git.oblomov.eu Git - git/blob - sequencer.c

   1 #include "cache.h"
   2 #include "sequencer.h"
   3 #include "dir.h"
   4 #include "object.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "run-command.h"
   8 #include "exec_cmd.h"
   9 #include "utf8.h"
  10 #include "cache-tree.h"
  11 #include "diff.h"
  12 #include "revision.h"
  13 #include "rerere.h"
  14 #include "merge-recursive.h"
  15 #include "refs.h"
  16 #include "argv-array.h"
  17 #include "rewrite.h"
  18
  19 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  20
  21 const char sign_off_header[] = "Signed-off-by: ";
  22 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  23 static struct rewritten rewritten;
  24
  25 static void finish(struct replay_opts *opts)
  26 {
  27         const char *name;
  28         struct strbuf msg = STRBUF_INIT;
  29
  30         if (opts->action != REPLAY_PICK)
  31                 return;
  32
  33         name = opts->action_name ? opts->action_name : "cherry-pick";
  34
  35         if (!*name)
  36                 return;
  37
  38         strbuf_addf(&msg, "Notes added by 'git %s'", name);
  39         copy_rewrite_notes(&rewritten, name, msg.buf);
  40         run_rewrite_hook(&rewritten, name);
  41         strbuf_release(&msg);
  42 }
  43
  44 static int is_rfc2822_line(const char *buf, int len)
  45 {
  46         int i;
  47
  48         for (i = 0; i < len; i++) {
  49                 int ch = buf[i];
  50                 if (ch == ':')
  51                         return 1;
  52                 if (!isalnum(ch) && ch != '-')
  53                         break;
  54         }
  55
  56         return 0;
  57 }
  58
  59 static int is_cherry_picked_from_line(const char *buf, int len)
  60 {
  61         /*
  62          * We only care that it looks roughly like (cherry picked from ...)
  63          */
  64         return len > strlen(cherry_picked_prefix) + 1 &&
  65                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  66 }
  67
  68 /*
  69  * Returns 0 for non-conforming footer
  70  * Returns 1 for conforming footer
  71  * Returns 2 when sob exists within conforming footer
  72  * Returns 3 when sob exists within conforming footer as last entry
  73  */
  74 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  75         int ignore_footer)
  76 {
  77         char prev;
  78         int i, k;
  79         int len = sb->len - ignore_footer;
  80         const char *buf = sb->buf;
  81         int found_sob = 0;
  82
  83         /* footer must end with newline */
  84         if (!len || buf[len - 1] != '\n')
  85                 return 0;
  86
  87         prev = '\0';
  88         for (i = len - 1; i > 0; i--) {
  89                 char ch = buf[i];
  90                 if (prev == '\n' && ch == '\n') /* paragraph break */
  91                         break;
  92                 prev = ch;
  93         }
  94
  95         /* require at least one blank line */
  96         if (prev != '\n' || buf[i] != '\n')
  97                 return 0;
  98
  99         /* advance to start of last paragraph */
 100         while (i < len - 1 && buf[i] == '\n')
 101                 i++;
 102
 103         for (; i < len; i = k) {
 104                 int found_rfc2822;
 105
 106                 for (k = i; k < len && buf[k] != '\n'; k++)
 107                         ; /* do nothing */
 108                 k++;
 109
 110                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
 111                 if (found_rfc2822 && sob &&
 112                     !strncmp(buf + i, sob->buf, sob->len))
 113                         found_sob = k;
 114
 115                 if (!(found_rfc2822 ||
 116                       is_cherry_picked_from_line(buf + i, k - i - 1)))
 117                         return 0;
 118         }
 119         if (found_sob == i)
 120                 return 3;
 121         if (found_sob)
 122                 return 2;
 123         return 1;
 124 }
 125
 126 static void remove_sequencer_state(void)
 127 {
 128         struct strbuf seq_dir = STRBUF_INIT;
 129
 130         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 131         remove_dir_recursively(&seq_dir, 0);
 132         strbuf_release(&seq_dir);
 133 }
 134
 135 static const char *action_name(const struct replay_opts *opts)
 136 {
 137         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 138 }
 139
 140 static char *get_encoding(const char *message);
 141
 142 struct commit_message {
 143         char *parent_label;
 144         const char *label;
 145         const char *subject;
 146         char *reencoded_message;
 147         const char *message;
 148 };
 149
 150 static int get_message(struct commit *commit, struct commit_message *out)
 151 {
 152         const char *encoding;
 153         const char *abbrev, *subject;
 154         int abbrev_len, subject_len;
 155         char *q;
 156
 157         if (!commit->buffer)
 158                 return -1;
 159         encoding = get_encoding(commit->buffer);
 160         if (!encoding)
 161                 encoding = "UTF-8";
 162         if (!git_commit_encoding)
 163                 git_commit_encoding = "UTF-8";
 164
 165         out->reencoded_message = NULL;
 166         out->message = commit->buffer;
 167         if (same_encoding(encoding, git_commit_encoding))
 168                 out->reencoded_message = reencode_string(commit->buffer,
 169                                         git_commit_encoding, encoding);
 170         if (out->reencoded_message)
 171                 out->message = out->reencoded_message;
 172
 173         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 174         abbrev_len = strlen(abbrev);
 175
 176         subject_len = find_commit_subject(out->message, &subject);
 177
 178         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 179                               strlen("... ") + subject_len + 1);
 180         q = out->parent_label;
 181         q = mempcpy(q, "parent of ", strlen("parent of "));
 182         out->label = q;
 183         q = mempcpy(q, abbrev, abbrev_len);
 184         q = mempcpy(q, "... ", strlen("... "));
 185         out->subject = q;
 186         q = mempcpy(q, subject, subject_len);
 187         *q = '\0';
 188         return 0;
 189 }
 190
 191 static void free_message(struct commit_message *msg)
 192 {
 193         free(msg->parent_label);
 194         free(msg->reencoded_message);
 195 }
 196
 197 static char *get_encoding(const char *message)
 198 {
 199         const char *p = message, *eol;
 200
 201         while (*p && *p != '\n') {
 202                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
 203                         ; /* do nothing */
 204                 if (starts_with(p, "encoding ")) {
 205                         char *result = xmalloc(eol - 8 - p);
 206                         strlcpy(result, p + 9, eol - 8 - p);
 207                         return result;
 208                 }
 209                 p = eol;
 210                 if (*p == '\n')
 211                         p++;
 212         }
 213         return NULL;
 214 }
 215
