git.oblomov.eu Git - git/blob - builtin/am.c

   1 /*
   2  * Builtin "git am"
   3  *
   4  * Based on git-am.sh by Junio C Hamano.
   5  */
   6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   7 #include "cache.h"
   8 #include "config.h"
   9 #include "builtin.h"
  10 #include "exec-cmd.h"
  11 #include "parse-options.h"
  12 #include "dir.h"
  13 #include "run-command.h"
  14 #include "quote.h"
  15 #include "tempfile.h"
  16 #include "lockfile.h"
  17 #include "cache-tree.h"
  18 #include "refs.h"
  19 #include "commit.h"
  20 #include "diff.h"
  21 #include "diffcore.h"
  22 #include "unpack-trees.h"
  23 #include "branch.h"
  24 #include "sequencer.h"
  25 #include "revision.h"
  26 #include "merge-recursive.h"
  27 #include "revision.h"
  28 #include "log-tree.h"
  29 #include "notes-utils.h"
  30 #include "rerere.h"
  31 #include "prompt.h"
  32 #include "mailinfo.h"
  33 #include "apply.h"
  34 #include "string-list.h"
  35 #include "packfile.h"
  36 #include "repository.h"
  37
  38 /**
  39  * Returns the length of the first line of msg.
  40  */
  41 static int linelen(const char *msg)
  42 {
  43         return strchrnul(msg, '\n') - msg;
  44 }
  45
  46 /**
  47  * Returns true if `str` consists of only whitespace, false otherwise.
  48  */
  49 static int str_isspace(const char *str)
  50 {
  51         for (; *str; str++)
  52                 if (!isspace(*str))
  53                         return 0;
  54
  55         return 1;
  56 }
  57
  58 enum patch_format {
  59         PATCH_FORMAT_UNKNOWN = 0,
  60         PATCH_FORMAT_MBOX,
  61         PATCH_FORMAT_STGIT,
  62         PATCH_FORMAT_STGIT_SERIES,
  63         PATCH_FORMAT_HG,
  64         PATCH_FORMAT_MBOXRD
  65 };
  66
  67 enum keep_type {
  68         KEEP_FALSE = 0,
  69         KEEP_TRUE,      /* pass -k flag to git-mailinfo */
  70         KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
  71 };
  72
  73 enum scissors_type {
  74         SCISSORS_UNSET = -1,
  75         SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
  76         SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
  77 };
  78
  79 enum signoff_type {
  80         SIGNOFF_FALSE = 0,
  81         SIGNOFF_TRUE = 1,
  82         SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
  83 };
  84
  85 struct am_state {
  86         /* state directory path */
  87         char *dir;
  88
  89         /* current and last patch numbers, 1-indexed */
  90         int cur;
  91         int last;
  92
  93         /* commit metadata and message */
  94         char *author_name;
  95         char *author_email;
  96         char *author_date;
  97         char *msg;
  98         size_t msg_len;
  99
 100         /* when --rebasing, records the original commit the patch came from */
 101         struct object_id orig_commit;
 102
 103         /* number of digits in patch filename */
 104         int prec;
 105
 106         /* various operating modes and command line options */
 107         int interactive;
 108         int threeway;
 109         int quiet;
 110         int signoff; /* enum signoff_type */
 111         int utf8;
 112         int keep; /* enum keep_type */
 113         int message_id;
 114         int scissors; /* enum scissors_type */
 115         struct argv_array git_apply_opts;
 116         const char *resolvemsg;
 117         int committer_date_is_author_date;
 118         int ignore_date;
 119         int allow_rerere_autoupdate;
 120         const char *sign_commit;
 121         int rebasing;
 122 };
 123
 124 /**
 125  * Initializes am_state with the default values.
 126  */
 127 static void am_state_init(struct am_state *state)
 128 {
 129         int gpgsign;
 130
 131         memset(state, 0, sizeof(*state));
 132
 133         state->dir = git_pathdup("rebase-apply");
 134
 135         state->prec = 4;
 136
 137         git_config_get_bool("am.threeway", &state->threeway);
 138
 139         state->utf8 = 1;
 140
 141         git_config_get_bool("am.messageid", &state->message_id);
 142
 143         state->scissors = SCISSORS_UNSET;
 144
 145         argv_array_init(&state->git_apply_opts);
 146
 147         if (!git_config_get_bool("commit.gpgsign", &gpgsign))
 148                 state->sign_commit = gpgsign ? "" : NULL;
 149 }
 150
 151 /**
 152  * Releases memory allocated by an am_state.
 153  */
 154 static void am_state_release(struct am_state *state)
 155 {
 156         free(state->dir);
 157         free(state->author_name);
 158         free(state->author_email);
 159         free(state->author_date);
 160         free(state->msg);
 161         argv_array_clear(&state->git_apply_opts);
 162 }
 163
 164 /**
 165  * Returns path relative to the am_state directory.
 166  */
 167 static inline const char *am_path(const struct am_state *state, const char *path)
 168 {
 169         return mkpath("%s/%s", state->dir, path);
 170 }
 171
 172 /**
 173  * For convenience to call write_file()
 174  */
 175 static void write_state_text(const struct am_state *state,
 176                              const char *name, const char *string)
 177 {
 178         write_file(am_path(state, name), "%s", string);
 179 }
 180
 181 static void write_state_count(const struct am_state *state,
 182                               const char *name, int value)
 183 {
 184         write_file(am_path(state, name), "%d", value);
 185 }
 186
 187 static void write_state_bool(const struct am_state *state,
 188                              const char *name, int value)
 189 {
 190         write_state_text(state, name, value ? "t" : "f");
 191 }
 192
 193 /**
 194  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
 195  * at the end.
 196  */
 197 static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
 198 {
 199         va_list ap;
 200
 201         va_start(ap, fmt);
 202         if (!state->quiet) {
 203                 vfprintf(fp, fmt, ap);
 204                 putc('\n', fp);
 205         }
 206         va_end(ap);
 207 }
 208
 209 /**
 210  * Returns 1 if there is an am session in progress, 0 otherwise.
 211  */
 212 static int am_in_progress(const struct am_state *state)
 213 {
 214         struct stat st;
 215
 216         if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
 217                 return 0;
 218         if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
 219                 return 0;
 220         if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
 221                 return 0;
 222         return 1;
 223 }
 224
 225 /**
 226  * Reads the contents of `file` in the `state` directory into `sb`. Returns the
 227  * number of bytes read on success, -1 if the file does not exist. If `trim` is
 228  * set, trailing whitespace will be removed.
 229  */
 230 static int read_state_file(struct strbuf *sb, const struct am_state *state,
 231                         const char *file, int trim)
 232 {
 233         strbuf_reset(sb);
 234
 235         if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
 236                 if (trim)
 237                         strbuf_trim(sb);
 238
 239                 return sb->len;
 240         }
 241
 242         if (errno == ENOENT)
 243                 return -1;
 244
 245         die_errno(_("could not read '%s'"), am_path(state, file));
 246 }
 247
 248 /**
 249  * Reads and parses the state directory's "author-script" file, and sets
 250  * state->author_name, state->author_email and state->author_date accordingly.
 251  * Returns 0 on success, -1 if the file could not be parsed.
 252  *
 253  * The author script is of the format:
 254  *
 255  *      GIT_AUTHOR_NAME='$author_name'
 256  *      GIT_AUTHOR_EMAIL='$author_email'
 257  *      GIT_AUTHOR_DATE='$author_date'
 258  *
 259  * where $author_name, $author_email and $author_date are quoted. We are strict
 260  * with our parsing, as the file was meant to be eval'd in the old git-am.sh
 261  * script, and thus if the file differs from what this function expects, it is
 262  * better to bail out than to do something that the user does not expect.
 263  */
 264 static int read_am_author_script(struct am_state *state)
 265 {
 266         const char *filename = am_path(state, "author-script");
 267
 268         assert(!state->author_name);
 269         assert(!state->author_email);
 270         assert(!state->author_date);
 271
 272         return read_author_script(filename, &state->author_name,
 273                                   &state->author_email, &state->author_date, 1);
 274 }
 275
 276 /**
 277  * Saves state->author_name, state->author_email and state->author_date in the
 278  * state directory's "author-script" file.
 279  */
 280 static void write_author_script(const struct am_state *state)
 281 {
 282         struct strbuf sb = STRBUF_INIT;
 283
 284         strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
 285         sq_quote_buf(&sb, state->author_name);
 286         strbuf_addch(&sb, '\n');
 287
 288         strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
 289         sq_quote_buf(&sb, state->author_email);
 290         strbuf_addch(&sb, '\n');
 291
 292         strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
 293         sq_quote_buf(&sb, state->author_date);
 294         strbuf_addch(&sb, '\n');
 295
 296         write_state_text(state, "author-script", sb.buf);
 297
 298         strbuf_release(&sb);
 299 }
 300
 301 /**
 302  * Reads the commit message from the state directory's "final-commit" file,
 303  * setting state->msg to its contents and state->msg_len to the length of its
 304  * contents in bytes.
 305  *
 306  * Returns 0 on success, -1 if the file does not exist.
