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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(state->msg);
 488                 state->msg = NULL;
 489                 if (read_commit_msg(state) < 0)
 490                         die(_("'%s' was deleted by the applypatch-msg hook"),
 491                                 am_path(state, "final-commit"));
 492         }
 493
 494         return ret;
 495 }
 496
 497 /**
 498  * Runs post-rewrite hook. Returns it exit code.
 499  */
 500 static int run_post_rewrite_hook(const struct am_state *state)
 501 {
 502         struct child_process cp = CHILD_PROCESS_INIT;
 503         const char *hook = find_hook("post-rewrite");
 504         int ret;
 505
 506         if (!hook)
 507                 return 0;
 508
 509         argv_array_push(&cp.args, hook);
 510         argv_array_push(&cp.args, "rebase");
 511
 512         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
 513         cp.stdout_to_stderr = 1;
 514
 515         ret = run_command(&cp);
 516
 517         close(cp.in);
 518         return ret;
 519 }
 520
 521 /**
 522  * Reads the state directory's "rewritten" file, and copies notes from the old
 523  * commits listed in the file to their rewritten commits.
 524  *
 525  * Returns 0 on success, -1 on failure.
 526  */
 527 static int copy_notes_for_rebase(const struct am_state *state)
 528 {
 529         struct notes_rewrite_cfg *c;
 530         struct strbuf sb = STRBUF_INIT;
 531         const char *invalid_line = _("Malformed input line: '%s'.");
 532         const char *msg = "Notes added by 'git rebase'";
 533         FILE *fp;
 534         int ret = 0;
 535
 536         assert(state->rebasing);
 537
 538         c = init_copy_notes_for_rewrite("rebase");
 539         if (!c)
 540                 return 0;
 541
 542         fp = xfopen(am_path(state, "rewritten"), "r");
 543
 544         while (!strbuf_getline_lf(&sb, fp)) {
 545                 struct object_id from_obj, to_obj;
 546
 547                 if (sb.len != GIT_SHA1_HEXSZ * 2 + 1) {
 548                         ret = error(invalid_line, sb.buf);
 549                         goto finish;
 550                 }
 551
 552                 if (get_oid_hex(sb.buf, &from_obj)) {
 553                         ret = error(invalid_line, sb.buf);
 554                         goto finish;
 555                 }
 556
 557                 if (sb.buf[GIT_SHA1_HEXSZ] != ' ') {
 558                         ret = error(invalid_line, sb.buf);
 559                         goto finish;
 560                 }
 561
 562                 if (get_oid_hex(sb.buf + GIT_SHA1_HEXSZ + 1, &to_obj)) {
 563                         ret = error(invalid_line, sb.buf);
 564                         goto finish;
 565                 }
 566
 567                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
 568                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
 569                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
 570         }
 571
 572 finish:
 573         finish_copy_notes_for_rewrite(c, msg);
 574         fclose(fp);
 575         strbuf_release(&sb);
 576         return ret;
 577 }
 578
 579 /**
 580  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
 581  * non-indented lines and checking if they look like they begin with valid
 582  * header field names.
 583  *
 584  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
 585  */
 586 static int is_mail(FILE *fp)
 587 {
 588         const char *header_regex = "^[!-9;-~]+:";
 589         struct strbuf sb = STRBUF_INIT;
 590         regex_t regex;
 591         int ret = 1;
 592
 593         if (fseek(fp, 0L, SEEK_SET))
 594                 die_errno(_("fseek failed"));
 595
 596         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
 597                 die("invalid pattern: %s", header_regex);
 598
 599         while (!strbuf_getline(&sb, fp)) {
 600                 if (!sb.len)
 601                         break; /* End of header */
 602
 603                 /* Ignore indented folded lines */
 604                 if (*sb.buf == '\t' || *sb.buf == ' ')
 605                         continue;
 606
 607                 /* It's a header if it matches header_regex */
 608                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
 609                         ret = 0;
 610                         goto done;
 611                 }
 612         }
 613
 614 done:
 615         regfree(&regex);
 616         strbuf_release(&sb);
 617         return ret;
 618 }
 619
 620 /**
 621  * Attempts to detect the patch_format of the patches contained in `paths`,
 622  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
 623  * detection fails.
 624  */
 625 static int detect_patch_format(const char **paths)
 626 {
 627         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
 628         struct strbuf l1 = STRBUF_INIT;
 629         struct strbuf l2 = STRBUF_INIT;
 630         struct strbuf l3 = STRBUF_INIT;
 631         FILE *fp;
 632
 633         /*
 634          * We default to mbox format if input is from stdin and for directories
 635          */
 636         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
 637                 return PATCH_FORMAT_MBOX;
 638
 639         /*
 640          * Otherwise, check the first few lines of the first patch, starting
 641          * from the first non-blank line, to try to detect its format.
 642          */
 643
 644         fp = xfopen(*paths, "r");
 645
 646         while (!strbuf_getline(&l1, fp)) {
 647                 if (l1.len)
 648                         break;
 649         }
 650
 651         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
 652                 ret = PATCH_FORMAT_MBOX;
 653                 goto done;
 654         }
 655
 656         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
 657                 ret = PATCH_FORMAT_STGIT_SERIES;
 658                 goto done;
 659         }
 660
 661         if (!strcmp(l1.buf, "# HG changeset patch")) {
 662                 ret = PATCH_FORMAT_HG;
 663                 goto done;
 664         }
 665
 666         strbuf_reset(&l2);
 667         strbuf_getline(&l2, fp);
 668         strbuf_reset(&l3);
 669         strbuf_getline(&l3, fp);
 670
 671         /*
 672          * If the second line is empty and the third is a From, Author or Date
 673          * entry, this is likely an StGit patch.
 674          */
 675         if (l1.len && !l2.len &&
 676                 (starts_with(l3.buf, "From:") ||
 677                  starts_with(l3.buf, "Author:") ||
 678                  starts_with(l3.buf, "Date:"))) {
 679                 ret = PATCH_FORMAT_STGIT;
 680                 goto done;
 681         }
 682
 683         if (l1.len && is_mail(fp)) {
 684                 ret = PATCH_FORMAT_MBOX;
 685                 goto done;
 686         }
 687
 688 done:
 689         fclose(fp);
 690         strbuf_release(&l1);
 691         return ret;
 692 }
 693
 694 /**
 695  * Splits out individual email patches from `paths`, where each path is either
 696  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
 697  */
 698 static int split_mail_mbox(struct am_state *state, const char **paths,
 699                                 int keep_cr, int mboxrd)
 700 {
 701         struct child_process cp = CHILD_PROCESS_INIT;
 702         struct strbuf last = STRBUF_INIT;
 703
 704         cp.git_cmd = 1;
 705         argv_array_push(&cp.args, "mailsplit");
 706         argv_array_pushf(&cp.args, "-d%d", state->prec);
 707         argv_array_pushf(&cp.args, "-o%s", state->dir);
 708         argv_array_push(&cp.args, "-b");
 709         if (keep_cr)
 710                 argv_array_push(&cp.args, "--keep-cr");
 711         if (mboxrd)
 712                 argv_array_push(&cp.args, "--mboxrd");
 713         argv_array_push(&cp.args, "--");
 714         argv_array_pushv(&cp.args, paths);
 715
 716         if (capture_command(&cp, &last, 8))
 717                 return -1;
 718
 719         state->cur = 1;
 720         state->last = strtol(last.buf, NULL, 10);
 721
 722         return 0;
 723 }
 724
 725 /**
 726  * Callback signature for split_mail_conv(). The foreign patch should be
 727  * read from `in`, and the converted patch (in RFC2822 mail format) should be
 728  * written to `out`. Return 0 on success, or -1 on failure.