 216 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 217 {
 218         const char *filename;
 219         int fd;
 220         struct strbuf buf = STRBUF_INIT;
 221
 222         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 223
 224         filename = git_path("%s", pseudoref);
 225         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 226         if (fd < 0)
 227                 die_errno(_("Could not open '%s' for writing"), filename);
 228         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 229                 die_errno(_("Could not write to '%s'"), filename);
 230         strbuf_release(&buf);
 231 }
 232
 233 static void print_advice(int show_hint, struct replay_opts *opts)
 234 {
 235         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 236
 237         if (msg) {
 238                 fprintf(stderr, "%s\n", msg);
 239                 /*
 240                  * A conflict has occurred but the porcelain
 241                  * (typically rebase --interactive) wants to take care
 242                  * of the commit itself so remove CHERRY_PICK_HEAD
 243                  */
 244                 unlink(git_path("CHERRY_PICK_HEAD"));
 245                 return;
 246         }
 247
 248         if (show_hint) {
 249                 if (opts->no_commit)
 250                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 251                                  "with 'git add <paths>' or 'git rm <paths>'"));
 252                 else
 253                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 254                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 255                                  "and commit the result with 'git commit'"));
 256         }
 257 }
 258
 259 static void write_message(struct strbuf *msgbuf, const char *filename)
 260 {
 261         static struct lock_file msg_file;
 262
 263         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 264                                                LOCK_DIE_ON_ERROR);
 265         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 266                 die_errno(_("Could not write to %s"), filename);
 267         strbuf_release(msgbuf);
 268         if (commit_lock_file(&msg_file) < 0)
 269                 die(_("Error wrapping up %s"), filename);
 270 }
 271
 272 static struct tree *empty_tree(void)
 273 {
 274         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 275 }
 276
 277 static int error_dirty_index(struct replay_opts *opts)
 278 {
 279         if (read_cache_unmerged())
 280                 return error_resolve_conflict(action_name(opts));
 281
 282         /* Different translation strings for cherry-pick and revert */
 283         if (opts->action == REPLAY_PICK)
 284                 error(_("Your local changes would be overwritten by cherry-pick."));
 285         else
 286                 error(_("Your local changes would be overwritten by revert."));
 287
 288         if (advice_commit_before_merge)
 289                 advise(_("Commit your changes or stash them to proceed."));
 290         return -1;
 291 }
 292
 293 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 294                         int unborn, struct replay_opts *opts)
 295 {
 296         struct ref_lock *ref_lock;
 297         struct strbuf sb = STRBUF_INIT;
 298         int ret;
 299
 300         read_cache();
 301         if (checkout_fast_forward(from, to, 1))
 302                 exit(1); /* the callee should have complained already */
 303         ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from,
 304                                            0, NULL);
 305         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 306         ret = write_ref_sha1(ref_lock, to, sb.buf);
 307         strbuf_release(&sb);
 308         return ret;
 309 }
 310
 311 static int do_recursive_merge(struct commit *base, struct commit *next,
 312                               const char *base_label, const char *next_label,
 313                               unsigned char *head, struct strbuf *msgbuf,
 314                               struct replay_opts *opts)
 315 {
 316         struct merge_options o;
 317         struct tree *result, *next_tree, *base_tree, *head_tree;
 318         int clean, index_fd;
 319         const char **xopt;
 320         static struct lock_file index_lock;
 321
 322         index_fd = hold_locked_index(&index_lock, 1);
 323
 324         read_cache();
 325
 326         init_merge_options(&o);
 327         o.ancestor = base ? base_label : "(empty tree)";
 328         o.branch1 = "HEAD";
 329         o.branch2 = next ? next_label : "(empty tree)";
 330
 331         head_tree = parse_tree_indirect(head);
 332         next_tree = next ? next->tree : empty_tree();
 333         base_tree = base ? base->tree : empty_tree();
 334
 335         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 336                 parse_merge_opt(&o, *xopt);
 337
 338         clean = merge_trees(&o,
 339                             head_tree,
 340                             next_tree, base_tree, &result);
 341
 342         if (active_cache_changed &&
 343             (write_cache(index_fd, active_cache, active_nr) ||
 344              commit_locked_index(&index_lock)))
 345                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 346                 die(_("%s: Unable to write new index file"), action_name(opts));
 347         rollback_lock_file(&index_lock);
 348
 349         if (opts->signoff)
 350                 append_signoff(msgbuf, 0, 0);
 351
 352         if (!clean) {
 353                 int i;
 354                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 355                 for (i = 0; i < active_nr;) {
 356                         const struct cache_entry *ce = active_cache[i++];
 357                         if (ce_stage(ce)) {
 358                                 strbuf_addch(msgbuf, '\t');
 359                                 strbuf_addstr(msgbuf, ce->name);
 360                                 strbuf_addch(msgbuf, '\n');
 361                                 while (i < active_nr && !strcmp(ce->name,
 362                                                 active_cache[i]->name))
 363                                         i++;
 364                         }
 365                 }
 366         }
 367
 368         return !clean;
 369 }
 370
 371 static int is_index_unchanged(void)
 372 {
 373         unsigned char head_sha1[20];
 374         struct commit *head_commit;
 375
 376         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 377                 return error(_("Could not resolve HEAD commit\n"));
 378
 379         head_commit = lookup_commit(head_sha1);
 380
 381         /*
 382          * If head_commit is NULL, check_commit, called from
 383          * lookup_commit, would have indicated that head_commit is not
 384          * a commit object already.  parse_commit() will return failure
 385          * without further complaints in such a case.  Otherwise, if
 386          * the commit is invalid, parse_commit() will complain.  So
 387          * there is nothing for us to say here.  Just return failure.