 307  */
 308 static int read_commit_msg(struct am_state *state)
 309 {
 310         struct strbuf sb = STRBUF_INIT;
 311
 312         assert(!state->msg);
 313
 314         if (read_state_file(&sb, state, "final-commit", 0) < 0) {
 315                 strbuf_release(&sb);
 316                 return -1;
 317         }
 318
 319         state->msg = strbuf_detach(&sb, &state->msg_len);
 320         return 0;
 321 }
 322
 323 /**
 324  * Saves state->msg in the state directory's "final-commit" file.
 325  */
 326 static void write_commit_msg(const struct am_state *state)
 327 {
 328         const char *filename = am_path(state, "final-commit");
 329         write_file_buf(filename, state->msg, state->msg_len);
 330 }
 331
 332 /**
 333  * Loads state from disk.
 334  */
 335 static void am_load(struct am_state *state)
 336 {
 337         struct strbuf sb = STRBUF_INIT;
 338
 339         if (read_state_file(&sb, state, "next", 1) < 0)
 340                 BUG("state file 'next' does not exist");
 341         state->cur = strtol(sb.buf, NULL, 10);
 342
 343         if (read_state_file(&sb, state, "last", 1) < 0)
 344                 BUG("state file 'last' does not exist");
 345         state->last = strtol(sb.buf, NULL, 10);
 346
 347         if (read_am_author_script(state) < 0)
 348                 die(_("could not parse author script"));
 349
 350         read_commit_msg(state);
 351
 352         if (read_state_file(&sb, state, "original-commit", 1) < 0)
 353                 oidclr(&state->orig_commit);
 354         else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
 355                 die(_("could not parse %s"), am_path(state, "original-commit"));
 356
 357         read_state_file(&sb, state, "threeway", 1);
 358         state->threeway = !strcmp(sb.buf, "t");
 359
 360         read_state_file(&sb, state, "quiet", 1);
 361         state->quiet = !strcmp(sb.buf, "t");
 362
 363         read_state_file(&sb, state, "sign", 1);
 364         state->signoff = !strcmp(sb.buf, "t");
 365
 366         read_state_file(&sb, state, "utf8", 1);
 367         state->utf8 = !strcmp(sb.buf, "t");
 368
 369         if (file_exists(am_path(state, "rerere-autoupdate"))) {
 370                 read_state_file(&sb, state, "rerere-autoupdate", 1);
 371                 state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
 372                         RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
 373         } else {
 374                 state->allow_rerere_autoupdate = 0;
 375         }
 376
 377         read_state_file(&sb, state, "keep", 1);
 378         if (!strcmp(sb.buf, "t"))
 379                 state->keep = KEEP_TRUE;
 380         else if (!strcmp(sb.buf, "b"))
 381                 state->keep = KEEP_NON_PATCH;
 382         else
 383                 state->keep = KEEP_FALSE;
 384
 385         read_state_file(&sb, state, "messageid", 1);
 386         state->message_id = !strcmp(sb.buf, "t");
 387
 388         read_state_file(&sb, state, "scissors", 1);
 389         if (!strcmp(sb.buf, "t"))
 390                 state->scissors = SCISSORS_TRUE;
 391         else if (!strcmp(sb.buf, "f"))
 392                 state->scissors = SCISSORS_FALSE;
 393         else
 394                 state->scissors = SCISSORS_UNSET;
 395
 396         read_state_file(&sb, state, "apply-opt", 1);
 397         argv_array_clear(&state->git_apply_opts);
 398         if (sq_dequote_to_argv_array(sb.buf, &state->git_apply_opts) < 0)
 399                 die(_("could not parse %s"), am_path(state, "apply-opt"));
 400
 401         state->rebasing = !!file_exists(am_path(state, "rebasing"));
 402
 403         strbuf_release(&sb);
 404 }
 405
 406 /**
 407  * Removes the am_state directory, forcefully terminating the current am
 408  * session.
 409  */
 410 static void am_destroy(const struct am_state *state)
 411 {
 412         struct strbuf sb = STRBUF_INIT;
 413
 414         strbuf_addstr(&sb, state->dir);
 415         remove_dir_recursively(&sb, 0);
 416         strbuf_release(&sb);
 417 }
 418
 419 /**
 420  * Runs applypatch-msg hook. Returns its exit code.
 421  */
 422 static int run_applypatch_msg_hook(struct am_state *state)
 423 {
 424         int ret;
 425
 426         assert(state->msg);
 427         ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
 428
 429         if (!ret) {
 430                 FREE_AND_NULL(state->msg);
 431                 if (read_commit_msg(state) < 0)
 432                         die(_("'%s' was deleted by the applypatch-msg hook"),
 433                                 am_path(state, "final-commit"));
 434         }
 435
 436         return ret;
 437 }
 438
 439 /**
 440  * Runs post-rewrite hook. Returns it exit code.
 441  */
 442 static int run_post_rewrite_hook(const struct am_state *state)
 443 {
 444         struct child_process cp = CHILD_PROCESS_INIT;
 445         const char *hook = find_hook("post-rewrite");
 446         int ret;
 447
 448         if (!hook)
 449                 return 0;
 450
 451         argv_array_push(&cp.args, hook);
 452         argv_array_push(&cp.args, "rebase");
 453
 454         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
 455         cp.stdout_to_stderr = 1;
 456         cp.trace2_hook_name = "post-rewrite";
 457
 458         ret = run_command(&cp);
 459
 460         close(cp.in);
 461         return ret;
 462 }
 463
 464 /**
 465  * Reads the state directory's "rewritten" file, and copies notes from the old
 466  * commits listed in the file to their rewritten commits.
 467  *
 468  * Returns 0 on success, -1 on failure.
 469  */
 470 static int copy_notes_for_rebase(const struct am_state *state)
 471 {
 472         struct notes_rewrite_cfg *c;
 473         struct strbuf sb = STRBUF_INIT;
 474         const char *invalid_line = _("Malformed input line: '%s'.");
 475         const char *msg = "Notes added by 'git rebase'";
 476         FILE *fp;
 477         int ret = 0;
 478
 479         assert(state->rebasing);
 480
 481         c = init_copy_notes_for_rewrite("rebase");
 482         if (!c)
 483                 return 0;
 484
 485         fp = xfopen(am_path(state, "rewritten"), "r");
 486
 487         while (!strbuf_getline_lf(&sb, fp)) {
 488                 struct object_id from_obj, to_obj;
 489                 const char *p;
 490
 491                 if (sb.len != the_hash_algo->hexsz * 2 + 1) {
 492                         ret = error(invalid_line, sb.buf);
 493                         goto finish;
 494                 }
 495
 496                 if (parse_oid_hex(sb.buf, &from_obj, &p)) {
 497                         ret = error(invalid_line, sb.buf);
 498                         goto finish;
 499                 }
 500
 501                 if (*p != ' ') {
 502                         ret = error(invalid_line, sb.buf);
 503                         goto finish;
 504                 }
 505
 506                 if (get_oid_hex(p + 1, &to_obj)) {
 507                         ret = error(invalid_line, sb.buf);
 508                         goto finish;
 509                 }
 510
 511                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
 512                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
 513                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
 514         }
 515
 516 finish:
 517         finish_copy_notes_for_rewrite(the_repository, c, msg);
 518         fclose(fp);
 519         strbuf_release(&sb);
 520         return ret;
 521 }
 522
 523 /**
 524  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
 525  * non-indented lines and checking if they look like they begin with valid
 526  * header field names.
 527  *
 528  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
 529  */
 530 static int is_mail(FILE *fp)
 531 {
 532         const char *header_regex = "^[!-9;-~]+:";
 533         struct strbuf sb = STRBUF_INIT;
 534         regex_t regex;
 535         int ret = 1;
 536
 537         if (fseek(fp, 0L, SEEK_SET))
 538                 die_errno(_("fseek failed"));
 539
 540         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
 541                 die("invalid pattern: %s", header_regex);
 542
 543         while (!strbuf_getline(&sb, fp)) {
 544                 if (!sb.len)
 545                         break; /* End of header */
 546
 547                 /* Ignore indented folded lines */
 548                 if (*sb.buf == '\t' || *sb.buf == ' ')
 549                         continue;
 550
 551                 /* It's a header if it matches header_regex */
 552                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
 553                         ret = 0;
 554                         goto done;
 555                 }
 556         }
 557
 558 done:
 559         regfree(&regex);
 560         strbuf_release(&sb);
 561         return ret;
 562 }
 563
 564 /**
 565  * Attempts to detect the patch_format of the patches contained in `paths`,
 566  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
 567  * detection fails.
 568  */
 569 static int detect_patch_format(const char **paths)
 570 {
 571         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
 572         struct strbuf l1 = STRBUF_INIT;
 573         struct strbuf l2 = STRBUF_INIT;
 574         struct strbuf l3 = STRBUF_INIT;
 575         FILE *fp;
 576
 577         /*
 578          * We default to mbox format if input is from stdin and for directories
 579          */
 580         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
 581                 return PATCH_FORMAT_MBOX;
 582
 583         /*
 584          * Otherwise, check the first few lines of the first patch, starting
 585          * from the first non-blank line, to try to detect its format.
 586          */
 587
 588         fp = xfopen(*paths, "r");
 589
 590         while (!strbuf_getline(&l1, fp)) {
 591                 if (l1.len)
 592                         break;
 593         }
 594
 595         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
 596                 ret = PATCH_FORMAT_MBOX;
 597                 goto done;
 598         }
 599
 600         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
 601                 ret = PATCH_FORMAT_STGIT_SERIES;
 602                 goto done;
 603         }
 604
 605         if (!strcmp(l1.buf, "# HG changeset patch")) {
 606                 ret = PATCH_FORMAT_HG;
 607                 goto done;
 608         }
 609
 610         strbuf_getline(&l2, fp);
 611         strbuf_getline(&l3, fp);
 612
 613         /*
 614          * If the second line is empty and the third is a From, Author or Date
 615          * entry, this is likely an StGit patch.
