3950
3951        if (new_name && old_name) {
3952                int same = !strcmp(old_name, new_name);
3953                if (!patch->new_mode)
3954                        patch->new_mode = patch->old_mode;
3955                if ((patch->old_mode ^ patch->new_mode) & S_IFMT) {
3956                        if (same)
3957                                return error(_("new mode (%o) of %s does not "
3958                                               "match old mode (%o)"),
3959                                        patch->new_mode, new_name,
3960                                        patch->old_mode);
3961                        else
3962                                return error(_("new mode (%o) of %s does not "
3963                                               "match old mode (%o) of %s"),
3964                                        patch->new_mode, new_name,
3965                                        patch->old_mode, old_name);
3966                }
3967        }
3968
3969        if (!state->unsafe_paths && check_unsafe_path(patch))
3970                return -128;
3971
3972        /*
3973         * An attempt to read from or delete a path that is beyond a
3974         * symbolic link will be prevented by load_patch_target() that
3975         * is called at the beginning of apply_data() so we do not
3976         * have to worry about a patch marked with "is_delete" bit
3977         * here.  We however need to make sure that the patch result
3978         * is not deposited to a path that is beyond a symbolic link
3979         * here.
3980         */
3981        if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
3982                return error(_("affected file '%s' is beyond a symbolic link"),
3983                             patch->new_name);
3984
3985        if (apply_data(state, patch, &st, ce) < 0)
3986                return error(_("%s: patch does not apply"), name);
3987        patch->rejected = 0;
3988        return 0;
3989}
3990
3991static int check_patch_list(struct apply_state *state, struct patch *patch)
3992{
3993        int err = 0;
3994
3995        prepare_symlink_changes(state, patch);
3996        prepare_fn_table(state, patch);
3997        while (patch) {
3998                int res;
3999                if (state->apply_verbosity > verbosity_normal)
4000                        say_patch_name(stderr,
4001                                       _("Checking patch %s..."), patch);
4002                res = check_patch(state, patch);
4003                if (res == -128)
4004                        return -128;
4005                err |= res;
4006                patch = patch->next;
4007        }
4008        return err;
4009}
4010
4011static int read_apply_cache(struct apply_state *state)
4012{
4013        if (state->index_file)
4014                return read_index_from(state->repo->index, state->index_file,
4015                                       get_git_dir());
4016        else
4017                return read_index(state->repo->index);
4018}
4019
4020/* This function tries to read the object name from the current index */
4021static int get_current_oid(struct apply_state *state, const char *path,
4022                           struct object_id *oid)
4023{
4024        int pos;
4025
4026        if (read_apply_cache(state) < 0)
4027                return -1;
4028        pos = index_name_pos(state->repo->index, path, strlen(path));
4029        if (pos < 0)
4030                return -1;
4031        oidcpy(oid, &state->repo->index->cache[pos]->oid);
4032        return 0;
4033}
4034
4035static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
4036{
4037        /*
4038         * A usable gitlink patch has only one fragment (hunk) that looks like:
4039         * @@ -1 +1 @@
4040         * -Subproject commit <old sha1>
4041         * +Subproject commit <new sha1>
4042         * or
4043         * @@ -1 +0,0 @@
4044         * -Subproject commit <old sha1>
4045         * for a removal patch.
4046         */
4047        struct fragment *hunk = p->fragments;
4048        static const char heading[] = "-Subproject commit ";
4049        char *preimage;
4050
4051        if (/* does the patch have only one hunk? */
4052            hunk && !hunk->next &&
4053            /* is its preimage one line? */
4054            hunk->oldpos == 1 && hunk->oldlines == 1 &&
4055            /* does preimage begin with the heading? */
4056            (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
4057            starts_with(++preimage, heading) &&
4058            /* does it record full SHA-1? */
4059            !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
4060            preimage[sizeof(heading) + the_hash_algo->hexsz - 1] == '\n' &&
4061            /* does the abbreviated name on the index line agree with it? */
4062            starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
4063                return 0; /* it all looks fine */
4064
4065        /* we may have full object name on the index line */
4066        return get_oid_hex(p->old_sha1_prefix, oid);
4067}
4068
4069/* Build an index that contains just the files needed for a 3way merge */
4070static int build_fake_ancestor(struct apply_state *state, struct patch *list)
4071{
4072        struct patch *patch;
4073        struct index_state result = { NULL };
4074        struct lock_file lock = LOCK_INIT;
4075        int res;
4076
4077        /* Once we start supporting the reverse patch, it may be
4078         * worth showing the new sha1 prefix, but until then...