 388          */
 389         if (parse_commit(head_commit))
 390                 return -1;
 391
 392         if (!active_cache_tree)
 393                 active_cache_tree = cache_tree();
 394
 395         if (!cache_tree_fully_valid(active_cache_tree))
 396                 if (cache_tree_update(active_cache_tree,
 397                                       (const struct cache_entry * const *)active_cache,
 398                                       active_nr, 0))
 399                         return error(_("Unable to update cache tree\n"));
 400
 401         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 402 }
 403
 404 /*
 405  * If we are cherry-pick, and if the merge did not result in
 406  * hand-editing, we will hit this commit and inherit the original
 407  * author date and name.
 408  * If we are revert, or if our cherry-pick results in a hand merge,
 409  * we had better say that the current user is responsible for that.
 410  */
 411 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 412                           int allow_empty)
 413 {
 414         struct argv_array array;
 415         int rc;
 416
 417         argv_array_init(&array);
 418         argv_array_push(&array, "commit");
 419         argv_array_push(&array, "-n");
 420         if (opts->quiet)
 421                 argv_array_push(&array, "-q");
 422
 423         if (opts->signoff)
 424                 argv_array_push(&array, "-s");
 425         if (!opts->edit) {
 426                 argv_array_push(&array, "-F");
 427                 argv_array_push(&array, defmsg);
 428         }
 429
 430         if (allow_empty)
 431                 argv_array_push(&array, "--allow-empty");
 432
 433         if (opts->allow_empty_message)
 434                 argv_array_push(&array, "--allow-empty-message");
 435
 436         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 437         argv_array_clear(&array);
 438         return rc;
 439 }
 440
 441 static int is_original_commit_empty(struct commit *commit)
 442 {
 443         const unsigned char *ptree_sha1;
 444
 445         if (parse_commit(commit))
 446                 return error(_("Could not parse commit %s\n"),
 447                              sha1_to_hex(commit->object.sha1));
 448         if (commit->parents) {
 449                 struct commit *parent = commit->parents->item;
 450                 if (parse_commit(parent))
 451                         return error(_("Could not parse parent commit %s\n"),
 452                                 sha1_to_hex(parent->object.sha1));
 453                 ptree_sha1 = parent->tree->object.sha1;
 454         } else {
 455                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 456         }
 457
 458         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 459 }
 460
 461 /*
 462  * Do we run "git commit" with "--allow-empty"?
 463  */
 464 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 465 {
 466         int index_unchanged, empty_commit;
 467
 468         /*
 469          * Three cases:
 470          *
 471          * (1) we do not allow empty at all and error out.
 472          *
 473          * (2) we allow ones that were initially empty, but
 474          * forbid the ones that become empty;
 475          *
 476          * (3) we allow both.
 477          */
 478         if (!opts->allow_empty)
 479                 return 0; /* let "git commit" barf as necessary */
 480
 481         index_unchanged = is_index_unchanged();
 482         if (index_unchanged < 0)
 483                 return index_unchanged;
 484         if (!index_unchanged)
 485                 return 0; /* we do not have to say --allow-empty */
 486
 487         if (opts->keep_redundant_commits)
 488                 return 1;
 489
 490         empty_commit = is_original_commit_empty(commit);
 491         if (empty_commit < 0)
 492                 return empty_commit;
 493         if (!empty_commit)
 494                 return 0;
 495         else
 496                 return 1;
 497 }
 498
 499 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 500 {
 501         unsigned char head[20];
 502         struct commit *base, *next, *parent;
 503         const char *base_label, *next_label;
 504         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 505         char *defmsg = NULL;
 506         struct strbuf msgbuf = STRBUF_INIT;
 507         int res, unborn = 0, allow;
 508
 509         if (opts->no_commit) {
 510                 /*
 511                  * We do not intend to commit immediately.  We just want to
 512                  * merge the differences in, so let's compute the tree
 513                  * that represents the "current" state for merge-recursive
 514                  * to work on.