 616          */
 617         if (l1.len && !l2.len &&
 618                 (starts_with(l3.buf, "From:") ||
 619                  starts_with(l3.buf, "Author:") ||
 620                  starts_with(l3.buf, "Date:"))) {
 621                 ret = PATCH_FORMAT_STGIT;
 622                 goto done;
 623         }
 624
 625         if (l1.len && is_mail(fp)) {
 626                 ret = PATCH_FORMAT_MBOX;
 627                 goto done;
 628         }
 629
 630 done:
 631         fclose(fp);
 632         strbuf_release(&l1);
 633         strbuf_release(&l2);
 634         strbuf_release(&l3);
 635         return ret;
 636 }
 637
 638 /**
 639  * Splits out individual email patches from `paths`, where each path is either
 640  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
 641  */
 642 static int split_mail_mbox(struct am_state *state, const char **paths,
 643                                 int keep_cr, int mboxrd)
 644 {
 645         struct child_process cp = CHILD_PROCESS_INIT;
 646         struct strbuf last = STRBUF_INIT;
 647         int ret;
 648
 649         cp.git_cmd = 1;
 650         argv_array_push(&cp.args, "mailsplit");
 651         argv_array_pushf(&cp.args, "-d%d", state->prec);
 652         argv_array_pushf(&cp.args, "-o%s", state->dir);
 653         argv_array_push(&cp.args, "-b");
 654         if (keep_cr)
 655                 argv_array_push(&cp.args, "--keep-cr");
 656         if (mboxrd)
 657                 argv_array_push(&cp.args, "--mboxrd");
 658         argv_array_push(&cp.args, "--");
 659         argv_array_pushv(&cp.args, paths);
 660
 661         ret = capture_command(&cp, &last, 8);
 662         if (ret)
 663                 goto exit;
 664
 665         state->cur = 1;
 666         state->last = strtol(last.buf, NULL, 10);
 667
 668 exit:
 669         strbuf_release(&last);
 670         return ret ? -1 : 0;
 671 }
 672
 673 /**
 674  * Callback signature for split_mail_conv(). The foreign patch should be
 675  * read from `in`, and the converted patch (in RFC2822 mail format) should be
 676  * written to `out`. Return 0 on success, or -1 on failure.
 677  */
 678 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
 679
 680 /**
 681  * Calls `fn` for each file in `paths` to convert the foreign patch to the
 682  * RFC2822 mail format suitable for parsing with git-mailinfo.
 683  *
 684  * Returns 0 on success, -1 on failure.
 685  */
 686 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
 687                         const char **paths, int keep_cr)
 688 {
 689         static const char *stdin_only[] = {"-", NULL};
 690         int i;
 691
 692         if (!*paths)
 693                 paths = stdin_only;
 694
 695         for (i = 0; *paths; paths++, i++) {
 696                 FILE *in, *out;
 697                 const char *mail;
 698                 int ret;
 699
 700                 if (!strcmp(*paths, "-"))
 701                         in = stdin;
 702                 else
 703                         in = fopen(*paths, "r");
 704
 705                 if (!in)
 706                         return error_errno(_("could not open '%s' for reading"),
 707                                            *paths);
 708
 709                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
 710
 711                 out = fopen(mail, "w");
 712                 if (!out) {
 713                         if (in != stdin)
 714                                 fclose(in);
 715                         return error_errno(_("could not open '%s' for writing"),
 716                                            mail);
 717                 }
 718
 719                 ret = fn(out, in, keep_cr);
 720
 721                 fclose(out);
 722                 if (in != stdin)
 723                         fclose(in);
 724
 725                 if (ret)
 726                         return error(_("could not parse patch '%s'"), *paths);
 727         }
 728
 729         state->cur = 1;
 730         state->last = i;
 731         return 0;
 732 }
 733
 734 /**
 735  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
 736  * message suitable for parsing with git-mailinfo.
 737  */
 738 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 739 {
 740         struct strbuf sb = STRBUF_INIT;
 741         int subject_printed = 0;
 742
 743         while (!strbuf_getline_lf(&sb, in)) {
 744                 const char *str;
 745
 746                 if (str_isspace(sb.buf))
 747                         continue;
 748                 else if (skip_prefix(sb.buf, "Author:", &str))
 749                         fprintf(out, "From:%s\n", str);
 750                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
 751                         fprintf(out, "%s\n", sb.buf);
 752                 else if (!subject_printed) {
 753                         fprintf(out, "Subject: %s\n", sb.buf);
 754                         subject_printed = 1;
 755                 } else {
 756                         fprintf(out, "\n%s\n", sb.buf);
 757                         break;
 758                 }
 759         }
 760
 761         strbuf_reset(&sb);
 762         while (strbuf_fread(&sb, 8192, in) > 0) {
 763                 fwrite(sb.buf, 1, sb.len, out);
 764                 strbuf_reset(&sb);
 765         }
 766
 767         strbuf_release(&sb);
 768         return 0;
 769 }
 770
 771 /**
 772  * This function only supports a single StGit series file in `paths`.
 773  *
 774  * Given an StGit series file, converts the StGit patches in the series into
 775  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
 776  * the state directory.
 777  *
 778  * Returns 0 on success, -1 on failure.
 779  */
 780 static int split_mail_stgit_series(struct am_state *state, const char **paths,
 781                                         int keep_cr)
 782 {
 783         const char *series_dir;
 784         char *series_dir_buf;
 785         FILE *fp;
 786         struct argv_array patches = ARGV_ARRAY_INIT;
 787         struct strbuf sb = STRBUF_INIT;
 788         int ret;
 789
 790         if (!paths[0] || paths[1])
 791                 return error(_("Only one StGIT patch series can be applied at once"));
 792
 793         series_dir_buf = xstrdup(*paths);
 794         series_dir = dirname(series_dir_buf);
 795
 796         fp = fopen(*paths, "r");
 797         if (!fp)
 798                 return error_errno(_("could not open '%s' for reading"), *paths);
 799
 800         while (!strbuf_getline_lf(&sb, fp)) {
 801                 if (*sb.buf == '#')
 802                         continue; /* skip comment lines */
 803
 804                 argv_array_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
 805         }
 806
 807         fclose(fp);
 808         strbuf_release(&sb);
 809         free(series_dir_buf);
 810
 811         ret = split_mail_conv(stgit_patch_to_mail, state, patches.argv, keep_cr);
 812
 813         argv_array_clear(&patches);
 814         return ret;
 815 }
 816
 817 /**
 818  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
 819  * message suitable for parsing with git-mailinfo.
 820  */
 821 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 822 {
 823         struct strbuf sb = STRBUF_INIT;
 824         int rc = 0;
 825
 826         while (!strbuf_getline_lf(&sb, in)) {
 827                 const char *str;
 828
 829                 if (skip_prefix(sb.buf, "# User ", &str))
 830                         fprintf(out, "From: %s\n", str);
 831                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
 832                         timestamp_t timestamp;
 833                         long tz, tz2;
 834                         char *end;
 835
 836                         errno = 0;
 837                         timestamp = parse_timestamp(str, &end, 10);
 838                         if (errno) {
 839                                 rc = error(_("invalid timestamp"));
 840                                 goto exit;
 841                         }
 842
 843                         if (!skip_prefix(end, " ", &str)) {
 844                                 rc = error(_("invalid Date line"));
 845                                 goto exit;
 846                         }
 847
 848                         errno = 0;
 849                         tz = strtol(str, &end, 10);
 850                         if (errno) {
 851                                 rc = error(_("invalid timezone offset"));
 852                                 goto exit;
 853                         }
 854
 855                         if (*end) {
 856                                 rc = error(_("invalid Date line"));
 857                                 goto exit;
 858                         }
 859
 860                         /*
 861                          * mercurial's timezone is in seconds west of UTC,
 862                          * however git's timezone is in hours + minutes east of
 863                          * UTC. Convert it.
 864                          */
 865                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
 866                         if (tz > 0)
 867                                 tz2 = -tz2;
 868
 869                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
 870                 } else if (starts_with(sb.buf, "# ")) {
 871                         continue;
 872                 } else {
 873                         fprintf(out, "\n%s\n", sb.buf);
 874                         break;
 875                 }
 876         }
 877
 878         strbuf_reset(&sb);
 879         while (strbuf_fread(&sb, 8192, in) > 0) {
 880                 fwrite(sb.buf, 1, sb.len, out);
 881                 strbuf_reset(&sb);
 882         }
 883 exit:
 884         strbuf_release(&sb);
 885         return rc;
 886 }
 887
 888 /**
 889  * Splits a list of files/directories into individual email patches. Each path
 890  * in `paths` must be a file/directory that is formatted according to
 891  * `patch_format`.
 892  *
 893  * Once split out, the individual email patches will be stored in the state
 894  * directory, with each patch's filename being its index, padded to state->prec
 895  * digits.
 896  *
 897  * state->cur will be set to the index of the first mail, and state->last will
 898  * be set to the index of the last mail.
