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   1 /*
   2  * Builtin "git am"
   3  *
   4  * Based on git-am.sh by Junio C Hamano.
   5  */
   6 #include "cache.h"
   7 #include "config.h"
   8 #include "builtin.h"
   9 #include "exec-cmd.h"
  10 #include "parse-options.h"
  11 #include "dir.h"
  12 #include "run-command.h"
  13 #include "quote.h"
  14 #include "tempfile.h"
  15 #include "lockfile.h"
  16 #include "cache-tree.h"
  17 #include "refs.h"
  18 #include "commit.h"
  19 #include "diff.h"
  20 #include "diffcore.h"
  21 #include "unpack-trees.h"
  22 #include "branch.h"
  23 #include "sequencer.h"
  24 #include "revision.h"
  25 #include "merge-recursive.h"
  26 #include "revision.h"
  27 #include "log-tree.h"
  28 #include "notes-utils.h"
  29 #include "rerere.h"
  30 #include "prompt.h"
  31 #include "mailinfo.h"
  32 #include "apply.h"
  33 #include "string-list.h"
  34 #include "packfile.h"
  35 #include "repository.h"
  36
  37 /**
  38  * Returns 1 if the file is empty or does not exist, 0 otherwise.
  39  */
  40 static int is_empty_file(const char *filename)
  41 {
  42         struct stat st;
  43
  44         if (stat(filename, &st) < 0) {
  45                 if (errno == ENOENT)
  46                         return 1;
  47                 die_errno(_("could not stat %s"), filename);
  48         }
  49
  50         return !st.st_size;
  51 }
  52
  53 /**
  54  * Returns the length of the first line of msg.
  55  */
  56 static int linelen(const char *msg)
  57 {
  58         return strchrnul(msg, '\n') - msg;
  59 }
  60
  61 /**
  62  * Returns true if `str` consists of only whitespace, false otherwise.
  63  */
  64 static int str_isspace(const char *str)
  65 {
  66         for (; *str; str++)
  67                 if (!isspace(*str))
  68                         return 0;
  69
  70         return 1;
  71 }
  72
  73 enum patch_format {
  74         PATCH_FORMAT_UNKNOWN = 0,
  75         PATCH_FORMAT_MBOX,
  76         PATCH_FORMAT_STGIT,
  77         PATCH_FORMAT_STGIT_SERIES,
  78         PATCH_FORMAT_HG,
  79         PATCH_FORMAT_MBOXRD
  80 };
  81
  82 enum keep_type {
  83         KEEP_FALSE = 0,
  84         KEEP_TRUE,      /* pass -k flag to git-mailinfo */
  85         KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
  86 };
  87
  88 enum scissors_type {
  89         SCISSORS_UNSET = -1,
  90         SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
  91         SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
  92 };
  93
  94 enum signoff_type {
  95         SIGNOFF_FALSE = 0,
  96         SIGNOFF_TRUE = 1,
  97         SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
  98 };
  99
 100 struct am_state {
 101         /* state directory path */
 102         char *dir;
 103
 104         /* current and last patch numbers, 1-indexed */
 105         int cur;
 106         int last;
 107
 108         /* commit metadata and message */
 109         char *author_name;
 110         char *author_email;
 111         char *author_date;
 112         char *msg;
 113         size_t msg_len;
 114
 115         /* when --rebasing, records the original commit the patch came from */
 116         struct object_id orig_commit;
 117
 118         /* number of digits in patch filename */
 119         int prec;
 120
 121         /* various operating modes and command line options */
 122         int interactive;
 123         int threeway;
 124         int quiet;
 125         int signoff; /* enum signoff_type */
 126         int utf8;
 127         int keep; /* enum keep_type */
 128         int message_id;
 129         int scissors; /* enum scissors_type */
 130         struct argv_array git_apply_opts;
 131         const char *resolvemsg;
 132         int committer_date_is_author_date;
 133         int ignore_date;
 134         int allow_rerere_autoupdate;
 135         const char *sign_commit;
 136         int rebasing;
 137 };
 138
 139 /**
 140  * Initializes am_state with the default values.
 141  */
 142 static void am_state_init(struct am_state *state)
 143 {
 144         int gpgsign;
 145
 146         memset(state, 0, sizeof(*state));
 147
 148         state->dir = git_pathdup("rebase-apply");
 149
 150         state->prec = 4;
 151
 152         git_config_get_bool("am.threeway", &state->threeway);
 153
 154         state->utf8 = 1;
 155
 156         git_config_get_bool("am.messageid", &state->message_id);
 157
 158         state->scissors = SCISSORS_UNSET;
 159
 160         argv_array_init(&state->git_apply_opts);
 161
 162         if (!git_config_get_bool("commit.gpgsign", &gpgsign))
 163                 state->sign_commit = gpgsign ? "" : NULL;
 164 }
 165
 166 /**
 167  * Releases memory allocated by an am_state.
 168  */
 169 static void am_state_release(struct am_state *state)
 170 {
 171         free(state->dir);
 172         free(state->author_name);
 173         free(state->author_email);
 174         free(state->author_date);
 175         free(state->msg);
 176         argv_array_clear(&state->git_apply_opts);
 177 }
 178
 179 /**
 180  * Returns path relative to the am_state directory.
 181  */
 182 static inline const char *am_path(const struct am_state *state, const char *path)
 183 {
 184         return mkpath("%s/%s", state->dir, path);
 185 }
 186
 187 /**
 188  * For convenience to call write_file()
 189  */
 190 static void write_state_text(const struct am_state *state,
 191                              const char *name, const char *string)
 192 {
 193         write_file(am_path(state, name), "%s", string);
 194 }
 195
 196 static void write_state_count(const struct am_state *state,
 197                               const char *name, int value)
 198 {
 199         write_file(am_path(state, name), "%d", value);
 200 }
 201
 202 static void write_state_bool(const struct am_state *state,
 203                              const char *name, int value)
 204 {
 205         write_state_text(state, name, value ? "t" : "f");
 206 }
 207
 208 /**
 209  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
 210  * at the end.
 211  */
 212 static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
 213 {
 214         va_list ap;
 215
 216         va_start(ap, fmt);
 217         if (!state->quiet) {
 218                 vfprintf(fp, fmt, ap);
 219                 putc('\n', fp);
 220         }
 221         va_end(ap);
 222 }
 223
 224 /**
 225  * Returns 1 if there is an am session in progress, 0 otherwise.
 226  */
 227 static int am_in_progress(const struct am_state *state)
 228 {
 229         struct stat st;
 230
 231         if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
 232                 return 0;
 233         if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
 234                 return 0;
 235         if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
 236                 return 0;
 237         return 1;
 238 }
 239
 240 /**
 241  * Reads the contents of `file` in the `state` directory into `sb`. Returns the
 242  * number of bytes read on success, -1 if the file does not exist. If `trim` is
 243  * set, trailing whitespace will be removed.
 244  */
 245 static int read_state_file(struct strbuf *sb, const struct am_state *state,
 246                         const char *file, int trim)
 247 {
 248         strbuf_reset(sb);
 249
 250         if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
 251                 if (trim)
 252                         strbuf_trim(sb);
 253
 254                 return sb->len;
 255         }
 256
 257         if (errno == ENOENT)
 258                 return -1;
 259
 260         die_errno(_("could not read '%s'"), am_path(state, file));
 261 }
 262
 263 /**
 264  * Take a series of KEY='VALUE' lines where VALUE part is
 265  * sq-quoted, and append <KEY, VALUE> at the end of the string list
 266  */
 267 static int parse_key_value_squoted(char *buf, struct string_list *list)
 268 {
 269         while (*buf) {
 270                 struct string_list_item *item;
 271                 char *np;
 272                 char *cp = strchr(buf, '=');
 273                 if (!cp)
 274                         return -1;
 275                 np = strchrnul(cp, '\n');
 276                 *cp++ = '\0';
 277                 item = string_list_append(list, buf);
 278
 279                 buf = np + (*np == '\n');
 280                 *np = '\0';
 281                 cp = sq_dequote(cp);
 282                 if (!cp)
 283                         return -1;
 284                 item->util = xstrdup(cp);
 285         }
 286         return 0;
 287 }
 288
 289 /**
 290  * Reads and parses the state directory's "author-script" file, and sets
 291  * state->author_name, state->author_email and state->author_date accordingly.
 292  * Returns 0 on success, -1 if the file could not be parsed.
 293  *
 294  * The author script is of the format:
 295  *
 296  *      GIT_AUTHOR_NAME='$author_name'
 297  *      GIT_AUTHOR_EMAIL='$author_email'
 298  *      GIT_AUTHOR_DATE='$author_date'
 299  *
 300  * where $author_name, $author_email and $author_date are quoted. We are strict
 301  * with our parsing, as the file was meant to be eval'd in the old git-am.sh
 302  * script, and thus if the file differs from what this function expects, it is
 303  * better to bail out than to do something that the user does not expect.