 729  */
 730 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
 731
 732 /**
 733  * Calls `fn` for each file in `paths` to convert the foreign patch to the
 734  * RFC2822 mail format suitable for parsing with git-mailinfo.
 735  *
 736  * Returns 0 on success, -1 on failure.
 737  */
 738 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
 739                         const char **paths, int keep_cr)
 740 {
 741         static const char *stdin_only[] = {"-", NULL};
 742         int i;
 743
 744         if (!*paths)
 745                 paths = stdin_only;
 746
 747         for (i = 0; *paths; paths++, i++) {
 748                 FILE *in, *out;
 749                 const char *mail;
 750                 int ret;
 751
 752                 if (!strcmp(*paths, "-"))
 753                         in = stdin;
 754                 else
 755                         in = fopen(*paths, "r");
 756
 757                 if (!in)
 758                         return error_errno(_("could not open '%s' for reading"),
 759                                            *paths);
 760
 761                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
 762
 763                 out = fopen(mail, "w");
 764                 if (!out) {
 765                         if (in != stdin)
 766                                 fclose(in);
 767                         return error_errno(_("could not open '%s' for writing"),
 768                                            mail);
 769                 }
 770
 771                 ret = fn(out, in, keep_cr);
 772
 773                 fclose(out);
 774                 if (in != stdin)
 775                         fclose(in);
 776
 777                 if (ret)
 778                         return error(_("could not parse patch '%s'"), *paths);
 779         }
 780
 781         state->cur = 1;
 782         state->last = i;
 783         return 0;
 784 }
 785
 786 /**
 787  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
 788  * message suitable for parsing with git-mailinfo.
 789  */
 790 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 791 {
 792         struct strbuf sb = STRBUF_INIT;
 793         int subject_printed = 0;
 794
 795         while (!strbuf_getline_lf(&sb, in)) {
 796                 const char *str;
 797
 798                 if (str_isspace(sb.buf))
 799                         continue;
 800                 else if (skip_prefix(sb.buf, "Author:", &str))
 801                         fprintf(out, "From:%s\n", str);
 802                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
 803                         fprintf(out, "%s\n", sb.buf);
 804                 else if (!subject_printed) {
 805                         fprintf(out, "Subject: %s\n", sb.buf);
 806                         subject_printed = 1;
 807                 } else {
 808                         fprintf(out, "\n%s\n", sb.buf);
 809                         break;
 810                 }
 811         }
 812
 813         strbuf_reset(&sb);
 814         while (strbuf_fread(&sb, 8192, in) > 0) {
 815                 fwrite(sb.buf, 1, sb.len, out);
 816                 strbuf_reset(&sb);
 817         }
 818
 819         strbuf_release(&sb);
 820         return 0;
 821 }
 822
 823 /**
 824  * This function only supports a single StGit series file in `paths`.
 825  *
 826  * Given an StGit series file, converts the StGit patches in the series into
 827  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
 828  * the state directory.
 829  *
 830  * Returns 0 on success, -1 on failure.
 831  */
 832 static int split_mail_stgit_series(struct am_state *state, const char **paths,
 833                                         int keep_cr)
 834 {
 835         const char *series_dir;
 836         char *series_dir_buf;
 837         FILE *fp;
 838         struct argv_array patches = ARGV_ARRAY_INIT;
 839         struct strbuf sb = STRBUF_INIT;
 840         int ret;
 841
 842         if (!paths[0] || paths[1])
 843                 return error(_("Only one StGIT patch series can be applied at once"));
 844
 845         series_dir_buf = xstrdup(*paths);
 846         series_dir = dirname(series_dir_buf);
 847
 848         fp = fopen(*paths, "r");
 849         if (!fp)
 850                 return error_errno(_("could not open '%s' for reading"), *paths);
 851
 852         while (!strbuf_getline_lf(&sb, fp)) {
 853                 if (*sb.buf == '#')
 854                         continue; /* skip comment lines */
 855
 856                 argv_array_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
 857         }
 858
 859         fclose(fp);
 860         strbuf_release(&sb);
 861         free(series_dir_buf);
 862
 863         ret = split_mail_conv(stgit_patch_to_mail, state, patches.argv, keep_cr);
 864
 865         argv_array_clear(&patches);
 866         return ret;
 867 }
 868
 869 /**
 870  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
 871  * message suitable for parsing with git-mailinfo.
 872  */
 873 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 874 {
 875         struct strbuf sb = STRBUF_INIT;
 876
 877         while (!strbuf_getline_lf(&sb, in)) {
 878                 const char *str;
 879
 880                 if (skip_prefix(sb.buf, "# User ", &str))
 881                         fprintf(out, "From: %s\n", str);
 882                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
 883                         timestamp_t timestamp;
 884                         long tz, tz2;
 885                         char *end;
 886
 887                         errno = 0;
 888                         timestamp = parse_timestamp(str, &end, 10);
 889                         if (errno)
 890                                 return error(_("invalid timestamp"));
 891
 892                         if (!skip_prefix(end, " ", &str))
 893                                 return error(_("invalid Date line"));
 894
 895                         errno = 0;
 896                         tz = strtol(str, &end, 10);
 897                         if (errno)
 898                                 return error(_("invalid timezone offset"));
 899
 900                         if (*end)
 901                                 return error(_("invalid Date line"));
 902
 903                         /*
 904                          * mercurial's timezone is in seconds west of UTC,
 905                          * however git's timezone is in hours + minutes east of
 906                          * UTC. Convert it.
 907                          */
 908                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
 909                         if (tz > 0)
 910                                 tz2 = -tz2;
 911
 912                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
 913                 } else if (starts_with(sb.buf, "# ")) {
 914                         continue;
 915                 } else {
 916                         fprintf(out, "\n%s\n", sb.buf);
 917                         break;
 918                 }
 919         }
 920
 921         strbuf_reset(&sb);
 922         while (strbuf_fread(&sb, 8192, in) > 0) {
 923                 fwrite(sb.buf, 1, sb.len, out);
 924                 strbuf_reset(&sb);
 925         }
 926
 927         strbuf_release(&sb);
 928         return 0;
 929 }
 930
 931 /**
 932  * Splits a list of files/directories into individual email patches. Each path
 933  * in `paths` must be a file/directory that is formatted according to
 934  * `patch_format`.
 935  *
 936  * Once split out, the individual email patches will be stored in the state
 937  * directory, with each patch's filename being its index, padded to state->prec
 938  * digits.
 939  *
 940  * state->cur will be set to the index of the first mail, and state->last will
 941  * be set to the index of the last mail.
 942  *
 943  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
 944  * to disable this behavior, -1 to use the default configured setting.
 945  *
 946  * Returns 0 on success, -1 on failure.
