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   1 /*
   2  * Builtin "git am"
   3  *
   4  * Based on git-am.sh by Junio C Hamano.
   5  */
   6 #include "cache.h"
   7 #include "config.h"
   8 #include "builtin.h"
   9 #include "exec_cmd.h"
  10 #include "parse-options.h"
  11 #include "dir.h"
  12 #include "run-command.h"
  13 #include "quote.h"
  14 #include "tempfile.h"
  15 #include "lockfile.h"
  16 #include "cache-tree.h"
  17 #include "refs.h"
  18 #include "commit.h"
  19 #include "diff.h"
  20 #include "diffcore.h"
  21 #include "unpack-trees.h"
  22 #include "branch.h"
  23 #include "sequencer.h"
  24 #include "revision.h"
  25 #include "merge-recursive.h"
  26 #include "revision.h"
  27 #include "log-tree.h"
  28 #include "notes-utils.h"
  29 #include "rerere.h"
  30 #include "prompt.h"
  31 #include "mailinfo.h"
  32 #include "apply.h"
  33 #include "string-list.h"
  34
  35 /**
  36  * Returns 1 if the file is empty or does not exist, 0 otherwise.
  37  */
  38 static int is_empty_file(const char *filename)
  39 {
  40         struct stat st;
  41
  42         if (stat(filename, &st) < 0) {
  43                 if (errno == ENOENT)
  44                         return 1;
  45                 die_errno(_("could not stat %s"), filename);
  46         }
  47
  48         return !st.st_size;
  49 }
  50
  51 /**
  52  * Returns the length of the first line of msg.
  53  */
  54 static int linelen(const char *msg)
  55 {
  56         return strchrnul(msg, '\n') - msg;
  57 }
  58
  59 /**
  60  * Returns true if `str` consists of only whitespace, false otherwise.
  61  */
  62 static int str_isspace(const char *str)
  63 {
  64         for (; *str; str++)
  65                 if (!isspace(*str))
  66                         return 0;
  67
  68         return 1;
  69 }
  70
  71 enum patch_format {
  72         PATCH_FORMAT_UNKNOWN = 0,
  73         PATCH_FORMAT_MBOX,
  74         PATCH_FORMAT_STGIT,
  75         PATCH_FORMAT_STGIT_SERIES,
  76         PATCH_FORMAT_HG,
  77         PATCH_FORMAT_MBOXRD
  78 };
  79
  80 enum keep_type {
  81         KEEP_FALSE = 0,
  82         KEEP_TRUE,      /* pass -k flag to git-mailinfo */
  83         KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
  84 };
  85
  86 enum scissors_type {
  87         SCISSORS_UNSET = -1,
  88         SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
  89         SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
  90 };
  91
  92 enum signoff_type {
  93         SIGNOFF_FALSE = 0,
  94         SIGNOFF_TRUE = 1,
  95         SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
  96 };
  97
  98 struct am_state {
  99         /* state directory path */
 100         char *dir;
 101
 102         /* current and last patch numbers, 1-indexed */
 103         int cur;
 104         int last;
 105
 106         /* commit metadata and message */
 107         char *author_name;
 108         char *author_email;
 109         char *author_date;
 110         char *msg;
 111         size_t msg_len;
 112
 113         /* when --rebasing, records the original commit the patch came from */
 114         struct object_id orig_commit;
 115
 116         /* number of digits in patch filename */
 117         int prec;
 118
 119         /* various operating modes and command line options */
 120         int interactive;
 121         int threeway;
 122         int quiet;
 123         int signoff; /* enum signoff_type */
 124         int utf8;
 125         int keep; /* enum keep_type */
 126         int message_id;
 127         int scissors; /* enum scissors_type */
 128         struct argv_array git_apply_opts;
 129         const char *resolvemsg;
 130         int committer_date_is_author_date;
 131         int ignore_date;
 132         int allow_rerere_autoupdate;
 133         const char *sign_commit;
 134         int rebasing;
 135 };
 136
 137 /**
 138  * Initializes am_state with the default values.
 139  */
 140 static void am_state_init(struct am_state *state)
 141 {
 142         int gpgsign;
 143
 144         memset(state, 0, sizeof(*state));
 145
 146         state->dir = git_pathdup("rebase-apply");
 147
 148         state->prec = 4;
 149
 150         git_config_get_bool("am.threeway", &state->threeway);
 151
 152         state->utf8 = 1;
 153
 154         git_config_get_bool("am.messageid", &state->message_id);
 155
 156         state->scissors = SCISSORS_UNSET;
 157
 158         argv_array_init(&state->git_apply_opts);
 159
 160         if (!git_config_get_bool("commit.gpgsign", &gpgsign))
 161                 state->sign_commit = gpgsign ? "" : NULL;
 162 }
 163
 164 /**
 165  * Releases memory allocated by an am_state.
 166  */
 167 static void am_state_release(struct am_state *state)
 168 {
 169         free(state->dir);
 170         free(state->author_name);
 171         free(state->author_email);
 172         free(state->author_date);
 173         free(state->msg);
 174         argv_array_clear(&state->git_apply_opts);
 175 }
 176
 177 /**
 178  * Returns path relative to the am_state directory.
 179  */
 180 static inline const char *am_path(const struct am_state *state, const char *path)
 181 {
 182         return mkpath("%s/%s", state->dir, path);
 183 }
 184
 185 /**
 186  * For convenience to call write_file()
 187  */
 188 static void write_state_text(const struct am_state *state,
 189                              const char *name, const char *string)
 190 {
 191         write_file(am_path(state, name), "%s", string);
 192 }
 193
 194 static void write_state_count(const struct am_state *state,
 195                               const char *name, int value)
 196 {
 197         write_file(am_path(state, name), "%d", value);
 198 }
 199
 200 static void write_state_bool(const struct am_state *state,
 201                              const char *name, int value)
 202 {
 203         write_state_text(state, name, value ? "t" : "f");
 204 }
 205
 206 /**
 207  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
 208  * at the end.
 209  */
 210 static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
 211 {
 212         va_list ap;
 213
 214         va_start(ap, fmt);
 215         if (!state->quiet) {
 216                 vfprintf(fp, fmt, ap);
 217                 putc('\n', fp);
 218         }
 219         va_end(ap);
 220 }
 221
 222 /**
 223  * Returns 1 if there is an am session in progress, 0 otherwise.
 224  */
 225 static int am_in_progress(const struct am_state *state)
 226 {
 227         struct stat st;
 228
 229         if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
 230                 return 0;
 231         if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
 232                 return 0;
 233         if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
 234                 return 0;
 235         return 1;
 236 }
 237
 238 /**
 239  * Reads the contents of `file` in the `state` directory into `sb`. Returns the
 240  * number of bytes read on success, -1 if the file does not exist. If `trim` is
 241  * set, trailing whitespace will be removed.
 242  */
 243 static int read_state_file(struct strbuf *sb, const struct am_state *state,
 244                         const char *file, int trim)
 245 {
 246         strbuf_reset(sb);
 247
 248         if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
 249                 if (trim)
 250                         strbuf_trim(sb);
 251
 252                 return sb->len;
 253         }
 254
 255         if (errno == ENOENT)
 256                 return -1;
 257
 258         die_errno(_("could not read '%s'"), am_path(state, file));
 259 }
 260
 261 /**
 262  * Take a series of KEY='VALUE' lines where VALUE part is
 263  * sq-quoted, and append <KEY, VALUE> at the end of the string list
 264  */
 265 static int parse_key_value_squoted(char *buf, struct string_list *list)
 266 {
 267         while (*buf) {
 268                 struct string_list_item *item;
 269                 char *np;
 270                 char *cp = strchr(buf, '=');
 271                 if (!cp)
 272                         return -1;
 273                 np = strchrnul(cp, '\n');
 274                 *cp++ = '\0';
 275                 item = string_list_append(list, buf);
 276
 277                 buf = np + (*np == '\n');
 278                 *np = '\0';
 279                 cp = sq_dequote(cp);
 280                 if (!cp)
 281                         return -1;
 282                 item->util = xstrdup(cp);
 283         }
 284         return 0;
 285 }
 286
 287 /**
 288  * Reads and parses the state directory's "author-script" file, and sets
 289  * state->author_name, state->author_email and state->author_date accordingly.
 290  * Returns 0 on success, -1 if the file could not be parsed.
 291  *
 292  * The author script is of the format:
 293  *
 294  *      GIT_AUTHOR_NAME='$author_name'
 295  *      GIT_AUTHOR_EMAIL='$author_email'
 296  *      GIT_AUTHOR_DATE='$author_date'
 297  *
 298  * where $author_name, $author_email and $author_date are quoted. We are strict
 299  * with our parsing, as the file was meant to be eval'd in the old git-am.sh
 300  * script, and thus if the file differs from what this function expects, it is
 301  * better to bail out than to do something that the user does not expect.