 304  */
 305 static int read_author_script(struct am_state *state)
 306 {
 307         const char *filename = am_path(state, "author-script");
 308         struct strbuf buf = STRBUF_INIT;
 309         struct string_list kv = STRING_LIST_INIT_DUP;
 310         int retval = -1; /* assume failure */
 311         int fd;
 312
 313         assert(!state->author_name);
 314         assert(!state->author_email);
 315         assert(!state->author_date);
 316
 317         fd = open(filename, O_RDONLY);
 318         if (fd < 0) {
 319                 if (errno == ENOENT)
 320                         return 0;
 321                 die_errno(_("could not open '%s' for reading"), filename);
 322         }
 323         strbuf_read(&buf, fd, 0);
 324         close(fd);
 325         if (parse_key_value_squoted(buf.buf, &kv))
 326                 goto finish;
 327
 328         if (kv.nr != 3 ||
 329             strcmp(kv.items[0].string, "GIT_AUTHOR_NAME") ||
 330             strcmp(kv.items[1].string, "GIT_AUTHOR_EMAIL") ||
 331             strcmp(kv.items[2].string, "GIT_AUTHOR_DATE"))
 332                 goto finish;
 333         state->author_name = kv.items[0].util;
 334         state->author_email = kv.items[1].util;
 335         state->author_date = kv.items[2].util;
 336         retval = 0;
 337 finish:
 338         string_list_clear(&kv, !!retval);
 339         strbuf_release(&buf);
 340         return retval;
 341 }
 342
 343 /**
 344  * Saves state->author_name, state->author_email and state->author_date in the
 345  * state directory's "author-script" file.
 346  */
 347 static void write_author_script(const struct am_state *state)
 348 {
 349         struct strbuf sb = STRBUF_INIT;
 350
 351         strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
 352         sq_quote_buf(&sb, state->author_name);
 353         strbuf_addch(&sb, '\n');
 354
 355         strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
 356         sq_quote_buf(&sb, state->author_email);
 357         strbuf_addch(&sb, '\n');
 358
 359         strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
 360         sq_quote_buf(&sb, state->author_date);
 361         strbuf_addch(&sb, '\n');
 362
 363         write_state_text(state, "author-script", sb.buf);
 364
 365         strbuf_release(&sb);
 366 }
 367
 368 /**
 369  * Reads the commit message from the state directory's "final-commit" file,
 370  * setting state->msg to its contents and state->msg_len to the length of its
 371  * contents in bytes.
 372  *
 373  * Returns 0 on success, -1 if the file does not exist.
 374  */
 375 static int read_commit_msg(struct am_state *state)
 376 {
 377         struct strbuf sb = STRBUF_INIT;
 378
 379         assert(!state->msg);
 380
 381         if (read_state_file(&sb, state, "final-commit", 0) < 0) {
 382                 strbuf_release(&sb);
 383                 return -1;
 384         }
 385
 386         state->msg = strbuf_detach(&sb, &state->msg_len);
 387         return 0;
 388 }
 389
 390 /**
 391  * Saves state->msg in the state directory's "final-commit" file.
 392  */
 393 static void write_commit_msg(const struct am_state *state)
 394 {
 395         const char *filename = am_path(state, "final-commit");
 396         write_file_buf(filename, state->msg, state->msg_len);
 397 }
 398
 399 /**
 400  * Loads state from disk.
 401  */
 402 static void am_load(struct am_state *state)
 403 {
 404         struct strbuf sb = STRBUF_INIT;
 405
 406         if (read_state_file(&sb, state, "next", 1) < 0)
 407                 BUG("state file 'next' does not exist");
 408         state->cur = strtol(sb.buf, NULL, 10);
 409
 410         if (read_state_file(&sb, state, "last", 1) < 0)
 411                 BUG("state file 'last' does not exist");
 412         state->last = strtol(sb.buf, NULL, 10);
 413
 414         if (read_author_script(state) < 0)
 415                 die(_("could not parse author script"));
 416
 417         read_commit_msg(state);
 418
 419         if (read_state_file(&sb, state, "original-commit", 1) < 0)
 420                 oidclr(&state->orig_commit);
 421         else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
 422                 die(_("could not parse %s"), am_path(state, "original-commit"));
 423
 424         read_state_file(&sb, state, "threeway", 1);
 425         state->threeway = !strcmp(sb.buf, "t");
 426
 427         read_state_file(&sb, state, "quiet", 1);
 428         state->quiet = !strcmp(sb.buf, "t");
 429
 430         read_state_file(&sb, state, "sign", 1);
 431         state->signoff = !strcmp(sb.buf, "t");
 432
 433         read_state_file(&sb, state, "utf8", 1);
 434         state->utf8 = !strcmp(sb.buf, "t");
 435
 436         if (file_exists(am_path(state, "rerere-autoupdate"))) {
 437                 read_state_file(&sb, state, "rerere-autoupdate", 1);
 438                 state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
 439                         RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
 440         } else {
 441                 state->allow_rerere_autoupdate = 0;
 442         }
 443
 444         read_state_file(&sb, state, "keep", 1);
 445         if (!strcmp(sb.buf, "t"))
 446                 state->keep = KEEP_TRUE;
 447         else if (!strcmp(sb.buf, "b"))
 448                 state->keep = KEEP_NON_PATCH;
 449         else
 450                 state->keep = KEEP_FALSE;
 451
 452         read_state_file(&sb, state, "messageid", 1);
 453         state->message_id = !strcmp(sb.buf, "t");
 454
 455         read_state_file(&sb, state, "scissors", 1);
 456         if (!strcmp(sb.buf, "t"))
 457                 state->scissors = SCISSORS_TRUE;
 458         else if (!strcmp(sb.buf, "f"))
 459                 state->scissors = SCISSORS_FALSE;
 460         else
 461                 state->scissors = SCISSORS_UNSET;
 462
 463         read_state_file(&sb, state, "apply-opt", 1);
 464         argv_array_clear(&state->git_apply_opts);
 465         if (sq_dequote_to_argv_array(sb.buf, &state->git_apply_opts) < 0)
 466                 die(_("could not parse %s"), am_path(state, "apply-opt"));
 467
 468         state->rebasing = !!file_exists(am_path(state, "rebasing"));
 469
 470         strbuf_release(&sb);
 471 }
 472
 473 /**
 474  * Removes the am_state directory, forcefully terminating the current am
 475  * session.
 476  */
 477 static void am_destroy(const struct am_state *state)
 478 {
 479         struct strbuf sb = STRBUF_INIT;
 480
 481         strbuf_addstr(&sb, state->dir);
 482         remove_dir_recursively(&sb, 0);
 483         strbuf_release(&sb);
 484 }
 485
 486 /**
 487  * Runs applypatch-msg hook. Returns its exit code.
 488  */
 489 static int run_applypatch_msg_hook(struct am_state *state)
 490 {
 491         int ret;
 492
 493         assert(state->msg);
 494         ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
 495
 496         if (!ret) {
 497                 FREE_AND_NULL(state->msg);
 498                 if (read_commit_msg(state) < 0)
 499                         die(_("'%s' was deleted by the applypatch-msg hook"),
 500                                 am_path(state, "final-commit"));
 501         }
 502
 503         return ret;
 504 }
 505
 506 /**
 507  * Runs post-rewrite hook. Returns it exit code.
 508  */
 509 static int run_post_rewrite_hook(const struct am_state *state)
 510 {
 511         struct child_process cp = CHILD_PROCESS_INIT;
 512         const char *hook = find_hook("post-rewrite");
 513         int ret;
 514
 515         if (!hook)
 516                 return 0;
 517
 518         argv_array_push(&cp.args, hook);
 519         argv_array_push(&cp.args, "rebase");
 520
 521         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
 522         cp.stdout_to_stderr = 1;
 523
 524         ret = run_command(&cp);
 525
 526         close(cp.in);
 527         return ret;
 528 }
 529
 530 /**
 531  * Reads the state directory's "rewritten" file, and copies notes from the old
 532  * commits listed in the file to their rewritten commits.
 533  *
 534  * Returns 0 on success, -1 on failure.
 535  */
 536 static int copy_notes_for_rebase(const struct am_state *state)
 537 {
 538         struct notes_rewrite_cfg *c;
 539         struct strbuf sb = STRBUF_INIT;
 540         const char *invalid_line = _("Malformed input line: '%s'.");
 541         const char *msg = "Notes added by 'git rebase'";
 542         FILE *fp;
 543         int ret = 0;
 544
 545         assert(state->rebasing);
 546
 547         c = init_copy_notes_for_rewrite("rebase");
 548         if (!c)
 549                 return 0;
 550
 551         fp = xfopen(am_path(state, "rewritten"), "r");
 552
 553         while (!strbuf_getline_lf(&sb, fp)) {
 554                 struct object_id from_obj, to_obj;
 555
 556                 if (sb.len != GIT_SHA1_HEXSZ * 2 + 1) {
 557                         ret = error(invalid_line, sb.buf);
 558                         goto finish;
 559                 }
 560
 561                 if (get_oid_hex(sb.buf, &from_obj)) {
 562                         ret = error(invalid_line, sb.buf);
 563                         goto finish;
 564                 }
 565
 566                 if (sb.buf[GIT_SHA1_HEXSZ] != ' ') {
 567                         ret = error(invalid_line, sb.buf);
 568                         goto finish;
 569                 }
 570
 571                 if (get_oid_hex(sb.buf + GIT_SHA1_HEXSZ + 1, &to_obj)) {
 572                         ret = error(invalid_line, sb.buf);
 573                         goto finish;
 574                 }
 575
 576                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
 577                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
 578                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
 579         }
 580
 581 finish:
 582         finish_copy_notes_for_rewrite(c, msg);
 583         fclose(fp);
 584         strbuf_release(&sb);
 585         return ret;
 586 }
 587
 588 /**
 589  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
 590  * non-indented lines and checking if they look like they begin with valid
 591  * header field names.