 947  */
 948 static int split_mail(struct am_state *state, enum patch_format patch_format,
 949                         const char **paths, int keep_cr)
 950 {
 951         if (keep_cr < 0) {
 952                 keep_cr = 0;
 953                 git_config_get_bool("am.keepcr", &keep_cr);
 954         }
 955
 956         switch (patch_format) {
 957         case PATCH_FORMAT_MBOX:
 958                 return split_mail_mbox(state, paths, keep_cr, 0);
 959         case PATCH_FORMAT_STGIT:
 960                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
 961         case PATCH_FORMAT_STGIT_SERIES:
 962                 return split_mail_stgit_series(state, paths, keep_cr);
 963         case PATCH_FORMAT_HG:
 964                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
 965         case PATCH_FORMAT_MBOXRD:
 966                 return split_mail_mbox(state, paths, keep_cr, 1);
 967         default:
 968                 die("BUG: invalid patch_format");
 969         }
 970         return -1;
 971 }
 972
 973 /**
 974  * Setup a new am session for applying patches
 975  */
 976 static void am_setup(struct am_state *state, enum patch_format patch_format,
 977                         const char **paths, int keep_cr)
 978 {
 979         struct object_id curr_head;
 980         const char *str;
 981         struct strbuf sb = STRBUF_INIT;
 982
 983         if (!patch_format)
 984                 patch_format = detect_patch_format(paths);
 985
 986         if (!patch_format) {
 987                 fprintf_ln(stderr, _("Patch format detection failed."));
 988                 exit(128);
 989         }
 990
 991         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
 992                 die_errno(_("failed to create directory '%s'"), state->dir);
 993
 994         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
 995                 am_destroy(state);
 996                 die(_("Failed to split patches."));
 997         }
 998
 999         if (state->rebasing)
1000                 state->threeway = 1;
1001
1002         write_state_bool(state, "threeway", state->threeway);
1003         write_state_bool(state, "quiet", state->quiet);
1004         write_state_bool(state, "sign", state->signoff);
1005         write_state_bool(state, "utf8", state->utf8);
1006
1007         switch (state->keep) {
1008         case KEEP_FALSE:
1009                 str = "f";
1010                 break;
1011         case KEEP_TRUE:
1012                 str = "t";
1013                 break;
1014         case KEEP_NON_PATCH:
1015                 str = "b";
1016                 break;
1017         default:
1018                 die("BUG: invalid value for state->keep");
1019         }
1020
1021         write_state_text(state, "keep", str);
1022         write_state_bool(state, "messageid", state->message_id);
1023
1024         switch (state->scissors) {
1025         case SCISSORS_UNSET:
1026                 str = "";
1027                 break;
1028         case SCISSORS_FALSE:
1029                 str = "f";
1030                 break;
1031         case SCISSORS_TRUE:
1032                 str = "t";
1033                 break;
1034         default:
1035                 die("BUG: invalid value for state->scissors");
1036         }
1037         write_state_text(state, "scissors", str);
1038
1039         sq_quote_argv(&sb, state->git_apply_opts.argv, 0);
1040         write_state_text(state, "apply-opt", sb.buf);
1041
1042         if (state->rebasing)
1043                 write_state_text(state, "rebasing", "");
1044         else
1045                 write_state_text(state, "applying", "");
1046
1047         if (!get_oid("HEAD", &curr_head)) {
1048                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1049                 if (!state->rebasing)
1050                         update_ref_oid("am", "ORIG_HEAD", &curr_head, NULL, 0,
1051                                         UPDATE_REFS_DIE_ON_ERR);
1052         } else {
1053                 write_state_text(state, "abort-safety", "");
1054                 if (!state->rebasing)
1055                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1056         }
1057
1058         /*
1059          * NOTE: Since the "next" and "last" files determine if an am_state
1060          * session is in progress, they should be written last.
1061          */
1062
1063         write_state_count(state, "next", state->cur);
1064         write_state_count(state, "last", state->last);
1065
1066         strbuf_release(&sb);
1067 }
1068
1069 /**
1070  * Increments the patch pointer, and cleans am_state for the application of the
1071  * next patch.
1072  */
1073 static void am_next(struct am_state *state)
1074 {
1075         struct object_id head;
1076
1077         free(state->author_name);
1078         state->author_name = NULL;
1079
1080         free(state->author_email);
1081         state->author_email = NULL;
1082
1083         free(state->author_date);
1084         state->author_date = NULL;
1085
1086         free(state->msg);
1087         state->msg = NULL;
1088         state->msg_len = 0;
1089
1090         unlink(am_path(state, "author-script"));
1091         unlink(am_path(state, "final-commit"));
1092
1093         oidclr(&state->orig_commit);
1094         unlink(am_path(state, "original-commit"));
1095
1096         if (!get_oid("HEAD", &head))
1097                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1098         else
1099                 write_state_text(state, "abort-safety", "");
1100
1101         state->cur++;
1102         write_state_count(state, "next", state->cur);
1103 }
1104
1105 /**
1106  * Returns the filename of the current patch email.
1107  */
1108 static const char *msgnum(const struct am_state *state)
1109 {
1110         static struct strbuf sb = STRBUF_INIT;
1111
1112         strbuf_reset(&sb);
1113         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1114
1115         return sb.buf;
1116 }
1117
1118 /**
1119  * Refresh and write index.
1120  */
1121 static void refresh_and_write_cache(void)
1122 {
1123         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
1124
1125         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
1126         refresh_cache(REFRESH_QUIET);
1127         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
1128                 die(_("unable to write index file"));
1129 }
1130
1131 /**
1132  * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
1133  * branch, returns 1 if there are entries in the index, 0 otherwise. If an
1134  * strbuf is provided, the space-separated list of files that differ will be
1135  * appended to it.
1136  */
1137 static int index_has_changes(struct strbuf *sb)
1138 {
1139         struct object_id head;
1140         int i;
1141
1142         if (!get_sha1_tree("HEAD", head.hash)) {
1143                 struct diff_options opt;
1144
1145                 diff_setup(&opt);
1146                 DIFF_OPT_SET(&opt, EXIT_WITH_STATUS);
1147                 if (!sb)
1148                         DIFF_OPT_SET(&opt, QUICK);
1149                 do_diff_cache(&head, &opt);
1150                 diffcore_std(&opt);
1151                 for (i = 0; sb && i < diff_queued_diff.nr; i++) {
1152                         if (i)
1153                                 strbuf_addch(sb, ' ');
1154                         strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
1155                 }
1156                 diff_flush(&opt);
1157                 return DIFF_OPT_TST(&opt, HAS_CHANGES) != 0;
1158         } else {
1159                 for (i = 0; sb && i < active_nr; i++) {
1160                         if (i)
1161                                 strbuf_addch(sb, ' ');
1162                         strbuf_addstr(sb, active_cache[i]->name);
1163                 }
1164                 return !!active_nr;
1165         }
1166 }
1167
1168 /**
1169  * Dies with a user-friendly message on how to proceed after resolving the
1170  * problem. This message can be overridden with state->resolvemsg.
1171  */
1172 static void NORETURN die_user_resolve(const struct am_state *state)
1173 {
1174         if (state->resolvemsg) {
1175                 printf_ln("%s", state->resolvemsg);
1176         } else {
1177                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1178
1179                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1180                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1181                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1182         }
1183
1184         exit(128);
1185 }
1186
1187 /**
1188  * Appends signoff to the "msg" field of the am_state.
1189  */
1190 static void am_append_signoff(struct am_state *state)
1191 {
1192         char *cp;
1193         struct strbuf mine = STRBUF_INIT;
1194         struct strbuf sb = STRBUF_INIT;
1195
1196         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1197
1198         /* our sign-off */
1199         strbuf_addf(&mine, "\n%s%s\n",
1200                     sign_off_header,
1201                     fmt_name(getenv("GIT_COMMITTER_NAME"),
1202                              getenv("GIT_COMMITTER_EMAIL")));
1203
1204         /* Does sb end with it already? */
1205         if (mine.len < sb.len &&
1206             !strcmp(mine.buf, sb.buf + sb.len - mine.len))
1207                 goto exit; /* no need to duplicate */
1208
1209         /* Does it have any Signed-off-by: in the text */
1210         for (cp = sb.buf;
1211              cp && *cp && (cp = strstr(cp, sign_off_header)) != NULL;
1212              cp = strchr(cp, '\n')) {
1213                 if (sb.buf == cp || cp[-1] == '\n')
1214                         break;
1215         }
1216
1217         strbuf_addstr(&sb, mine.buf + !!cp);
1218 exit:
1219         strbuf_release(&mine);
1220         state->msg = strbuf_detach(&sb, &state->msg_len);
1221 }
1222
1223 /**
1224  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1225  * state->msg will be set to the patch message. state->author_name,
1226  * state->author_email and state->author_date will be set to the patch author's
1227  * name, email and date respectively. The patch body will be written to the
1228  * state directory's "patch" file.