 899  *
 900  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
 901  * to disable this behavior, -1 to use the default configured setting.
 902  *
 903  * Returns 0 on success, -1 on failure.
 904  */
 905 static int split_mail(struct am_state *state, enum patch_format patch_format,
 906                         const char **paths, int keep_cr)
 907 {
 908         if (keep_cr < 0) {
 909                 keep_cr = 0;
 910                 git_config_get_bool("am.keepcr", &keep_cr);
 911         }
 912
 913         switch (patch_format) {
 914         case PATCH_FORMAT_MBOX:
 915                 return split_mail_mbox(state, paths, keep_cr, 0);
 916         case PATCH_FORMAT_STGIT:
 917                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
 918         case PATCH_FORMAT_STGIT_SERIES:
 919                 return split_mail_stgit_series(state, paths, keep_cr);
 920         case PATCH_FORMAT_HG:
 921                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
 922         case PATCH_FORMAT_MBOXRD:
 923                 return split_mail_mbox(state, paths, keep_cr, 1);
 924         default:
 925                 BUG("invalid patch_format");
 926         }
 927         return -1;
 928 }
 929
 930 /**
 931  * Setup a new am session for applying patches
 932  */
 933 static void am_setup(struct am_state *state, enum patch_format patch_format,
 934                         const char **paths, int keep_cr)
 935 {
 936         struct object_id curr_head;
 937         const char *str;
 938         struct strbuf sb = STRBUF_INIT;
 939
 940         if (!patch_format)
 941                 patch_format = detect_patch_format(paths);
 942
 943         if (!patch_format) {
 944                 fprintf_ln(stderr, _("Patch format detection failed."));
 945                 exit(128);
 946         }
 947
 948         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
 949                 die_errno(_("failed to create directory '%s'"), state->dir);
 950         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 951
 952         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
 953                 am_destroy(state);
 954                 die(_("Failed to split patches."));
 955         }
 956
 957         if (state->rebasing)
 958                 state->threeway = 1;
 959
 960         write_state_bool(state, "threeway", state->threeway);
 961         write_state_bool(state, "quiet", state->quiet);
 962         write_state_bool(state, "sign", state->signoff);
 963         write_state_bool(state, "utf8", state->utf8);
 964
 965         if (state->allow_rerere_autoupdate)
 966                 write_state_bool(state, "rerere-autoupdate",
 967                          state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
 968
 969         switch (state->keep) {
 970         case KEEP_FALSE:
 971                 str = "f";
 972                 break;
 973         case KEEP_TRUE:
 974                 str = "t";
 975                 break;
 976         case KEEP_NON_PATCH:
 977                 str = "b";
 978                 break;
 979         default:
 980                 BUG("invalid value for state->keep");
 981         }
 982
 983         write_state_text(state, "keep", str);
 984         write_state_bool(state, "messageid", state->message_id);
 985
 986         switch (state->scissors) {
 987         case SCISSORS_UNSET:
 988                 str = "";
 989                 break;
 990         case SCISSORS_FALSE:
 991                 str = "f";
 992                 break;
 993         case SCISSORS_TRUE:
 994                 str = "t";
 995                 break;
 996         default:
 997                 BUG("invalid value for state->scissors");
 998         }
 999         write_state_text(state, "scissors", str);
1000
1001         sq_quote_argv(&sb, state->git_apply_opts.argv);
1002         write_state_text(state, "apply-opt", sb.buf);
1003
1004         if (state->rebasing)
1005                 write_state_text(state, "rebasing", "");
1006         else
1007                 write_state_text(state, "applying", "");
1008
1009         if (!get_oid("HEAD", &curr_head)) {
1010                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1011                 if (!state->rebasing)
1012                         update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
1013                                    UPDATE_REFS_DIE_ON_ERR);
1014         } else {
1015                 write_state_text(state, "abort-safety", "");
1016                 if (!state->rebasing)
1017                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1018         }
1019
1020         /*
1021          * NOTE: Since the "next" and "last" files determine if an am_state
1022          * session is in progress, they should be written last.
1023          */
1024
1025         write_state_count(state, "next", state->cur);
1026         write_state_count(state, "last", state->last);
1027
1028         strbuf_release(&sb);
1029 }
1030
1031 /**
1032  * Increments the patch pointer, and cleans am_state for the application of the
1033  * next patch.
1034  */
1035 static void am_next(struct am_state *state)
1036 {
1037         struct object_id head;
1038
1039         FREE_AND_NULL(state->author_name);
1040         FREE_AND_NULL(state->author_email);
1041         FREE_AND_NULL(state->author_date);
1042         FREE_AND_NULL(state->msg);
1043         state->msg_len = 0;
1044
1045         unlink(am_path(state, "author-script"));
1046         unlink(am_path(state, "final-commit"));
1047
1048         oidclr(&state->orig_commit);
1049         unlink(am_path(state, "original-commit"));
1050         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
1051
1052         if (!get_oid("HEAD", &head))
1053                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1054         else
1055                 write_state_text(state, "abort-safety", "");
1056
1057         state->cur++;
1058         write_state_count(state, "next", state->cur);
1059 }
1060
1061 /**
1062  * Returns the filename of the current patch email.
1063  */
1064 static const char *msgnum(const struct am_state *state)
1065 {
1066         static struct strbuf sb = STRBUF_INIT;
1067
1068         strbuf_reset(&sb);
1069         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1070
1071         return sb.buf;
1072 }
1073
1074 /**
1075  * Refresh and write index.
1076  */
1077 static void refresh_and_write_cache(void)
1078 {
1079         struct lock_file lock_file = LOCK_INIT;
1080
1081         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1082         refresh_cache(REFRESH_QUIET);
1083         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1084                 die(_("unable to write index file"));
1085 }
1086
1087 /**
1088  * Dies with a user-friendly message on how to proceed after resolving the
1089  * problem. This message can be overridden with state->resolvemsg.
1090  */
1091 static void NORETURN die_user_resolve(const struct am_state *state)
1092 {
1093         if (state->resolvemsg) {
1094                 printf_ln("%s", state->resolvemsg);
1095         } else {
1096                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1097
1098                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1099                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1100                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1101         }
1102
1103         exit(128);
1104 }
1105
1106 /**
1107  * Appends signoff to the "msg" field of the am_state.
1108  */
1109 static void am_append_signoff(struct am_state *state)
1110 {
1111         struct strbuf sb = STRBUF_INIT;
1112
1113         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1114         append_signoff(&sb, 0, 0);
1115         state->msg = strbuf_detach(&sb, &state->msg_len);
1116 }
1117
1118 /**
1119  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1120  * state->msg will be set to the patch message. state->author_name,
1121  * state->author_email and state->author_date will be set to the patch author's
1122  * name, email and date respectively. The patch body will be written to the
1123  * state directory's "patch" file.
1124  *
1125  * Returns 1 if the patch should be skipped, 0 otherwise.
1126  */
1127 static int parse_mail(struct am_state *state, const char *mail)
1128 {
1129         FILE *fp;
1130         struct strbuf sb = STRBUF_INIT;
1131         struct strbuf msg = STRBUF_INIT;
1132         struct strbuf author_name = STRBUF_INIT;
1133         struct strbuf author_date = STRBUF_INIT;
1134         struct strbuf author_email = STRBUF_INIT;
1135         int ret = 0;
1136         struct mailinfo mi;
1137
1138         setup_mailinfo(&mi);
1139
1140         if (state->utf8)
1141                 mi.metainfo_charset = get_commit_output_encoding();
1142         else
1143                 mi.metainfo_charset = NULL;
1144
1145         switch (state->keep) {
1146         case KEEP_FALSE:
1147                 break;
1148         case KEEP_TRUE:
1149                 mi.keep_subject = 1;
1150                 break;
1151         case KEEP_NON_PATCH:
1152                 mi.keep_non_patch_brackets_in_subject = 1;
1153                 break;
1154         default:
1155                 BUG("invalid value for state->keep");
1156         }
1157
1158         if (state->message_id)
1159                 mi.add_message_id = 1;
1160
1161         switch (state->scissors) {
1162         case SCISSORS_UNSET:
1163                 break;
1164         case SCISSORS_FALSE:
1165                 mi.use_scissors = 0;
1166                 break;
1167         case SCISSORS_TRUE:
1168                 mi.use_scissors = 1;
1169                 break;
1170         default:
1171                 BUG("invalid value for state->scissors");
1172         }
1173
1174         mi.input = xfopen(mail, "r");
1175         mi.output = xfopen(am_path(state, "info"), "w");
1176         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1177                 die("could not parse patch");
1178
1179         fclose(mi.input);
1180         fclose(mi.output);
1181
1182         if (mi.format_flowed)
1183                 warning(_("Patch sent with format=flowed; "
1184                           "space at the end of lines might be lost."));
1185
1186         /* Extract message and author information */
1187         fp = xfopen(am_path(state, "info"), "r");
1188         while (!strbuf_getline_lf(&sb, fp)) {
1189                 const char *x;
1190
1191                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1192                         if (msg.len)
1193                                 strbuf_addch(&msg, '\n');
1194                         strbuf_addstr(&msg, x);
1195                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1196                         strbuf_addstr(&author_name, x);
1197                 else if (skip_prefix(sb.buf, "Email: ", &x))
1198                         strbuf_addstr(&author_email, x);
1199                 else if (skip_prefix(sb.buf, "Date: ", &x))
1200                         strbuf_addstr(&author_date, x);
1201         }
1202         fclose(fp);
1203
1204         /* Skip pine's internal folder data */
1205         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1206                 ret = 1;
1207                 goto finish;
1208         }
1209
1210         if (is_empty_or_missing_file(am_path(state, "patch"))) {
1211                 printf_ln(_("Patch is empty."));
1212                 die_user_resolve(state);
1213         }
1214
1215         strbuf_addstr(&msg, "\n\n");
1216         strbuf_addbuf(&msg, &mi.log_message);
1217         strbuf_stripspace(&msg, 0);
1218
1219         assert(!state->author_name);
1220         state->author_name = strbuf_detach(&author_name, NULL);
1221
1222         assert(!state->author_email);
1223         state->author_email = strbuf_detach(&author_email, NULL);
1224
1225         assert(!state->author_date);
1226         state->author_date = strbuf_detach(&author_date, NULL);
1227
1228         assert(!state->msg);
1229         state->msg = strbuf_detach(&msg, &state->msg_len);
1230
1231 finish:
1232         strbuf_release(&msg);
1233         strbuf_release(&author_date);
1234         strbuf_release(&author_email);
1235         strbuf_release(&author_name);
1236         strbuf_release(&sb);
1237         clear_mailinfo(&mi);
1238         return ret;
1239 }
1240
1241 /**
1242  * Sets commit_id to the commit hash where the mail was generated from.