 592  *
 593  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
 594  */
 595 static int is_mail(FILE *fp)
 596 {
 597         const char *header_regex = "^[!-9;-~]+:";
 598         struct strbuf sb = STRBUF_INIT;
 599         regex_t regex;
 600         int ret = 1;
 601
 602         if (fseek(fp, 0L, SEEK_SET))
 603                 die_errno(_("fseek failed"));
 604
 605         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
 606                 die("invalid pattern: %s", header_regex);
 607
 608         while (!strbuf_getline(&sb, fp)) {
 609                 if (!sb.len)
 610                         break; /* End of header */
 611
 612                 /* Ignore indented folded lines */
 613                 if (*sb.buf == '\t' || *sb.buf == ' ')
 614                         continue;
 615
 616                 /* It's a header if it matches header_regex */
 617                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
 618                         ret = 0;
 619                         goto done;
 620                 }
 621         }
 622
 623 done:
 624         regfree(&regex);
 625         strbuf_release(&sb);
 626         return ret;
 627 }
 628
 629 /**
 630  * Attempts to detect the patch_format of the patches contained in `paths`,
 631  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
 632  * detection fails.
 633  */
 634 static int detect_patch_format(const char **paths)
 635 {
 636         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
 637         struct strbuf l1 = STRBUF_INIT;
 638         struct strbuf l2 = STRBUF_INIT;
 639         struct strbuf l3 = STRBUF_INIT;
 640         FILE *fp;
 641
 642         /*
 643          * We default to mbox format if input is from stdin and for directories
 644          */
 645         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
 646                 return PATCH_FORMAT_MBOX;
 647
 648         /*
 649          * Otherwise, check the first few lines of the first patch, starting
 650          * from the first non-blank line, to try to detect its format.
 651          */
 652
 653         fp = xfopen(*paths, "r");
 654
 655         while (!strbuf_getline(&l1, fp)) {
 656                 if (l1.len)
 657                         break;
 658         }
 659
 660         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
 661                 ret = PATCH_FORMAT_MBOX;
 662                 goto done;
 663         }
 664
 665         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
 666                 ret = PATCH_FORMAT_STGIT_SERIES;
 667                 goto done;
 668         }
 669
 670         if (!strcmp(l1.buf, "# HG changeset patch")) {
 671                 ret = PATCH_FORMAT_HG;
 672                 goto done;
 673         }
 674
 675         strbuf_getline(&l2, fp);
 676         strbuf_getline(&l3, fp);
 677
 678         /*
 679          * If the second line is empty and the third is a From, Author or Date
 680          * entry, this is likely an StGit patch.
 681          */
 682         if (l1.len && !l2.len &&
 683                 (starts_with(l3.buf, "From:") ||
 684                  starts_with(l3.buf, "Author:") ||
 685                  starts_with(l3.buf, "Date:"))) {
 686                 ret = PATCH_FORMAT_STGIT;
 687                 goto done;
 688         }
 689
 690         if (l1.len && is_mail(fp)) {
 691                 ret = PATCH_FORMAT_MBOX;
 692                 goto done;
 693         }
 694
 695 done:
 696         fclose(fp);
 697         strbuf_release(&l1);
 698         strbuf_release(&l2);
 699         strbuf_release(&l3);
 700         return ret;
 701 }
 702
 703 /**
 704  * Splits out individual email patches from `paths`, where each path is either
 705  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
 706  */
 707 static int split_mail_mbox(struct am_state *state, const char **paths,
 708                                 int keep_cr, int mboxrd)
 709 {
 710         struct child_process cp = CHILD_PROCESS_INIT;
 711         struct strbuf last = STRBUF_INIT;
 712         int ret;
 713
 714         cp.git_cmd = 1;
 715         argv_array_push(&cp.args, "mailsplit");
 716         argv_array_pushf(&cp.args, "-d%d", state->prec);
 717         argv_array_pushf(&cp.args, "-o%s", state->dir);
 718         argv_array_push(&cp.args, "-b");
 719         if (keep_cr)
 720                 argv_array_push(&cp.args, "--keep-cr");
 721         if (mboxrd)
 722                 argv_array_push(&cp.args, "--mboxrd");
 723         argv_array_push(&cp.args, "--");
 724         argv_array_pushv(&cp.args, paths);
 725
 726         ret = capture_command(&cp, &last, 8);
 727         if (ret)
 728                 goto exit;
 729
 730         state->cur = 1;
 731         state->last = strtol(last.buf, NULL, 10);
 732
 733 exit:
 734         strbuf_release(&last);
 735         return ret ? -1 : 0;
 736 }
 737
 738 /**
 739  * Callback signature for split_mail_conv(). The foreign patch should be
 740  * read from `in`, and the converted patch (in RFC2822 mail format) should be
 741  * written to `out`. Return 0 on success, or -1 on failure.
 742  */
 743 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
 744
 745 /**
 746  * Calls `fn` for each file in `paths` to convert the foreign patch to the
 747  * RFC2822 mail format suitable for parsing with git-mailinfo.
 748  *
 749  * Returns 0 on success, -1 on failure.
 750  */
 751 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
 752                         const char **paths, int keep_cr)
 753 {
 754         static const char *stdin_only[] = {"-", NULL};
 755         int i;
 756
 757         if (!*paths)
 758                 paths = stdin_only;
 759
 760         for (i = 0; *paths; paths++, i++) {
 761                 FILE *in, *out;
 762                 const char *mail;
 763                 int ret;
 764
 765                 if (!strcmp(*paths, "-"))
 766                         in = stdin;
 767                 else
 768                         in = fopen(*paths, "r");
 769
 770                 if (!in)
 771                         return error_errno(_("could not open '%s' for reading"),
 772                                            *paths);
 773
 774                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
 775
 776                 out = fopen(mail, "w");
 777                 if (!out) {
 778                         if (in != stdin)
 779                                 fclose(in);
 780                         return error_errno(_("could not open '%s' for writing"),
 781                                            mail);
 782                 }
 783
 784                 ret = fn(out, in, keep_cr);
 785
 786                 fclose(out);
 787                 if (in != stdin)
 788                         fclose(in);
 789
 790                 if (ret)
 791                         return error(_("could not parse patch '%s'"), *paths);
 792         }
 793
 794         state->cur = 1;
 795         state->last = i;
 796         return 0;
 797 }
 798
 799 /**
 800  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
 801  * message suitable for parsing with git-mailinfo.
 802  */
 803 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 804 {
 805         struct strbuf sb = STRBUF_INIT;
 806         int subject_printed = 0;
 807
 808         while (!strbuf_getline_lf(&sb, in)) {
 809                 const char *str;
 810
 811                 if (str_isspace(sb.buf))
 812                         continue;
 813                 else if (skip_prefix(sb.buf, "Author:", &str))
 814                         fprintf(out, "From:%s\n", str);
 815                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
 816                         fprintf(out, "%s\n", sb.buf);
 817                 else if (!subject_printed) {
 818                         fprintf(out, "Subject: %s\n", sb.buf);
 819                         subject_printed = 1;
 820                 } else {
 821                         fprintf(out, "\n%s\n", sb.buf);
 822                         break;
 823                 }
 824         }
 825
 826         strbuf_reset(&sb);
 827         while (strbuf_fread(&sb, 8192, in) > 0) {
 828                 fwrite(sb.buf, 1, sb.len, out);
 829                 strbuf_reset(&sb);
 830         }
 831
 832         strbuf_release(&sb);
 833         return 0;
 834 }
 835
 836 /**
 837  * This function only supports a single StGit series file in `paths`.
 838  *
 839  * Given an StGit series file, converts the StGit patches in the series into
 840  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
 841  * the state directory.
 842  *
 843  * Returns 0 on success, -1 on failure.
 844  */
 845 static int split_mail_stgit_series(struct am_state *state, const char **paths,
 846                                         int keep_cr)
 847 {
 848         const char *series_dir;
 849         char *series_dir_buf;
 850         FILE *fp;
 851         struct argv_array patches = ARGV_ARRAY_INIT;
 852         struct strbuf sb = STRBUF_INIT;
 853         int ret;
 854
 855         if (!paths[0] || paths[1])
 856                 return error(_("Only one StGIT patch series can be applied at once"));
 857
 858         series_dir_buf = xstrdup(*paths);
 859         series_dir = dirname(series_dir_buf);
 860
 861         fp = fopen(*paths, "r");
 862         if (!fp)
 863                 return error_errno(_("could not open '%s' for reading"), *paths);
 864
 865         while (!strbuf_getline_lf(&sb, fp)) {
 866                 if (*sb.buf == '#')
 867                         continue; /* skip comment lines */
 868
 869                 argv_array_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
 870         }
 871
 872         fclose(fp);
 873         strbuf_release(&sb);
 874         free(series_dir_buf);
 875
 876         ret = split_mail_conv(stgit_patch_to_mail, state, patches.argv, keep_cr);
 877
 878         argv_array_clear(&patches);
 879         return ret;
 880 }
 881
 882 /**
 883  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
 884  * message suitable for parsing with git-mailinfo.
 885  */
 886 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 887 {
 888         struct strbuf sb = STRBUF_INIT;
 889         int rc = 0;
 890
 891         while (!strbuf_getline_lf(&sb, in)) {
 892                 const char *str;
 893
 894                 if (skip_prefix(sb.buf, "# User ", &str))
 895                         fprintf(out, "From: %s\n", str);
 896                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
 897                         timestamp_t timestamp;
 898                         long tz, tz2;
 899                         char *end;
 900
 901                         errno = 0;
 902                         timestamp = parse_timestamp(str, &end, 10);
 903                         if (errno) {
 904                                 rc = error(_("invalid timestamp"));
 905                                 goto exit;
 906                         }
 907
 908                         if (!skip_prefix(end, " ", &str)) {
 909                                 rc = error(_("invalid Date line"));
 910                                 goto exit;
 911                         }
 912
 913                         errno = 0;
 914                         tz = strtol(str, &end, 10);
 915                         if (errno) {
 916                                 rc = error(_("invalid timezone offset"));
 917                                 goto exit;
 918                         }
 919
 920                         if (*end) {
 921                                 rc = error(_("invalid Date line"));
 922                                 goto exit;
 923                         }
 924
 925                         /*
 926                          * mercurial's timezone is in seconds west of UTC,
 927                          * however git's timezone is in hours + minutes east of
 928                          * UTC. Convert it.