 515                  */
 516                 if (write_cache_as_tree(head, 0, NULL))
 517                         die (_("Your index file is unmerged."));
 518         } else {
 519                 unborn = get_sha1("HEAD", head);
 520                 if (unborn)
 521                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 522                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 523                         return error_dirty_index(opts);
 524         }
 525         discard_cache();
 526
 527         if (!commit->parents) {
 528                 parent = NULL;
 529         }
 530         else if (commit->parents->next) {
 531                 /* Reverting or cherry-picking a merge commit */
 532                 int cnt;
 533                 struct commit_list *p;
 534
 535                 if (!opts->mainline)
 536                         return error(_("Commit %s is a merge but no -m option was given."),
 537                                 sha1_to_hex(commit->object.sha1));
 538
 539                 for (cnt = 1, p = commit->parents;
 540                      cnt != opts->mainline && p;
 541                      cnt++)
 542                         p = p->next;
 543                 if (cnt != opts->mainline || !p)
 544                         return error(_("Commit %s does not have parent %d"),
 545                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 546                 parent = p->item;
 547         } else if (0 < opts->mainline)
 548                 return error(_("Mainline was specified but commit %s is not a merge."),
 549                         sha1_to_hex(commit->object.sha1));
 550         else
 551                 parent = commit->parents->item;
 552
 553         if (opts->allow_ff &&
 554             ((parent && !hashcmp(parent->object.sha1, head)) ||
 555              (!parent && unborn)))
 556                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 557
 558         if (parent && parse_commit(parent) < 0)
 559                 /* TRANSLATORS: The first %s will be "revert" or
 560                    "cherry-pick", the second %s a SHA1 */
 561                 return error(_("%s: cannot parse parent commit %s"),
 562                         action_name(opts), sha1_to_hex(parent->object.sha1));
 563
 564         if (get_message(commit, &msg) != 0)
 565                 return error(_("Cannot get commit message for %s"),
 566                         sha1_to_hex(commit->object.sha1));
 567
 568         /*
 569          * "commit" is an existing commit.  We would want to apply
 570          * the difference it introduces since its first parent "prev"
 571          * on top of the current HEAD if we are cherry-pick.  Or the
 572          * reverse of it if we are revert.
 573          */
 574
 575         defmsg = git_pathdup("MERGE_MSG");
 576
 577         if (opts->action == REPLAY_REVERT) {
 578                 base = commit;
 579                 base_label = msg.label;
 580                 next = parent;
 581                 next_label = msg.parent_label;
 582                 strbuf_addstr(&msgbuf, "Revert \"");
 583                 strbuf_addstr(&msgbuf, msg.subject);
 584                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 585                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 586
 587                 if (commit->parents && commit->parents->next) {
 588                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 589                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 590                 }
 591                 strbuf_addstr(&msgbuf, ".\n");
 592         } else {
 593                 const char *p;
 594
 595                 base = parent;
 596                 base_label = msg.parent_label;
 597                 next = commit;
 598                 next_label = msg.label;
 599
 600                 /*
 601                  * Append the commit log message to msgbuf; it starts
 602                  * after the tree, parent, author, committer
 603                  * information followed by "\n\n".
 604                  */
 605                 p = strstr(msg.message, "\n\n");
 606                 if (p) {
 607                         p += 2;
 608                         strbuf_addstr(&msgbuf, p);
 609                 }
 610
 611                 if (opts->record_origin) {
 612                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 613                                 strbuf_addch(&msgbuf, '\n');
 614                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 615                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 616                         strbuf_addstr(&msgbuf, ")\n");
 617                 }
 618         }
 619
 620         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 621                 res = do_recursive_merge(base, next, base_label, next_label,
 622                                          head, &msgbuf, opts);
 623                 write_message(&msgbuf, defmsg);
 624         } else {
 625                 struct commit_list *common = NULL;
 626                 struct commit_list *remotes = NULL;
 627
 628                 write_message(&msgbuf, defmsg);
 629
 630                 commit_list_insert(base, &common);
 631                 commit_list_insert(next, &remotes);
 632                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 633                                         common, sha1_to_hex(head), remotes);
 634                 free_commit_list(common);
 635                 free_commit_list(remotes);
 636         }
 637
 638         /*
 639          * If the merge was clean or if it failed due to conflict, we write
 640          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 641          * However, if the merge did not even start, then we don't want to
 642          * write it at all.