1229  *
1230  * Returns 1 if the patch should be skipped, 0 otherwise.
1231  */
1232 static int parse_mail(struct am_state *state, const char *mail)
1233 {
1234         FILE *fp;
1235         struct strbuf sb = STRBUF_INIT;
1236         struct strbuf msg = STRBUF_INIT;
1237         struct strbuf author_name = STRBUF_INIT;
1238         struct strbuf author_date = STRBUF_INIT;
1239         struct strbuf author_email = STRBUF_INIT;
1240         int ret = 0;
1241         struct mailinfo mi;
1242
1243         setup_mailinfo(&mi);
1244
1245         if (state->utf8)
1246                 mi.metainfo_charset = get_commit_output_encoding();
1247         else
1248                 mi.metainfo_charset = NULL;
1249
1250         switch (state->keep) {
1251         case KEEP_FALSE:
1252                 break;
1253         case KEEP_TRUE:
1254                 mi.keep_subject = 1;
1255                 break;
1256         case KEEP_NON_PATCH:
1257                 mi.keep_non_patch_brackets_in_subject = 1;
1258                 break;
1259         default:
1260                 die("BUG: invalid value for state->keep");
1261         }
1262
1263         if (state->message_id)
1264                 mi.add_message_id = 1;
1265
1266         switch (state->scissors) {
1267         case SCISSORS_UNSET:
1268                 break;
1269         case SCISSORS_FALSE:
1270                 mi.use_scissors = 0;
1271                 break;
1272         case SCISSORS_TRUE:
1273                 mi.use_scissors = 1;
1274                 break;
1275         default:
1276                 die("BUG: invalid value for state->scissors");
1277         }
1278
1279         mi.input = xfopen(mail, "r");
1280         mi.output = xfopen(am_path(state, "info"), "w");
1281         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1282                 die("could not parse patch");
1283
1284         fclose(mi.input);
1285         fclose(mi.output);
1286
1287         /* Extract message and author information */
1288         fp = xfopen(am_path(state, "info"), "r");
1289         while (!strbuf_getline_lf(&sb, fp)) {
1290                 const char *x;
1291
1292                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1293                         if (msg.len)
1294                                 strbuf_addch(&msg, '\n');
1295                         strbuf_addstr(&msg, x);
1296                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1297                         strbuf_addstr(&author_name, x);
1298                 else if (skip_prefix(sb.buf, "Email: ", &x))
1299                         strbuf_addstr(&author_email, x);
1300                 else if (skip_prefix(sb.buf, "Date: ", &x))
1301                         strbuf_addstr(&author_date, x);
1302         }
1303         fclose(fp);
1304
1305         /* Skip pine's internal folder data */
1306         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1307                 ret = 1;
1308                 goto finish;
1309         }
1310
1311         if (is_empty_file(am_path(state, "patch"))) {
1312                 printf_ln(_("Patch is empty."));
1313                 die_user_resolve(state);
1314         }
1315
1316         strbuf_addstr(&msg, "\n\n");
1317         strbuf_addbuf(&msg, &mi.log_message);
1318         strbuf_stripspace(&msg, 0);
1319
1320         assert(!state->author_name);
1321         state->author_name = strbuf_detach(&author_name, NULL);
1322
1323         assert(!state->author_email);
1324         state->author_email = strbuf_detach(&author_email, NULL);
1325
1326         assert(!state->author_date);
1327         state->author_date = strbuf_detach(&author_date, NULL);
1328
1329         assert(!state->msg);
1330         state->msg = strbuf_detach(&msg, &state->msg_len);
1331
1332 finish:
1333         strbuf_release(&msg);
1334         strbuf_release(&author_date);
1335         strbuf_release(&author_email);
1336         strbuf_release(&author_name);
1337         strbuf_release(&sb);
1338         clear_mailinfo(&mi);
1339         return ret;
1340 }
1341
1342 /**
1343  * Sets commit_id to the commit hash where the mail was generated from.
1344  * Returns 0 on success, -1 on failure.
1345  */
1346 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1347 {
1348         struct strbuf sb = STRBUF_INIT;
1349         FILE *fp = xfopen(mail, "r");
1350         const char *x;
1351         int ret = 0;
1352
1353         if (strbuf_getline_lf(&sb, fp) ||
1354             !skip_prefix(sb.buf, "From ", &x) ||
1355             get_oid_hex(x, commit_id) < 0)
1356                 ret = -1;
1357
1358         strbuf_release(&sb);
1359         fclose(fp);
1360         return ret;
1361 }
1362
1363 /**
1364  * Sets state->msg, state->author_name, state->author_email, state->author_date
1365  * to the commit's respective info.
1366  */
1367 static void get_commit_info(struct am_state *state, struct commit *commit)
1368 {
1369         const char *buffer, *ident_line, *msg;
1370         size_t ident_len;
1371         struct ident_split id;
1372
1373         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1374
1375         ident_line = find_commit_header(buffer, "author", &ident_len);
1376
1377         if (split_ident_line(&id, ident_line, ident_len) < 0)
1378                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1379
1380         assert(!state->author_name);
1381         if (id.name_begin)
1382                 state->author_name =
1383                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1384         else
1385                 state->author_name = xstrdup("");
1386
1387         assert(!state->author_email);
1388         if (id.mail_begin)
1389                 state->author_email =
1390                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1391         else
1392                 state->author_email = xstrdup("");
1393
1394         assert(!state->author_date);
1395         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1396
1397         assert(!state->msg);
1398         msg = strstr(buffer, "\n\n");
1399         if (!msg)
1400                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1401         state->msg = xstrdup(msg + 2);
1402         state->msg_len = strlen(state->msg);
1403         unuse_commit_buffer(commit, buffer);
1404 }
1405
1406 /**
1407  * Writes `commit` as a patch to the state directory's "patch" file.
1408  */
1409 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1410 {
1411         struct rev_info rev_info;
1412         FILE *fp;
1413
1414         fp = xfopen(am_path(state, "patch"), "w");
1415         init_revisions(&rev_info, NULL);
1416         rev_info.diff = 1;
1417         rev_info.abbrev = 0;
1418         rev_info.disable_stdin = 1;
1419         rev_info.show_root_diff = 1;
1420         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1421         rev_info.no_commit_id = 1;
1422         DIFF_OPT_SET(&rev_info.diffopt, BINARY);
1423         DIFF_OPT_SET(&rev_info.diffopt, FULL_INDEX);
1424         rev_info.diffopt.use_color = 0;
1425         rev_info.diffopt.file = fp;
1426         rev_info.diffopt.close_file = 1;
1427         add_pending_object(&rev_info, &commit->object, "");
1428         diff_setup_done(&rev_info.diffopt);
1429         log_tree_commit(&rev_info, commit);
1430 }
1431
1432 /**
1433  * Writes the diff of the index against HEAD as a patch to the state
1434  * directory's "patch" file.