 929                          */
 930                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
 931                         if (tz > 0)
 932                                 tz2 = -tz2;
 933
 934                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
 935                 } else if (starts_with(sb.buf, "# ")) {
 936                         continue;
 937                 } else {
 938                         fprintf(out, "\n%s\n", sb.buf);
 939                         break;
 940                 }
 941         }
 942
 943         strbuf_reset(&sb);
 944         while (strbuf_fread(&sb, 8192, in) > 0) {
 945                 fwrite(sb.buf, 1, sb.len, out);
 946                 strbuf_reset(&sb);
 947         }
 948 exit:
 949         strbuf_release(&sb);
 950         return rc;
 951 }
 952
 953 /**
 954  * Splits a list of files/directories into individual email patches. Each path
 955  * in `paths` must be a file/directory that is formatted according to
 956  * `patch_format`.
 957  *
 958  * Once split out, the individual email patches will be stored in the state
 959  * directory, with each patch's filename being its index, padded to state->prec
 960  * digits.
 961  *
 962  * state->cur will be set to the index of the first mail, and state->last will
 963  * be set to the index of the last mail.
 964  *
 965  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
 966  * to disable this behavior, -1 to use the default configured setting.
 967  *
 968  * Returns 0 on success, -1 on failure.
 969  */
 970 static int split_mail(struct am_state *state, enum patch_format patch_format,
 971                         const char **paths, int keep_cr)
 972 {
 973         if (keep_cr < 0) {
 974                 keep_cr = 0;
 975                 git_config_get_bool("am.keepcr", &keep_cr);
 976         }
 977
 978         switch (patch_format) {
 979         case PATCH_FORMAT_MBOX:
 980                 return split_mail_mbox(state, paths, keep_cr, 0);
 981         case PATCH_FORMAT_STGIT:
 982                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
 983         case PATCH_FORMAT_STGIT_SERIES:
 984                 return split_mail_stgit_series(state, paths, keep_cr);
 985         case PATCH_FORMAT_HG:
 986                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
 987         case PATCH_FORMAT_MBOXRD:
 988                 return split_mail_mbox(state, paths, keep_cr, 1);
 989         default:
 990                 BUG("invalid patch_format");
 991         }
 992         return -1;
 993 }
 994
 995 /**
 996  * Setup a new am session for applying patches
 997  */
 998 static void am_setup(struct am_state *state, enum patch_format patch_format,
 999                         const char **paths, int keep_cr)
1000 {
1001         struct object_id curr_head;
1002         const char *str;
1003         struct strbuf sb = STRBUF_INIT;
1004
1005         if (!patch_format)
1006                 patch_format = detect_patch_format(paths);
1007
1008         if (!patch_format) {
1009                 fprintf_ln(stderr, _("Patch format detection failed."));
1010                 exit(128);
1011         }
1012
1013         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
1014                 die_errno(_("failed to create directory '%s'"), state->dir);
1015         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
1016
1017         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
1018                 am_destroy(state);
1019                 die(_("Failed to split patches."));
1020         }
1021
1022         if (state->rebasing)
1023                 state->threeway = 1;
1024
1025         write_state_bool(state, "threeway", state->threeway);
1026         write_state_bool(state, "quiet", state->quiet);
1027         write_state_bool(state, "sign", state->signoff);
1028         write_state_bool(state, "utf8", state->utf8);
1029
1030         if (state->allow_rerere_autoupdate)
1031                 write_state_bool(state, "rerere-autoupdate",
1032                          state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
1033
1034         switch (state->keep) {
1035         case KEEP_FALSE:
1036                 str = "f";
1037                 break;
1038         case KEEP_TRUE:
1039                 str = "t";
1040                 break;
1041         case KEEP_NON_PATCH:
1042                 str = "b";
1043                 break;
1044         default:
1045                 BUG("invalid value for state->keep");
1046         }
1047
1048         write_state_text(state, "keep", str);
1049         write_state_bool(state, "messageid", state->message_id);
1050
1051         switch (state->scissors) {
1052         case SCISSORS_UNSET:
1053                 str = "";
1054                 break;
1055         case SCISSORS_FALSE:
1056                 str = "f";
1057                 break;
1058         case SCISSORS_TRUE:
1059                 str = "t";
1060                 break;
1061         default:
1062                 BUG("invalid value for state->scissors");
1063         }
1064         write_state_text(state, "scissors", str);
1065
1066         sq_quote_argv(&sb, state->git_apply_opts.argv);
1067         write_state_text(state, "apply-opt", sb.buf);
1068
1069         if (state->rebasing)
1070                 write_state_text(state, "rebasing", "");
1071         else
1072                 write_state_text(state, "applying", "");
1073
1074         if (!get_oid("HEAD", &curr_head)) {
1075                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1076                 if (!state->rebasing)
1077                         update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
1078                                    UPDATE_REFS_DIE_ON_ERR);
1079         } else {
1080                 write_state_text(state, "abort-safety", "");
1081                 if (!state->rebasing)
1082                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1083         }
1084
1085         /*
1086          * NOTE: Since the "next" and "last" files determine if an am_state
1087          * session is in progress, they should be written last.
1088          */
1089
1090         write_state_count(state, "next", state->cur);
1091         write_state_count(state, "last", state->last);
1092
1093         strbuf_release(&sb);
1094 }
1095
1096 /**
1097  * Increments the patch pointer, and cleans am_state for the application of the
1098  * next patch.
1099  */
1100 static void am_next(struct am_state *state)
1101 {
1102         struct object_id head;
1103
1104         FREE_AND_NULL(state->author_name);
1105         FREE_AND_NULL(state->author_email);
1106         FREE_AND_NULL(state->author_date);
1107         FREE_AND_NULL(state->msg);
1108         state->msg_len = 0;
1109
1110         unlink(am_path(state, "author-script"));
1111         unlink(am_path(state, "final-commit"));
1112
1113         oidclr(&state->orig_commit);
1114         unlink(am_path(state, "original-commit"));
1115         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
1116
1117         if (!get_oid("HEAD", &head))
1118                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1119         else
1120                 write_state_text(state, "abort-safety", "");
1121
1122         state->cur++;
1123         write_state_count(state, "next", state->cur);
1124 }
1125
1126 /**
1127  * Returns the filename of the current patch email.
1128  */
1129 static const char *msgnum(const struct am_state *state)
1130 {
1131         static struct strbuf sb = STRBUF_INIT;
1132
1133         strbuf_reset(&sb);
1134         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1135
1136         return sb.buf;
1137 }
1138
1139 /**
1140  * Refresh and write index.
1141  */
1142 static void refresh_and_write_cache(void)
1143 {
1144         struct lock_file lock_file = LOCK_INIT;
1145
1146         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1147         refresh_cache(REFRESH_QUIET);
1148         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1149                 die(_("unable to write index file"));
1150 }
1151
1152 /**
1153  * Dies with a user-friendly message on how to proceed after resolving the
1154  * problem. This message can be overridden with state->resolvemsg.
1155  */
1156 static void NORETURN die_user_resolve(const struct am_state *state)
1157 {
1158         if (state->resolvemsg) {
1159                 printf_ln("%s", state->resolvemsg);
1160         } else {
1161                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1162
1163                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1164                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1165                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1166         }
1167
1168         exit(128);
1169 }
1170
1171 /**
1172  * Appends signoff to the "msg" field of the am_state.
1173  */
1174 static void am_append_signoff(struct am_state *state)
1175 {
1176         struct strbuf sb = STRBUF_INIT;
1177
1178         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1179         append_signoff(&sb, 0, 0);
1180         state->msg = strbuf_detach(&sb, &state->msg_len);
1181 }
1182
1183 /**
1184  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1185  * state->msg will be set to the patch message. state->author_name,
1186  * state->author_email and state->author_date will be set to the patch author's
1187  * name, email and date respectively. The patch body will be written to the
1188  * state directory's "patch" file.
1189  *
1190  * Returns 1 if the patch should be skipped, 0 otherwise.