4079         */
4080        for (patch = list; patch; patch = patch->next) {
4081                struct object_id oid;
4082                struct cache_entry *ce;
4083                const char *name;
4084
4085                name = patch->old_name ? patch->old_name : patch->new_name;
4086                if (0 < patch->is_new)
4087                        continue;
4088
4089                if (S_ISGITLINK(patch->old_mode)) {
4090                        if (!preimage_oid_in_gitlink_patch(patch, &oid))
4091                                ; /* ok, the textual part looks sane */
4092                        else
4093                                return error(_("sha1 information is lacking or "
4094                                               "useless for submodule %s"), name);
4095                } else if (!get_oid_blob(patch->old_sha1_prefix, &oid)) {
4096                        ; /* ok */
4097                } else if (!patch->lines_added && !patch->lines_deleted) {
4098                        /* mode-only change: update the current */
4099                        if (get_current_oid(state, patch->old_name, &oid))
4100                                return error(_("mode change for %s, which is not "
4101                                               "in current HEAD"), name);
4102                } else
4103                        return error(_("sha1 information is lacking or useless "
4104                                       "(%s)."), name);
4105
4106                ce = make_cache_entry(&result, patch->old_mode, &oid, name, 0, 0);
4107                if (!ce)
4108                        return error(_("make_cache_entry failed for path '%s'"),
4109                                     name);
4110                if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD)) {
4111                        discard_cache_entry(ce);
4112                        return error(_("could not add %s to temporary index"),
4113                                     name);
4114                }
4115        }
4116
4117        hold_lock_file_for_update(&lock, state->fake_ancestor, LOCK_DIE_ON_ERROR);
4118        res = write_locked_index(&result, &lock, COMMIT_LOCK);
4119        discard_index(&result);
4120
4121        if (res)
4122                return error(_("could not write temporary index to %s"),
4123                             state->fake_ancestor);
4124
4125        return 0;
4126}
4127
4128static void stat_patch_list(struct apply_state *state, struct patch *patch)
4129{
4130        int files, adds, dels;
4131
4132        for (files = adds = dels = 0 ; patch ; patch = patch->next) {
4133                files++;
4134                adds += patch->lines_added;
4135                dels += patch->lines_deleted;
4136                show_stats(state, patch);
4137        }
4138
4139        print_stat_summary(stdout, files, adds, dels);
4140}
4141
4142static void numstat_patch_list(struct apply_state *state,
4143                               struct patch *patch)
4144{
4145        for ( ; patch; patch = patch->next) {
4146                const char *name;
4147                name = patch->new_name ? patch->new_name : patch->old_name;
4148                if (patch->is_binary)
4149                        printf("-\t-\t");
4150                else
4151                        printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
4152                write_name_quoted(name, stdout, state->line_termination);
4153        }
4154}
4155
4156static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
4157{
4158        if (mode)
4159                printf(" %s mode %06o %s\n", newdelete, mode, name);
4160        else
4161                printf(" %s %s\n", newdelete, name);
4162}
4163
4164static void show_mode_change(struct patch *p, int show_name)
4165{
4166        if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
4167                if (show_name)
4168                        printf(" mode change %06o => %06o %s\n",
4169                               p->old_mode, p->new_mode, p->new_name);
4170                else
4171                        printf(" mode change %06o => %06o\n",
4172                               p->old_mode, p->new_mode);
4173        }
4174}
4175
4176static void show_rename_copy(struct patch *p)
4177{
4178        const char *renamecopy = p->is_rename ? "rename" : "copy";
4179        const char *old_name, *new_name;
4180
4181        /* Find common prefix */
4182        old_name = p->old_name;
4183        new_name = p->new_name;
4184        while (1) {
4185                const char *slash_old, *slash_new;
4186                slash_old = strchr(old_name, '/');
4187                slash_new = strchr(new_name, '/');
4188                if (!slash_old ||
4189                    !slash_new ||
4190                    slash_old - old_name != slash_new - new_name ||
4191                    memcmp(old_name, new_name, slash_new - new_name))
4192                        break;
4193                old_name = slash_old + 1;
4194                new_name = slash_new + 1;
4195        }
4196        /* p->old_name thru old_name is the common prefix, and old_name and new_name
4197         * through the end of names are renames
4198         */
4199        if (old_name != p->old_name)
4200                printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
4201                       (int)(old_name - p->old_name), p->old_name,
4202                       old_name, new_name, p->score);
4203        else
4204                printf(" %s %s => %s (%d%%)\n", renamecopy,
4205                       p->old_name, p->new_name, p->score);