1435  */
1436 static void write_index_patch(const struct am_state *state)
1437 {
1438         struct tree *tree;
1439         struct object_id head;
1440         struct rev_info rev_info;
1441         FILE *fp;
1442
1443         if (!get_sha1_tree("HEAD", head.hash))
1444                 tree = lookup_tree(&head);
1445         else
1446                 tree = lookup_tree(&empty_tree_oid);
1447
1448         fp = xfopen(am_path(state, "patch"), "w");
1449         init_revisions(&rev_info, NULL);
1450         rev_info.diff = 1;
1451         rev_info.disable_stdin = 1;
1452         rev_info.no_commit_id = 1;
1453         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1454         rev_info.diffopt.use_color = 0;
1455         rev_info.diffopt.file = fp;
1456         rev_info.diffopt.close_file = 1;
1457         add_pending_object(&rev_info, &tree->object, "");
1458         diff_setup_done(&rev_info.diffopt);
1459         run_diff_index(&rev_info, 1);
1460 }
1461
1462 /**
1463  * Like parse_mail(), but parses the mail by looking up its commit ID
1464  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1465  * of patches.
1466  *
1467  * state->orig_commit will be set to the original commit ID.
1468  *
1469  * Will always return 0 as the patch should never be skipped.
1470  */
1471 static int parse_mail_rebase(struct am_state *state, const char *mail)
1472 {
1473         struct commit *commit;
1474         struct object_id commit_oid;
1475
1476         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1477                 die(_("could not parse %s"), mail);
1478
1479         commit = lookup_commit_or_die(&commit_oid, mail);
1480
1481         get_commit_info(state, commit);
1482
1483         write_commit_patch(state, commit);
1484
1485         oidcpy(&state->orig_commit, &commit_oid);
1486         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1487
1488         return 0;
1489 }
1490
1491 /**
1492  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1493  * `index_file` is not NULL, the patch will be applied to that index.
1494  */
1495 static int run_apply(const struct am_state *state, const char *index_file)
1496 {
1497         struct argv_array apply_paths = ARGV_ARRAY_INIT;
1498         struct argv_array apply_opts = ARGV_ARRAY_INIT;
1499         struct apply_state apply_state;
1500         int res, opts_left;
1501         static struct lock_file lock_file;
1502         int force_apply = 0;
1503         int options = 0;
1504
1505         if (init_apply_state(&apply_state, NULL, &lock_file))
1506                 die("BUG: init_apply_state() failed");
1507
1508         argv_array_push(&apply_opts, "apply");
1509         argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
1510
1511         opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
1512                                         &apply_state, &force_apply, &options,
1513                                         NULL);
1514
1515         if (opts_left != 0)
1516                 die("unknown option passed through to git apply");
1517
1518         if (index_file) {
1519                 apply_state.index_file = index_file;
1520                 apply_state.cached = 1;
1521         } else
1522                 apply_state.check_index = 1;
1523
1524         /*
1525          * If we are allowed to fall back on 3-way merge, don't give false
1526          * errors during the initial attempt.
1527          */
1528         if (state->threeway && !index_file)
1529                 apply_state.apply_verbosity = verbosity_silent;
1530
1531         if (check_apply_state(&apply_state, force_apply))
1532                 die("BUG: check_apply_state() failed");
1533
1534         argv_array_push(&apply_paths, am_path(state, "patch"));
1535
1536         res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
1537
1538         argv_array_clear(&apply_paths);
1539         argv_array_clear(&apply_opts);
1540         clear_apply_state(&apply_state);
1541
1542         if (res)
1543                 return res;
1544
1545         if (index_file) {
1546                 /* Reload index as apply_all_patches() will have modified it. */
1547                 discard_cache();
1548                 read_cache_from(index_file);
1549         }
1550
1551         return 0;
1552 }
1553
1554 /**
1555  * Builds an index that contains just the blobs needed for a 3way merge.
1556  */
1557 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1558 {
1559         struct child_process cp = CHILD_PROCESS_INIT;
1560
1561         cp.git_cmd = 1;
1562         argv_array_push(&cp.args, "apply");
1563         argv_array_pushv(&cp.args, state->git_apply_opts.argv);
1564         argv_array_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1565         argv_array_push(&cp.args, am_path(state, "patch"));
1566
1567         if (run_command(&cp))
1568                 return -1;
1569
1570         return 0;
1571 }
1572
1573 /**
1574  * Attempt a threeway merge, using index_path as the temporary index.
1575  */
1576 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1577 {
1578         struct object_id orig_tree, their_tree, our_tree;
1579         const struct object_id *bases[1] = { &orig_tree };
1580         struct merge_options o;
1581         struct commit *result;
1582         char *their_tree_name;
1583
1584         if (get_oid("HEAD", &our_tree) < 0)
1585                 hashcpy(our_tree.hash, EMPTY_TREE_SHA1_BIN);
1586
1587         if (build_fake_ancestor(state, index_path))
1588                 return error("could not build fake ancestor");
1589
1590         discard_cache();
1591         read_cache_from(index_path);
1592
1593         if (write_index_as_tree(orig_tree.hash, &the_index, index_path, 0, NULL))
1594                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1595
1596         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1597
1598         if (!state->quiet) {
1599                 /*
1600                  * List paths that needed 3-way fallback, so that the user can
1601                  * review them with extra care to spot mismerges.
1602                  */
1603                 struct rev_info rev_info;
1604                 const char *diff_filter_str = "--diff-filter=AM";
1605
1606                 init_revisions(&rev_info, NULL);
1607                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1608                 diff_opt_parse(&rev_info.diffopt, &diff_filter_str, 1, rev_info.prefix);
1609                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1610                 diff_setup_done(&rev_info.diffopt);
1611                 run_diff_index(&rev_info, 1);
1612         }
1613
1614         if (run_apply(state, index_path))
1615                 return error(_("Did you hand edit your patch?\n"
1616                                 "It does not apply to blobs recorded in its index."));
1617
1618         if (write_index_as_tree(their_tree.hash, &the_index, index_path, 0, NULL))
1619                 return error("could not write tree");
1620
1621         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1622
1623         discard_cache();
1624         read_cache();
1625
1626         /*
1627          * This is not so wrong. Depending on which base we picked, orig_tree
1628          * may be wildly different from ours, but their_tree has the same set of
1629          * wildly different changes in parts the patch did not touch, so
1630          * recursive ends up canceling them, saying that we reverted all those
1631          * changes.
1632          */
1633
1634         init_merge_options(&o);
1635
1636         o.branch1 = "HEAD";
1637         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1638         o.branch2 = their_tree_name;
1639
1640         if (state->quiet)
1641                 o.verbosity = 0;
1642
1643         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1644                 rerere(state->allow_rerere_autoupdate);
1645                 free(their_tree_name);
1646                 return error(_("Failed to merge in the changes."));
1647         }
1648
1649         free(their_tree_name);
1650         return 0;
1651 }
1652
1653 /**
1654  * Commits the current index with state->msg as the commit message and
1655  * state->author_name, state->author_email and state->author_date as the author
1656  * information.