 302  */
 303 static int read_author_script(struct am_state *state)
 304 {
 305         const char *filename = am_path(state, "author-script");
 306         struct strbuf buf = STRBUF_INIT;
 307         struct string_list kv = STRING_LIST_INIT_DUP;
 308         int retval = -1; /* assume failure */
 309         int fd;
 310
 311         assert(!state->author_name);
 312         assert(!state->author_email);
 313         assert(!state->author_date);
 314
 315         fd = open(filename, O_RDONLY);
 316         if (fd < 0) {
 317                 if (errno == ENOENT)
 318                         return 0;
 319                 die_errno(_("could not open '%s' for reading"), filename);
 320         }
 321         strbuf_read(&buf, fd, 0);
 322         close(fd);
 323         if (parse_key_value_squoted(buf.buf, &kv))
 324                 goto finish;
 325
 326         if (kv.nr != 3 ||
 327             strcmp(kv.items[0].string, "GIT_AUTHOR_NAME") ||
 328             strcmp(kv.items[1].string, "GIT_AUTHOR_EMAIL") ||
 329             strcmp(kv.items[2].string, "GIT_AUTHOR_DATE"))
 330                 goto finish;
 331         state->author_name = kv.items[0].util;
 332         state->author_email = kv.items[1].util;
 333         state->author_date = kv.items[2].util;
 334         retval = 0;
 335 finish:
 336         string_list_clear(&kv, !!retval);
 337         strbuf_release(&buf);
 338         return retval;
 339 }
 340
 341 /**
 342  * Saves state->author_name, state->author_email and state->author_date in the
 343  * state directory's "author-script" file.
 344  */
 345 static void write_author_script(const struct am_state *state)
 346 {
 347         struct strbuf sb = STRBUF_INIT;
 348
 349         strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
 350         sq_quote_buf(&sb, state->author_name);
 351         strbuf_addch(&sb, '\n');
 352
 353         strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
 354         sq_quote_buf(&sb, state->author_email);
 355         strbuf_addch(&sb, '\n');
 356
 357         strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
 358         sq_quote_buf(&sb, state->author_date);
 359         strbuf_addch(&sb, '\n');
 360
 361         write_state_text(state, "author-script", sb.buf);
 362
 363         strbuf_release(&sb);
 364 }
 365
 366 /**
 367  * Reads the commit message from the state directory's "final-commit" file,
 368  * setting state->msg to its contents and state->msg_len to the length of its
 369  * contents in bytes.
 370  *
 371  * Returns 0 on success, -1 if the file does not exist.
 372  */
 373 static int read_commit_msg(struct am_state *state)
 374 {
 375         struct strbuf sb = STRBUF_INIT;
 376
 377         assert(!state->msg);
 378
 379         if (read_state_file(&sb, state, "final-commit", 0) < 0) {
 380                 strbuf_release(&sb);
 381                 return -1;
 382         }
 383
 384         state->msg = strbuf_detach(&sb, &state->msg_len);
 385         return 0;
 386 }
 387
 388 /**
 389  * Saves state->msg in the state directory's "final-commit" file.
 390  */
 391 static void write_commit_msg(const struct am_state *state)
 392 {
 393         const char *filename = am_path(state, "final-commit");
 394         write_file_buf(filename, state->msg, state->msg_len);
 395 }
 396
 397 /**
 398  * Loads state from disk.
 399  */
 400 static void am_load(struct am_state *state)
 401 {
 402         struct strbuf sb = STRBUF_INIT;
 403
 404         if (read_state_file(&sb, state, "next", 1) < 0)
 405                 die("BUG: state file 'next' does not exist");
 406         state->cur = strtol(sb.buf, NULL, 10);
 407
 408         if (read_state_file(&sb, state, "last", 1) < 0)
 409                 die("BUG: state file 'last' does not exist");
 410         state->last = strtol(sb.buf, NULL, 10);
 411
 412         if (read_author_script(state) < 0)
 413                 die(_("could not parse author script"));
 414
 415         read_commit_msg(state);
 416
 417         if (read_state_file(&sb, state, "original-commit", 1) < 0)
 418                 oidclr(&state->orig_commit);
 419         else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
 420                 die(_("could not parse %s"), am_path(state, "original-commit"));
 421
 422         read_state_file(&sb, state, "threeway", 1);
 423         state->threeway = !strcmp(sb.buf, "t");
 424
 425         read_state_file(&sb, state, "quiet", 1);
 426         state->quiet = !strcmp(sb.buf, "t");
 427
 428         read_state_file(&sb, state, "sign", 1);
 429         state->signoff = !strcmp(sb.buf, "t");
 430
 431         read_state_file(&sb, state, "utf8", 1);
 432         state->utf8 = !strcmp(sb.buf, "t");
 433
 434         read_state_file(&sb, state, "keep", 1);
 435         if (!strcmp(sb.buf, "t"))
 436                 state->keep = KEEP_TRUE;
 437         else if (!strcmp(sb.buf, "b"))
 438                 state->keep = KEEP_NON_PATCH;
 439         else
 440                 state->keep = KEEP_FALSE;
 441
 442         read_state_file(&sb, state, "messageid", 1);
 443         state->message_id = !strcmp(sb.buf, "t");
 444
 445         read_state_file(&sb, state, "scissors", 1);
 446         if (!strcmp(sb.buf, "t"))
 447                 state->scissors = SCISSORS_TRUE;
 448         else if (!strcmp(sb.buf, "f"))
 449                 state->scissors = SCISSORS_FALSE;
 450         else
 451                 state->scissors = SCISSORS_UNSET;
 452
 453         read_state_file(&sb, state, "apply-opt", 1);
 454         argv_array_clear(&state->git_apply_opts);
 455         if (sq_dequote_to_argv_array(sb.buf, &state->git_apply_opts) < 0)
 456                 die(_("could not parse %s"), am_path(state, "apply-opt"));
 457
 458         state->rebasing = !!file_exists(am_path(state, "rebasing"));
 459
 460         strbuf_release(&sb);
 461 }
 462
 463 /**
 464  * Removes the am_state directory, forcefully terminating the current am
 465  * session.
 466  */
 467 static void am_destroy(const struct am_state *state)
 468 {
 469         struct strbuf sb = STRBUF_INIT;
 470
 471         strbuf_addstr(&sb, state->dir);
 472         remove_dir_recursively(&sb, 0);
 473         strbuf_release(&sb);
 474 }
 475
 476 /**
 477  * Runs applypatch-msg hook. Returns its exit code.
 478  */
 479 static int run_applypatch_msg_hook(struct am_state *state)
 480 {
 481         int ret;
 482
 483         assert(state->msg);
 484         ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
 485
 486         if (!ret) {
 487                 FREE_AND_NULL(state->msg);
 488                 if (read_commit_msg(state) < 0)
 489                         die(_("'%s' was deleted by the applypatch-msg hook"),
 490                                 am_path(state, "final-commit"));
 491         }
 492
 493         return ret;
 494 }
 495
 496 /**
 497  * Runs post-rewrite hook. Returns it exit code.
 498  */
 499 static int run_post_rewrite_hook(const struct am_state *state)
 500 {
 501         struct child_process cp = CHILD_PROCESS_INIT;
 502         const char *hook = find_hook("post-rewrite");
 503         int ret;
 504
 505         if (!hook)
 506                 return 0;
 507
 508         argv_array_push(&cp.args, hook);
 509         argv_array_push(&cp.args, "rebase");
 510
 511         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
 512         cp.stdout_to_stderr = 1;
 513
 514         ret = run_command(&cp);
 515
 516         close(cp.in);
 517         return ret;
 518 }
 519
 520 /**
 521  * Reads the state directory's "rewritten" file, and copies notes from the old
 522  * commits listed in the file to their rewritten commits.
 523  *
 524  * Returns 0 on success, -1 on failure.
 525  */
 526 static int copy_notes_for_rebase(const struct am_state *state)
 527 {
 528         struct notes_rewrite_cfg *c;
 529         struct strbuf sb = STRBUF_INIT;
 530         const char *invalid_line = _("Malformed input line: '%s'.");
 531         const char *msg = "Notes added by 'git rebase'";
 532         FILE *fp;
 533         int ret = 0;
 534
 535         assert(state->rebasing);
 536
 537         c = init_copy_notes_for_rewrite("rebase");
 538         if (!c)
 539                 return 0;
 540
 541         fp = xfopen(am_path(state, "rewritten"), "r");
 542
 543         while (!strbuf_getline_lf(&sb, fp)) {
 544                 struct object_id from_obj, to_obj;
 545
 546                 if (sb.len != GIT_SHA1_HEXSZ * 2 + 1) {
 547                         ret = error(invalid_line, sb.buf);
 548                         goto finish;
 549                 }
 550
 551                 if (get_oid_hex(sb.buf, &from_obj)) {
 552                         ret = error(invalid_line, sb.buf);
 553                         goto finish;
 554                 }
 555
 556                 if (sb.buf[GIT_SHA1_HEXSZ] != ' ') {
 557                         ret = error(invalid_line, sb.buf);
 558                         goto finish;
 559                 }
 560
 561                 if (get_oid_hex(sb.buf + GIT_SHA1_HEXSZ + 1, &to_obj)) {
 562                         ret = error(invalid_line, sb.buf);
 563                         goto finish;
 564                 }
 565
 566                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
 567                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
 568                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
 569         }
 570
 571 finish:
 572         finish_copy_notes_for_rewrite(c, msg);
 573         fclose(fp);
 574         strbuf_release(&sb);
 575         return ret;
 576 }
 577
 578 /**
 579  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
 580  * non-indented lines and checking if they look like they begin with valid
 581  * header field names.