1243  * Returns 0 on success, -1 on failure.
1244  */
1245 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1246 {
1247         struct strbuf sb = STRBUF_INIT;
1248         FILE *fp = xfopen(mail, "r");
1249         const char *x;
1250         int ret = 0;
1251
1252         if (strbuf_getline_lf(&sb, fp) ||
1253             !skip_prefix(sb.buf, "From ", &x) ||
1254             get_oid_hex(x, commit_id) < 0)
1255                 ret = -1;
1256
1257         strbuf_release(&sb);
1258         fclose(fp);
1259         return ret;
1260 }
1261
1262 /**
1263  * Sets state->msg, state->author_name, state->author_email, state->author_date
1264  * to the commit's respective info.
1265  */
1266 static void get_commit_info(struct am_state *state, struct commit *commit)
1267 {
1268         const char *buffer, *ident_line, *msg;
1269         size_t ident_len;
1270         struct ident_split id;
1271
1272         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1273
1274         ident_line = find_commit_header(buffer, "author", &ident_len);
1275
1276         if (split_ident_line(&id, ident_line, ident_len) < 0)
1277                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1278
1279         assert(!state->author_name);
1280         if (id.name_begin)
1281                 state->author_name =
1282                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1283         else
1284                 state->author_name = xstrdup("");
1285
1286         assert(!state->author_email);
1287         if (id.mail_begin)
1288                 state->author_email =
1289                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1290         else
1291                 state->author_email = xstrdup("");
1292
1293         assert(!state->author_date);
1294         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1295
1296         assert(!state->msg);
1297         msg = strstr(buffer, "\n\n");
1298         if (!msg)
1299                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1300         state->msg = xstrdup(msg + 2);
1301         state->msg_len = strlen(state->msg);
1302         unuse_commit_buffer(commit, buffer);
1303 }
1304
1305 /**
1306  * Writes `commit` as a patch to the state directory's "patch" file.
1307  */
1308 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1309 {
1310         struct rev_info rev_info;
1311         FILE *fp;
1312
1313         fp = xfopen(am_path(state, "patch"), "w");
1314         repo_init_revisions(the_repository, &rev_info, NULL);
1315         rev_info.diff = 1;
1316         rev_info.abbrev = 0;
1317         rev_info.disable_stdin = 1;
1318         rev_info.show_root_diff = 1;
1319         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1320         rev_info.no_commit_id = 1;
1321         rev_info.diffopt.flags.binary = 1;
1322         rev_info.diffopt.flags.full_index = 1;
1323         rev_info.diffopt.use_color = 0;
1324         rev_info.diffopt.file = fp;
1325         rev_info.diffopt.close_file = 1;
1326         add_pending_object(&rev_info, &commit->object, "");
1327         diff_setup_done(&rev_info.diffopt);
1328         log_tree_commit(&rev_info, commit);
1329 }
1330
1331 /**
1332  * Writes the diff of the index against HEAD as a patch to the state
1333  * directory's "patch" file.
1334  */
1335 static void write_index_patch(const struct am_state *state)
1336 {
1337         struct tree *tree;
1338         struct object_id head;
1339         struct rev_info rev_info;
1340         FILE *fp;
1341
1342         if (!get_oid("HEAD", &head)) {
1343                 struct commit *commit = lookup_commit_or_die(&head, "HEAD");
1344                 tree = get_commit_tree(commit);
1345         } else
1346                 tree = lookup_tree(the_repository,
1347                                    the_repository->hash_algo->empty_tree);
1348
1349         fp = xfopen(am_path(state, "patch"), "w");
1350         repo_init_revisions(the_repository, &rev_info, NULL);
1351         rev_info.diff = 1;
1352         rev_info.disable_stdin = 1;
1353         rev_info.no_commit_id = 1;
1354         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1355         rev_info.diffopt.use_color = 0;
1356         rev_info.diffopt.file = fp;
1357         rev_info.diffopt.close_file = 1;
1358         add_pending_object(&rev_info, &tree->object, "");
1359         diff_setup_done(&rev_info.diffopt);
1360         run_diff_index(&rev_info, 1);
1361 }
1362
1363 /**
1364  * Like parse_mail(), but parses the mail by looking up its commit ID
1365  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1366  * of patches.
1367  *
1368  * state->orig_commit will be set to the original commit ID.
1369  *
1370  * Will always return 0 as the patch should never be skipped.
1371  */
1372 static int parse_mail_rebase(struct am_state *state, const char *mail)
1373 {
1374         struct commit *commit;
1375         struct object_id commit_oid;
1376
1377         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1378                 die(_("could not parse %s"), mail);
1379
1380         commit = lookup_commit_or_die(&commit_oid, mail);
1381
1382         get_commit_info(state, commit);
1383
1384         write_commit_patch(state, commit);
1385
1386         oidcpy(&state->orig_commit, &commit_oid);
1387         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1388         update_ref("am", "REBASE_HEAD", &commit_oid,
1389                    NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
1390
1391         return 0;
1392 }
1393
1394 /**
1395  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1396  * `index_file` is not NULL, the patch will be applied to that index.
1397  */
1398 static int run_apply(const struct am_state *state, const char *index_file)
1399 {
1400         struct argv_array apply_paths = ARGV_ARRAY_INIT;
1401         struct argv_array apply_opts = ARGV_ARRAY_INIT;
1402         struct apply_state apply_state;
1403         int res, opts_left;
1404         int force_apply = 0;
1405         int options = 0;
1406
1407         if (init_apply_state(&apply_state, the_repository, NULL))
1408                 BUG("init_apply_state() failed");
1409
1410         argv_array_push(&apply_opts, "apply");
1411         argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
1412
1413         opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
1414                                         &apply_state, &force_apply, &options,
1415                                         NULL);
1416
1417         if (opts_left != 0)
1418                 die("unknown option passed through to git apply");
1419
1420         if (index_file) {
1421                 apply_state.index_file = index_file;
1422                 apply_state.cached = 1;
1423         } else
1424                 apply_state.check_index = 1;
1425
1426         /*
1427          * If we are allowed to fall back on 3-way merge, don't give false
1428          * errors during the initial attempt.
1429          */
1430         if (state->threeway && !index_file)
1431                 apply_state.apply_verbosity = verbosity_silent;
1432
1433         if (check_apply_state(&apply_state, force_apply))
1434                 BUG("check_apply_state() failed");
1435
1436         argv_array_push(&apply_paths, am_path(state, "patch"));
1437
1438         res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
1439
1440         argv_array_clear(&apply_paths);
1441         argv_array_clear(&apply_opts);
1442         clear_apply_state(&apply_state);
1443
1444         if (res)
1445                 return res;
1446
1447         if (index_file) {
1448                 /* Reload index as apply_all_patches() will have modified it. */
1449                 discard_cache();
1450                 read_cache_from(index_file);
1451         }
1452
1453         return 0;
1454 }
1455
1456 /**
1457  * Builds an index that contains just the blobs needed for a 3way merge.
1458  */
1459 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1460 {
1461         struct child_process cp = CHILD_PROCESS_INIT;
1462
1463         cp.git_cmd = 1;
1464         argv_array_push(&cp.args, "apply");
1465         argv_array_pushv(&cp.args, state->git_apply_opts.argv);
1466         argv_array_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1467         argv_array_push(&cp.args, am_path(state, "patch"));
1468
1469         if (run_command(&cp))
1470                 return -1;
1471
1472         return 0;
1473 }
1474
1475 /**
1476  * Attempt a threeway merge, using index_path as the temporary index.
1477  */
1478 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1479 {
1480         struct object_id orig_tree, their_tree, our_tree;
1481         const struct object_id *bases[1] = { &orig_tree };
1482         struct merge_options o;
1483         struct commit *result;
1484         char *their_tree_name;
1485
1486         if (get_oid("HEAD", &our_tree) < 0)
1487                 oidcpy(&our_tree, the_hash_algo->empty_tree);
1488
1489         if (build_fake_ancestor(state, index_path))
1490                 return error("could not build fake ancestor");
1491
1492         discard_cache();
1493         read_cache_from(index_path);
1494
1495         if (write_index_as_tree(&orig_tree, &the_index, index_path, 0, NULL))
1496                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1497
1498         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1499
1500         if (!state->quiet) {
1501                 /*
1502                  * List paths that needed 3-way fallback, so that the user can
1503                  * review them with extra care to spot mismerges.