 643          */
 644         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 645                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 646         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 647                 write_cherry_pick_head(commit, "REVERT_HEAD");
 648
 649         if (res) {
 650                 error(opts->action == REPLAY_REVERT
 651                       ? _("could not revert %s... %s")
 652                       : _("could not apply %s... %s"),
 653                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 654                       msg.subject);
 655                 print_advice(res == 1, opts);
 656                 rerere(opts->allow_rerere_auto);
 657                 goto leave;
 658         }
 659
 660         if (opts->skip_empty && is_index_unchanged() == 1) {
 661                 if (!opts->quiet)
 662                         warning(_("skipping %s... %s"),
 663                                 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 664                                 msg.subject);
 665                 goto leave;
 666         }
 667         allow = allow_empty(opts, commit);
 668         if (allow < 0) {
 669                 res = allow;
 670                 goto leave;
 671         }
 672         if (!opts->no_commit)
 673                 res = run_git_commit(defmsg, opts, allow);
 674
 675         if (!res && opts->action == REPLAY_PICK) {
 676                 unsigned char to[20];
 677
 678                 if (read_ref("HEAD", to))
 679                         goto leave;
 680
 681                 add_rewritten(&rewritten, commit->object.sha1, to);
 682         }
 683 leave:
 684         free_message(&msg);
 685         free(defmsg);
 686
 687         return res;
 688 }
 689
 690 static void prepare_revs(struct replay_opts *opts)
 691 {
 692         /*
 693          * picking (but not reverting) ranges (but not individual revisions)
 694          * should be done in reverse
 695          */
 696         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 697                 opts->revs->reverse ^= 1;
 698
 699         if (prepare_revision_walk(opts->revs))
 700                 die(_("revision walk setup failed"));
 701
 702         if (!opts->revs->commits && !opts->quiet)
 703                 error(_("empty commit set passed"));
 704 }
 705
 706 static void read_and_refresh_cache(struct replay_opts *opts)
 707 {
 708         static struct lock_file index_lock;
 709         int index_fd = hold_locked_index(&index_lock, 0);
 710         if (read_index_preload(&the_index, NULL) < 0)
 711                 die(_("git %s: failed to read the index"), action_name(opts));
 712         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 713         if (the_index.cache_changed) {
 714                 if (write_index(&the_index, index_fd) ||
 715                     commit_locked_index(&index_lock))
 716                         die(_("git %s: failed to refresh the index"), action_name(opts));
 717         }
 718         rollback_lock_file(&index_lock);
 719 }
 720
 721 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 722                 struct replay_opts *opts)
 723 {
 724         struct commit_list *cur = NULL;
 725         const char *sha1_abbrev = NULL;
 726         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 727         const char *subject;
 728         int subject_len;
 729
 730         for (cur = todo_list; cur; cur = cur->next) {
 731                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 732                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 733                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 734                         subject_len, subject);
 735         }
 736         return 0;
 737 }
 738
 739 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 740 {
 741         unsigned char commit_sha1[20];
 742         enum replay_action action;
 743         char *end_of_object_name;
 744         int saved, status, padding;
 745
 746         if (starts_with(bol, "pick")) {
 747                 action = REPLAY_PICK;
 748                 bol += strlen("pick");
 749         } else if (starts_with(bol, "revert")) {
 750                 action = REPLAY_REVERT;
 751                 bol += strlen("revert");
 752         } else
 753                 return NULL;
 754
 755         /* Eat up extra spaces/ tabs before object name */
 756         padding = strspn(bol, " \t");
 757         if (!padding)
 758                 return NULL;
 759         bol += padding;
 760
 761         end_of_object_name = bol + strcspn(bol, " \t\n");
 762         saved = *end_of_object_name;
 763         *end_of_object_name = '\0';
 764         status = get_sha1(bol, commit_sha1);
 765         *end_of_object_name = saved;
 766
 767         /*
 768          * Verify that the action matches up with the one in
 769          * opts; we don't support arbitrary instructions
 770          */
 771         if (action != opts->action) {
 772                 const char *action_str;
 773                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 774                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 775                 return NULL;
 776         }
 777
 778         if (status < 0)
 779                 return NULL;
 780
 781         return lookup_commit_reference(commit_sha1);
 782 }
 783
 784 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 785                         struct replay_opts *opts)
 786 {
 787         struct commit_list **next = todo_list;
 788         struct commit *commit;
 789         char *p = buf;
 790         int i;
 791
 792         for (i = 1; *p; i++) {
 793                 char *eol = strchrnul(p, '\n');
 794                 commit = parse_insn_line(p, eol, opts);
 795                 if (!commit)
 796                         return error(_("Could not parse line %d."), i);
 797                 next = commit_list_append(commit, next);
 798                 p = *eol ? eol + 1 : eol;
 799         }
 800         if (!*todo_list)
 801                 return error(_("No commits parsed."));