 582  *
 583  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
 584  */
 585 static int is_mail(FILE *fp)
 586 {
 587         const char *header_regex = "^[!-9;-~]+:";
 588         struct strbuf sb = STRBUF_INIT;
 589         regex_t regex;
 590         int ret = 1;
 591
 592         if (fseek(fp, 0L, SEEK_SET))
 593                 die_errno(_("fseek failed"));
 594
 595         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
 596                 die("invalid pattern: %s", header_regex);
 597
 598         while (!strbuf_getline(&sb, fp)) {
 599                 if (!sb.len)
 600                         break; /* End of header */
 601
 602                 /* Ignore indented folded lines */
 603                 if (*sb.buf == '\t' || *sb.buf == ' ')
 604                         continue;
 605
 606                 /* It's a header if it matches header_regex */
 607                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
 608                         ret = 0;
 609                         goto done;
 610                 }
 611         }
 612
 613 done:
 614         regfree(&regex);
 615         strbuf_release(&sb);
 616         return ret;
 617 }
 618
 619 /**
 620  * Attempts to detect the patch_format of the patches contained in `paths`,
 621  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
 622  * detection fails.
 623  */
 624 static int detect_patch_format(const char **paths)
 625 {
 626         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
 627         struct strbuf l1 = STRBUF_INIT;
 628         struct strbuf l2 = STRBUF_INIT;
 629         struct strbuf l3 = STRBUF_INIT;
 630         FILE *fp;
 631
 632         /*
 633          * We default to mbox format if input is from stdin and for directories
 634          */
 635         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
 636                 return PATCH_FORMAT_MBOX;
 637
 638         /*
 639          * Otherwise, check the first few lines of the first patch, starting
 640          * from the first non-blank line, to try to detect its format.
 641          */
 642
 643         fp = xfopen(*paths, "r");
 644
 645         while (!strbuf_getline(&l1, fp)) {
 646                 if (l1.len)
 647                         break;
 648         }
 649
 650         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
 651                 ret = PATCH_FORMAT_MBOX;
 652                 goto done;
 653         }
 654
 655         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
 656                 ret = PATCH_FORMAT_STGIT_SERIES;
 657                 goto done;
 658         }
 659
 660         if (!strcmp(l1.buf, "# HG changeset patch")) {
 661                 ret = PATCH_FORMAT_HG;
 662                 goto done;
 663         }
 664
 665         strbuf_reset(&l2);
 666         strbuf_getline(&l2, fp);
 667         strbuf_reset(&l3);
 668         strbuf_getline(&l3, fp);
 669
 670         /*
 671          * If the second line is empty and the third is a From, Author or Date
 672          * entry, this is likely an StGit patch.
 673          */
 674         if (l1.len && !l2.len &&
 675                 (starts_with(l3.buf, "From:") ||
 676                  starts_with(l3.buf, "Author:") ||
 677                  starts_with(l3.buf, "Date:"))) {
 678                 ret = PATCH_FORMAT_STGIT;
 679                 goto done;
 680         }
 681
 682         if (l1.len && is_mail(fp)) {
 683                 ret = PATCH_FORMAT_MBOX;
 684                 goto done;
 685         }
 686
 687 done:
 688         fclose(fp);
 689         strbuf_release(&l1);
 690         return ret;
 691 }
 692
 693 /**
 694  * Splits out individual email patches from `paths`, where each path is either
 695  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
 696  */
 697 static int split_mail_mbox(struct am_state *state, const char **paths,
 698                                 int keep_cr, int mboxrd)
 699 {
 700         struct child_process cp = CHILD_PROCESS_INIT;
 701         struct strbuf last = STRBUF_INIT;
 702
 703         cp.git_cmd = 1;
 704         argv_array_push(&cp.args, "mailsplit");
 705         argv_array_pushf(&cp.args, "-d%d", state->prec);
 706         argv_array_pushf(&cp.args, "-o%s", state->dir);
 707         argv_array_push(&cp.args, "-b");
 708         if (keep_cr)
 709                 argv_array_push(&cp.args, "--keep-cr");
 710         if (mboxrd)
 711                 argv_array_push(&cp.args, "--mboxrd");
 712         argv_array_push(&cp.args, "--");
 713         argv_array_pushv(&cp.args, paths);
 714
 715         if (capture_command(&cp, &last, 8))
 716                 return -1;
 717
 718         state->cur = 1;
 719         state->last = strtol(last.buf, NULL, 10);
 720
 721         return 0;
 722 }
 723
 724 /**
 725  * Callback signature for split_mail_conv(). The foreign patch should be
 726  * read from `in`, and the converted patch (in RFC2822 mail format) should be
 727  * written to `out`. Return 0 on success, or -1 on failure.
 728  */
 729 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
 730
 731 /**
 732  * Calls `fn` for each file in `paths` to convert the foreign patch to the
 733  * RFC2822 mail format suitable for parsing with git-mailinfo.
 734  *
 735  * Returns 0 on success, -1 on failure.
 736  */
 737 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
 738                         const char **paths, int keep_cr)
 739 {
 740         static const char *stdin_only[] = {"-", NULL};
 741         int i;
 742
 743         if (!*paths)
 744                 paths = stdin_only;
 745
 746         for (i = 0; *paths; paths++, i++) {
 747                 FILE *in, *out;
 748                 const char *mail;
 749                 int ret;
 750
 751                 if (!strcmp(*paths, "-"))
 752                         in = stdin;
 753                 else
 754                         in = fopen(*paths, "r");
 755
 756                 if (!in)
 757                         return error_errno(_("could not open '%s' for reading"),
 758                                            *paths);
 759
 760                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
 761
 762                 out = fopen(mail, "w");
 763                 if (!out) {
 764                         if (in != stdin)
 765                                 fclose(in);
 766                         return error_errno(_("could not open '%s' for writing"),
 767                                            mail);
 768                 }
 769
 770                 ret = fn(out, in, keep_cr);
 771
 772                 fclose(out);
 773                 if (in != stdin)
 774                         fclose(in);
 775
 776                 if (ret)
 777                         return error(_("could not parse patch '%s'"), *paths);
 778         }
 779
 780         state->cur = 1;
 781         state->last = i;
 782         return 0;
 783 }
 784
 785 /**
 786  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
 787  * message suitable for parsing with git-mailinfo.
 788  */
 789 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 790 {
 791         struct strbuf sb = STRBUF_INIT;
 792         int subject_printed = 0;
 793
 794         while (!strbuf_getline_lf(&sb, in)) {
 795                 const char *str;
 796
 797                 if (str_isspace(sb.buf))
 798                         continue;
 799                 else if (skip_prefix(sb.buf, "Author:", &str))
 800                         fprintf(out, "From:%s\n", str);
 801                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
 802                         fprintf(out, "%s\n", sb.buf);
 803                 else if (!subject_printed) {
 804                         fprintf(out, "Subject: %s\n", sb.buf);
 805                         subject_printed = 1;
 806                 } else {
 807                         fprintf(out, "\n%s\n", sb.buf);
 808                         break;
 809                 }
 810         }
 811
 812         strbuf_reset(&sb);
 813         while (strbuf_fread(&sb, 8192, in) > 0) {
 814                 fwrite(sb.buf, 1, sb.len, out);
 815                 strbuf_reset(&sb);
 816         }
 817
 818         strbuf_release(&sb);
 819         return 0;
 820 }
 821
 822 /**
 823  * This function only supports a single StGit series file in `paths`.
 824  *
 825  * Given an StGit series file, converts the StGit patches in the series into
 826  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
 827  * the state directory.
 828  *
 829  * Returns 0 on success, -1 on failure.
 830  */
 831 static int split_mail_stgit_series(struct am_state *state, const char **paths,
 832                                         int keep_cr)
 833 {
 834         const char *series_dir;
 835         char *series_dir_buf;
 836         FILE *fp;
 837         struct argv_array patches = ARGV_ARRAY_INIT;
 838         struct strbuf sb = STRBUF_INIT;
 839         int ret;
 840
 841         if (!paths[0] || paths[1])
 842                 return error(_("Only one StGIT patch series can be applied at once"));
 843
 844         series_dir_buf = xstrdup(*paths);
 845         series_dir = dirname(series_dir_buf);
 846
 847         fp = fopen(*paths, "r");
 848         if (!fp)
 849                 return error_errno(_("could not open '%s' for reading"), *paths);
 850
 851         while (!strbuf_getline_lf(&sb, fp)) {
 852                 if (*sb.buf == '#')
 853                         continue; /* skip comment lines */
 854
 855                 argv_array_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
 856         }
 857
 858         fclose(fp);
 859         strbuf_release(&sb);
 860         free(series_dir_buf);
 861
 862         ret = split_mail_conv(stgit_patch_to_mail, state, patches.argv, keep_cr);
 863
 864         argv_array_clear(&patches);
 865         return ret;
 866 }
 867
 868 /**
 869  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
 870  * message suitable for parsing with git-mailinfo.
 871  */
 872 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 873 {
 874         struct strbuf sb = STRBUF_INIT;
 875
 876         while (!strbuf_getline_lf(&sb, in)) {
 877                 const char *str;
 878
 879                 if (skip_prefix(sb.buf, "# User ", &str))
 880                         fprintf(out, "From: %s\n", str);
 881                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
 882                         timestamp_t timestamp;
 883                         long tz, tz2;
 884                         char *end;
 885
 886                         errno = 0;
 887                         timestamp = parse_timestamp(str, &end, 10);
 888                         if (errno)
 889                                 return error(_("invalid timestamp"));
 890
 891                         if (!skip_prefix(end, " ", &str))
 892                                 return error(_("invalid Date line"));
 893
 894                         errno = 0;
 895                         tz = strtol(str, &end, 10);
 896                         if (errno)
 897                                 return error(_("invalid timezone offset"));
 898
 899                         if (*end)
 900                                 return error(_("invalid Date line"));
 901
 902                         /*
 903                          * mercurial's timezone is in seconds west of UTC,
 904                          * however git's timezone is in hours + minutes east of
 905                          * UTC. Convert it.