1504                  */
1505                 struct rev_info rev_info;
1506
1507                 repo_init_revisions(the_repository, &rev_info, NULL);
1508                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1509                 rev_info.diffopt.filter |= diff_filter_bit('A');
1510                 rev_info.diffopt.filter |= diff_filter_bit('M');
1511                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1512                 diff_setup_done(&rev_info.diffopt);
1513                 run_diff_index(&rev_info, 1);
1514         }
1515
1516         if (run_apply(state, index_path))
1517                 return error(_("Did you hand edit your patch?\n"
1518                                 "It does not apply to blobs recorded in its index."));
1519
1520         if (write_index_as_tree(&their_tree, &the_index, index_path, 0, NULL))
1521                 return error("could not write tree");
1522
1523         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1524
1525         discard_cache();
1526         read_cache();
1527
1528         /*
1529          * This is not so wrong. Depending on which base we picked, orig_tree
1530          * may be wildly different from ours, but their_tree has the same set of
1531          * wildly different changes in parts the patch did not touch, so
1532          * recursive ends up canceling them, saying that we reverted all those
1533          * changes.
1534          */
1535
1536         init_merge_options(&o, the_repository);
1537
1538         o.branch1 = "HEAD";
1539         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1540         o.branch2 = their_tree_name;
1541         o.detect_directory_renames = 0;
1542
1543         if (state->quiet)
1544                 o.verbosity = 0;
1545
1546         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1547                 repo_rerere(the_repository, state->allow_rerere_autoupdate);
1548                 free(their_tree_name);
1549                 return error(_("Failed to merge in the changes."));
1550         }
1551
1552         free(their_tree_name);
1553         return 0;
1554 }
1555
1556 /**
1557  * Commits the current index with state->msg as the commit message and
1558  * state->author_name, state->author_email and state->author_date as the author
1559  * information.
1560  */
1561 static void do_commit(const struct am_state *state)
1562 {
1563         struct object_id tree, parent, commit;
1564         const struct object_id *old_oid;
1565         struct commit_list *parents = NULL;
1566         const char *reflog_msg, *author;
1567         struct strbuf sb = STRBUF_INIT;
1568
1569         if (run_hook_le(NULL, "pre-applypatch", NULL))
1570                 exit(1);
1571
1572         if (write_cache_as_tree(&tree, 0, NULL))
1573                 die(_("git write-tree failed to write a tree"));
1574
1575         if (!get_oid_commit("HEAD", &parent)) {
1576                 old_oid = &parent;
1577                 commit_list_insert(lookup_commit(the_repository, &parent),
1578                                    &parents);
1579         } else {
1580                 old_oid = NULL;
1581                 say(state, stderr, _("applying to an empty history"));
1582         }
1583
1584         author = fmt_ident(state->author_name, state->author_email,
1585                 WANT_AUTHOR_IDENT,
1586                         state->ignore_date ? NULL : state->author_date,
1587                         IDENT_STRICT);
1588
1589         if (state->committer_date_is_author_date)
1590                 setenv("GIT_COMMITTER_DATE",
1591                         state->ignore_date ? "" : state->author_date, 1);
1592
1593         if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
1594                         author, state->sign_commit))
1595                 die(_("failed to write commit object"));
1596
1597         reflog_msg = getenv("GIT_REFLOG_ACTION");
1598         if (!reflog_msg)
1599                 reflog_msg = "am";
1600
1601         strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1602                         state->msg);
1603
1604         update_ref(sb.buf, "HEAD", &commit, old_oid, 0,
1605                    UPDATE_REFS_DIE_ON_ERR);
1606
1607         if (state->rebasing) {
1608                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1609
1610                 assert(!is_null_oid(&state->orig_commit));
1611                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1612                 fprintf(fp, "%s\n", oid_to_hex(&commit));
1613                 fclose(fp);
1614         }
1615
1616         run_hook_le(NULL, "post-applypatch", NULL);
1617
1618         strbuf_release(&sb);
1619 }
1620
1621 /**
1622  * Validates the am_state for resuming -- the "msg" and authorship fields must
1623  * be filled up.
1624  */
1625 static void validate_resume_state(const struct am_state *state)
1626 {
1627         if (!state->msg)
1628                 die(_("cannot resume: %s does not exist."),
1629                         am_path(state, "final-commit"));
1630
1631         if (!state->author_name || !state->author_email || !state->author_date)
1632                 die(_("cannot resume: %s does not exist."),
1633                         am_path(state, "author-script"));
1634 }
1635
1636 /**
1637  * Interactively prompt the user on whether the current patch should be
1638  * applied.
1639  *
1640  * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1641  * skip it.
1642  */
1643 static int do_interactive(struct am_state *state)
1644 {
1645         assert(state->msg);
1646
1647         for (;;) {
1648                 char reply[64];
1649
1650                 puts(_("Commit Body is:"));
1651                 puts("--------------------------");
1652                 printf("%s", state->msg);
1653                 puts("--------------------------");
1654
1655                 /*
1656                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1657                  * in your translation. The program will only accept English
1658                  * input at this point.
1659                  */
1660                 printf(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "));
1661                 if (!fgets(reply, sizeof(reply), stdin))
1662                         die("unable to read from stdin; aborting");
1663
1664                 if (*reply == 'y' || *reply == 'Y') {
1665                         return 0;
1666                 } else if (*reply == 'a' || *reply == 'A') {
1667                         state->interactive = 0;
1668                         return 0;
1669                 } else if (*reply == 'n' || *reply == 'N') {
1670                         return 1;
1671                 } else if (*reply == 'e' || *reply == 'E') {
1672                         struct strbuf msg = STRBUF_INIT;
1673
1674                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1675                                 free(state->msg);
1676                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1677                         }
1678                         strbuf_release(&msg);
1679                 } else if (*reply == 'v' || *reply == 'V') {
1680                         const char *pager = git_pager(1);
1681                         struct child_process cp = CHILD_PROCESS_INIT;
1682
1683                         if (!pager)
1684                                 pager = "cat";
1685                         prepare_pager_args(&cp, pager);
1686                         argv_array_push(&cp.args, am_path(state, "patch"));
1687                         run_command(&cp);
1688                 }
1689         }
1690 }
1691
1692 /**
1693  * Applies all queued mail.
1694  *
1695  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1696  * well as the state directory's "patch" file is used as-is for applying the
1697  * patch and committing it.
1698  */
1699 static void am_run(struct am_state *state, int resume)
1700 {
1701         const char *argv_gc_auto[] = {"gc", "--auto", NULL};
1702         struct strbuf sb = STRBUF_INIT;
1703
1704         unlink(am_path(state, "dirtyindex"));
1705
1706         refresh_and_write_cache();
1707
1708         if (repo_index_has_changes(the_repository, NULL, &sb)) {
1709                 write_state_bool(state, "dirtyindex", 1);
1710                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1711         }
1712
1713         strbuf_release(&sb);
1714
1715         while (state->cur <= state->last) {
1716                 const char *mail = am_path(state, msgnum(state));
1717                 int apply_status;
1718
1719                 reset_ident_date();
1720
1721                 if (!file_exists(mail))
1722                         goto next;
1723
1724                 if (resume) {
1725                         validate_resume_state(state);
1726                 } else {
1727                         int skip;
1728
1729                         if (state->rebasing)
1730                                 skip = parse_mail_rebase(state, mail);
1731                         else
1732                                 skip = parse_mail(state, mail);
1733
1734                         if (skip)
1735                                 goto next; /* mail should be skipped */
1736
1737                         if (state->signoff)
1738                                 am_append_signoff(state);
1739
1740                         write_author_script(state);
1741                         write_commit_msg(state);
1742                 }
1743
1744                 if (state->interactive && do_interactive(state))
1745                         goto next;
1746
1747                 if (run_applypatch_msg_hook(state))
1748                         exit(1);
1749
1750                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1751
1752                 apply_status = run_apply(state, NULL);
1753
1754                 if (apply_status && state->threeway) {
1755                         struct strbuf sb = STRBUF_INIT;
1756
1757                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1758                         apply_status = fall_back_threeway(state, sb.buf);
1759                         strbuf_release(&sb);
1760
1761                         /*
1762                          * Applying the patch to an earlier tree and merging
1763                          * the result may have produced the same tree as ours.
1764                          */
1765                         if (!apply_status &&
1766                             !repo_index_has_changes(the_repository, NULL, NULL)) {
1767                                 say(state, stdout, _("No changes -- Patch already applied."));
1768                                 goto next;
1769                         }
1770                 }
1771
1772                 if (apply_status) {
1773                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1774                                 linelen(state->msg), state->msg);
1775
1776                         if (advice_amworkdir)
1777                                 advise(_("Use 'git am --show-current-patch' to see the failed patch"));
1778
1779                         die_user_resolve(state);
1780                 }
1781
1782                 do_commit(state);
1783
1784 next:
1785                 am_next(state);
1786
1787                 if (resume)
1788                         am_load(state);
1789                 resume = 0;
1790         }
1791
1792         if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
1793                 assert(state->rebasing);
1794                 copy_notes_for_rebase(state);
1795                 run_post_rewrite_hook(state);
1796         }
1797
1798         /*
1799          * In rebasing mode, it's up to the caller to take care of
1800          * housekeeping.