4206        show_mode_change(p, 0);
4207}
4208
4209static void summary_patch_list(struct patch *patch)
4210{
4211        struct patch *p;
4212
4213        for (p = patch; p; p = p->next) {
4214                if (p->is_new)
4215                        show_file_mode_name("create", p->new_mode, p->new_name);
4216                else if (p->is_delete)
4217                        show_file_mode_name("delete", p->old_mode, p->old_name);
4218                else {
4219                        if (p->is_rename || p->is_copy)
4220                                show_rename_copy(p);
4221                        else {
4222                                if (p->score) {
4223                                        printf(" rewrite %s (%d%%)\n",
4224                                               p->new_name, p->score);
4225                                        show_mode_change(p, 0);
4226                                }
4227                                else
4228                                        show_mode_change(p, 1);
4229                        }
4230                }
4231        }
4232}
4233
4234static void patch_stats(struct apply_state *state, struct patch *patch)
4235{
4236        int lines = patch->lines_added + patch->lines_deleted;
4237
4238        if (lines > state->max_change)
4239                state->max_change = lines;
4240        if (patch->old_name) {
4241                int len = quote_c_style(patch->old_name, NULL, NULL, 0);
4242                if (!len)
4243                        len = strlen(patch->old_name);
4244                if (len > state->max_len)
4245                        state->max_len = len;
4246        }
4247        if (patch->new_name) {
4248                int len = quote_c_style(patch->new_name, NULL, NULL, 0);
4249                if (!len)
4250                        len = strlen(patch->new_name);
4251                if (len > state->max_len)
4252                        state->max_len = len;
4253        }
4254}
4255
4256static int remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
4257{
4258        if (state->update_index && !state->ita_only) {
4259                if (remove_file_from_index(state->repo->index, patch->old_name) < 0)
4260                        return error(_("unable to remove %s from index"), patch->old_name);
4261        }
4262        if (!state->cached) {
4263                if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
4264                        remove_path(patch->old_name);
4265                }
4266        }
4267        return 0;
4268}
4269
4270static int add_index_file(struct apply_state *state,
4271                          const char *path,
4272                          unsigned mode,
4273                          void *buf,
4274                          unsigned long size)
4275{
4276        struct stat st;
4277        struct cache_entry *ce;
4278        int namelen = strlen(path);
4279
4280        ce = make_empty_cache_entry(state->repo->index, namelen);
4281        memcpy(ce->name, path, namelen);
4282        ce->ce_mode = create_ce_mode(mode);
4283        ce->ce_flags = create_ce_flags(0);
4284        ce->ce_namelen = namelen;
4285        if (state->ita_only) {
4286                ce->ce_flags |= CE_INTENT_TO_ADD;
4287                set_object_name_for_intent_to_add_entry(ce);
4288        } else if (S_ISGITLINK(mode)) {
4289                const char *s;
4290
4291                if (!skip_prefix(buf, "Subproject commit ", &s) ||
4292                    get_oid_hex(s, &ce->oid)) {
4293                        discard_cache_entry(ce);
4294                        return error(_("corrupt patch for submodule %s"), path);
4295                }
4296        } else {
4297                if (!state->cached) {
4298                        if (lstat(path, &st) < 0) {
4299                                discard_cache_entry(ce);
4300                                return error_errno(_("unable to stat newly "
4301                                                     "created file '%s'"),
4302                                                   path);
4303                        }
4304                        fill_stat_cache_info(ce, &st);
4305                }
4306                if (write_object_file(buf, size, blob_type, &ce->oid) < 0) {
4307                        discard_cache_entry(ce);
4308                        return error(_("unable to create backing store "
4309                                       "for newly created file %s"), path);
4310                }
4311        }
4312        if (add_index_entry(state->repo->index, ce, ADD_CACHE_OK_TO_ADD) < 0) {
4313                discard_cache_entry(ce);
4314                return error(_("unable to add cache entry for %s"), path);
4315        }
4316
4317        return 0;
4318}
4319
4320/*
4321 * Returns:
4322 *  -1 if an unrecoverable error happened
4323 *   0 if everything went well
4324 *   1 if a recoverable error happened
4325 */
4326static int try_create_file(struct apply_state *state, const char *path,
4327                           unsigned int mode, const char *buf,
4328                           unsigned long size)
4329{
4330        int fd, res;
4331        struct strbuf nbuf = STRBUF_INIT;
4332
4333        if (S_ISGITLINK(mode)) {
4334                struct stat st;
4335                if (!lstat(path, &st) && S_ISDIR(st.st_mode))
4336                        return 0;
4337                return !!mkdir(path, 0777);
4338        }
4339
4340        if (has_symlinks && S_ISLNK(mode))
4341                /* Although buf:size is counted string, it also is NUL
4342                 * terminated.