 906                          */
 907                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
 908                         if (tz > 0)
 909                                 tz2 = -tz2;
 910
 911                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
 912                 } else if (starts_with(sb.buf, "# ")) {
 913                         continue;
 914                 } else {
 915                         fprintf(out, "\n%s\n", sb.buf);
 916                         break;
 917                 }
 918         }
 919
 920         strbuf_reset(&sb);
 921         while (strbuf_fread(&sb, 8192, in) > 0) {
 922                 fwrite(sb.buf, 1, sb.len, out);
 923                 strbuf_reset(&sb);
 924         }
 925
 926         strbuf_release(&sb);
 927         return 0;
 928 }
 929
 930 /**
 931  * Splits a list of files/directories into individual email patches. Each path
 932  * in `paths` must be a file/directory that is formatted according to
 933  * `patch_format`.
 934  *
 935  * Once split out, the individual email patches will be stored in the state
 936  * directory, with each patch's filename being its index, padded to state->prec
 937  * digits.
 938  *
 939  * state->cur will be set to the index of the first mail, and state->last will
 940  * be set to the index of the last mail.
 941  *
 942  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
 943  * to disable this behavior, -1 to use the default configured setting.
 944  *
 945  * Returns 0 on success, -1 on failure.
 946  */
 947 static int split_mail(struct am_state *state, enum patch_format patch_format,
 948                         const char **paths, int keep_cr)
 949 {
 950         if (keep_cr < 0) {
 951                 keep_cr = 0;
 952                 git_config_get_bool("am.keepcr", &keep_cr);
 953         }
 954
 955         switch (patch_format) {
 956         case PATCH_FORMAT_MBOX:
 957                 return split_mail_mbox(state, paths, keep_cr, 0);
 958         case PATCH_FORMAT_STGIT:
 959                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
 960         case PATCH_FORMAT_STGIT_SERIES:
 961                 return split_mail_stgit_series(state, paths, keep_cr);
 962         case PATCH_FORMAT_HG:
 963                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
 964         case PATCH_FORMAT_MBOXRD:
 965                 return split_mail_mbox(state, paths, keep_cr, 1);
 966         default:
 967                 die("BUG: invalid patch_format");
 968         }
 969         return -1;
 970 }
 971
 972 /**
 973  * Setup a new am session for applying patches
 974  */
 975 static void am_setup(struct am_state *state, enum patch_format patch_format,
 976                         const char **paths, int keep_cr)
 977 {
 978         struct object_id curr_head;
 979         const char *str;
 980         struct strbuf sb = STRBUF_INIT;
 981
 982         if (!patch_format)
 983                 patch_format = detect_patch_format(paths);
 984
 985         if (!patch_format) {
 986                 fprintf_ln(stderr, _("Patch format detection failed."));
 987                 exit(128);
 988         }
 989
 990         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
 991                 die_errno(_("failed to create directory '%s'"), state->dir);
 992
 993         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
 994                 am_destroy(state);
 995                 die(_("Failed to split patches."));
 996         }
 997
 998         if (state->rebasing)
 999                 state->threeway = 1;
1000
1001         write_state_bool(state, "threeway", state->threeway);
1002         write_state_bool(state, "quiet", state->quiet);
1003         write_state_bool(state, "sign", state->signoff);
1004         write_state_bool(state, "utf8", state->utf8);
1005
1006         switch (state->keep) {
1007         case KEEP_FALSE:
1008                 str = "f";
1009                 break;
1010         case KEEP_TRUE:
1011                 str = "t";
1012                 break;
1013         case KEEP_NON_PATCH:
1014                 str = "b";
1015                 break;
1016         default:
1017                 die("BUG: invalid value for state->keep");
1018         }
1019
1020         write_state_text(state, "keep", str);
1021         write_state_bool(state, "messageid", state->message_id);
1022
1023         switch (state->scissors) {
1024         case SCISSORS_UNSET:
1025                 str = "";
1026                 break;
1027         case SCISSORS_FALSE:
1028                 str = "f";
1029                 break;
1030         case SCISSORS_TRUE:
1031                 str = "t";
1032                 break;
1033         default:
1034                 die("BUG: invalid value for state->scissors");
1035         }
1036         write_state_text(state, "scissors", str);
1037
1038         sq_quote_argv(&sb, state->git_apply_opts.argv, 0);
1039         write_state_text(state, "apply-opt", sb.buf);
1040
1041         if (state->rebasing)
1042                 write_state_text(state, "rebasing", "");
1043         else
1044                 write_state_text(state, "applying", "");
1045
1046         if (!get_oid("HEAD", &curr_head)) {
1047                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1048                 if (!state->rebasing)
1049                         update_ref_oid("am", "ORIG_HEAD", &curr_head, NULL, 0,
1050                                         UPDATE_REFS_DIE_ON_ERR);
1051         } else {
1052                 write_state_text(state, "abort-safety", "");
1053                 if (!state->rebasing)
1054                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1055         }
1056
1057         /*
1058          * NOTE: Since the "next" and "last" files determine if an am_state
1059          * session is in progress, they should be written last.
1060          */
1061
1062         write_state_count(state, "next", state->cur);
1063         write_state_count(state, "last", state->last);
1064
1065         strbuf_release(&sb);
1066 }
1067
1068 /**
1069  * Increments the patch pointer, and cleans am_state for the application of the
1070  * next patch.
1071  */
1072 static void am_next(struct am_state *state)
1073 {
1074         struct object_id head;
1075
1076         FREE_AND_NULL(state->author_name);
1077         FREE_AND_NULL(state->author_email);
1078         FREE_AND_NULL(state->author_date);
1079         FREE_AND_NULL(state->msg);
1080         state->msg_len = 0;
1081
1082         unlink(am_path(state, "author-script"));
1083         unlink(am_path(state, "final-commit"));
1084
1085         oidclr(&state->orig_commit);
1086         unlink(am_path(state, "original-commit"));
1087
1088         if (!get_oid("HEAD", &head))
1089                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1090         else
1091                 write_state_text(state, "abort-safety", "");
1092
1093         state->cur++;
1094         write_state_count(state, "next", state->cur);
1095 }
1096
1097 /**
1098  * Returns the filename of the current patch email.
1099  */
1100 static const char *msgnum(const struct am_state *state)
1101 {
1102         static struct strbuf sb = STRBUF_INIT;
1103
1104         strbuf_reset(&sb);
1105         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1106
1107         return sb.buf;
1108 }
1109
1110 /**
1111  * Refresh and write index.
1112  */
1113 static void refresh_and_write_cache(void)
1114 {
1115         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
1116
1117         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
1118         refresh_cache(REFRESH_QUIET);
1119         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
1120                 die(_("unable to write index file"));
1121 }
1122
1123 /**
1124  * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
1125  * branch, returns 1 if there are entries in the index, 0 otherwise. If an
1126  * strbuf is provided, the space-separated list of files that differ will be
1127  * appended to it.
1128  */
1129 static int index_has_changes(struct strbuf *sb)
1130 {
1131         struct object_id head;
1132         int i;
1133
1134         if (!get_sha1_tree("HEAD", head.hash)) {
1135                 struct diff_options opt;
1136
1137                 diff_setup(&opt);
1138                 DIFF_OPT_SET(&opt, EXIT_WITH_STATUS);
1139                 if (!sb)
1140                         DIFF_OPT_SET(&opt, QUICK);
1141                 do_diff_cache(&head, &opt);
1142                 diffcore_std(&opt);
1143                 for (i = 0; sb && i < diff_queued_diff.nr; i++) {
1144                         if (i)
1145                                 strbuf_addch(sb, ' ');
1146                         strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
1147                 }
1148                 diff_flush(&opt);
1149                 return DIFF_OPT_TST(&opt, HAS_CHANGES) != 0;
1150         } else {
1151                 for (i = 0; sb && i < active_nr; i++) {
1152                         if (i)
1153                                 strbuf_addch(sb, ' ');
1154                         strbuf_addstr(sb, active_cache[i]->name);
1155                 }
1156                 return !!active_nr;
1157         }
1158 }
1159
1160 /**
1161  * Dies with a user-friendly message on how to proceed after resolving the
1162  * problem. This message can be overridden with state->resolvemsg.
1163  */
1164 static void NORETURN die_user_resolve(const struct am_state *state)
1165 {
1166         if (state->resolvemsg) {
1167                 printf_ln("%s", state->resolvemsg);
1168         } else {
1169                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1170
1171                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1172                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1173                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1174         }
1175
1176         exit(128);
1177 }
1178
1179 /**
1180  * Appends signoff to the "msg" field of the am_state.
1181  */
1182 static void am_append_signoff(struct am_state *state)
1183 {
1184         char *cp;
1185         struct strbuf mine = STRBUF_INIT;
1186         struct strbuf sb = STRBUF_INIT;
1187
1188         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1189
1190         /* our sign-off */
1191         strbuf_addf(&mine, "\n%s%s\n",
1192                     sign_off_header,
1193                     fmt_name(getenv("GIT_COMMITTER_NAME"),
1194                              getenv("GIT_COMMITTER_EMAIL")));
1195
1196         /* Does sb end with it already? */
1197         if (mine.len < sb.len &&
1198             !strcmp(mine.buf, sb.buf + sb.len - mine.len))
1199                 goto exit; /* no need to duplicate */
1200
1201         /* Does it have any Signed-off-by: in the text */
1202         for (cp = sb.buf;
1203              cp && *cp && (cp = strstr(cp, sign_off_header)) != NULL;
1204              cp = strchr(cp, '\n')) {
1205                 if (sb.buf == cp || cp[-1] == '\n')
1206                         break;
1207         }
1208
1209         strbuf_addstr(&sb, mine.buf + !!cp);
1210 exit:
1211         strbuf_release(&mine);
1212         state->msg = strbuf_detach(&sb, &state->msg_len);
1213 }
1214
1215 /**
1216  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1217  * state->msg will be set to the patch message. state->author_name,
1218  * state->author_email and state->author_date will be set to the patch author's
1219  * name, email and date respectively. The patch body will be written to the
1220  * state directory's "patch" file.