 802         return 0;
 803 }
 804
 805 static void read_populate_todo(struct commit_list **todo_list,
 806                         struct replay_opts *opts)
 807 {
 808         const char *todo_file = git_path(SEQ_TODO_FILE);
 809         struct strbuf buf = STRBUF_INIT;
 810         int fd, res;
 811
 812         fd = open(todo_file, O_RDONLY);
 813         if (fd < 0)
 814                 die_errno(_("Could not open %s"), todo_file);
 815         if (strbuf_read(&buf, fd, 0) < 0) {
 816                 close(fd);
 817                 strbuf_release(&buf);
 818                 die(_("Could not read %s."), todo_file);
 819         }
 820         close(fd);
 821
 822         res = parse_insn_buffer(buf.buf, todo_list, opts);
 823         strbuf_release(&buf);
 824         if (res)
 825                 die(_("Unusable instruction sheet: %s"), todo_file);
 826 }
 827
 828 static int populate_opts_cb(const char *key, const char *value, void *data)
 829 {
 830         struct replay_opts *opts = data;
 831         int error_flag = 1;
 832
 833         if (!value)
 834                 error_flag = 0;
 835         else if (!strcmp(key, "options.no-commit"))
 836                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 837         else if (!strcmp(key, "options.edit"))
 838                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 839         else if (!strcmp(key, "options.signoff"))
 840                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 841         else if (!strcmp(key, "options.record-origin"))
 842                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 843         else if (!strcmp(key, "options.allow-ff"))
 844                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 845         else if (!strcmp(key, "options.mainline"))
 846                 opts->mainline = git_config_int(key, value);
 847         else if (!strcmp(key, "options.strategy"))
 848                 git_config_string(&opts->strategy, key, value);
 849         else if (!strcmp(key, "options.strategy-option")) {
 850                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 851                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 852         } else if (!strcmp(key, "options.action-name"))
 853                 git_config_string(&opts->action_name, key, value);
 854         else if (!strcmp(key, "options.allow-rerere-auto"))
 855                 opts->allow_rerere_auto = git_config_int(key, value);
 856         else
 857                 return error(_("Invalid key: %s"), key);
 858
 859         if (!error_flag)
 860                 return error(_("Invalid value for %s: %s"), key, value);
 861
 862         return 0;
 863 }
 864
 865 static void read_populate_opts(struct replay_opts **opts_ptr)
 866 {
 867         const char *opts_file = git_path(SEQ_OPTS_FILE);
 868
 869         if (!file_exists(opts_file))
 870                 return;
 871         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 872                 die(_("Malformed options sheet: %s"), opts_file);
 873 }
 874
 875 static void walk_revs_populate_todo(struct commit_list **todo_list,
 876                                 struct replay_opts *opts)
 877 {
 878         struct commit *commit;
 879         struct commit_list **next;
 880
 881         prepare_revs(opts);
 882
 883         next = todo_list;
 884         while ((commit = get_revision(opts->revs)))
 885                 next = commit_list_append(commit, next);
 886 }
 887
 888 static int create_seq_dir(void)
 889 {
 890         const char *seq_dir = git_path(SEQ_DIR);
 891
 892         if (file_exists(seq_dir)) {
 893                 error(_("a cherry-pick or revert is already in progress"));
 894                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 895                 return -1;
 896         }
 897         else if (mkdir(seq_dir, 0777) < 0)
 898                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 899         return 0;
 900 }
 901
 902 static void save_head(const char *head)
 903 {
 904         const char *head_file = git_path(SEQ_HEAD_FILE);
 905         static struct lock_file head_lock;
 906         struct strbuf buf = STRBUF_INIT;
 907         int fd;
 908
 909         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 910         strbuf_addf(&buf, "%s\n", head);
 911         if (write_in_full(fd, buf.buf, buf.len) < 0)
 912                 die_errno(_("Could not write to %s"), head_file);
 913         if (commit_lock_file(&head_lock) < 0)
 914                 die(_("Error wrapping up %s."), head_file);
 915 }
 916
 917 static int reset_for_rollback(const unsigned char *sha1)
 918 {
 919         const char *argv[4];    /* reset --merge <arg> + NULL */
 920         argv[0] = "reset";
 921         argv[1] = "--merge";
 922         argv[2] = sha1_to_hex(sha1);
 923         argv[3] = NULL;
 924         return run_command_v_opt(argv, RUN_GIT_CMD);
 925 }
 926
 927 static int rollback_single_pick(void)
 928 {
 929         unsigned char head_sha1[20];
 930
 931         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 932             !file_exists(git_path("REVERT_HEAD")))
 933                 return error(_("no cherry-pick or revert in progress"));
 934         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 935                 return error(_("cannot resolve HEAD"));
 936         if (is_null_sha1(head_sha1))
 937                 return error(_("cannot abort from a branch yet to be born"));
 938         return reset_for_rollback(head_sha1);
 939 }
 940
 941 static int sequencer_rollback(struct replay_opts *opts)
 942 {
 943         const char *filename;
 944         FILE *f;
 945         unsigned char sha1[20];
 946         struct strbuf buf = STRBUF_INIT;
 947
 948         filename = git_path(SEQ_HEAD_FILE);
 949         f = fopen(filename, "r");
 950         if (!f && errno == ENOENT) {
 951                 /*
 952                  * There is no multiple-cherry-pick in progress.
 953                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 954                  * a single-cherry-pick in progress, abort that.