1191  */
1192 static int parse_mail(struct am_state *state, const char *mail)
1193 {
1194         FILE *fp;
1195         struct strbuf sb = STRBUF_INIT;
1196         struct strbuf msg = STRBUF_INIT;
1197         struct strbuf author_name = STRBUF_INIT;
1198         struct strbuf author_date = STRBUF_INIT;
1199         struct strbuf author_email = STRBUF_INIT;
1200         int ret = 0;
1201         struct mailinfo mi;
1202
1203         setup_mailinfo(&mi);
1204
1205         if (state->utf8)
1206                 mi.metainfo_charset = get_commit_output_encoding();
1207         else
1208                 mi.metainfo_charset = NULL;
1209
1210         switch (state->keep) {
1211         case KEEP_FALSE:
1212                 break;
1213         case KEEP_TRUE:
1214                 mi.keep_subject = 1;
1215                 break;
1216         case KEEP_NON_PATCH:
1217                 mi.keep_non_patch_brackets_in_subject = 1;
1218                 break;
1219         default:
1220                 BUG("invalid value for state->keep");
1221         }
1222
1223         if (state->message_id)
1224                 mi.add_message_id = 1;
1225
1226         switch (state->scissors) {
1227         case SCISSORS_UNSET:
1228                 break;
1229         case SCISSORS_FALSE:
1230                 mi.use_scissors = 0;
1231                 break;
1232         case SCISSORS_TRUE:
1233                 mi.use_scissors = 1;
1234                 break;
1235         default:
1236                 BUG("invalid value for state->scissors");
1237         }
1238
1239         mi.input = xfopen(mail, "r");
1240         mi.output = xfopen(am_path(state, "info"), "w");
1241         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1242                 die("could not parse patch");
1243
1244         fclose(mi.input);
1245         fclose(mi.output);
1246
1247         if (mi.format_flowed)
1248                 warning(_("Patch sent with format=flowed; "
1249                           "space at the end of lines might be lost."));
1250
1251         /* Extract message and author information */
1252         fp = xfopen(am_path(state, "info"), "r");
1253         while (!strbuf_getline_lf(&sb, fp)) {
1254                 const char *x;
1255
1256                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1257                         if (msg.len)
1258                                 strbuf_addch(&msg, '\n');
1259                         strbuf_addstr(&msg, x);
1260                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1261                         strbuf_addstr(&author_name, x);
1262                 else if (skip_prefix(sb.buf, "Email: ", &x))
1263                         strbuf_addstr(&author_email, x);
1264                 else if (skip_prefix(sb.buf, "Date: ", &x))
1265                         strbuf_addstr(&author_date, x);
1266         }
1267         fclose(fp);
1268
1269         /* Skip pine's internal folder data */
1270         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1271                 ret = 1;
1272                 goto finish;
1273         }
1274
1275         if (is_empty_file(am_path(state, "patch"))) {
1276                 printf_ln(_("Patch is empty."));
1277                 die_user_resolve(state);
1278         }
1279
1280         strbuf_addstr(&msg, "\n\n");
1281         strbuf_addbuf(&msg, &mi.log_message);
1282         strbuf_stripspace(&msg, 0);
1283
1284         assert(!state->author_name);
1285         state->author_name = strbuf_detach(&author_name, NULL);
1286
1287         assert(!state->author_email);
1288         state->author_email = strbuf_detach(&author_email, NULL);
1289
1290         assert(!state->author_date);
1291         state->author_date = strbuf_detach(&author_date, NULL);
1292
1293         assert(!state->msg);
1294         state->msg = strbuf_detach(&msg, &state->msg_len);
1295
1296 finish:
1297         strbuf_release(&msg);
1298         strbuf_release(&author_date);
1299         strbuf_release(&author_email);
1300         strbuf_release(&author_name);
1301         strbuf_release(&sb);
1302         clear_mailinfo(&mi);
1303         return ret;
1304 }
1305
1306 /**
1307  * Sets commit_id to the commit hash where the mail was generated from.
1308  * Returns 0 on success, -1 on failure.
1309  */
1310 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1311 {
1312         struct strbuf sb = STRBUF_INIT;
1313         FILE *fp = xfopen(mail, "r");
1314         const char *x;
1315         int ret = 0;
1316
1317         if (strbuf_getline_lf(&sb, fp) ||
1318             !skip_prefix(sb.buf, "From ", &x) ||
1319             get_oid_hex(x, commit_id) < 0)
1320                 ret = -1;
1321
1322         strbuf_release(&sb);
1323         fclose(fp);
1324         return ret;
1325 }
1326
1327 /**
1328  * Sets state->msg, state->author_name, state->author_email, state->author_date
1329  * to the commit's respective info.
1330  */
1331 static void get_commit_info(struct am_state *state, struct commit *commit)
1332 {
1333         const char *buffer, *ident_line, *msg;
1334         size_t ident_len;
1335         struct ident_split id;
1336
1337         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1338
1339         ident_line = find_commit_header(buffer, "author", &ident_len);
1340
1341         if (split_ident_line(&id, ident_line, ident_len) < 0)
1342                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1343
1344         assert(!state->author_name);
1345         if (id.name_begin)
1346                 state->author_name =
1347                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1348         else
1349                 state->author_name = xstrdup("");
1350
1351         assert(!state->author_email);
1352         if (id.mail_begin)
1353                 state->author_email =
1354                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1355         else
1356                 state->author_email = xstrdup("");
1357
1358         assert(!state->author_date);
1359         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1360
1361         assert(!state->msg);
1362         msg = strstr(buffer, "\n\n");
1363         if (!msg)
1364                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1365         state->msg = xstrdup(msg + 2);
1366         state->msg_len = strlen(state->msg);
1367         unuse_commit_buffer(commit, buffer);
1368 }
1369
1370 /**
1371  * Writes `commit` as a patch to the state directory's "patch" file.
1372  */
1373 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1374 {
1375         struct rev_info rev_info;
1376         FILE *fp;
1377
1378         fp = xfopen(am_path(state, "patch"), "w");
1379         repo_init_revisions(the_repository, &rev_info, NULL);
1380         rev_info.diff = 1;
1381         rev_info.abbrev = 0;
1382         rev_info.disable_stdin = 1;
1383         rev_info.show_root_diff = 1;
1384         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1385         rev_info.no_commit_id = 1;
1386         rev_info.diffopt.flags.binary = 1;
1387         rev_info.diffopt.flags.full_index = 1;
1388         rev_info.diffopt.use_color = 0;
1389         rev_info.diffopt.file = fp;
1390         rev_info.diffopt.close_file = 1;
1391         add_pending_object(&rev_info, &commit->object, "");
1392         diff_setup_done(&rev_info.diffopt);
1393         log_tree_commit(&rev_info, commit);
1394 }
1395
1396 /**
1397  * Writes the diff of the index against HEAD as a patch to the state
1398  * directory's "patch" file.
1399  */
1400 static void write_index_patch(const struct am_state *state)
1401 {
1402         struct tree *tree;
1403         struct object_id head;
1404         struct rev_info rev_info;
1405         FILE *fp;
1406
1407         if (!get_oid_tree("HEAD", &head))
1408                 tree = lookup_tree(the_repository, &head);
1409         else
1410                 tree = lookup_tree(the_repository,
1411                                    the_repository->hash_algo->empty_tree);
1412
1413         fp = xfopen(am_path(state, "patch"), "w");
1414         repo_init_revisions(the_repository, &rev_info, NULL);
1415         rev_info.diff = 1;
1416         rev_info.disable_stdin = 1;
1417         rev_info.no_commit_id = 1;
1418         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1419         rev_info.diffopt.use_color = 0;
1420         rev_info.diffopt.file = fp;
1421         rev_info.diffopt.close_file = 1;
1422         add_pending_object(&rev_info, &tree->object, "");
1423         diff_setup_done(&rev_info.diffopt);
1424         run_diff_index(&rev_info, 1);
1425 }
1426
1427 /**
1428  * Like parse_mail(), but parses the mail by looking up its commit ID
1429  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1430  * of patches.
1431  *
1432  * state->orig_commit will be set to the original commit ID.
1433  *
1434  * Will always return 0 as the patch should never be skipped.
1435  */
1436 static int parse_mail_rebase(struct am_state *state, const char *mail)
1437 {
1438         struct commit *commit;
1439         struct object_id commit_oid;
1440
1441         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1442                 die(_("could not parse %s"), mail);
1443
1444         commit = lookup_commit_or_die(&commit_oid, mail);
1445
1446         get_commit_info(state, commit);
1447
1448         write_commit_patch(state, commit);
1449
1450         oidcpy(&state->orig_commit, &commit_oid);
1451         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1452         update_ref("am", "REBASE_HEAD", &commit_oid,
1453                    NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
1454
1455         return 0;
1456 }
1457
1458 /**
1459  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1460  * `index_file` is not NULL, the patch will be applied to that index.
1461  */
1462 static int run_apply(const struct am_state *state, const char *index_file)
1463 {
1464         struct argv_array apply_paths = ARGV_ARRAY_INIT;
1465         struct argv_array apply_opts = ARGV_ARRAY_INIT;
1466         struct apply_state apply_state;
1467         int res, opts_left;
1468         int force_apply = 0;
1469         int options = 0;
1470
1471         if (init_apply_state(&apply_state, the_repository, NULL))
1472                 BUG("init_apply_state() failed");
1473
1474         argv_array_push(&apply_opts, "apply");
1475         argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
1476
1477         opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
1478                                         &apply_state, &force_apply, &options,
1479                                         NULL);
1480
1481         if (opts_left != 0)
1482                 die("unknown option passed through to git apply");
1483
1484         if (index_file) {
1485                 apply_state.index_file = index_file;
1486                 apply_state.cached = 1;
1487         } else
1488                 apply_state.check_index = 1;
1489
1490         /*
1491          * If we are allowed to fall back on 3-way merge, don't give false
1492          * errors during the initial attempt.
1493          */
1494         if (state->threeway && !index_file)
1495                 apply_state.apply_verbosity = verbosity_silent;
1496
1497         if (check_apply_state(&apply_state, force_apply))
1498                 BUG("check_apply_state() failed");
1499
1500         argv_array_push(&apply_paths, am_path(state, "patch"));
1501
1502         res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
1503
1504         argv_array_clear(&apply_paths);
1505         argv_array_clear(&apply_opts);
1506         clear_apply_state(&apply_state);
1507
1508         if (res)
1509                 return res;
1510
1511         if (index_file) {
1512                 /* Reload index as apply_all_patches() will have modified it. */
1513                 discard_cache();
1514                 read_cache_from(index_file);
1515         }
1516
1517         return 0;
1518 }
1519
1520 /**
1521  * Builds an index that contains just the blobs needed for a 3way merge.