1221  *
1222  * Returns 1 if the patch should be skipped, 0 otherwise.
1223  */
1224 static int parse_mail(struct am_state *state, const char *mail)
1225 {
1226         FILE *fp;
1227         struct strbuf sb = STRBUF_INIT;
1228         struct strbuf msg = STRBUF_INIT;
1229         struct strbuf author_name = STRBUF_INIT;
1230         struct strbuf author_date = STRBUF_INIT;
1231         struct strbuf author_email = STRBUF_INIT;
1232         int ret = 0;
1233         struct mailinfo mi;
1234
1235         setup_mailinfo(&mi);
1236
1237         if (state->utf8)
1238                 mi.metainfo_charset = get_commit_output_encoding();
1239         else
1240                 mi.metainfo_charset = NULL;
1241
1242         switch (state->keep) {
1243         case KEEP_FALSE:
1244                 break;
1245         case KEEP_TRUE:
1246                 mi.keep_subject = 1;
1247                 break;
1248         case KEEP_NON_PATCH:
1249                 mi.keep_non_patch_brackets_in_subject = 1;
1250                 break;
1251         default:
1252                 die("BUG: invalid value for state->keep");
1253         }
1254
1255         if (state->message_id)
1256                 mi.add_message_id = 1;
1257
1258         switch (state->scissors) {
1259         case SCISSORS_UNSET:
1260                 break;
1261         case SCISSORS_FALSE:
1262                 mi.use_scissors = 0;
1263                 break;
1264         case SCISSORS_TRUE:
1265                 mi.use_scissors = 1;
1266                 break;
1267         default:
1268                 die("BUG: invalid value for state->scissors");
1269         }
1270
1271         mi.input = xfopen(mail, "r");
1272         mi.output = xfopen(am_path(state, "info"), "w");
1273         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1274                 die("could not parse patch");
1275
1276         fclose(mi.input);
1277         fclose(mi.output);
1278
1279         /* Extract message and author information */
1280         fp = xfopen(am_path(state, "info"), "r");
1281         while (!strbuf_getline_lf(&sb, fp)) {
1282                 const char *x;
1283
1284                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1285                         if (msg.len)
1286                                 strbuf_addch(&msg, '\n');
1287                         strbuf_addstr(&msg, x);
1288                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1289                         strbuf_addstr(&author_name, x);
1290                 else if (skip_prefix(sb.buf, "Email: ", &x))
1291                         strbuf_addstr(&author_email, x);
1292                 else if (skip_prefix(sb.buf, "Date: ", &x))
1293                         strbuf_addstr(&author_date, x);
1294         }
1295         fclose(fp);
1296
1297         /* Skip pine's internal folder data */
1298         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1299                 ret = 1;
1300                 goto finish;
1301         }
1302
1303         if (is_empty_file(am_path(state, "patch"))) {
1304                 printf_ln(_("Patch is empty."));
1305                 die_user_resolve(state);
1306         }
1307
1308         strbuf_addstr(&msg, "\n\n");
1309         strbuf_addbuf(&msg, &mi.log_message);
1310         strbuf_stripspace(&msg, 0);
1311
1312         assert(!state->author_name);
1313         state->author_name = strbuf_detach(&author_name, NULL);
1314
1315         assert(!state->author_email);
1316         state->author_email = strbuf_detach(&author_email, NULL);
1317
1318         assert(!state->author_date);
1319         state->author_date = strbuf_detach(&author_date, NULL);
1320
1321         assert(!state->msg);
1322         state->msg = strbuf_detach(&msg, &state->msg_len);
1323
1324 finish:
1325         strbuf_release(&msg);
1326         strbuf_release(&author_date);
1327         strbuf_release(&author_email);
1328         strbuf_release(&author_name);
1329         strbuf_release(&sb);
1330         clear_mailinfo(&mi);
1331         return ret;
1332 }
1333
1334 /**
1335  * Sets commit_id to the commit hash where the mail was generated from.
1336  * Returns 0 on success, -1 on failure.
1337  */
1338 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1339 {
1340         struct strbuf sb = STRBUF_INIT;
1341         FILE *fp = xfopen(mail, "r");
1342         const char *x;
1343         int ret = 0;
1344
1345         if (strbuf_getline_lf(&sb, fp) ||
1346             !skip_prefix(sb.buf, "From ", &x) ||
1347             get_oid_hex(x, commit_id) < 0)
1348                 ret = -1;
1349
1350         strbuf_release(&sb);
1351         fclose(fp);
1352         return ret;
1353 }
1354
1355 /**
1356  * Sets state->msg, state->author_name, state->author_email, state->author_date
1357  * to the commit's respective info.
1358  */
1359 static void get_commit_info(struct am_state *state, struct commit *commit)
1360 {
1361         const char *buffer, *ident_line, *msg;
1362         size_t ident_len;
1363         struct ident_split id;
1364
1365         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1366
1367         ident_line = find_commit_header(buffer, "author", &ident_len);
1368
1369         if (split_ident_line(&id, ident_line, ident_len) < 0)
1370                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1371
1372         assert(!state->author_name);
1373         if (id.name_begin)
1374                 state->author_name =
1375                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1376         else
1377                 state->author_name = xstrdup("");
1378
1379         assert(!state->author_email);
1380         if (id.mail_begin)
1381                 state->author_email =
1382                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1383         else
1384                 state->author_email = xstrdup("");
1385
1386         assert(!state->author_date);
1387         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1388
1389         assert(!state->msg);
1390         msg = strstr(buffer, "\n\n");
1391         if (!msg)
1392                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1393         state->msg = xstrdup(msg + 2);
1394         state->msg_len = strlen(state->msg);
1395         unuse_commit_buffer(commit, buffer);
1396 }
1397
1398 /**
1399  * Writes `commit` as a patch to the state directory's "patch" file.
1400  */
1401 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1402 {
1403         struct rev_info rev_info;
1404         FILE *fp;
1405
1406         fp = xfopen(am_path(state, "patch"), "w");
1407         init_revisions(&rev_info, NULL);
1408         rev_info.diff = 1;
1409         rev_info.abbrev = 0;
1410         rev_info.disable_stdin = 1;
1411         rev_info.show_root_diff = 1;
1412         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1413         rev_info.no_commit_id = 1;
1414         DIFF_OPT_SET(&rev_info.diffopt, BINARY);
1415         DIFF_OPT_SET(&rev_info.diffopt, FULL_INDEX);
1416         rev_info.diffopt.use_color = 0;
1417         rev_info.diffopt.file = fp;
1418         rev_info.diffopt.close_file = 1;
1419         add_pending_object(&rev_info, &commit->object, "");
1420         diff_setup_done(&rev_info.diffopt);
1421         log_tree_commit(&rev_info, commit);
1422 }
1423
1424 /**
1425  * Writes the diff of the index against HEAD as a patch to the state
1426  * directory's "patch" file.
1427  */
1428 static void write_index_patch(const struct am_state *state)
1429 {
1430         struct tree *tree;
1431         struct object_id head;
1432         struct rev_info rev_info;
1433         FILE *fp;
1434
1435         if (!get_sha1_tree("HEAD", head.hash))
1436                 tree = lookup_tree(&head);
1437         else
1438                 tree = lookup_tree(&empty_tree_oid);
1439
1440         fp = xfopen(am_path(state, "patch"), "w");
1441         init_revisions(&rev_info, NULL);
1442         rev_info.diff = 1;
1443         rev_info.disable_stdin = 1;
1444         rev_info.no_commit_id = 1;
1445         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1446         rev_info.diffopt.use_color = 0;
1447         rev_info.diffopt.file = fp;
1448         rev_info.diffopt.close_file = 1;
1449         add_pending_object(&rev_info, &tree->object, "");
1450         diff_setup_done(&rev_info.diffopt);
1451         run_diff_index(&rev_info, 1);
1452 }
1453
1454 /**
1455  * Like parse_mail(), but parses the mail by looking up its commit ID
1456  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1457  * of patches.
1458  *
1459  * state->orig_commit will be set to the original commit ID.
1460  *
1461  * Will always return 0 as the patch should never be skipped.
1462  */
1463 static int parse_mail_rebase(struct am_state *state, const char *mail)
1464 {
1465         struct commit *commit;
1466         struct object_id commit_oid;
1467
1468         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1469                 die(_("could not parse %s"), mail);
1470
1471         commit = lookup_commit_or_die(&commit_oid, mail);
1472
1473         get_commit_info(state, commit);
1474
1475         write_commit_patch(state, commit);
1476
1477         oidcpy(&state->orig_commit, &commit_oid);
1478         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1479
1480         return 0;
1481 }
1482
1483 /**
1484  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1485  * `index_file` is not NULL, the patch will be applied to that index.