4343                 */
4344                return !!symlink(buf, path);
4345
4346        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
4347        if (fd < 0)
4348                return 1;
4349
4350        if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf)) {
4351                size = nbuf.len;
4352                buf  = nbuf.buf;
4353        }
4354
4355        res = write_in_full(fd, buf, size) < 0;
4356        if (res)
4357                error_errno(_("failed to write to '%s'"), path);
4358        strbuf_release(&nbuf);
4359
4360        if (close(fd) < 0 && !res)
4361                return error_errno(_("closing file '%s'"), path);
4362
4363        return res ? -1 : 0;
4364}
4365
4366/*
4367 * We optimistically assume that the directories exist,
4368 * which is true 99% of the time anyway. If they don't,
4369 * we create them and try again.
4370 *
4371 * Returns:
4372 *   -1 on error
4373 *   0 otherwise
4374 */
4375static int create_one_file(struct apply_state *state,
4376                           char *path,
4377                           unsigned mode,
4378                           const char *buf,
4379                           unsigned long size)
4380{
4381        int res;
4382
4383        if (state->cached)
4384                return 0;
4385
4386        res = try_create_file(state, path, mode, buf, size);
4387        if (res < 0)
4388                return -1;
4389        if (!res)
4390                return 0;
4391
4392        if (errno == ENOENT) {
4393                if (safe_create_leading_directories(path))
4394                        return 0;
4395                res = try_create_file(state, path, mode, buf, size);
4396                if (res < 0)
4397                        return -1;
4398                if (!res)
4399                        return 0;
4400        }
4401
4402        if (errno == EEXIST || errno == EACCES) {
4403                /* We may be trying to create a file where a directory
4404                 * used to be.
4405                 */
4406                struct stat st;
4407                if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
4408                        errno = EEXIST;
4409        }
4410
4411        if (errno == EEXIST) {
4412                unsigned int nr = getpid();
4413
4414                for (;;) {
4415                        char newpath[PATH_MAX];
4416                        mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
4417                        res = try_create_file(state, newpath, mode, buf, size);
4418                        if (res < 0)
4419                                return -1;
4420                        if (!res) {
4421                                if (!rename(newpath, path))
4422                                        return 0;
4423                                unlink_or_warn(newpath);
4424                                break;
4425                        }
4426                        if (errno != EEXIST)
4427                                break;
4428                        ++nr;
4429                }
4430        }
4431        return error_errno(_("unable to write file '%s' mode %o"),
4432                           path, mode);
4433}
4434
4435static int add_conflicted_stages_file(struct apply_state *state,
4436                                       struct patch *patch)
4437{
4438        int stage, namelen;
4439        unsigned mode;
4440        struct cache_entry *ce;
4441
4442        if (!state->update_index)
4443                return 0;
4444        namelen = strlen(patch->new_name);
4445        mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
4446
4447        remove_file_from_index(state->repo->index, patch->new_name);
4448        for (stage = 1; stage < 4; stage++) {
4449                if (is_null_oid(&patch->threeway_stage[stage - 1]))
4450                        continue;
4451                ce = make_empty_cache_entry(state->repo->index, namelen);
4452                memcpy(ce->name, patch->new_name, namelen);
4453                ce->ce_mode = create_ce_mode(mode);
4454                ce->ce_flags = create_ce_flags(stage);
4455                ce->ce_namelen = namelen;
4456                oidcpy(&ce->oid, &patch->threeway_stage[stage - 1]);
4457                if (add_index_entry(state->repo->index, ce, ADD_CACHE_OK_TO_ADD) < 0) {
4458                        discard_cache_entry(ce);
4459                        return error(_("unable to add cache entry for %s"),
4460                                     patch->new_name);
4461                }
4462        }
4463
4464        return 0;
4465}
4466
4467static int create_file(struct apply_state *state, struct patch *patch)
4468{
4469        char *path = patch->new_name;
4470        unsigned mode = patch->new_mode;
4471        unsigned long size = patch->resultsize;
4472        char *buf = patch->result;
4473
4474        if (!mode)
4475                mode = S_IFREG | 0644;
4476        if (create_one_file(state, path, mode, buf, size))
4477                return -1;
4478
4479        if (patch->conflicted_threeway)
4480                return add_conflicted_stages_file(state, patch);
4481        else if (state->update_index)
4482                return add_index_file(state, path, mode, buf, size);
4483        return 0;
4484}
4485
4486/* phase zero is to remove, phase one is to create */
4487static int write_out_one_result(struct apply_state *state,
4488                                struct patch *patch,
4489                                int phase)
4490{
4491        if (patch->is_delete > 0) {
4492                if (phase == 0)
4493                        return remove_file(state, patch, 1);
4494                return 0;
4495        }
4496        if (patch->is_new > 0 || patch->is_copy) {
4497                if (phase == 1)
4498                        return create_file(state, patch);
4499                return 0;
4500        }
4501        /*
4502         * Rename or modification boils down to the same
4503         * thing: remove the old, write the new
4504         */
4505        if (phase == 0)
4506                return remove_file(state, patch, patch->is_rename);
4507        if (phase == 1)
4508                return create_file(state, patch);
4509        return 0;
4510}
4511
4512static int write_out_one_reject(struct apply_state *state, struct patch *patch)
4513{
4514        FILE *rej;
4515        char namebuf[PATH_MAX];
4516        struct fragment *frag;
4517        int cnt = 0;
4518        struct strbuf sb = STRBUF_INIT;
4519
4520        for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
4521                if (!frag->rejected)
4522                        continue;
4523                cnt++;
4524        }
4525
4526        if (!cnt) {
4527                if (state->apply_verbosity > verbosity_normal)
4528                        say_patch_name(stderr,
4529                                       _("Applied patch %s cleanly."), patch);
4530                return 0;
4531        }
4532
4533        /* This should not happen, because a removal patch that leaves
4534         * contents are marked "rejected" at the patch level.