1522  */
1523 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1524 {
1525         struct child_process cp = CHILD_PROCESS_INIT;
1526
1527         cp.git_cmd = 1;
1528         argv_array_push(&cp.args, "apply");
1529         argv_array_pushv(&cp.args, state->git_apply_opts.argv);
1530         argv_array_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1531         argv_array_push(&cp.args, am_path(state, "patch"));
1532
1533         if (run_command(&cp))
1534                 return -1;
1535
1536         return 0;
1537 }
1538
1539 /**
1540  * Attempt a threeway merge, using index_path as the temporary index.
1541  */
1542 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1543 {
1544         struct object_id orig_tree, their_tree, our_tree;
1545         const struct object_id *bases[1] = { &orig_tree };
1546         struct merge_options o;
1547         struct commit *result;
1548         char *their_tree_name;
1549
1550         if (get_oid("HEAD", &our_tree) < 0)
1551                 oidcpy(&our_tree, the_hash_algo->empty_tree);
1552
1553         if (build_fake_ancestor(state, index_path))
1554                 return error("could not build fake ancestor");
1555
1556         discard_cache();
1557         read_cache_from(index_path);
1558
1559         if (write_index_as_tree(&orig_tree, &the_index, index_path, 0, NULL))
1560                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1561
1562         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1563
1564         if (!state->quiet) {
1565                 /*
1566                  * List paths that needed 3-way fallback, so that the user can
1567                  * review them with extra care to spot mismerges.
1568                  */
1569                 struct rev_info rev_info;
1570                 const char *diff_filter_str = "--diff-filter=AM";
1571
1572                 repo_init_revisions(the_repository, &rev_info, NULL);
1573                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1574                 diff_opt_parse(&rev_info.diffopt, &diff_filter_str, 1, rev_info.prefix);
1575                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1576                 diff_setup_done(&rev_info.diffopt);
1577                 run_diff_index(&rev_info, 1);
1578         }
1579
1580         if (run_apply(state, index_path))
1581                 return error(_("Did you hand edit your patch?\n"
1582                                 "It does not apply to blobs recorded in its index."));
1583
1584         if (write_index_as_tree(&their_tree, &the_index, index_path, 0, NULL))
1585                 return error("could not write tree");
1586
1587         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1588
1589         discard_cache();
1590         read_cache();
1591
1592         /*
1593          * This is not so wrong. Depending on which base we picked, orig_tree
1594          * may be wildly different from ours, but their_tree has the same set of
1595          * wildly different changes in parts the patch did not touch, so
1596          * recursive ends up canceling them, saying that we reverted all those
1597          * changes.
1598          */
1599
1600         init_merge_options(&o);
1601
1602         o.branch1 = "HEAD";
1603         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1604         o.branch2 = their_tree_name;
1605         o.detect_directory_renames = 0;
1606
1607         if (state->quiet)
1608                 o.verbosity = 0;
1609
1610         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1611                 repo_rerere(the_repository, state->allow_rerere_autoupdate);
1612                 free(their_tree_name);
1613                 return error(_("Failed to merge in the changes."));
1614         }
1615
1616         free(their_tree_name);
1617         return 0;
1618 }
1619
1620 /**
1621  * Commits the current index with state->msg as the commit message and
1622  * state->author_name, state->author_email and state->author_date as the author
1623  * information.
1624  */
1625 static void do_commit(const struct am_state *state)
1626 {
1627         struct object_id tree, parent, commit;
1628         const struct object_id *old_oid;
1629         struct commit_list *parents = NULL;
1630         const char *reflog_msg, *author;
1631         struct strbuf sb = STRBUF_INIT;
1632
1633         if (run_hook_le(NULL, "pre-applypatch", NULL))
1634                 exit(1);
1635
1636         if (write_cache_as_tree(&tree, 0, NULL))
1637                 die(_("git write-tree failed to write a tree"));
1638
1639         if (!get_oid_commit("HEAD", &parent)) {
1640                 old_oid = &parent;
1641                 commit_list_insert(lookup_commit(the_repository, &parent),
1642                                    &parents);
1643         } else {
1644                 old_oid = NULL;
1645                 say(state, stderr, _("applying to an empty history"));
1646         }
1647
1648         author = fmt_ident(state->author_name, state->author_email,
1649                         state->ignore_date ? NULL : state->author_date,
1650                         IDENT_STRICT);
1651
1652         if (state->committer_date_is_author_date)
1653                 setenv("GIT_COMMITTER_DATE",
1654                         state->ignore_date ? "" : state->author_date, 1);
1655
1656         if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
1657                         author, state->sign_commit))
1658                 die(_("failed to write commit object"));
1659
1660         reflog_msg = getenv("GIT_REFLOG_ACTION");
1661         if (!reflog_msg)
1662                 reflog_msg = "am";
1663
1664         strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1665                         state->msg);
1666
1667         update_ref(sb.buf, "HEAD", &commit, old_oid, 0,
1668                    UPDATE_REFS_DIE_ON_ERR);
1669
1670         if (state->rebasing) {
1671                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1672
1673                 assert(!is_null_oid(&state->orig_commit));
1674                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1675                 fprintf(fp, "%s\n", oid_to_hex(&commit));
1676                 fclose(fp);
1677         }
1678
1679         run_hook_le(NULL, "post-applypatch", NULL);
1680
1681         strbuf_release(&sb);
1682 }
1683
1684 /**
1685  * Validates the am_state for resuming -- the "msg" and authorship fields must
1686  * be filled up.
1687  */
1688 static void validate_resume_state(const struct am_state *state)
1689 {
1690         if (!state->msg)
1691                 die(_("cannot resume: %s does not exist."),
1692                         am_path(state, "final-commit"));
1693
1694         if (!state->author_name || !state->author_email || !state->author_date)
1695                 die(_("cannot resume: %s does not exist."),
1696                         am_path(state, "author-script"));
1697 }
1698
1699 /**
1700  * Interactively prompt the user on whether the current patch should be
1701  * applied.
1702  *
1703  * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1704  * skip it.
1705  */
1706 static int do_interactive(struct am_state *state)
1707 {
1708         assert(state->msg);
1709
1710         if (!isatty(0))
1711                 die(_("cannot be interactive without stdin connected to a terminal."));
1712
1713         for (;;) {
1714                 const char *reply;
1715
1716                 puts(_("Commit Body is:"));
1717                 puts("--------------------------");
1718                 printf("%s", state->msg);
1719                 puts("--------------------------");
1720
1721                 /*
1722                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1723                  * in your translation. The program will only accept English
1724                  * input at this point.
1725                  */
1726                 reply = git_prompt(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "), PROMPT_ECHO);
1727
1728                 if (!reply) {
1729                         continue;
1730                 } else if (*reply == 'y' || *reply == 'Y') {
1731                         return 0;
1732                 } else if (*reply == 'a' || *reply == 'A') {
1733                         state->interactive = 0;
1734                         return 0;
1735                 } else if (*reply == 'n' || *reply == 'N') {
1736                         return 1;
1737                 } else if (*reply == 'e' || *reply == 'E') {
1738                         struct strbuf msg = STRBUF_INIT;
1739
1740                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1741                                 free(state->msg);
1742                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1743                         }
1744                         strbuf_release(&msg);
1745                 } else if (*reply == 'v' || *reply == 'V') {
1746                         const char *pager = git_pager(1);
1747                         struct child_process cp = CHILD_PROCESS_INIT;
1748
1749                         if (!pager)
1750                                 pager = "cat";
1751                         prepare_pager_args(&cp, pager);
1752                         argv_array_push(&cp.args, am_path(state, "patch"));
1753                         run_command(&cp);
1754                 }
1755         }
1756 }
1757
1758 /**
1759  * Applies all queued mail.
1760  *
1761  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1762  * well as the state directory's "patch" file is used as-is for applying the
1763  * patch and committing it.
1764  */
1765 static void am_run(struct am_state *state, int resume)
1766 {
1767         const char *argv_gc_auto[] = {"gc", "--auto", NULL};
1768         struct strbuf sb = STRBUF_INIT;
1769
1770         unlink(am_path(state, "dirtyindex"));
1771
1772         refresh_and_write_cache();
1773
1774         if (index_has_changes(&the_index, NULL, &sb)) {
1775                 write_state_bool(state, "dirtyindex", 1);
1776                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1777         }
1778
1779         strbuf_release(&sb);
1780
1781         while (state->cur <= state->last) {
1782                 const char *mail = am_path(state, msgnum(state));
1783                 int apply_status;
1784
1785                 reset_ident_date();
1786
1787                 if (!file_exists(mail))
1788                         goto next;
1789
1790                 if (resume) {
1791                         validate_resume_state(state);
1792                 } else {
1793                         int skip;
1794
1795                         if (state->rebasing)
1796                                 skip = parse_mail_rebase(state, mail);
1797                         else
1798                                 skip = parse_mail(state, mail);
1799
1800                         if (skip)
1801                                 goto next; /* mail should be skipped */
1802
1803                         if (state->signoff)
1804                                 am_append_signoff(state);
1805
1806                         write_author_script(state);
1807                         write_commit_msg(state);
1808                 }
1809
1810                 if (state->interactive && do_interactive(state))
1811                         goto next;
1812
1813                 if (run_applypatch_msg_hook(state))
1814                         exit(1);
1815
1816                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1817
1818                 apply_status = run_apply(state, NULL);
1819
1820                 if (apply_status && state->threeway) {
1821                         struct strbuf sb = STRBUF_INIT;
1822
1823                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1824                         apply_status = fall_back_threeway(state, sb.buf);
1825                         strbuf_release(&sb);
1826
1827                         /*
1828                          * Applying the patch to an earlier tree and merging
1829                          * the result may have produced the same tree as ours.