1486  */
1487 static int run_apply(const struct am_state *state, const char *index_file)
1488 {
1489         struct argv_array apply_paths = ARGV_ARRAY_INIT;
1490         struct argv_array apply_opts = ARGV_ARRAY_INIT;
1491         struct apply_state apply_state;
1492         int res, opts_left;
1493         static struct lock_file lock_file;
1494         int force_apply = 0;
1495         int options = 0;
1496
1497         if (init_apply_state(&apply_state, NULL, &lock_file))
1498                 die("BUG: init_apply_state() failed");
1499
1500         argv_array_push(&apply_opts, "apply");
1501         argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
1502
1503         opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
1504                                         &apply_state, &force_apply, &options,
1505                                         NULL);
1506
1507         if (opts_left != 0)
1508                 die("unknown option passed through to git apply");
1509
1510         if (index_file) {
1511                 apply_state.index_file = index_file;
1512                 apply_state.cached = 1;
1513         } else
1514                 apply_state.check_index = 1;
1515
1516         /*
1517          * If we are allowed to fall back on 3-way merge, don't give false
1518          * errors during the initial attempt.
1519          */
1520         if (state->threeway && !index_file)
1521                 apply_state.apply_verbosity = verbosity_silent;
1522
1523         if (check_apply_state(&apply_state, force_apply))
1524                 die("BUG: check_apply_state() failed");
1525
1526         argv_array_push(&apply_paths, am_path(state, "patch"));
1527
1528         res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
1529
1530         argv_array_clear(&apply_paths);
1531         argv_array_clear(&apply_opts);
1532         clear_apply_state(&apply_state);
1533
1534         if (res)
1535                 return res;
1536
1537         if (index_file) {
1538                 /* Reload index as apply_all_patches() will have modified it. */
1539                 discard_cache();
1540                 read_cache_from(index_file);
1541         }
1542
1543         return 0;
1544 }
1545
1546 /**
1547  * Builds an index that contains just the blobs needed for a 3way merge.
1548  */
1549 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1550 {
1551         struct child_process cp = CHILD_PROCESS_INIT;
1552
1553         cp.git_cmd = 1;
1554         argv_array_push(&cp.args, "apply");
1555         argv_array_pushv(&cp.args, state->git_apply_opts.argv);
1556         argv_array_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1557         argv_array_push(&cp.args, am_path(state, "patch"));
1558
1559         if (run_command(&cp))
1560                 return -1;
1561
1562         return 0;
1563 }
1564
1565 /**
1566  * Attempt a threeway merge, using index_path as the temporary index.
1567  */
1568 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1569 {
1570         struct object_id orig_tree, their_tree, our_tree;
1571         const struct object_id *bases[1] = { &orig_tree };
1572         struct merge_options o;
1573         struct commit *result;
1574         char *their_tree_name;
1575
1576         if (get_oid("HEAD", &our_tree) < 0)
1577                 hashcpy(our_tree.hash, EMPTY_TREE_SHA1_BIN);
1578
1579         if (build_fake_ancestor(state, index_path))
1580                 return error("could not build fake ancestor");
1581
1582         discard_cache();
1583         read_cache_from(index_path);
1584
1585         if (write_index_as_tree(orig_tree.hash, &the_index, index_path, 0, NULL))
1586                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1587
1588         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1589
1590         if (!state->quiet) {
1591                 /*
1592                  * List paths that needed 3-way fallback, so that the user can
1593                  * review them with extra care to spot mismerges.
1594                  */
1595                 struct rev_info rev_info;
1596                 const char *diff_filter_str = "--diff-filter=AM";
1597
1598                 init_revisions(&rev_info, NULL);
1599                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1600                 diff_opt_parse(&rev_info.diffopt, &diff_filter_str, 1, rev_info.prefix);
1601                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1602                 diff_setup_done(&rev_info.diffopt);
1603                 run_diff_index(&rev_info, 1);
1604         }
1605
1606         if (run_apply(state, index_path))
1607                 return error(_("Did you hand edit your patch?\n"
1608                                 "It does not apply to blobs recorded in its index."));
1609
1610         if (write_index_as_tree(their_tree.hash, &the_index, index_path, 0, NULL))
1611                 return error("could not write tree");
1612
1613         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1614
1615         discard_cache();
1616         read_cache();
1617
1618         /*
1619          * This is not so wrong. Depending on which base we picked, orig_tree
1620          * may be wildly different from ours, but their_tree has the same set of
1621          * wildly different changes in parts the patch did not touch, so
1622          * recursive ends up canceling them, saying that we reverted all those
1623          * changes.
1624          */
1625
1626         init_merge_options(&o);
1627
1628         o.branch1 = "HEAD";
1629         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1630         o.branch2 = their_tree_name;
1631
1632         if (state->quiet)
1633                 o.verbosity = 0;
1634
1635         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1636                 rerere(state->allow_rerere_autoupdate);
1637                 free(their_tree_name);
1638                 return error(_("Failed to merge in the changes."));
1639         }
1640
1641         free(their_tree_name);
1642         return 0;
1643 }
1644
1645 /**
1646  * Commits the current index with state->msg as the commit message and
1647  * state->author_name, state->author_email and state->author_date as the author
1648  * information.
1649  */
1650 static void do_commit(const struct am_state *state)
1651 {
1652         struct object_id tree, parent, commit;
1653         const struct object_id *old_oid;
1654         struct commit_list *parents = NULL;
1655         const char *reflog_msg, *author;
1656         struct strbuf sb = STRBUF_INIT;
1657
1658         if (run_hook_le(NULL, "pre-applypatch", NULL))
1659                 exit(1);
1660
1661         if (write_cache_as_tree(tree.hash, 0, NULL))
1662                 die(_("git write-tree failed to write a tree"));
1663
1664         if (!get_sha1_commit("HEAD", parent.hash)) {
1665                 old_oid = &parent;
1666                 commit_list_insert(lookup_commit(&parent), &parents);
1667         } else {
1668                 old_oid = NULL;
1669                 say(state, stderr, _("applying to an empty history"));
1670         }
1671
1672         author = fmt_ident(state->author_name, state->author_email,
1673                         state->ignore_date ? NULL : state->author_date,
1674                         IDENT_STRICT);
1675
1676         if (state->committer_date_is_author_date)
1677                 setenv("GIT_COMMITTER_DATE",
1678                         state->ignore_date ? "" : state->author_date, 1);
1679
1680         if (commit_tree(state->msg, state->msg_len, tree.hash, parents, commit.hash,
1681                                 author, state->sign_commit))
1682                 die(_("failed to write commit object"));
1683
1684         reflog_msg = getenv("GIT_REFLOG_ACTION");
1685         if (!reflog_msg)
1686                 reflog_msg = "am";
1687
1688         strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1689                         state->msg);
1690
1691         update_ref_oid(sb.buf, "HEAD", &commit, old_oid, 0,
1692                         UPDATE_REFS_DIE_ON_ERR);
1693
1694         if (state->rebasing) {
1695                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1696
1697                 assert(!is_null_oid(&state->orig_commit));
1698                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1699                 fprintf(fp, "%s\n", oid_to_hex(&commit));
1700                 fclose(fp);
1701         }
1702
1703         run_hook_le(NULL, "post-applypatch", NULL);
1704
1705         strbuf_release(&sb);
1706 }
1707
1708 /**
1709  * Validates the am_state for resuming -- the "msg" and authorship fields must
1710  * be filled up.
1711  */
1712 static void validate_resume_state(const struct am_state *state)
1713 {
1714         if (!state->msg)
1715                 die(_("cannot resume: %s does not exist."),
1716                         am_path(state, "final-commit"));
1717
1718         if (!state->author_name || !state->author_email || !state->author_date)
1719                 die(_("cannot resume: %s does not exist."),
1720                         am_path(state, "author-script"));
1721 }
1722
1723 /**
1724  * Interactively prompt the user on whether the current patch should be
1725  * applied.
1726  *
1727  * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1728  * skip it.
1729  */
1730 static int do_interactive(struct am_state *state)
1731 {
1732         assert(state->msg);
1733
1734         if (!isatty(0))
1735                 die(_("cannot be interactive without stdin connected to a terminal."));
1736
1737         for (;;) {
1738                 const char *reply;
1739
1740                 puts(_("Commit Body is:"));
1741                 puts("--------------------------");
1742                 printf("%s", state->msg);
1743                 puts("--------------------------");
1744
1745                 /*
1746                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1747                  * in your translation. The program will only accept English
1748                  * input at this point.
1749                  */
1750                 reply = git_prompt(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "), PROMPT_ECHO);
1751
1752                 if (!reply) {
1753                         continue;
1754                 } else if (*reply == 'y' || *reply == 'Y') {
1755                         return 0;
1756                 } else if (*reply == 'a' || *reply == 'A') {
1757                         state->interactive = 0;
1758                         return 0;
1759                 } else if (*reply == 'n' || *reply == 'N') {
1760                         return 1;
1761                 } else if (*reply == 'e' || *reply == 'E') {
1762                         struct strbuf msg = STRBUF_INIT;
1763
1764                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1765                                 free(state->msg);
1766                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1767                         }
1768                         strbuf_release(&msg);
1769                 } else if (*reply == 'v' || *reply == 'V') {
1770                         const char *pager = git_pager(1);
1771                         struct child_process cp = CHILD_PROCESS_INIT;
1772
1773                         if (!pager)
1774                                 pager = "cat";
1775                         prepare_pager_args(&cp, pager);
1776                         argv_array_push(&cp.args, am_path(state, "patch"));
1777                         run_command(&cp);
1778                 }
1779         }
1780 }
1781
1782 /**
1783  * Applies all queued mail.
1784  *
1785  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1786  * well as the state directory's "patch" file is used as-is for applying the
1787  * patch and committing it.