1657  */
1658 static void do_commit(const struct am_state *state)
1659 {
1660         struct object_id tree, parent, commit;
1661         const struct object_id *old_oid;
1662         struct commit_list *parents = NULL;
1663         const char *reflog_msg, *author;
1664         struct strbuf sb = STRBUF_INIT;
1665
1666         if (run_hook_le(NULL, "pre-applypatch", NULL))
1667                 exit(1);
1668
1669         if (write_cache_as_tree(tree.hash, 0, NULL))
1670                 die(_("git write-tree failed to write a tree"));
1671
1672         if (!get_sha1_commit("HEAD", parent.hash)) {
1673                 old_oid = &parent;
1674                 commit_list_insert(lookup_commit(&parent), &parents);
1675         } else {
1676                 old_oid = NULL;
1677                 say(state, stderr, _("applying to an empty history"));
1678         }
1679
1680         author = fmt_ident(state->author_name, state->author_email,
1681                         state->ignore_date ? NULL : state->author_date,
1682                         IDENT_STRICT);
1683
1684         if (state->committer_date_is_author_date)
1685                 setenv("GIT_COMMITTER_DATE",
1686                         state->ignore_date ? "" : state->author_date, 1);
1687
1688         if (commit_tree(state->msg, state->msg_len, tree.hash, parents, commit.hash,
1689                                 author, state->sign_commit))
1690                 die(_("failed to write commit object"));
1691
1692         reflog_msg = getenv("GIT_REFLOG_ACTION");
1693         if (!reflog_msg)
1694                 reflog_msg = "am";
1695
1696         strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1697                         state->msg);
1698
1699         update_ref_oid(sb.buf, "HEAD", &commit, old_oid, 0,
1700                         UPDATE_REFS_DIE_ON_ERR);
1701
1702         if (state->rebasing) {
1703                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1704
1705                 assert(!is_null_oid(&state->orig_commit));
1706                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1707                 fprintf(fp, "%s\n", oid_to_hex(&commit));
1708                 fclose(fp);
1709         }
1710
1711         run_hook_le(NULL, "post-applypatch", NULL);
1712
1713         strbuf_release(&sb);
1714 }
1715
1716 /**
1717  * Validates the am_state for resuming -- the "msg" and authorship fields must
1718  * be filled up.
1719  */
1720 static void validate_resume_state(const struct am_state *state)
1721 {
1722         if (!state->msg)
1723                 die(_("cannot resume: %s does not exist."),
1724                         am_path(state, "final-commit"));
1725
1726         if (!state->author_name || !state->author_email || !state->author_date)
1727                 die(_("cannot resume: %s does not exist."),
1728                         am_path(state, "author-script"));
1729 }
1730
1731 /**
1732  * Interactively prompt the user on whether the current patch should be
1733  * applied.
1734  *
1735  * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1736  * skip it.
1737  */
1738 static int do_interactive(struct am_state *state)
1739 {
1740         assert(state->msg);
1741
1742         if (!isatty(0))
1743                 die(_("cannot be interactive without stdin connected to a terminal."));
1744
1745         for (;;) {
1746                 const char *reply;
1747
1748                 puts(_("Commit Body is:"));
1749                 puts("--------------------------");
1750                 printf("%s", state->msg);
1751                 puts("--------------------------");
1752
1753                 /*
1754                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1755                  * in your translation. The program will only accept English
1756                  * input at this point.
1757                  */
1758                 reply = git_prompt(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "), PROMPT_ECHO);
1759
1760                 if (!reply) {
1761                         continue;
1762                 } else if (*reply == 'y' || *reply == 'Y') {
1763                         return 0;
1764                 } else if (*reply == 'a' || *reply == 'A') {
1765                         state->interactive = 0;
1766                         return 0;
1767                 } else if (*reply == 'n' || *reply == 'N') {
1768                         return 1;
1769                 } else if (*reply == 'e' || *reply == 'E') {
1770                         struct strbuf msg = STRBUF_INIT;
1771
1772                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1773                                 free(state->msg);
1774                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1775                         }
1776                         strbuf_release(&msg);
1777                 } else if (*reply == 'v' || *reply == 'V') {
1778                         const char *pager = git_pager(1);
1779                         struct child_process cp = CHILD_PROCESS_INIT;
1780
1781                         if (!pager)
1782                                 pager = "cat";
1783                         prepare_pager_args(&cp, pager);
1784                         argv_array_push(&cp.args, am_path(state, "patch"));
1785                         run_command(&cp);
1786                 }
1787         }
1788 }
1789
1790 /**
1791  * Applies all queued mail.
1792  *
1793  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1794  * well as the state directory's "patch" file is used as-is for applying the
1795  * patch and committing it.
1796  */
1797 static void am_run(struct am_state *state, int resume)
1798 {
1799         const char *argv_gc_auto[] = {"gc", "--auto", NULL};
1800         struct strbuf sb = STRBUF_INIT;
1801
1802         unlink(am_path(state, "dirtyindex"));
1803
1804         refresh_and_write_cache();
1805
1806         if (index_has_changes(&sb)) {
1807                 write_state_bool(state, "dirtyindex", 1);
1808                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1809         }
1810
1811         strbuf_release(&sb);
1812
1813         while (state->cur <= state->last) {
1814                 const char *mail = am_path(state, msgnum(state));
1815                 int apply_status;
1816
1817                 reset_ident_date();
1818
1819                 if (!file_exists(mail))
1820                         goto next;
1821
1822                 if (resume) {
1823                         validate_resume_state(state);
1824                 } else {
1825                         int skip;
1826
1827                         if (state->rebasing)
1828                                 skip = parse_mail_rebase(state, mail);
1829                         else
1830                                 skip = parse_mail(state, mail);
1831
1832                         if (skip)
1833                                 goto next; /* mail should be skipped */
1834
1835                         if (state->signoff)
1836                                 am_append_signoff(state);
1837
1838                         write_author_script(state);
1839                         write_commit_msg(state);
1840                 }
1841
1842                 if (state->interactive && do_interactive(state))
1843                         goto next;
1844
1845                 if (run_applypatch_msg_hook(state))
1846                         exit(1);
1847
1848                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1849
1850                 apply_status = run_apply(state, NULL);
1851
1852                 if (apply_status && state->threeway) {
1853                         struct strbuf sb = STRBUF_INIT;
1854
1855                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1856                         apply_status = fall_back_threeway(state, sb.buf);
1857                         strbuf_release(&sb);
1858
1859                         /*
1860                          * Applying the patch to an earlier tree and merging
1861                          * the result may have produced the same tree as ours.
1862                          */
1863                         if (!apply_status && !index_has_changes(NULL)) {
1864                                 say(state, stdout, _("No changes -- Patch already applied."));
1865                                 goto next;
1866                         }
1867                 }
1868
1869                 if (apply_status) {
1870                         int advice_amworkdir = 1;
1871
1872                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1873                                 linelen(state->msg), state->msg);
1874
1875                         git_config_get_bool("advice.amworkdir", &advice_amworkdir);
1876
1877                         if (advice_amworkdir)
1878                                 printf_ln(_("The copy of the patch that failed is found in: %s"),
1879                                                 am_path(state, "patch"));
1880
1881                         die_user_resolve(state);
1882                 }
1883
1884                 do_commit(state);
1885
1886 next:
1887                 am_next(state);
1888
1889                 if (resume)
1890                         am_load(state);
1891                 resume = 0;
1892         }
1893
1894         if (!is_empty_file(am_path(state, "rewritten"))) {
1895                 assert(state->rebasing);
1896                 copy_notes_for_rebase(state);
1897                 run_post_rewrite_hook(state);
1898         }
1899
1900         /*
1901          * In rebasing mode, it's up to the caller to take care of
1902          * housekeeping.
1903          */
1904         if (!state->rebasing) {
1905                 am_destroy(state);
1906                 close_all_packs();
1907                 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1908         }
1909 }
1910
1911 /**
1912  * Resume the current am session after patch application failure. The user did
1913  * all the hard work, and we do not have to do any patch application. Just
1914  * trust and commit what the user has in the index and working tree.
1915  */
1916 static void am_resolve(struct am_state *state)
1917 {
1918         validate_resume_state(state);
1919
1920         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1921
1922         if (!index_has_changes(NULL)) {
1923                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1924                         "If there is nothing left to stage, chances are that something else\n"
1925                         "already introduced the same changes; you might want to skip this patch."));
1926                 die_user_resolve(state);
1927         }
1928
1929         if (unmerged_cache()) {
1930                 printf_ln(_("You still have unmerged paths in your index.\n"
1931                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1932                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1933                 die_user_resolve(state);
1934         }
1935
1936         if (state->interactive) {
1937                 write_index_patch(state);
1938                 if (do_interactive(state))
1939                         goto next;
1940         }
1941
1942         rerere(0);
1943
1944         do_commit(state);
1945
1946 next:
1947         am_next(state);
1948         am_load(state);
1949         am_run(state, 0);
1950 }
1951
1952 /**
1953  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1954  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1955  * failure.