1830                          */
1831                         if (!apply_status &&
1832                             !index_has_changes(&the_index, NULL, NULL)) {
1833                                 say(state, stdout, _("No changes -- Patch already applied."));
1834                                 goto next;
1835                         }
1836                 }
1837
1838                 if (apply_status) {
1839                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1840                                 linelen(state->msg), state->msg);
1841
1842                         if (advice_amworkdir)
1843                                 advise(_("Use 'git am --show-current-patch' to see the failed patch"));
1844
1845                         die_user_resolve(state);
1846                 }
1847
1848                 do_commit(state);
1849
1850 next:
1851                 am_next(state);
1852
1853                 if (resume)
1854                         am_load(state);
1855                 resume = 0;
1856         }
1857
1858         if (!is_empty_file(am_path(state, "rewritten"))) {
1859                 assert(state->rebasing);
1860                 copy_notes_for_rebase(state);
1861                 run_post_rewrite_hook(state);
1862         }
1863
1864         /*
1865          * In rebasing mode, it's up to the caller to take care of
1866          * housekeeping.
1867          */
1868         if (!state->rebasing) {
1869                 am_destroy(state);
1870                 close_all_packs(the_repository->objects);
1871                 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1872         }
1873 }
1874
1875 /**
1876  * Resume the current am session after patch application failure. The user did
1877  * all the hard work, and we do not have to do any patch application. Just
1878  * trust and commit what the user has in the index and working tree.
1879  */
1880 static void am_resolve(struct am_state *state)
1881 {
1882         validate_resume_state(state);
1883
1884         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1885
1886         if (!index_has_changes(&the_index, NULL, NULL)) {
1887                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1888                         "If there is nothing left to stage, chances are that something else\n"
1889                         "already introduced the same changes; you might want to skip this patch."));
1890                 die_user_resolve(state);
1891         }
1892
1893         if (unmerged_cache()) {
1894                 printf_ln(_("You still have unmerged paths in your index.\n"
1895                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1896                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1897                 die_user_resolve(state);
1898         }
1899
1900         if (state->interactive) {
1901                 write_index_patch(state);
1902                 if (do_interactive(state))
1903                         goto next;
1904         }
1905
1906         repo_rerere(the_repository, 0);
1907
1908         do_commit(state);
1909
1910 next:
1911         am_next(state);
1912         am_load(state);
1913         am_run(state, 0);
1914 }
1915
1916 /**
1917  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1918  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1919  * failure.
1920  */
1921 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1922 {
1923         struct lock_file lock_file = LOCK_INIT;
1924         struct unpack_trees_options opts;
1925         struct tree_desc t[2];
1926
1927         if (parse_tree(head) || parse_tree(remote))
1928                 return -1;
1929
1930         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1931
1932         refresh_cache(REFRESH_QUIET);
1933
1934         memset(&opts, 0, sizeof(opts));
1935         opts.head_idx = 1;
1936         opts.src_index = &the_index;
1937         opts.dst_index = &the_index;
1938         opts.update = 1;
1939         opts.merge = 1;
1940         opts.reset = reset;
1941         opts.fn = twoway_merge;
1942         init_tree_desc(&t[0], head->buffer, head->size);
1943         init_tree_desc(&t[1], remote->buffer, remote->size);
1944
1945         if (unpack_trees(2, t, &opts)) {
1946                 rollback_lock_file(&lock_file);
1947                 return -1;
1948         }
1949
1950         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1951                 die(_("unable to write new index file"));
1952
1953         return 0;
1954 }
1955
1956 /**
1957  * Merges a tree into the index. The index's stat info will take precedence
1958  * over the merged tree's. Returns 0 on success, -1 on failure.
1959  */
1960 static int merge_tree(struct tree *tree)
1961 {
1962         struct lock_file lock_file = LOCK_INIT;
1963         struct unpack_trees_options opts;
1964         struct tree_desc t[1];
1965
1966         if (parse_tree(tree))
1967                 return -1;
1968
1969         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1970
1971         memset(&opts, 0, sizeof(opts));
1972         opts.head_idx = 1;
1973         opts.src_index = &the_index;
1974         opts.dst_index = &the_index;
1975         opts.merge = 1;
1976         opts.fn = oneway_merge;
1977         init_tree_desc(&t[0], tree->buffer, tree->size);
1978
1979         if (unpack_trees(1, t, &opts)) {
1980                 rollback_lock_file(&lock_file);
1981                 return -1;
1982         }
1983
1984         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1985                 die(_("unable to write new index file"));
1986
1987         return 0;
1988 }
1989
1990 /**
1991  * Clean the index without touching entries that are not modified between
1992  * `head` and `remote`.
1993  */
1994 static int clean_index(const struct object_id *head, const struct object_id *remote)
1995 {
1996         struct tree *head_tree, *remote_tree, *index_tree;
1997         struct object_id index;
1998
1999         head_tree = parse_tree_indirect(head);
2000         if (!head_tree)
2001                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
2002
2003         remote_tree = parse_tree_indirect(remote);
2004         if (!remote_tree)
2005                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
2006
2007         read_cache_unmerged();
2008
2009         if (fast_forward_to(head_tree, head_tree, 1))
2010                 return -1;
2011
2012         if (write_cache_as_tree(&index, 0, NULL))
2013                 return -1;
2014
2015         index_tree = parse_tree_indirect(&index);
2016         if (!index_tree)
2017                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
2018
2019         if (fast_forward_to(index_tree, remote_tree, 0))
2020                 return -1;
2021
2022         if (merge_tree(remote_tree))
2023                 return -1;
2024
2025         remove_branch_state();
2026
2027         return 0;
2028 }
2029
2030 /**
2031  * Resets rerere's merge resolution metadata.
2032  */
2033 static void am_rerere_clear(void)
2034 {
2035         struct string_list merge_rr = STRING_LIST_INIT_DUP;
2036         rerere_clear(&merge_rr);
2037         string_list_clear(&merge_rr, 1);
2038 }
2039
2040 /**
2041  * Resume the current am session by skipping the current patch.
2042  */
2043 static void am_skip(struct am_state *state)
2044 {
2045         struct object_id head;
2046
2047         am_rerere_clear();
2048
2049         if (get_oid("HEAD", &head))
2050                 oidcpy(&head, the_hash_algo->empty_tree);
2051
2052         if (clean_index(&head, &head))
2053                 die(_("failed to clean index"));
2054
2055         am_next(state);
2056         am_load(state);
2057         am_run(state, 0);
2058 }
2059
2060 /**
2061  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2062  *
2063  * It is not safe to reset HEAD when:
2064  * 1. git-am previously failed because the index was dirty.
2065  * 2. HEAD has moved since git-am previously failed.
2066  */
2067 static int safe_to_abort(const struct am_state *state)
2068 {
2069         struct strbuf sb = STRBUF_INIT;
2070         struct object_id abort_safety, head;
2071
2072         if (file_exists(am_path(state, "dirtyindex")))
2073                 return 0;
2074
2075         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2076                 if (get_oid_hex(sb.buf, &abort_safety))
2077                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2078         } else
2079                 oidclr(&abort_safety);
2080         strbuf_release(&sb);
2081
2082         if (get_oid("HEAD", &head))
2083                 oidclr(&head);
2084
2085         if (oideq(&head, &abort_safety))
2086                 return 1;
2087
2088         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2089                 "Not rewinding to ORIG_HEAD"));
2090
2091         return 0;
2092 }
2093
2094 /**
2095  * Aborts the current am session if it is safe to do so.
2096  */
2097 static void am_abort(struct am_state *state)
2098 {
2099         struct object_id curr_head, orig_head;
2100         int has_curr_head, has_orig_head;
2101         char *curr_branch;
2102
2103         if (!safe_to_abort(state)) {
2104                 am_destroy(state);
2105                 return;
2106         }
2107
2108         am_rerere_clear();
2109
2110         curr_branch = resolve_refdup("HEAD", 0, &curr_head, NULL);
2111         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2112         if (!has_curr_head)
2113                 oidcpy(&curr_head, the_hash_algo->empty_tree);
2114
2115         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2116         if (!has_orig_head)
2117                 oidcpy(&orig_head, the_hash_algo->empty_tree);
2118
2119         clean_index(&curr_head, &orig_head);
2120
2121         if (has_orig_head)
2122                 update_ref("am --abort", "HEAD", &orig_head,
2123                            has_curr_head ? &curr_head : NULL, 0,
2124                            UPDATE_REFS_DIE_ON_ERR);
2125         else if (curr_branch)
2126                 delete_ref(NULL, curr_branch, NULL, REF_NO_DEREF);
2127
2128         free(curr_branch);
2129         am_destroy(state);
2130 }
2131
2132 static int show_patch(struct am_state *state)
2133 {
2134         struct strbuf sb = STRBUF_INIT;
2135         const char *patch_path;
2136         int len;
2137
2138         if (!is_null_oid(&state->orig_commit)) {
2139                 const char *av[4] = { "show", NULL, "--", NULL };
2140                 char *new_oid_str;
2141                 int ret;
2142
2143                 av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
2144                 ret = run_command_v_opt(av, RUN_GIT_CMD);
2145                 free(new_oid_str);
2146                 return ret;
2147         }
2148
2149         patch_path = am_path(state, msgnum(state));
2150         len = strbuf_read_file(&sb, patch_path, 0);
2151         if (len < 0)
2152                 die_errno(_("failed to read '%s'"), patch_path);
2153
2154         setup_pager();
2155         write_in_full(1, sb.buf, sb.len);
2156         strbuf_release(&sb);
2157         return 0;
2158 }
2159
2160 /**
2161  * parse_options() callback that validates and sets opt->value to the
2162  * PATCH_FORMAT_* enum value corresponding to `arg`.