1801          */
1802         if (!state->rebasing) {
1803                 am_destroy(state);
1804                 close_object_store(the_repository->objects);
1805                 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1806         }
1807 }
1808
1809 /**
1810  * Resume the current am session after patch application failure. The user did
1811  * all the hard work, and we do not have to do any patch application. Just
1812  * trust and commit what the user has in the index and working tree.
1813  */
1814 static void am_resolve(struct am_state *state)
1815 {
1816         validate_resume_state(state);
1817
1818         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1819
1820         if (!repo_index_has_changes(the_repository, NULL, NULL)) {
1821                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1822                         "If there is nothing left to stage, chances are that something else\n"
1823                         "already introduced the same changes; you might want to skip this patch."));
1824                 die_user_resolve(state);
1825         }
1826
1827         if (unmerged_cache()) {
1828                 printf_ln(_("You still have unmerged paths in your index.\n"
1829                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1830                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1831                 die_user_resolve(state);
1832         }
1833
1834         if (state->interactive) {
1835                 write_index_patch(state);
1836                 if (do_interactive(state))
1837                         goto next;
1838         }
1839
1840         repo_rerere(the_repository, 0);
1841
1842         do_commit(state);
1843
1844 next:
1845         am_next(state);
1846         am_load(state);
1847         am_run(state, 0);
1848 }
1849
1850 /**
1851  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1852  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1853  * failure.
1854  */
1855 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1856 {
1857         struct lock_file lock_file = LOCK_INIT;
1858         struct unpack_trees_options opts;
1859         struct tree_desc t[2];
1860
1861         if (parse_tree(head) || parse_tree(remote))
1862                 return -1;
1863
1864         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1865
1866         refresh_cache(REFRESH_QUIET);
1867
1868         memset(&opts, 0, sizeof(opts));
1869         opts.head_idx = 1;
1870         opts.src_index = &the_index;
1871         opts.dst_index = &the_index;
1872         opts.update = 1;
1873         opts.merge = 1;
1874         opts.reset = reset;
1875         opts.fn = twoway_merge;
1876         init_tree_desc(&t[0], head->buffer, head->size);
1877         init_tree_desc(&t[1], remote->buffer, remote->size);
1878
1879         if (unpack_trees(2, t, &opts)) {
1880                 rollback_lock_file(&lock_file);
1881                 return -1;
1882         }
1883
1884         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1885                 die(_("unable to write new index file"));
1886
1887         return 0;
1888 }
1889
1890 /**
1891  * Merges a tree into the index. The index's stat info will take precedence
1892  * over the merged tree's. Returns 0 on success, -1 on failure.
1893  */
1894 static int merge_tree(struct tree *tree)
1895 {
1896         struct lock_file lock_file = LOCK_INIT;
1897         struct unpack_trees_options opts;
1898         struct tree_desc t[1];
1899
1900         if (parse_tree(tree))
1901                 return -1;
1902
1903         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1904
1905         memset(&opts, 0, sizeof(opts));
1906         opts.head_idx = 1;
1907         opts.src_index = &the_index;
1908         opts.dst_index = &the_index;
1909         opts.merge = 1;
1910         opts.fn = oneway_merge;
1911         init_tree_desc(&t[0], tree->buffer, tree->size);
1912
1913         if (unpack_trees(1, t, &opts)) {
1914                 rollback_lock_file(&lock_file);
1915                 return -1;
1916         }
1917
1918         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1919                 die(_("unable to write new index file"));
1920
1921         return 0;
1922 }
1923
1924 /**
1925  * Clean the index without touching entries that are not modified between
1926  * `head` and `remote`.
1927  */
1928 static int clean_index(const struct object_id *head, const struct object_id *remote)
1929 {
1930         struct tree *head_tree, *remote_tree, *index_tree;
1931         struct object_id index;
1932
1933         head_tree = parse_tree_indirect(head);
1934         if (!head_tree)
1935                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
1936
1937         remote_tree = parse_tree_indirect(remote);
1938         if (!remote_tree)
1939                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
1940
1941         read_cache_unmerged();
1942
1943         if (fast_forward_to(head_tree, head_tree, 1))
1944                 return -1;
1945
1946         if (write_cache_as_tree(&index, 0, NULL))
1947                 return -1;
1948
1949         index_tree = parse_tree_indirect(&index);
1950         if (!index_tree)
1951                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
1952
1953         if (fast_forward_to(index_tree, remote_tree, 0))
1954                 return -1;
1955
1956         if (merge_tree(remote_tree))
1957                 return -1;
1958
1959         remove_branch_state(the_repository);
1960
1961         return 0;
1962 }
1963
1964 /**
1965  * Resets rerere's merge resolution metadata.
1966  */
1967 static void am_rerere_clear(void)
1968 {
1969         struct string_list merge_rr = STRING_LIST_INIT_DUP;
1970         rerere_clear(the_repository, &merge_rr);
1971         string_list_clear(&merge_rr, 1);
1972 }
1973
1974 /**
1975  * Resume the current am session by skipping the current patch.
1976  */
1977 static void am_skip(struct am_state *state)
1978 {
1979         struct object_id head;
1980
1981         am_rerere_clear();
1982
1983         if (get_oid("HEAD", &head))
1984                 oidcpy(&head, the_hash_algo->empty_tree);
1985
1986         if (clean_index(&head, &head))
1987                 die(_("failed to clean index"));
1988
1989         if (state->rebasing) {
1990                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1991
1992                 assert(!is_null_oid(&state->orig_commit));
1993                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1994                 fprintf(fp, "%s\n", oid_to_hex(&head));
1995                 fclose(fp);
1996         }
1997
1998         am_next(state);
1999         am_load(state);
2000         am_run(state, 0);
2001 }
2002
2003 /**
2004  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2005  *
2006  * It is not safe to reset HEAD when:
2007  * 1. git-am previously failed because the index was dirty.
2008  * 2. HEAD has moved since git-am previously failed.
2009  */
2010 static int safe_to_abort(const struct am_state *state)
2011 {
2012         struct strbuf sb = STRBUF_INIT;
2013         struct object_id abort_safety, head;
2014
2015         if (file_exists(am_path(state, "dirtyindex")))
2016                 return 0;
2017
2018         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2019                 if (get_oid_hex(sb.buf, &abort_safety))
2020                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2021         } else
2022                 oidclr(&abort_safety);
2023         strbuf_release(&sb);
2024
2025         if (get_oid("HEAD", &head))
2026                 oidclr(&head);
2027
2028         if (oideq(&head, &abort_safety))
2029                 return 1;
2030
2031         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2032                 "Not rewinding to ORIG_HEAD"));
2033
2034         return 0;
2035 }
2036
2037 /**
2038  * Aborts the current am session if it is safe to do so.
2039  */
2040 static void am_abort(struct am_state *state)
2041 {
2042         struct object_id curr_head, orig_head;
2043         int has_curr_head, has_orig_head;
2044         char *curr_branch;
2045
2046         if (!safe_to_abort(state)) {
2047                 am_destroy(state);
2048                 return;
2049         }
2050
2051         am_rerere_clear();
2052
2053         curr_branch = resolve_refdup("HEAD", 0, &curr_head, NULL);
2054         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2055         if (!has_curr_head)
2056                 oidcpy(&curr_head, the_hash_algo->empty_tree);
2057
2058         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2059         if (!has_orig_head)
2060                 oidcpy(&orig_head, the_hash_algo->empty_tree);
2061
2062         clean_index(&curr_head, &orig_head);
2063
2064         if (has_orig_head)
2065                 update_ref("am --abort", "HEAD", &orig_head,
2066                            has_curr_head ? &curr_head : NULL, 0,
2067                            UPDATE_REFS_DIE_ON_ERR);
2068         else if (curr_branch)
2069                 delete_ref(NULL, curr_branch, NULL, REF_NO_DEREF);
2070
2071         free(curr_branch);
2072         am_destroy(state);
2073 }
2074
2075 static int show_patch(struct am_state *state)
2076 {
2077         struct strbuf sb = STRBUF_INIT;
2078         const char *patch_path;
2079         int len;
2080
2081         if (!is_null_oid(&state->orig_commit)) {
2082                 const char *av[4] = { "show", NULL, "--", NULL };
2083                 char *new_oid_str;
2084                 int ret;
2085
2086                 av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
2087                 ret = run_command_v_opt(av, RUN_GIT_CMD);
2088                 free(new_oid_str);
2089                 return ret;
2090         }
2091
2092         patch_path = am_path(state, msgnum(state));
2093         len = strbuf_read_file(&sb, patch_path, 0);
2094         if (len < 0)
2095                 die_errno(_("failed to read '%s'"), patch_path);
2096
2097         setup_pager();
2098         write_in_full(1, sb.buf, sb.len);
2099         strbuf_release(&sb);
2100         return 0;
2101 }
2102
2103 /**
2104  * parse_options() callback that validates and sets opt->value to the
2105  * PATCH_FORMAT_* enum value corresponding to `arg`.