1956  */
1957 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1958 {
1959         struct lock_file *lock_file;
1960         struct unpack_trees_options opts;
1961         struct tree_desc t[2];
1962
1963         if (parse_tree(head) || parse_tree(remote))
1964                 return -1;
1965
1966         lock_file = xcalloc(1, sizeof(struct lock_file));
1967         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
1968
1969         refresh_cache(REFRESH_QUIET);
1970
1971         memset(&opts, 0, sizeof(opts));
1972         opts.head_idx = 1;
1973         opts.src_index = &the_index;
1974         opts.dst_index = &the_index;
1975         opts.update = 1;
1976         opts.merge = 1;
1977         opts.reset = reset;
1978         opts.fn = twoway_merge;
1979         init_tree_desc(&t[0], head->buffer, head->size);
1980         init_tree_desc(&t[1], remote->buffer, remote->size);
1981
1982         if (unpack_trees(2, t, &opts)) {
1983                 rollback_lock_file(lock_file);
1984                 return -1;
1985         }
1986
1987         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
1988                 die(_("unable to write new index file"));
1989
1990         return 0;
1991 }
1992
1993 /**
1994  * Merges a tree into the index. The index's stat info will take precedence
1995  * over the merged tree's. Returns 0 on success, -1 on failure.
1996  */
1997 static int merge_tree(struct tree *tree)
1998 {
1999         struct lock_file *lock_file;
2000         struct unpack_trees_options opts;
2001         struct tree_desc t[1];
2002
2003         if (parse_tree(tree))
2004                 return -1;
2005
2006         lock_file = xcalloc(1, sizeof(struct lock_file));
2007         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
2008
2009         memset(&opts, 0, sizeof(opts));
2010         opts.head_idx = 1;
2011         opts.src_index = &the_index;
2012         opts.dst_index = &the_index;
2013         opts.merge = 1;
2014         opts.fn = oneway_merge;
2015         init_tree_desc(&t[0], tree->buffer, tree->size);
2016
2017         if (unpack_trees(1, t, &opts)) {
2018                 rollback_lock_file(lock_file);
2019                 return -1;
2020         }
2021
2022         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
2023                 die(_("unable to write new index file"));
2024
2025         return 0;
2026 }
2027
2028 /**
2029  * Clean the index without touching entries that are not modified between
2030  * `head` and `remote`.
2031  */
2032 static int clean_index(const struct object_id *head, const struct object_id *remote)
2033 {
2034         struct tree *head_tree, *remote_tree, *index_tree;
2035         struct object_id index;
2036
2037         head_tree = parse_tree_indirect(head);
2038         if (!head_tree)
2039                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
2040
2041         remote_tree = parse_tree_indirect(remote);
2042         if (!remote_tree)
2043                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
2044
2045         read_cache_unmerged();
2046
2047         if (fast_forward_to(head_tree, head_tree, 1))
2048                 return -1;
2049
2050         if (write_cache_as_tree(index.hash, 0, NULL))
2051                 return -1;
2052
2053         index_tree = parse_tree_indirect(&index);
2054         if (!index_tree)
2055                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
2056
2057         if (fast_forward_to(index_tree, remote_tree, 0))
2058                 return -1;
2059
2060         if (merge_tree(remote_tree))
2061                 return -1;
2062
2063         remove_branch_state();
2064
2065         return 0;
2066 }
2067
2068 /**
2069  * Resets rerere's merge resolution metadata.
2070  */
2071 static void am_rerere_clear(void)
2072 {
2073         struct string_list merge_rr = STRING_LIST_INIT_DUP;
2074         rerere_clear(&merge_rr);
2075         string_list_clear(&merge_rr, 1);
2076 }
2077
2078 /**
2079  * Resume the current am session by skipping the current patch.
2080  */
2081 static void am_skip(struct am_state *state)
2082 {
2083         struct object_id head;
2084
2085         am_rerere_clear();
2086
2087         if (get_oid("HEAD", &head))
2088                 hashcpy(head.hash, EMPTY_TREE_SHA1_BIN);
2089
2090         if (clean_index(&head, &head))
2091                 die(_("failed to clean index"));
2092
2093         am_next(state);
2094         am_load(state);
2095         am_run(state, 0);
2096 }
2097
2098 /**
2099  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2100  *
2101  * It is not safe to reset HEAD when:
2102  * 1. git-am previously failed because the index was dirty.
2103  * 2. HEAD has moved since git-am previously failed.
2104  */
2105 static int safe_to_abort(const struct am_state *state)
2106 {
2107         struct strbuf sb = STRBUF_INIT;
2108         struct object_id abort_safety, head;
2109
2110         if (file_exists(am_path(state, "dirtyindex")))
2111                 return 0;
2112
2113         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2114                 if (get_oid_hex(sb.buf, &abort_safety))
2115                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2116         } else
2117                 oidclr(&abort_safety);
2118
2119         if (get_oid("HEAD", &head))
2120                 oidclr(&head);
2121
2122         if (!oidcmp(&head, &abort_safety))
2123                 return 1;
2124
2125         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2126                 "Not rewinding to ORIG_HEAD"));
2127
2128         return 0;
2129 }
2130
2131 /**
2132  * Aborts the current am session if it is safe to do so.
2133  */
2134 static void am_abort(struct am_state *state)
2135 {
2136         struct object_id curr_head, orig_head;
2137         int has_curr_head, has_orig_head;
2138         char *curr_branch;
2139
2140         if (!safe_to_abort(state)) {
2141                 am_destroy(state);
2142                 return;
2143         }
2144
2145         am_rerere_clear();
2146
2147         curr_branch = resolve_refdup("HEAD", 0, curr_head.hash, NULL);
2148         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2149         if (!has_curr_head)
2150                 hashcpy(curr_head.hash, EMPTY_TREE_SHA1_BIN);
2151
2152         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2153         if (!has_orig_head)
2154                 hashcpy(orig_head.hash, EMPTY_TREE_SHA1_BIN);
2155
2156         clean_index(&curr_head, &orig_head);
2157
2158         if (has_orig_head)
2159                 update_ref_oid("am --abort", "HEAD", &orig_head,
2160                                 has_curr_head ? &curr_head : NULL, 0,
2161                                 UPDATE_REFS_DIE_ON_ERR);
2162         else if (curr_branch)
2163                 delete_ref(NULL, curr_branch, NULL, REF_NODEREF);
2164
2165         free(curr_branch);
2166         am_destroy(state);
2167 }
2168
2169 /**
2170  * parse_options() callback that validates and sets opt->value to the
2171  * PATCH_FORMAT_* enum value corresponding to `arg`.