2163  */
2164 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2165 {
2166         int *opt_value = opt->value;
2167
2168         if (!strcmp(arg, "mbox"))
2169                 *opt_value = PATCH_FORMAT_MBOX;
2170         else if (!strcmp(arg, "stgit"))
2171                 *opt_value = PATCH_FORMAT_STGIT;
2172         else if (!strcmp(arg, "stgit-series"))
2173                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2174         else if (!strcmp(arg, "hg"))
2175                 *opt_value = PATCH_FORMAT_HG;
2176         else if (!strcmp(arg, "mboxrd"))
2177                 *opt_value = PATCH_FORMAT_MBOXRD;
2178         else
2179                 return error(_("Invalid value for --patch-format: %s"), arg);
2180         return 0;
2181 }
2182
2183 enum resume_mode {
2184         RESUME_FALSE = 0,
2185         RESUME_APPLY,
2186         RESUME_RESOLVED,
2187         RESUME_SKIP,
2188         RESUME_ABORT,
2189         RESUME_QUIT,
2190         RESUME_SHOW_PATCH
2191 };
2192
2193 static int git_am_config(const char *k, const char *v, void *cb)
2194 {
2195         int status;
2196
2197         status = git_gpg_config(k, v, NULL);
2198         if (status)
2199                 return status;
2200
2201         return git_default_config(k, v, NULL);
2202 }
2203
2204 int cmd_am(int argc, const char **argv, const char *prefix)
2205 {
2206         struct am_state state;
2207         int binary = -1;
2208         int keep_cr = -1;
2209         int patch_format = PATCH_FORMAT_UNKNOWN;
2210         enum resume_mode resume = RESUME_FALSE;
2211         int in_progress;
2212         int ret = 0;
2213
2214         const char * const usage[] = {
2215                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2216                 N_("git am [<options>] (--continue | --skip | --abort)"),
2217                 NULL
2218         };
2219
2220         struct option options[] = {
2221                 OPT_BOOL('i', "interactive", &state.interactive,
2222                         N_("run interactively")),
2223                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2224                         N_("historical option -- no-op")),
2225                 OPT_BOOL('3', "3way", &state.threeway,
2226                         N_("allow fall back on 3way merging if needed")),
2227                 OPT__QUIET(&state.quiet, N_("be quiet")),
2228                 OPT_SET_INT('s', "signoff", &state.signoff,
2229                         N_("add a Signed-off-by line to the commit message"),
2230                         SIGNOFF_EXPLICIT),
2231                 OPT_BOOL('u', "utf8", &state.utf8,
2232                         N_("recode into utf8 (default)")),
2233                 OPT_SET_INT('k', "keep", &state.keep,
2234                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2235                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2236                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2237                 OPT_BOOL('m', "message-id", &state.message_id,
2238                         N_("pass -m flag to git-mailinfo")),
2239                 OPT_SET_INT_F(0, "keep-cr", &keep_cr,
2240                         N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2241                         1, PARSE_OPT_NONEG),
2242                 OPT_SET_INT_F(0, "no-keep-cr", &keep_cr,
2243                         N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2244                         0, PARSE_OPT_NONEG),
2245                 OPT_BOOL('c', "scissors", &state.scissors,
2246                         N_("strip everything before a scissors line")),
2247                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2248                         N_("pass it through git-apply"),
2249                         0),
2250                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2251                         N_("pass it through git-apply"),
2252                         PARSE_OPT_NOARG),
2253                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2254                         N_("pass it through git-apply"),
2255                         PARSE_OPT_NOARG),
2256                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2257                         N_("pass it through git-apply"),
2258                         0),
2259                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2260                         N_("pass it through git-apply"),
2261                         0),
2262                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2263                         N_("pass it through git-apply"),
2264                         0),
2265                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2266                         N_("pass it through git-apply"),
2267                         0),
2268                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2269                         N_("pass it through git-apply"),
2270                         0),
2271                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2272                         N_("format the patch(es) are in"),
2273                         parse_opt_patchformat),
2274                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2275                         N_("pass it through git-apply"),
2276                         PARSE_OPT_NOARG),
2277                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2278                         N_("override error message when patch failure occurs")),
2279                 OPT_CMDMODE(0, "continue", &resume,
2280                         N_("continue applying patches after resolving a conflict"),
2281                         RESUME_RESOLVED),
2282                 OPT_CMDMODE('r', "resolved", &resume,
2283                         N_("synonyms for --continue"),
2284                         RESUME_RESOLVED),
2285                 OPT_CMDMODE(0, "skip", &resume,
2286                         N_("skip the current patch"),
2287                         RESUME_SKIP),
2288                 OPT_CMDMODE(0, "abort", &resume,
2289                         N_("restore the original branch and abort the patching operation."),
2290                         RESUME_ABORT),
2291                 OPT_CMDMODE(0, "quit", &resume,
2292                         N_("abort the patching operation but keep HEAD where it is."),
2293                         RESUME_QUIT),
2294                 OPT_CMDMODE(0, "show-current-patch", &resume,
2295                         N_("show the patch being applied."),
2296                         RESUME_SHOW_PATCH),
2297                 OPT_BOOL(0, "committer-date-is-author-date",
2298                         &state.committer_date_is_author_date,
2299                         N_("lie about committer date")),
2300                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2301                         N_("use current timestamp for author date")),
2302                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2303                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2304                   N_("GPG-sign commits"),
2305                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2306                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2307                         N_("(internal use for git-rebase)")),
2308                 OPT_END()
2309         };
2310
2311         if (argc == 2 && !strcmp(argv[1], "-h"))
2312                 usage_with_options(usage, options);
2313
2314         git_config(git_am_config, NULL);
2315
2316         am_state_init(&state);
2317
2318         in_progress = am_in_progress(&state);
2319         if (in_progress)
2320                 am_load(&state);
2321
2322         argc = parse_options(argc, argv, prefix, options, usage, 0);
2323
2324         if (binary >= 0)
2325                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2326                                 "it will be removed. Please do not use it anymore."));
2327
2328         /* Ensure a valid committer ident can be constructed */
2329         git_committer_info(IDENT_STRICT);
2330
2331         if (read_index_preload(&the_index, NULL, 0) < 0)
2332                 die(_("failed to read the index"));
2333
2334         if (in_progress) {
2335                 /*
2336                  * Catch user error to feed us patches when there is a session
2337                  * in progress:
2338                  *
2339                  * 1. mbox path(s) are provided on the command-line.
2340                  * 2. stdin is not a tty: the user is trying to feed us a patch
2341                  *    from standard input. This is somewhat unreliable -- stdin
2342                  *    could be /dev/null for example and the caller did not
2343                  *    intend to feed us a patch but wanted to continue
2344                  *    unattended.
2345                  */
2346                 if (argc || (resume == RESUME_FALSE && !isatty(0)))
2347                         die(_("previous rebase directory %s still exists but mbox given."),
2348                                 state.dir);
2349
2350                 if (resume == RESUME_FALSE)
2351                         resume = RESUME_APPLY;
2352
2353                 if (state.signoff == SIGNOFF_EXPLICIT)
2354                         am_append_signoff(&state);
2355         } else {
2356                 struct argv_array paths = ARGV_ARRAY_INIT;
2357                 int i;
2358
2359                 /*
2360                  * Handle stray state directory in the independent-run case. In
2361                  * the --rebasing case, it is up to the caller to take care of
2362                  * stray directories.
2363                  */
2364                 if (file_exists(state.dir) && !state.rebasing) {
2365                         if (resume == RESUME_ABORT || resume == RESUME_QUIT) {
2366                                 am_destroy(&state);
2367                                 am_state_release(&state);
2368                                 return 0;
2369                         }
2370
2371                         die(_("Stray %s directory found.\n"
2372                                 "Use \"git am --abort\" to remove it."),
2373                                 state.dir);
2374                 }
2375
2376                 if (resume)
2377                         die(_("Resolve operation not in progress, we are not resuming."));
2378
2379                 for (i = 0; i < argc; i++) {
2380                         if (is_absolute_path(argv[i]) || !prefix)
2381                                 argv_array_push(&paths, argv[i]);
2382                         else
2383                                 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2384                 }
2385
2386                 am_setup(&state, patch_format, paths.argv, keep_cr);
2387
2388                 argv_array_clear(&paths);
2389         }
2390
2391         switch (resume) {
2392         case RESUME_FALSE:
2393                 am_run(&state, 0);
2394                 break;
2395         case RESUME_APPLY:
2396                 am_run(&state, 1);
2397                 break;
2398         case RESUME_RESOLVED:
2399                 am_resolve(&state);
2400                 break;
2401         case RESUME_SKIP:
2402                 am_skip(&state);
2403                 break;
2404         case RESUME_ABORT:
2405                 am_abort(&state);
2406                 break;
2407         case RESUME_QUIT:
2408                 am_rerere_clear();
2409                 am_destroy(&state);
2410                 break;
2411         case RESUME_SHOW_PATCH:
2412                 ret = show_patch(&state);
2413                 break;
2414         default:
2415                 BUG("invalid resume value");
2416         }
2417
2418         am_state_release(&state);
2419
2420         return ret;
2421 }