2106  */
2107 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2108 {
2109         int *opt_value = opt->value;
2110
2111         if (unset)
2112                 *opt_value = PATCH_FORMAT_UNKNOWN;
2113         else if (!strcmp(arg, "mbox"))
2114                 *opt_value = PATCH_FORMAT_MBOX;
2115         else if (!strcmp(arg, "stgit"))
2116                 *opt_value = PATCH_FORMAT_STGIT;
2117         else if (!strcmp(arg, "stgit-series"))
2118                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2119         else if (!strcmp(arg, "hg"))
2120                 *opt_value = PATCH_FORMAT_HG;
2121         else if (!strcmp(arg, "mboxrd"))
2122                 *opt_value = PATCH_FORMAT_MBOXRD;
2123         /*
2124          * Please update $__git_patchformat in git-completion.bash
2125          * when you add new options
2126          */
2127         else
2128                 return error(_("Invalid value for --patch-format: %s"), arg);
2129         return 0;
2130 }
2131
2132 enum resume_mode {
2133         RESUME_FALSE = 0,
2134         RESUME_APPLY,
2135         RESUME_RESOLVED,
2136         RESUME_SKIP,
2137         RESUME_ABORT,
2138         RESUME_QUIT,
2139         RESUME_SHOW_PATCH
2140 };
2141
2142 static int git_am_config(const char *k, const char *v, void *cb)
2143 {
2144         int status;
2145
2146         status = git_gpg_config(k, v, NULL);
2147         if (status)
2148                 return status;
2149
2150         return git_default_config(k, v, NULL);
2151 }
2152
2153 int cmd_am(int argc, const char **argv, const char *prefix)
2154 {
2155         struct am_state state;
2156         int binary = -1;
2157         int keep_cr = -1;
2158         int patch_format = PATCH_FORMAT_UNKNOWN;
2159         enum resume_mode resume = RESUME_FALSE;
2160         int in_progress;
2161         int ret = 0;
2162
2163         const char * const usage[] = {
2164                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2165                 N_("git am [<options>] (--continue | --skip | --abort)"),
2166                 NULL
2167         };
2168
2169         struct option options[] = {
2170                 OPT_BOOL('i', "interactive", &state.interactive,
2171                         N_("run interactively")),
2172                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2173                         N_("historical option -- no-op")),
2174                 OPT_BOOL('3', "3way", &state.threeway,
2175                         N_("allow fall back on 3way merging if needed")),
2176                 OPT__QUIET(&state.quiet, N_("be quiet")),
2177                 OPT_SET_INT('s', "signoff", &state.signoff,
2178                         N_("add a Signed-off-by line to the commit message"),
2179                         SIGNOFF_EXPLICIT),
2180                 OPT_BOOL('u', "utf8", &state.utf8,
2181                         N_("recode into utf8 (default)")),
2182                 OPT_SET_INT('k', "keep", &state.keep,
2183                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2184                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2185                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2186                 OPT_BOOL('m', "message-id", &state.message_id,
2187                         N_("pass -m flag to git-mailinfo")),
2188                 OPT_SET_INT_F(0, "keep-cr", &keep_cr,
2189                         N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2190                         1, PARSE_OPT_NONEG),
2191                 OPT_SET_INT_F(0, "no-keep-cr", &keep_cr,
2192                         N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2193                         0, PARSE_OPT_NONEG),
2194                 OPT_BOOL('c', "scissors", &state.scissors,
2195                         N_("strip everything before a scissors line")),
2196                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2197                         N_("pass it through git-apply"),
2198                         0),
2199                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2200                         N_("pass it through git-apply"),
2201                         PARSE_OPT_NOARG),
2202                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2203                         N_("pass it through git-apply"),
2204                         PARSE_OPT_NOARG),
2205                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2206                         N_("pass it through git-apply"),
2207                         0),
2208                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2209                         N_("pass it through git-apply"),
2210                         0),
2211                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2212                         N_("pass it through git-apply"),
2213                         0),
2214                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2215                         N_("pass it through git-apply"),
2216                         0),
2217                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2218                         N_("pass it through git-apply"),
2219                         0),
2220                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2221                         N_("format the patch(es) are in"),
2222                         parse_opt_patchformat),
2223                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2224                         N_("pass it through git-apply"),
2225                         PARSE_OPT_NOARG),
2226                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2227                         N_("override error message when patch failure occurs")),
2228                 OPT_CMDMODE(0, "continue", &resume,
2229                         N_("continue applying patches after resolving a conflict"),
2230                         RESUME_RESOLVED),
2231                 OPT_CMDMODE('r', "resolved", &resume,
2232                         N_("synonyms for --continue"),
2233                         RESUME_RESOLVED),
2234                 OPT_CMDMODE(0, "skip", &resume,
2235                         N_("skip the current patch"),
2236                         RESUME_SKIP),
2237                 OPT_CMDMODE(0, "abort", &resume,
2238                         N_("restore the original branch and abort the patching operation."),
2239                         RESUME_ABORT),
2240                 OPT_CMDMODE(0, "quit", &resume,
2241                         N_("abort the patching operation but keep HEAD where it is."),
2242                         RESUME_QUIT),
2243                 OPT_CMDMODE(0, "show-current-patch", &resume,
2244                         N_("show the patch being applied."),
2245                         RESUME_SHOW_PATCH),
2246                 OPT_BOOL(0, "committer-date-is-author-date",
2247                         &state.committer_date_is_author_date,
2248                         N_("lie about committer date")),
2249                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2250                         N_("use current timestamp for author date")),
2251                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2252                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2253                   N_("GPG-sign commits"),
2254                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2255                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2256                         N_("(internal use for git-rebase)")),
2257                 OPT_END()
2258         };
2259
2260         if (argc == 2 && !strcmp(argv[1], "-h"))
2261                 usage_with_options(usage, options);
2262
2263         git_config(git_am_config, NULL);
2264
2265         am_state_init(&state);
2266
2267         in_progress = am_in_progress(&state);
2268         if (in_progress)
2269                 am_load(&state);
2270
2271         argc = parse_options(argc, argv, prefix, options, usage, 0);
2272
2273         if (binary >= 0)
2274                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2275                                 "it will be removed. Please do not use it anymore."));
2276
2277         /* Ensure a valid committer ident can be constructed */
2278         git_committer_info(IDENT_STRICT);
2279
2280         if (repo_read_index_preload(the_repository, NULL, 0) < 0)
2281                 die(_("failed to read the index"));
2282
2283         if (in_progress) {
2284                 /*
2285                  * Catch user error to feed us patches when there is a session
2286                  * in progress:
2287                  *
2288                  * 1. mbox path(s) are provided on the command-line.
2289                  * 2. stdin is not a tty: the user is trying to feed us a patch
2290                  *    from standard input. This is somewhat unreliable -- stdin
2291                  *    could be /dev/null for example and the caller did not
2292                  *    intend to feed us a patch but wanted to continue
2293                  *    unattended.
2294                  */
2295                 if (argc || (resume == RESUME_FALSE && !isatty(0)))
2296                         die(_("previous rebase directory %s still exists but mbox given."),
2297                                 state.dir);
2298
2299                 if (resume == RESUME_FALSE)
2300                         resume = RESUME_APPLY;
2301
2302                 if (state.signoff == SIGNOFF_EXPLICIT)
2303                         am_append_signoff(&state);
2304         } else {
2305                 struct argv_array paths = ARGV_ARRAY_INIT;
2306                 int i;
2307
2308                 /*
2309                  * Handle stray state directory in the independent-run case. In
2310                  * the --rebasing case, it is up to the caller to take care of
2311                  * stray directories.
2312                  */
2313                 if (file_exists(state.dir) && !state.rebasing) {
2314                         if (resume == RESUME_ABORT || resume == RESUME_QUIT) {
2315                                 am_destroy(&state);
2316                                 am_state_release(&state);
2317                                 return 0;
2318                         }
2319
2320                         die(_("Stray %s directory found.\n"
2321                                 "Use \"git am --abort\" to remove it."),
2322                                 state.dir);
2323                 }
2324
2325                 if (resume)
2326                         die(_("Resolve operation not in progress, we are not resuming."));
2327
2328                 for (i = 0; i < argc; i++) {
2329                         if (is_absolute_path(argv[i]) || !prefix)
2330                                 argv_array_push(&paths, argv[i]);
2331                         else
2332                                 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2333                 }
2334
2335                 if (state.interactive && !paths.argc)
2336                         die(_("interactive mode requires patches on the command line"));
2337
2338                 am_setup(&state, patch_format, paths.argv, keep_cr);
2339
2340                 argv_array_clear(&paths);
2341         }
2342
2343         switch (resume) {
2344         case RESUME_FALSE:
2345                 am_run(&state, 0);
2346                 break;
2347         case RESUME_APPLY:
2348                 am_run(&state, 1);
2349                 break;
2350         case RESUME_RESOLVED:
2351                 am_resolve(&state);
2352                 break;
2353         case RESUME_SKIP:
2354                 am_skip(&state);
2355                 break;
2356         case RESUME_ABORT:
2357                 am_abort(&state);
2358                 break;
2359         case RESUME_QUIT:
2360                 am_rerere_clear();
2361                 am_destroy(&state);
2362                 break;
2363         case RESUME_SHOW_PATCH:
2364                 ret = show_patch(&state);
2365                 break;
2366         default:
2367                 BUG("invalid resume value");
2368         }
2369
2370         am_state_release(&state);
2371
2372         return ret;
2373 }