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