4535         */
4536        if (!patch->new_name)
4537                die(_("internal error"));
4538
4539        /* Say this even without --verbose */
4540        strbuf_addf(&sb, Q_("Applying patch %%s with %d reject...",
4541                            "Applying patch %%s with %d rejects...",
4542                            cnt),
4543                    cnt);
4544        if (state->apply_verbosity > verbosity_silent)
4545                say_patch_name(stderr, sb.buf, patch);
4546        strbuf_release(&sb);
4547
4548        cnt = strlen(patch->new_name);
4549        if (ARRAY_SIZE(namebuf) <= cnt + 5) {
4550                cnt = ARRAY_SIZE(namebuf) - 5;
4551                warning(_("truncating .rej filename to %.*s.rej"),
4552                        cnt - 1, patch->new_name);
4553        }
4554        memcpy(namebuf, patch->new_name, cnt);
4555        memcpy(namebuf + cnt, ".rej", 5);
4556
4557        rej = fopen(namebuf, "w");
4558        if (!rej)
4559                return error_errno(_("cannot open %s"), namebuf);
4560
4561        /* Normal git tools never deal with .rej, so do not pretend
4562         * this is a git patch by saying --git or giving extended
4563         * headers.  While at it, maybe please "kompare" that wants
4564         * the trailing TAB and some garbage at the end of line ;-).
4565         */
4566        fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
4567                patch->new_name, patch->new_name);
4568        for (cnt = 1, frag = patch->fragments;
4569             frag;
4570             cnt++, frag = frag->next) {
4571                if (!frag->rejected) {
4572                        if (state->apply_verbosity > verbosity_silent)
4573                                fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
4574                        continue;
4575                }
4576                if (state->apply_verbosity > verbosity_silent)
4577                        fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
4578                fprintf(rej, "%.*s", frag->size, frag->patch);
4579                if (frag->patch[frag->size-1] != '\n')
4580                        fputc('\n', rej);
4581        }
4582        fclose(rej);
4583        return -1;
4584}
4585
4586/*
4587 * Returns:
4588 *  -1 if an error happened
4589 *   0 if the patch applied cleanly
4590 *   1 if the patch did not apply cleanly
4591 */
4592static int write_out_results(struct apply_state *state, struct patch *list)
4593{
4594        int phase;
4595        int errs = 0;
4596        struct patch *l;
4597        struct string_list cpath = STRING_LIST_INIT_DUP;
4598
4599        for (phase = 0; phase < 2; phase++) {
4600                l = list;
4601                while (l) {
4602                        if (l->rejected)
4603                                errs = 1;
4604                        else {
4605                                if (write_out_one_result(state, l, phase)) {
4606                                        string_list_clear(&cpath, 0);
4607                                        return -1;
4608                                }
4609                                if (phase == 1) {
4610                                        if (write_out_one_reject(state, l))
4611                                                errs = 1;
4612                                        if (l->conflicted_threeway) {
4613                                                string_list_append(&cpath, l->new_name);
4614                                                errs = 1;
4615                                        }
4616                                }
4617                        }
4618                        l = l->next;
4619                }
4620        }
4621
4622        if (cpath.nr) {
4623                struct string_list_item *item;
4624
4625                string_list_sort(&cpath);
4626                if (state->apply_verbosity > verbosity_silent) {
4627                        for_each_string_list_item(item, &cpath)
4628                                fprintf(stderr, "U %s\n", item->string);
4629                }
4630                string_list_clear(&cpath, 0);
4631
4632                rerere(0);
4633        }
4634
4635        return errs;
4636}
4637
4638/*
4639 * Try to apply a patch.