1788  */
1789 static void am_run(struct am_state *state, int resume)
1790 {
1791         const char *argv_gc_auto[] = {"gc", "--auto", NULL};
1792         struct strbuf sb = STRBUF_INIT;
1793
1794         unlink(am_path(state, "dirtyindex"));
1795
1796         refresh_and_write_cache();
1797
1798         if (index_has_changes(&sb)) {
1799                 write_state_bool(state, "dirtyindex", 1);
1800                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1801         }
1802
1803         strbuf_release(&sb);
1804
1805         while (state->cur <= state->last) {
1806                 const char *mail = am_path(state, msgnum(state));
1807                 int apply_status;
1808
1809                 reset_ident_date();
1810
1811                 if (!file_exists(mail))
1812                         goto next;
1813
1814                 if (resume) {
1815                         validate_resume_state(state);
1816                 } else {
1817                         int skip;
1818
1819                         if (state->rebasing)
1820                                 skip = parse_mail_rebase(state, mail);
1821                         else
1822                                 skip = parse_mail(state, mail);
1823
1824                         if (skip)
1825                                 goto next; /* mail should be skipped */
1826
1827                         if (state->signoff)
1828                                 am_append_signoff(state);
1829
1830                         write_author_script(state);
1831                         write_commit_msg(state);
1832                 }
1833
1834                 if (state->interactive && do_interactive(state))
1835                         goto next;
1836
1837                 if (run_applypatch_msg_hook(state))
1838                         exit(1);
1839
1840                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1841
1842                 apply_status = run_apply(state, NULL);
1843
1844                 if (apply_status && state->threeway) {
1845                         struct strbuf sb = STRBUF_INIT;
1846
1847                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1848                         apply_status = fall_back_threeway(state, sb.buf);
1849                         strbuf_release(&sb);
1850
1851                         /*
1852                          * Applying the patch to an earlier tree and merging
1853                          * the result may have produced the same tree as ours.
1854                          */
1855                         if (!apply_status && !index_has_changes(NULL)) {
1856                                 say(state, stdout, _("No changes -- Patch already applied."));
1857                                 goto next;
1858                         }
1859                 }
1860
1861                 if (apply_status) {
1862                         int advice_amworkdir = 1;
1863
1864                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1865                                 linelen(state->msg), state->msg);
1866
1867                         git_config_get_bool("advice.amworkdir", &advice_amworkdir);
1868
1869                         if (advice_amworkdir)
1870                                 printf_ln(_("The copy of the patch that failed is found in: %s"),
1871                                                 am_path(state, "patch"));
1872
1873                         die_user_resolve(state);
1874                 }
1875
1876                 do_commit(state);
1877
1878 next:
1879                 am_next(state);
1880
1881                 if (resume)
1882                         am_load(state);
1883                 resume = 0;
1884         }
1885
1886         if (!is_empty_file(am_path(state, "rewritten"))) {
1887                 assert(state->rebasing);
1888                 copy_notes_for_rebase(state);
1889                 run_post_rewrite_hook(state);
1890         }
1891
1892         /*
1893          * In rebasing mode, it's up to the caller to take care of
1894          * housekeeping.
1895          */
1896         if (!state->rebasing) {
1897                 am_destroy(state);
1898                 close_all_packs();
1899                 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1900         }
1901 }
1902
1903 /**
1904  * Resume the current am session after patch application failure. The user did
1905  * all the hard work, and we do not have to do any patch application. Just
1906  * trust and commit what the user has in the index and working tree.
1907  */
1908 static void am_resolve(struct am_state *state)
1909 {
1910         validate_resume_state(state);
1911
1912         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1913
1914         if (!index_has_changes(NULL)) {
1915                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1916                         "If there is nothing left to stage, chances are that something else\n"
1917                         "already introduced the same changes; you might want to skip this patch."));
1918                 die_user_resolve(state);
1919         }
1920
1921         if (unmerged_cache()) {
1922                 printf_ln(_("You still have unmerged paths in your index.\n"
1923                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1924                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1925                 die_user_resolve(state);
1926         }
1927
1928         if (state->interactive) {
1929                 write_index_patch(state);
1930                 if (do_interactive(state))
1931                         goto next;
1932         }
1933
1934         rerere(0);
1935
1936         do_commit(state);
1937
1938 next:
1939         am_next(state);
1940         am_load(state);
1941         am_run(state, 0);
1942 }
1943
1944 /**
1945  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1946  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1947  * failure.
1948  */
1949 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1950 {
1951         struct lock_file *lock_file;
1952         struct unpack_trees_options opts;
1953         struct tree_desc t[2];
1954
1955         if (parse_tree(head) || parse_tree(remote))
1956                 return -1;
1957
1958         lock_file = xcalloc(1, sizeof(struct lock_file));
1959         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
1960
1961         refresh_cache(REFRESH_QUIET);
1962
1963         memset(&opts, 0, sizeof(opts));
1964         opts.head_idx = 1;
1965         opts.src_index = &the_index;
1966         opts.dst_index = &the_index;
1967         opts.update = 1;
1968         opts.merge = 1;
1969         opts.reset = reset;
1970         opts.fn = twoway_merge;
1971         init_tree_desc(&t[0], head->buffer, head->size);
1972         init_tree_desc(&t[1], remote->buffer, remote->size);
1973
1974         if (unpack_trees(2, 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  * Merges a tree into the index. The index's stat info will take precedence
1987  * over the merged tree's. Returns 0 on success, -1 on failure.
1988  */
1989 static int merge_tree(struct tree *tree)
1990 {
1991         struct lock_file *lock_file;
1992         struct unpack_trees_options opts;
1993         struct tree_desc t[1];
1994
1995         if (parse_tree(tree))
1996                 return -1;
1997
1998         lock_file = xcalloc(1, sizeof(struct lock_file));
1999         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
2000
2001         memset(&opts, 0, sizeof(opts));
2002         opts.head_idx = 1;
2003         opts.src_index = &the_index;
2004         opts.dst_index = &the_index;
2005         opts.merge = 1;
2006         opts.fn = oneway_merge;
2007         init_tree_desc(&t[0], tree->buffer, tree->size);
2008
2009         if (unpack_trees(1, t, &opts)) {
2010                 rollback_lock_file(lock_file);
2011                 return -1;
2012         }
2013
2014         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
2015                 die(_("unable to write new index file"));
2016
2017         return 0;
2018 }
2019
2020 /**
2021  * Clean the index without touching entries that are not modified between
2022  * `head` and `remote`.
2023  */
2024 static int clean_index(const struct object_id *head, const struct object_id *remote)
2025 {
2026         struct tree *head_tree, *remote_tree, *index_tree;
2027         struct object_id index;
2028
2029         head_tree = parse_tree_indirect(head);
2030         if (!head_tree)
2031                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
2032
2033         remote_tree = parse_tree_indirect(remote);
2034         if (!remote_tree)
2035                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
2036
2037         read_cache_unmerged();
2038
2039         if (fast_forward_to(head_tree, head_tree, 1))
2040                 return -1;
2041
2042         if (write_cache_as_tree(index.hash, 0, NULL))
2043                 return -1;
2044
2045         index_tree = parse_tree_indirect(&index);
2046         if (!index_tree)
2047                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
2048
2049         if (fast_forward_to(index_tree, remote_tree, 0))
2050                 return -1;
2051
2052         if (merge_tree(remote_tree))
2053                 return -1;
2054
2055         remove_branch_state();
2056
2057         return 0;
2058 }
2059
2060 /**
2061  * Resets rerere's merge resolution metadata.
2062  */
2063 static void am_rerere_clear(void)
2064 {
2065         struct string_list merge_rr = STRING_LIST_INIT_DUP;
2066         rerere_clear(&merge_rr);
2067         string_list_clear(&merge_rr, 1);
2068 }
2069
2070 /**
2071  * Resume the current am session by skipping the current patch.
2072  */
2073 static void am_skip(struct am_state *state)
2074 {
2075         struct object_id head;
2076
2077         am_rerere_clear();
2078
2079         if (get_oid("HEAD", &head))
2080                 hashcpy(head.hash, EMPTY_TREE_SHA1_BIN);
2081
2082         if (clean_index(&head, &head))
2083                 die(_("failed to clean index"));
2084
2085         am_next(state);
2086         am_load(state);
2087         am_run(state, 0);
2088 }
2089
2090 /**
2091  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2092  *
2093  * It is not safe to reset HEAD when:
2094  * 1. git-am previously failed because the index was dirty.
2095  * 2. HEAD has moved since git-am previously failed.
2096  */
2097 static int safe_to_abort(const struct am_state *state)
2098 {
2099         struct strbuf sb = STRBUF_INIT;
2100         struct object_id abort_safety, head;
2101
2102         if (file_exists(am_path(state, "dirtyindex")))
2103                 return 0;
2104
2105         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2106                 if (get_oid_hex(sb.buf, &abort_safety))
2107                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2108         } else
2109                 oidclr(&abort_safety);
2110
2111         if (get_oid("HEAD", &head))
2112                 oidclr(&head);
2113
2114         if (!oidcmp(&head, &abort_safety))
2115                 return 1;
2116
2117         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2118                 "Not rewinding to ORIG_HEAD"));
2119
2120         return 0;
2121 }
2122
2123 /**
2124  * Aborts the current am session if it is safe to do so.