 955                  */
 956                 return rollback_single_pick();
 957         }
 958         if (!f)
 959                 return error(_("cannot open %s: %s"), filename,
 960                                                 strerror(errno));
 961         if (strbuf_getline(&buf, f, '\n')) {
 962                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 963                         strerror(errno) : _("unexpected end of file"));
 964                 fclose(f);
 965                 goto fail;
 966         }
 967         fclose(f);
 968         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 969                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 970                         filename);
 971                 goto fail;
 972         }
 973         if (reset_for_rollback(sha1))
 974                 goto fail;
 975         remove_sequencer_state();
 976         strbuf_release(&buf);
 977         return 0;
 978 fail:
 979         strbuf_release(&buf);
 980         return -1;
 981 }
 982
 983 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 984 {
 985         const char *todo_file = git_path(SEQ_TODO_FILE);
 986         static struct lock_file todo_lock;
 987         struct strbuf buf = STRBUF_INIT;
 988         int fd;
 989
 990         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 991         if (format_todo(&buf, todo_list, opts) < 0)
 992                 die(_("Could not format %s."), todo_file);
 993         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 994                 strbuf_release(&buf);
 995                 die_errno(_("Could not write to %s"), todo_file);
 996         }
 997         if (commit_lock_file(&todo_lock) < 0) {
 998                 strbuf_release(&buf);
 999                 die(_("Error wrapping up %s."), todo_file);
1000         }
1001         strbuf_release(&buf);
1002 }
1003
1004 static void save_opts(struct replay_opts *opts)
1005 {
1006         const char *opts_file = git_path(SEQ_OPTS_FILE);
1007
1008         if (opts->no_commit)
1009                 git_config_set_in_file(opts_file, "options.no-commit", "true");
1010         if (opts->edit)
1011                 git_config_set_in_file(opts_file, "options.edit", "true");
1012         if (opts->signoff)
1013                 git_config_set_in_file(opts_file, "options.signoff", "true");
1014         if (opts->record_origin)
1015                 git_config_set_in_file(opts_file, "options.record-origin", "true");
1016         if (opts->allow_ff)
1017                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
1018         if (opts->mainline) {
1019                 struct strbuf buf = STRBUF_INIT;
1020                 strbuf_addf(&buf, "%d", opts->mainline);
1021                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
1022                 strbuf_release(&buf);
1023         }
1024         if (opts->strategy)
1025                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
1026         if (opts->xopts) {
1027                 int i;
1028                 for (i = 0; i < opts->xopts_nr; i++)
1029                         git_config_set_multivar_in_file(opts_file,
1030                                                         "options.strategy-option",
1031                                                         opts->xopts[i], "^$", 0);
1032         }
1033         if (opts->action_name)
1034                 git_config_set_in_file(opts_file, "options.action-name", opts->action_name);
1035         if (opts->allow_rerere_auto) {
1036                 struct strbuf buf = STRBUF_INIT;
1037                 strbuf_addf(&buf, "%d", opts->allow_rerere_auto);
1038                 git_config_set_in_file(opts_file, "options.allow-rerere-auto", buf.buf);
1039                 strbuf_release(&buf);
1040         }
1041 }
1042
1043 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1044 {
1045         struct commit_list *cur;
1046         int res;
1047
1048         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1049         if (opts->allow_ff)
1050                 assert(!(opts->signoff || opts->no_commit ||
1051                                 opts->record_origin || opts->edit));
1052         read_and_refresh_cache(opts);
1053
1054         for (cur = todo_list; cur; cur = cur->next) {
1055                 save_todo(cur, opts);
1056                 res = do_pick_commit(cur->item, opts);
1057                 if (res) {
1058                         if (opts->action == REPLAY_PICK)
1059                                 store_rewritten(&rewritten, git_path(SEQ_REWR_FILE));
1060                         return res;
1061                 }
1062         }
1063
1064         finish(opts);
1065
1066         /*
1067          * Sequence of picks finished successfully; cleanup by
1068          * removing the .git/sequencer directory
1069          */
1070         remove_sequencer_state();
1071         return 0;
1072 }
1073
1074 static int continue_single_pick(void)
1075 {
1076         const char *argv[] = { "commit", NULL };
1077
1078         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1079             !file_exists(git_path("REVERT_HEAD")))
1080                 return error(_("no cherry-pick or revert in progress"));
1081         return run_command_v_opt(argv, RUN_GIT_CMD);
1082 }
1083
1084 static int sequencer_continue(struct replay_opts *opts, int skip)
1085 {
1086         struct commit_list *todo_list = NULL;
1087
1088         if (!file_exists(git_path(SEQ_TODO_FILE)))
1089                 return continue_single_pick();
1090         read_populate_opts(&opts);
1091         read_populate_todo(&todo_list, opts);
1092         if (opts->action == REPLAY_PICK)
1093                 load_rewritten(&rewritten, git_path(SEQ_REWR_FILE));
1094
1095         /* Verify that the conflict has been resolved */
1096         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1097             file_exists(git_path("REVERT_HEAD"))) {
1098                 int ret = continue_single_pick();
1099                 if (ret)
1100                         return ret;
1101         }
1102         if (index_differs_from("HEAD", 0))
1103                 return error_dirty_index(opts);
1104         if (opts->action == REPLAY_PICK && !skip) {
1105                 unsigned char to[20];
1106                 if (!read_ref("HEAD", to))
1107                         add_rewritten(&rewritten, todo_list->item->object.sha1, to);
1108         }
1109         todo_list = todo_list->next;
1110         return pick_commits(todo_list, opts);
1111 }
1112
1113 static int sequencer_skip(struct replay_opts *opts)
1114 {
1115         const char *argv[4]; /* reset --hard HEAD + NULL */
1116         struct string_list merge_rr = STRING_LIST_INIT_DUP;
1117         int ret;
1118
1119         if (setup_rerere(&merge_rr, 0) >= 0) {
1120                 rerere_clear(&merge_rr);
1121                 string_list_clear(&merge_rr, 1);
1122         }
1123
1124         argv[0] = "reset";
1125         argv[1] = "--hard";
1126         argv[2] = "HEAD";