4640 *
4641 * Returns:
4642 *  -128 if a bad error happened (like patch unreadable)
4643 *  -1 if patch did not apply and user cannot deal with it
4644 *   0 if the patch applied
4645 *   1 if the patch did not apply but user might fix it
4646 */
4647static int apply_patch(struct apply_state *state,
4648                       int fd,
4649                       const char *filename,
4650                       int options)
4651{
4652        size_t offset;
4653        struct strbuf buf = STRBUF_INIT; /* owns the patch text */
4654        struct patch *list = NULL, **listp = &list;
4655        int skipped_patch = 0;
4656        int res = 0;
4657
4658        state->patch_input_file = filename;
4659        if (read_patch_file(&buf, fd) < 0)
4660                return -128;
4661        offset = 0;
4662        while (offset < buf.len) {
4663                struct patch *patch;
4664                int nr;
4665
4666                patch = xcalloc(1, sizeof(*patch));
4667                patch->inaccurate_eof = !!(options & APPLY_OPT_INACCURATE_EOF);
4668                patch->recount =  !!(options & APPLY_OPT_RECOUNT);
4669                nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
4670                if (nr < 0) {
4671                        free_patch(patch);
4672                        if (nr == -128) {
4673                                res = -128;
4674                                goto end;
4675                        }
4676                        break;
4677                }
4678                if (state->apply_in_reverse)
4679                        reverse_patches(patch);
4680                if (use_patch(state, patch)) {
4681                        patch_stats(state, patch);
4682                        *listp = patch;
4683                        listp = &patch->next;
4684                }
4685                else {
4686                        if (state->apply_verbosity > verbosity_normal)
4687                                say_patch_name(stderr, _("Skipped patch '%s'."), patch);
4688                        free_patch(patch);
4689                        skipped_patch++;
4690                }
4691                offset += nr;
4692        }
4693
4694        if (!list && !skipped_patch) {
4695                error(_("unrecognized input"));
4696                res = -128;
4697                goto end;
4698        }
4699
4700        if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
4701                state->apply = 0;
4702
4703        state->update_index = (state->check_index || state->ita_only) && state->apply;
4704        if (state->update_index && !is_lock_file_locked(&state->lock_file)) {
4705                if (state->index_file)
4706                        hold_lock_file_for_update(&state->lock_file,
4707                                                  state->index_file,
4708                                                  LOCK_DIE_ON_ERROR);
4709                else
4710                        hold_locked_index(&state->lock_file, LOCK_DIE_ON_ERROR);
4711        }
4712
4713        if (state->check_index && read_apply_cache(state) < 0) {
4714                error(_("unable to read index file"));
4715                res = -128;
4716                goto end;
4717        }
4718
4719        if (state->check || state->apply) {
4720                int r = check_patch_list(state, list);
4721                if (r == -128) {
4722                        res = -128;
4723                        goto end;
4724                }
4725                if (r < 0 && !state->apply_with_reject) {
4726                        res = -1;
4727                        goto end;
4728                }
4729        }
4730
4731        if (state->apply) {
4732                int write_res = write_out_results(state, list);
4733                if (write_res < 0) {
4734                        res = -128;
4735                        goto end;
4736                }
4737                if (write_res > 0) {
4738                        /* with --3way, we still need to write the index out */
4739                        res = state->apply_with_reject ? -1 : 1;
4740                        goto end;
4741                }
4742        }
4743
4744        if (state->fake_ancestor &&
4745            build_fake_ancestor(state, list)) {
4746                res = -128;
4747                goto end;
4748        }
4749
4750        if (state->diffstat && state->apply_verbosity > verbosity_silent)
4751                stat_patch_list(state, list);
4752
4753        if (state->numstat && state->apply_verbosity > verbosity_silent)
4754                numstat_patch_list(state, list);
4755
4756        if (state->summary && state->apply_verbosity > verbosity_silent)
4757                summary_patch_list(list);
4758
4759end:
4760        free_patch_list(list);
4761        strbuf_release(&buf);
4762        string_list_clear(&state->fn_table, 0);
4763        return res;
4764}
4765
4766static int apply_option_parse_exclude(const struct option *opt,
4767                                      const char *arg, int unset)
4768{
4769        struct apply_state *state = opt->value;
4770        add_name_limit(state, arg, 1);
4771        return 0;
4772}
4773
4774static int apply_option_parse_include(const struct option *opt,
4775                                      const char *arg, int unset)
4776{
4777        struct apply_state *state = opt->value;
4778        add_name_limit(state, arg, 0);
4779        state->has_include = 1;
4780        return 0;
4781}
4782
4783static int apply_option_parse_p(const struct option *opt,
4784                                const char *arg,