2172  */
2173 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2174 {
2175         int *opt_value = opt->value;
2176
2177         if (!strcmp(arg, "mbox"))
2178                 *opt_value = PATCH_FORMAT_MBOX;
2179         else if (!strcmp(arg, "stgit"))
2180                 *opt_value = PATCH_FORMAT_STGIT;
2181         else if (!strcmp(arg, "stgit-series"))
2182                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2183         else if (!strcmp(arg, "hg"))
2184                 *opt_value = PATCH_FORMAT_HG;
2185         else if (!strcmp(arg, "mboxrd"))
2186                 *opt_value = PATCH_FORMAT_MBOXRD;
2187         else
2188                 return error(_("Invalid value for --patch-format: %s"), arg);
2189         return 0;
2190 }
2191
2192 enum resume_mode {
2193         RESUME_FALSE = 0,
2194         RESUME_APPLY,
2195         RESUME_RESOLVED,
2196         RESUME_SKIP,
2197         RESUME_ABORT
2198 };
2199
2200 static int git_am_config(const char *k, const char *v, void *cb)
2201 {
2202         int status;
2203
2204         status = git_gpg_config(k, v, NULL);
2205         if (status)
2206                 return status;
2207
2208         return git_default_config(k, v, NULL);
2209 }
2210
2211 int cmd_am(int argc, const char **argv, const char *prefix)
2212 {
2213         struct am_state state;
2214         int binary = -1;
2215         int keep_cr = -1;
2216         int patch_format = PATCH_FORMAT_UNKNOWN;
2217         enum resume_mode resume = RESUME_FALSE;
2218         int in_progress;
2219
2220         const char * const usage[] = {
2221                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2222                 N_("git am [<options>] (--continue | --skip | --abort)"),
2223                 NULL
2224         };
2225
2226         struct option options[] = {
2227                 OPT_BOOL('i', "interactive", &state.interactive,
2228                         N_("run interactively")),
2229                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2230                         N_("historical option -- no-op")),
2231                 OPT_BOOL('3', "3way", &state.threeway,
2232                         N_("allow fall back on 3way merging if needed")),
2233                 OPT__QUIET(&state.quiet, N_("be quiet")),
2234                 OPT_SET_INT('s', "signoff", &state.signoff,
2235                         N_("add a Signed-off-by line to the commit message"),
2236                         SIGNOFF_EXPLICIT),
2237                 OPT_BOOL('u', "utf8", &state.utf8,
2238                         N_("recode into utf8 (default)")),
2239                 OPT_SET_INT('k', "keep", &state.keep,
2240                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2241                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2242                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2243                 OPT_BOOL('m', "message-id", &state.message_id,
2244                         N_("pass -m flag to git-mailinfo")),
2245                 { OPTION_SET_INT, 0, "keep-cr", &keep_cr, NULL,
2246                   N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2247                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1},
2248                 { OPTION_SET_INT, 0, "no-keep-cr", &keep_cr, NULL,
2249                   N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2250                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 0},
2251                 OPT_BOOL('c', "scissors", &state.scissors,
2252                         N_("strip everything before a scissors line")),
2253                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2254                         N_("pass it through git-apply"),
2255                         0),
2256                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2257                         N_("pass it through git-apply"),
2258                         PARSE_OPT_NOARG),
2259                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2260                         N_("pass it through git-apply"),
2261                         PARSE_OPT_NOARG),
2262                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2263                         N_("pass it through git-apply"),
2264                         0),
2265                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2266                         N_("pass it through git-apply"),
2267                         0),
2268                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2269                         N_("pass it through git-apply"),
2270                         0),
2271                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2272                         N_("pass it through git-apply"),
2273                         0),
2274                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2275                         N_("pass it through git-apply"),
2276                         0),
2277                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2278                         N_("format the patch(es) are in"),
2279                         parse_opt_patchformat),
2280                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2281                         N_("pass it through git-apply"),
2282                         PARSE_OPT_NOARG),
2283                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2284                         N_("override error message when patch failure occurs")),
2285                 OPT_CMDMODE(0, "continue", &resume,
2286                         N_("continue applying patches after resolving a conflict"),
2287                         RESUME_RESOLVED),
2288                 OPT_CMDMODE('r', "resolved", &resume,
2289                         N_("synonyms for --continue"),
2290                         RESUME_RESOLVED),
2291                 OPT_CMDMODE(0, "skip", &resume,
2292                         N_("skip the current patch"),
2293                         RESUME_SKIP),
2294                 OPT_CMDMODE(0, "abort", &resume,
2295                         N_("restore the original branch and abort the patching operation."),
2296                         RESUME_ABORT),
2297                 OPT_BOOL(0, "committer-date-is-author-date",
2298                         &state.committer_date_is_author_date,
2299                         N_("lie about committer date")),
2300                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2301                         N_("use current timestamp for author date")),
2302                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2303                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2304                   N_("GPG-sign commits"),
2305                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2306                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2307                         N_("(internal use for git-rebase)")),
2308                 OPT_END()
2309         };
2310
2311         if (argc == 2 && !strcmp(argv[1], "-h"))
2312                 usage_with_options(usage, options);
2313
2314         git_config(git_am_config, NULL);
2315
2316         am_state_init(&state);
2317
2318         in_progress = am_in_progress(&state);
2319         if (in_progress)
2320                 am_load(&state);
2321
2322         argc = parse_options(argc, argv, prefix, options, usage, 0);
2323
2324         if (binary >= 0)
2325                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2326                                 "it will be removed. Please do not use it anymore."));
2327
2328         /* Ensure a valid committer ident can be constructed */
2329         git_committer_info(IDENT_STRICT);
2330
2331         if (read_index_preload(&the_index, NULL) < 0)
2332                 die(_("failed to read the index"));
2333
2334         if (in_progress) {
2335                 /*
2336                  * Catch user error to feed us patches when there is a session
2337                  * in progress:
2338                  *
2339                  * 1. mbox path(s) are provided on the command-line.
2340                  * 2. stdin is not a tty: the user is trying to feed us a patch
2341                  *    from standard input. This is somewhat unreliable -- stdin
2342                  *    could be /dev/null for example and the caller did not
2343                  *    intend to feed us a patch but wanted to continue
2344                  *    unattended.
2345                  */
2346                 if (argc || (resume == RESUME_FALSE && !isatty(0)))
2347                         die(_("previous rebase directory %s still exists but mbox given."),
2348                                 state.dir);
2349
2350                 if (resume == RESUME_FALSE)
2351                         resume = RESUME_APPLY;
2352
2353                 if (state.signoff == SIGNOFF_EXPLICIT)
2354                         am_append_signoff(&state);
2355         } else {
2356                 struct argv_array paths = ARGV_ARRAY_INIT;
2357                 int i;
2358
2359                 /*
2360                  * Handle stray state directory in the independent-run case. In
2361                  * the --rebasing case, it is up to the caller to take care of
2362                  * stray directories.
2363                  */
2364                 if (file_exists(state.dir) && !state.rebasing) {
2365                         if (resume == RESUME_ABORT) {
2366                                 am_destroy(&state);
2367                                 am_state_release(&state);
2368                                 return 0;
2369                         }
2370
2371                         die(_("Stray %s directory found.\n"
2372                                 "Use \"git am --abort\" to remove it."),
2373                                 state.dir);
2374                 }
2375
2376                 if (resume)
2377                         die(_("Resolve operation not in progress, we are not resuming."));
2378
2379                 for (i = 0; i < argc; i++) {
2380                         if (is_absolute_path(argv[i]) || !prefix)
2381                                 argv_array_push(&paths, argv[i]);
2382                         else
2383                                 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2384                 }
2385
2386                 am_setup(&state, patch_format, paths.argv, keep_cr);
2387
2388                 argv_array_clear(&paths);
2389         }
2390
2391         switch (resume) {
2392         case RESUME_FALSE:
2393                 am_run(&state, 0);
2394                 break;
2395         case RESUME_APPLY:
2396                 am_run(&state, 1);
2397                 break;
2398         case RESUME_RESOLVED:
2399                 am_resolve(&state);
2400                 break;
2401         case RESUME_SKIP:
2402                 am_skip(&state);
2403                 break;
2404         case RESUME_ABORT:
2405                 am_abort(&state);
2406                 break;
2407         default:
2408                 die("BUG: invalid resume value");
2409         }
2410
2411         am_state_release(&state);
2412
2413         return 0;
2414 }