1127         argv[3] = NULL;
1128         ret = run_command_v_opt(argv, RUN_GIT_CMD);
1129         if (ret)
1130                 return ret;
1131
1132         return sequencer_continue(opts, 1);
1133 }
1134
1135 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1136 {
1137         int ret;
1138         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1139         ret = do_pick_commit(cmit, opts);
1140         if (ret)
1141                 return ret;
1142         finish(opts);
1143         return 0;
1144 }
1145
1146 int sequencer_pick_revisions(struct replay_opts *opts)
1147 {
1148         struct commit_list *todo_list = NULL;
1149         unsigned char sha1[20];
1150         int i;
1151
1152         if (opts->subcommand == REPLAY_NONE)
1153                 assert(opts->revs);
1154
1155         read_and_refresh_cache(opts);
1156
1157         /*
1158          * Decide what to do depending on the arguments; a fresh
1159          * cherry-pick should be handled differently from an existing
1160          * one that is being continued
1161          */
1162         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1163                 remove_sequencer_state();
1164                 return 0;
1165         }
1166         if (opts->subcommand == REPLAY_ROLLBACK)
1167                 return sequencer_rollback(opts);
1168         if (opts->subcommand == REPLAY_CONTINUE)
1169                 return sequencer_continue(opts, 0);
1170         if (opts->subcommand == REPLAY_SKIP)
1171                 return sequencer_skip(opts);
1172
1173         for (i = 0; i < opts->revs->pending.nr; i++) {
1174                 unsigned char sha1[20];
1175                 const char *name = opts->revs->pending.objects[i].name;
1176
1177                 /* This happens when using --stdin. */
1178                 if (!strlen(name))
1179                         continue;
1180
1181                 if (!get_sha1(name, sha1)) {
1182                         if (!lookup_commit_reference_gently(sha1, 1)) {
1183                                 enum object_type type = sha1_object_info(sha1, NULL);
1184                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1185                         }
1186                 } else
1187                         die(_("%s: bad revision"), name);
1188         }
1189
1190         /*
1191          * If we were called as "git cherry-pick <commit>", just
1192          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1193          * REVERT_HEAD, and don't touch the sequencer state.
1194          * This means it is possible to cherry-pick in the middle
1195          * of a cherry-pick sequence.
1196          */
1197         if (opts->revs->cmdline.nr == 1 &&
1198             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1199             opts->revs->no_walk &&
1200             !opts->revs->cmdline.rev->flags) {
1201                 struct commit *cmit;
1202                 if (prepare_revision_walk(opts->revs))
1203                         die(_("revision walk setup failed"));
1204                 cmit = get_revision(opts->revs);
1205                 if (!cmit || get_revision(opts->revs))
1206                         die("BUG: expected exactly one commit from walk");
1207                 return single_pick(cmit, opts);
1208         }
1209
1210         /*
1211          * Start a new cherry-pick/ revert sequence; but
1212          * first, make sure that an existing one isn't in
1213          * progress
1214          */
1215
1216         walk_revs_populate_todo(&todo_list, opts);
1217         if (create_seq_dir() < 0)
1218                 return -1;
1219         if (get_sha1("HEAD", sha1)) {
1220                 if (opts->action == REPLAY_REVERT)
1221                         return error(_("Can't revert as initial commit"));
1222                 return error(_("Can't cherry-pick into empty head"));
1223         }
1224         save_head(sha1_to_hex(sha1));
1225         save_opts(opts);
1226         return pick_commits(todo_list, opts);
1227 }
1228
1229 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1230 {
1231         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1232         struct strbuf sob = STRBUF_INIT;
1233         int has_footer;
1234
1235         strbuf_addstr(&sob, sign_off_header);
1236         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1237                                 getenv("GIT_COMMITTER_EMAIL")));
1238         strbuf_addch(&sob, '\n');
1239
1240         /*
1241          * If the whole message buffer is equal to the sob, pretend that we
1242          * found a conforming footer with a matching sob
1243          */
1244         if (msgbuf->len - ignore_footer == sob.len &&
1245             !strncmp(msgbuf->buf, sob.buf, sob.len))
1246                 has_footer = 3;
1247         else
1248                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1249
1250         if (!has_footer) {
1251                 const char *append_newlines = NULL;
1252                 size_t len = msgbuf->len - ignore_footer;
1253
1254                 if (!len) {
1255                         /*
1256                          * The buffer is completely empty.  Leave foom for
1257                          * the title and body to be filled in by the user.
1258                          */
1259                         append_newlines = "\n\n";
1260                 } else if (msgbuf->buf[len - 1] != '\n') {
1261                         /*
1262                          * Incomplete line.  Complete the line and add a
1263                          * blank one so that there is an empty line between
1264                          * the message body and the sob.
1265                          */
1266                         append_newlines = "\n\n";
1267                 } else if (len == 1) {
1268                         /*
1269                          * Buffer contains a single newline.  Add another
1270                          * so that we leave room for the title and body.
1271                          */
1272                         append_newlines = "\n";
1273                 } else if (msgbuf->buf[len - 2] != '\n') {
1274                         /*
1275                          * Buffer ends with a single newline.  Add another
1276                          * so that there is an empty line between the message
1277                          * body and the sob.
1278                          */
1279                         append_newlines = "\n";
1280                 } /* else, the buffer already ends with two newlines. */
1281
1282                 if (append_newlines)
1283                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1284                                 append_newlines, strlen(append_newlines));
1285         }
1286
1287         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1288                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1289                                 sob.buf, sob.len);
1290
1291         strbuf_release(&sob);
1292 }