2125  */
2126 static void am_abort(struct am_state *state)
2127 {
2128         struct object_id curr_head, orig_head;
2129         int has_curr_head, has_orig_head;
2130         char *curr_branch;
2131
2132         if (!safe_to_abort(state)) {
2133                 am_destroy(state);
2134                 return;
2135         }
2136
2137         am_rerere_clear();
2138
2139         curr_branch = resolve_refdup("HEAD", 0, curr_head.hash, NULL);
2140         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2141         if (!has_curr_head)
2142                 hashcpy(curr_head.hash, EMPTY_TREE_SHA1_BIN);
2143
2144         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2145         if (!has_orig_head)
2146                 hashcpy(orig_head.hash, EMPTY_TREE_SHA1_BIN);
2147
2148         clean_index(&curr_head, &orig_head);
2149
2150         if (has_orig_head)
2151                 update_ref_oid("am --abort", "HEAD", &orig_head,
2152                                 has_curr_head ? &curr_head : NULL, 0,
2153                                 UPDATE_REFS_DIE_ON_ERR);
2154         else if (curr_branch)
2155                 delete_ref(NULL, curr_branch, NULL, REF_NODEREF);
2156
2157         free(curr_branch);
2158         am_destroy(state);
2159 }
2160
2161 /**
2162  * parse_options() callback that validates and sets opt->value to the
2163  * PATCH_FORMAT_* enum value corresponding to `arg`.
2164  */
2165 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2166 {
2167         int *opt_value = opt->value;
2168
2169         if (!strcmp(arg, "mbox"))
2170                 *opt_value = PATCH_FORMAT_MBOX;
2171         else if (!strcmp(arg, "stgit"))
2172                 *opt_value = PATCH_FORMAT_STGIT;
2173         else if (!strcmp(arg, "stgit-series"))
2174                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2175         else if (!strcmp(arg, "hg"))
2176                 *opt_value = PATCH_FORMAT_HG;
2177         else if (!strcmp(arg, "mboxrd"))
2178                 *opt_value = PATCH_FORMAT_MBOXRD;
2179         else
2180                 return error(_("Invalid value for --patch-format: %s"), arg);
2181         return 0;
2182 }
2183
2184 enum resume_mode {
2185         RESUME_FALSE = 0,
2186         RESUME_APPLY,
2187         RESUME_RESOLVED,
2188         RESUME_SKIP,
2189         RESUME_ABORT
2190 };
2191
2192 static int git_am_config(const char *k, const char *v, void *cb)
2193 {
2194         int status;
2195
2196         status = git_gpg_config(k, v, NULL);
2197         if (status)
2198                 return status;
2199
2200         return git_default_config(k, v, NULL);
2201 }
2202
2203 int cmd_am(int argc, const char **argv, const char *prefix)
2204 {
2205         struct am_state state;
2206         int binary = -1;
2207         int keep_cr = -1;
2208         int patch_format = PATCH_FORMAT_UNKNOWN;
2209         enum resume_mode resume = RESUME_FALSE;
2210         int in_progress;
2211
2212         const char * const usage[] = {
2213                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2214                 N_("git am [<options>] (--continue | --skip | --abort)"),
2215                 NULL
2216         };
2217
2218         struct option options[] = {
2219                 OPT_BOOL('i', "interactive", &state.interactive,
2220                         N_("run interactively")),
2221                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2222                         N_("historical option -- no-op")),
2223                 OPT_BOOL('3', "3way", &state.threeway,
2224                         N_("allow fall back on 3way merging if needed")),
2225                 OPT__QUIET(&state.quiet, N_("be quiet")),
2226                 OPT_SET_INT('s', "signoff", &state.signoff,
2227                         N_("add a Signed-off-by line to the commit message"),
2228                         SIGNOFF_EXPLICIT),
2229                 OPT_BOOL('u', "utf8", &state.utf8,
2230                         N_("recode into utf8 (default)")),
2231                 OPT_SET_INT('k', "keep", &state.keep,
2232                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2233                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2234                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2235                 OPT_BOOL('m', "message-id", &state.message_id,
2236                         N_("pass -m flag to git-mailinfo")),
2237                 { OPTION_SET_INT, 0, "keep-cr", &keep_cr, NULL,
2238                   N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2239                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1},
2240                 { OPTION_SET_INT, 0, "no-keep-cr", &keep_cr, NULL,
2241                   N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2242                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 0},
2243                 OPT_BOOL('c', "scissors", &state.scissors,
2244                         N_("strip everything before a scissors line")),
2245                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2246                         N_("pass it through git-apply"),
2247                         0),
2248                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2249                         N_("pass it through git-apply"),
2250                         PARSE_OPT_NOARG),
2251                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2252                         N_("pass it through git-apply"),
2253                         PARSE_OPT_NOARG),
2254                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2255                         N_("pass it through git-apply"),
2256                         0),
2257                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2258                         N_("pass it through git-apply"),
2259                         0),
2260                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2261                         N_("pass it through git-apply"),
2262                         0),
2263                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2264                         N_("pass it through git-apply"),
2265                         0),
2266                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2267                         N_("pass it through git-apply"),
2268                         0),
2269                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2270                         N_("format the patch(es) are in"),
2271                         parse_opt_patchformat),
2272                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2273                         N_("pass it through git-apply"),
2274                         PARSE_OPT_NOARG),
2275                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2276                         N_("override error message when patch failure occurs")),
2277                 OPT_CMDMODE(0, "continue", &resume,
2278                         N_("continue applying patches after resolving a conflict"),
2279                         RESUME_RESOLVED),
2280                 OPT_CMDMODE('r', "resolved", &resume,
2281                         N_("synonyms for --continue"),
2282                         RESUME_RESOLVED),
2283                 OPT_CMDMODE(0, "skip", &resume,
2284                         N_("skip the current patch"),
2285                         RESUME_SKIP),
2286                 OPT_CMDMODE(0, "abort", &resume,
2287                         N_("restore the original branch and abort the patching operation."),
2288                         RESUME_ABORT),
2289                 OPT_BOOL(0, "committer-date-is-author-date",
2290                         &state.committer_date_is_author_date,
2291                         N_("lie about committer date")),
2292                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2293                         N_("use current timestamp for author date")),
2294                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2295                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2296                   N_("GPG-sign commits"),
2297                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2298                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2299                         N_("(internal use for git-rebase)")),
2300                 OPT_END()
2301         };
2302
2303         if (argc == 2 && !strcmp(argv[1], "-h"))
2304                 usage_with_options(usage, options);
2305
2306         git_config(git_am_config, NULL);
2307
2308         am_state_init(&state);
2309
2310         in_progress = am_in_progress(&state);
2311         if (in_progress)
2312                 am_load(&state);
2313
2314         argc = parse_options(argc, argv, prefix, options, usage, 0);
2315
2316         if (binary >= 0)
2317                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2318                                 "it will be removed. Please do not use it anymore."));
2319
2320         /* Ensure a valid committer ident can be constructed */
2321         git_committer_info(IDENT_STRICT);
2322
2323         if (read_index_preload(&the_index, NULL) < 0)
2324                 die(_("failed to read the index"));
2325
2326         if (in_progress) {
2327                 /*
2328                  * Catch user error to feed us patches when there is a session
2329                  * in progress:
2330                  *
2331                  * 1. mbox path(s) are provided on the command-line.
2332                  * 2. stdin is not a tty: the user is trying to feed us a patch
2333                  *    from standard input. This is somewhat unreliable -- stdin
2334                  *    could be /dev/null for example and the caller did not
2335                  *    intend to feed us a patch but wanted to continue
2336                  *    unattended.
2337                  */
2338                 if (argc || (resume == RESUME_FALSE && !isatty(0)))
2339                         die(_("previous rebase directory %s still exists but mbox given."),
2340                                 state.dir);
2341
2342                 if (resume == RESUME_FALSE)
2343                         resume = RESUME_APPLY;
2344
2345                 if (state.signoff == SIGNOFF_EXPLICIT)
2346                         am_append_signoff(&state);
2347         } else {
2348                 struct argv_array paths = ARGV_ARRAY_INIT;
2349                 int i;
2350
2351                 /*
2352                  * Handle stray state directory in the independent-run case. In
2353                  * the --rebasing case, it is up to the caller to take care of
2354                  * stray directories.
2355                  */
2356                 if (file_exists(state.dir) && !state.rebasing) {
2357                         if (resume == RESUME_ABORT) {
2358                                 am_destroy(&state);
2359                                 am_state_release(&state);
2360                                 return 0;
2361                         }
2362
2363                         die(_("Stray %s directory found.\n"
2364                                 "Use \"git am --abort\" to remove it."),
2365                                 state.dir);
2366                 }
2367
2368                 if (resume)
2369                         die(_("Resolve operation not in progress, we are not resuming."));
2370
2371                 for (i = 0; i < argc; i++) {
2372                         if (is_absolute_path(argv[i]) || !prefix)
2373                                 argv_array_push(&paths, argv[i]);
2374                         else
2375                                 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2376                 }
2377
2378                 am_setup(&state, patch_format, paths.argv, keep_cr);
2379
2380                 argv_array_clear(&paths);
2381         }
2382
2383         switch (resume) {
2384         case RESUME_FALSE:
2385                 am_run(&state, 0);
2386                 break;
2387         case RESUME_APPLY:
2388                 am_run(&state, 1);
2389                 break;
2390         case RESUME_RESOLVED:
2391                 am_resolve(&state);
2392                 break;
2393         case RESUME_SKIP:
2394                 am_skip(&state);
2395                 break;
2396         case RESUME_ABORT:
2397                 am_abort(&state);
2398                 break;
2399         default:
2400                 die("BUG: invalid resume value");
2401         }
2402
2403         am_state_release(&state);
2404
2405         return 0;
2406 }