4785                                int unset)
4786{
4787        struct apply_state *state = opt->value;
4788        state->p_value = atoi(arg);
4789        state->p_value_known = 1;
4790        return 0;
4791}
4792
4793static int apply_option_parse_space_change(const struct option *opt,
4794                                           const char *arg, int unset)
4795{
4796        struct apply_state *state = opt->value;
4797        if (unset)
4798                state->ws_ignore_action = ignore_ws_none;
4799        else
4800                state->ws_ignore_action = ignore_ws_change;
4801        return 0;
4802}
4803
4804static int apply_option_parse_whitespace(const struct option *opt,
4805                                         const char *arg, int unset)
4806{
4807        struct apply_state *state = opt->value;
4808        state->whitespace_option = arg;
4809        if (parse_whitespace_option(state, arg))
4810                exit(1);
4811        return 0;
4812}
4813
4814static int apply_option_parse_directory(const struct option *opt,
4815                                        const char *arg, int unset)
4816{
4817        struct apply_state *state = opt->value;
4818        strbuf_reset(&state->root);
4819        strbuf_addstr(&state->root, arg);
4820        strbuf_complete(&state->root, '/');
4821        return 0;
4822}
4823
4824int apply_all_patches(struct apply_state *state,
4825                      int argc,
4826                      const char **argv,
4827                      int options)
4828{
4829        int i;
4830        int res;
4831        int errs = 0;
4832        int read_stdin = 1;
4833
4834        for (i = 0; i < argc; i++) {
4835                const char *arg = argv[i];
4836                char *to_free = NULL;
4837                int fd;
4838
4839                if (!strcmp(arg, "-")) {
4840                        res = apply_patch(state, 0, "<stdin>", options);
4841                        if (res < 0)
4842                                goto end;
4843                        errs |= res;
4844                        read_stdin = 0;
4845                        continue;
4846                } else
4847                        arg = to_free = prefix_filename(state->prefix, arg);
4848
4849                fd = open(arg, O_RDONLY);
4850                if (fd < 0) {
4851                        error(_("can't open patch '%s': %s"), arg, strerror(errno));
4852                        res = -128;
4853                        free(to_free);
4854                        goto end;
4855                }
4856                read_stdin = 0;
4857                set_default_whitespace_mode(state);
4858                res = apply_patch(state, fd, arg, options);
4859                close(fd);
4860                free(to_free);
4861                if (res < 0)
4862                        goto end;
4863                errs |= res;
4864        }
4865        set_default_whitespace_mode(state);
4866        if (read_stdin) {
4867                res = apply_patch(state, 0, "<stdin>", options);
4868                if (res < 0)
4869                        goto end;
4870                errs |= res;
4871        }
4872
4873        if (state->whitespace_error) {
4874                if (state->squelch_whitespace_errors &&
4875                    state->squelch_whitespace_errors < state->whitespace_error) {
4876                        int squelched =
4877                                state->whitespace_error - state->squelch_whitespace_errors;
4878                        warning(Q_("squelched %d whitespace error",
4879                                   "squelched %d whitespace errors",
4880                                   squelched),
4881                                squelched);
4882                }
4883                if (state->ws_error_action == die_on_ws_error) {
4884                        error(Q_("%d line adds whitespace errors.",
4885                                 "%d lines add whitespace errors.",
4886                                 state->whitespace_error),
4887                              state->whitespace_error);
4888                        res = -128;
4889                        goto end;
4890                }
4891                if (state->applied_after_fixing_ws && state->apply)
4892                        warning(Q_("%d line applied after"
4893                                   " fixing whitespace errors.",
4894                                   "%d lines applied after"
4895                                   " fixing whitespace errors.",
4896                                   state->applied_after_fixing_ws),
4897                                state->applied_after_fixing_ws);
4898                else if (state->whitespace_error)
4899                        warning(Q_("%d line adds whitespace errors.",
4900                                   "%d lines add whitespace errors.",
4901                                   state->whitespace_error),
4902                                state->whitespace_error);
4903        }
4904
4905        if (state->update_index) {
4906                res = write_locked_index(state->repo->index, &state->lock_file, COMMIT_LOCK);
4907                if (res) {
4908                        error(_("Unable to write new index file"));
4909                        res = -128;
4910                        goto end;
4911                }
4912        }
4913
4914        res = !!errs;
4915
4916end:
4917        rollback_lock_file(&state->lock_file);
4918
4919        if (state->apply_verbosity <= verbosity_silent) {
4920                set_error_routine(state->saved_error_routine);
4921                set_warn_routine(state->saved_warn_routine);
4922        }
4923
4924        if (res > -1)
4925                return res;
4926        return (res == -1 ? 1 : 128);
4927}
4928
4929int apply_parse_options(int argc, const char **argv,
4930                        struct apply_state *state,
4931                        int *force_apply, int *options,
4932                        const char * const *apply_usage)
4933{
4934        struct option builtin_apply_options[] = {
4935                { OPTION_CALLBACK, 0, "exclude", state, N_("path"),
4936                        N_("don't apply changes matching the given path"),
4937                        0, apply_option_parse_exclude },
4938                { OPTION_CALLBACK, 0, "include", state, N_("path"),
4939                        N_("apply changes matching the given path"),
4940                        0, apply_option_parse_include },
4941                { OPTION_CALLBACK, 'p', NULL, state, N_("num"),
4942                        N_("remove <num> leading slashes from traditional diff paths"),
4943                        0, apply_option_parse_p },
4944                OPT_BOOL(0, "no-add", &state->no_add,
4945                        N_("ignore additions made by the patch")),
4946                OPT_BOOL(0, "stat", &state->diffstat,
4947                        N_("instead of applying the patch, output diffstat for the input")),
4948                OPT_NOOP_NOARG(0, "allow-binary-replacement"),
4949                OPT_NOOP_NOARG(0, "binary"),
4950                OPT_BOOL(0, "numstat", &state->numstat,
4951                        N_("show number of added and deleted lines in decimal notation")),
4952                OPT_BOOL(0, "summary", &state->summary,
4953                        N_("instead of applying the patch, output a summary for the input")),
4954                OPT_BOOL(0, "check", &state->check,
4955                        N_("instead of applying the patch, see if the patch is applicable")),
4956                OPT_BOOL(0, "index", &state->check_index,
4957                        N_("make sure the patch is applicable to the current index")),
4958                OPT_BOOL('N', "intent-to-add", &state->ita_only,
4959                        N_("mark new files with `git add --intent-to-add`")),
4960                OPT_BOOL(0, "cached", &state->cached,
4961                        N_("apply a patch without touching the working tree")),
4962                OPT_BOOL_F(0, "unsafe-paths", &state->unsafe_paths,
4963                           N_("accept a patch that touches outside the working area"),
4964                           PARSE_OPT_NOCOMPLETE),
4965                OPT_BOOL(0, "apply", force_apply,
4966                        N_("also apply the patch (use with --stat/--summary/--check)")),
4967                OPT_BOOL('3', "3way", &state->threeway,
4968                         N_( "attempt three-way merge if a patch does not apply")),
4969                OPT_FILENAME(0, "build-fake-ancestor", &state->fake_ancestor,
4970                        N_("build a temporary index based on embedded index information")),
4971                /* Think twice before adding "--nul" synonym to this */
4972                OPT_SET_INT('z', NULL, &state->line_termination,
4973                        N_("paths are separated with NUL character"), '\0'),
4974                OPT_INTEGER('C', NULL, &state->p_context,
4975                                N_("ensure at least <n> lines of context match")),
4976                { OPTION_CALLBACK, 0, "whitespace", state, N_("action"),
4977                        N_("detect new or modified lines that have whitespace errors"),
4978                        0, apply_option_parse_whitespace },
4979                { OPTION_CALLBACK, 0, "ignore-space-change", state, NULL,
4980                        N_("ignore changes in whitespace when finding context"),
4981                        PARSE_OPT_NOARG, apply_option_parse_space_change },
4982                { OPTION_CALLBACK, 0, "ignore-whitespace", state, NULL,
4983                        N_("ignore changes in whitespace when finding context"),
4984                        PARSE_OPT_NOARG, apply_option_parse_space_change },
4985                OPT_BOOL('R', "reverse", &state->apply_in_reverse,
4986                        N_("apply the patch in reverse")),
4987                OPT_BOOL(0, "unidiff-zero", &state->unidiff_zero,
4988                        N_("don't expect at least one line of context")),
4989                OPT_BOOL(0, "reject", &state->apply_with_reject,
4990                        N_("leave the rejected hunks in corresponding *.rej files")),
4991                OPT_BOOL(0, "allow-overlap", &state->allow_overlap,
4992                        N_("allow overlapping hunks")),
4993                OPT__VERBOSE(&state->apply_verbosity, N_("be verbose")),
4994                OPT_BIT(0, "inaccurate-eof", options,
4995                        N_("tolerate incorrectly detected missing new-line at the end of file"),
4996                        APPLY_OPT_INACCURATE_EOF),
4997                OPT_BIT(0, "recount", options,
4998                        N_("do not trust the line counts in the hunk headers"),
4999                        APPLY_OPT_RECOUNT),
5000                { OPTION_CALLBACK, 0, "directory", state, N_("root"),
5001                        N_("prepend <root> to all filenames"),
5002                        0, apply_option_parse_directory },
5003                OPT_END()
5004        };
5005
5006        return parse_options(argc, argv, state->prefix, builtin_apply_options, apply_usage, 0);
5007}