Merge branch 'jc/test-yes-doc'
[git] / builtin / rebase.c
1 /*
2  * "git rebase" builtin command
3  *
4  * Copyright (c) 2018 Pratik Karki
5  */
6
7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
8 #include "builtin.h"
9 #include "run-command.h"
10 #include "exec-cmd.h"
11 #include "argv-array.h"
12 #include "dir.h"
13 #include "packfile.h"
14 #include "refs.h"
15 #include "quote.h"
16 #include "config.h"
17 #include "cache-tree.h"
18 #include "unpack-trees.h"
19 #include "lockfile.h"
20 #include "parse-options.h"
21 #include "commit.h"
22 #include "diff.h"
23 #include "wt-status.h"
24 #include "revision.h"
25 #include "commit-reach.h"
26 #include "rerere.h"
27 #include "branch.h"
28
29 static char const * const builtin_rebase_usage[] = {
30         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
31                 "[<upstream>] [<branch>]"),
32         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
33                 "--root [<branch>]"),
34         N_("git rebase --continue | --abort | --skip | --edit-todo"),
35         NULL
36 };
37
38 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
39 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
40
41 enum rebase_type {
42         REBASE_UNSPECIFIED = -1,
43         REBASE_AM,
44         REBASE_MERGE,
45         REBASE_INTERACTIVE,
46         REBASE_PRESERVE_MERGES
47 };
48
49 static int use_builtin_rebase(void)
50 {
51         struct child_process cp = CHILD_PROCESS_INIT;
52         struct strbuf out = STRBUF_INIT;
53         int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
54
55         if (env != -1)
56                 return env;
57
58         argv_array_pushl(&cp.args,
59                          "config", "--bool", "rebase.usebuiltin", NULL);
60         cp.git_cmd = 1;
61         if (capture_command(&cp, &out, 6)) {
62                 strbuf_release(&out);
63                 return 1;
64         }
65
66         strbuf_trim(&out);
67         ret = !strcmp("true", out.buf);
68         strbuf_release(&out);
69         return ret;
70 }
71
72 struct rebase_options {
73         enum rebase_type type;
74         const char *state_dir;
75         struct commit *upstream;
76         const char *upstream_name;
77         const char *upstream_arg;
78         char *head_name;
79         struct object_id orig_head;
80         struct commit *onto;
81         const char *onto_name;
82         const char *revisions;
83         const char *switch_to;
84         int root;
85         struct object_id *squash_onto;
86         struct commit *restrict_revision;
87         int dont_finish_rebase;
88         enum {
89                 REBASE_NO_QUIET = 1<<0,
90                 REBASE_VERBOSE = 1<<1,
91                 REBASE_DIFFSTAT = 1<<2,
92                 REBASE_FORCE = 1<<3,
93                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
94         } flags;
95         struct argv_array git_am_opts;
96         const char *action;
97         int signoff;
98         int allow_rerere_autoupdate;
99         int keep_empty;
100         int autosquash;
101         char *gpg_sign_opt;
102         int autostash;
103         char *cmd;
104         int allow_empty_message;
105         int rebase_merges, rebase_cousins;
106         char *strategy, *strategy_opts;
107         struct strbuf git_format_patch_opt;
108         int reschedule_failed_exec;
109 };
110
111 static int is_interactive(struct rebase_options *opts)
112 {
113         return opts->type == REBASE_INTERACTIVE ||
114                 opts->type == REBASE_PRESERVE_MERGES;
115 }
116
117 static void imply_interactive(struct rebase_options *opts, const char *option)
118 {
119         switch (opts->type) {
120         case REBASE_AM:
121                 die(_("%s requires an interactive rebase"), option);
122                 break;
123         case REBASE_INTERACTIVE:
124         case REBASE_PRESERVE_MERGES:
125                 break;
126         case REBASE_MERGE:
127                 /* we now implement --merge via --interactive */
128         default:
129                 opts->type = REBASE_INTERACTIVE; /* implied */
130                 break;
131         }
132 }
133
134 /* Returns the filename prefixed by the state_dir */
135 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
136 {
137         static struct strbuf path = STRBUF_INIT;
138         static size_t prefix_len;
139
140         if (!prefix_len) {
141                 strbuf_addf(&path, "%s/", opts->state_dir);
142                 prefix_len = path.len;
143         }
144
145         strbuf_setlen(&path, prefix_len);
146         strbuf_addstr(&path, filename);
147         return path.buf;
148 }
149
150 /* Read one file, then strip line endings */
151 static int read_one(const char *path, struct strbuf *buf)
152 {
153         if (strbuf_read_file(buf, path, 0) < 0)
154                 return error_errno(_("could not read '%s'"), path);
155         strbuf_trim_trailing_newline(buf);
156         return 0;
157 }
158
159 /* Initialize the rebase options from the state directory. */
160 static int read_basic_state(struct rebase_options *opts)
161 {
162         struct strbuf head_name = STRBUF_INIT;
163         struct strbuf buf = STRBUF_INIT;
164         struct object_id oid;
165
166         if (read_one(state_dir_path("head-name", opts), &head_name) ||
167             read_one(state_dir_path("onto", opts), &buf))
168                 return -1;
169         opts->head_name = starts_with(head_name.buf, "refs/") ?
170                 xstrdup(head_name.buf) : NULL;
171         strbuf_release(&head_name);
172         if (get_oid(buf.buf, &oid))
173                 return error(_("could not get 'onto': '%s'"), buf.buf);
174         opts->onto = lookup_commit_or_die(&oid, buf.buf);
175
176         /*
177          * We always write to orig-head, but interactive rebase used to write to
178          * head. Fall back to reading from head to cover for the case that the
179          * user upgraded git with an ongoing interactive rebase.
180          */
181         strbuf_reset(&buf);
182         if (file_exists(state_dir_path("orig-head", opts))) {
183                 if (read_one(state_dir_path("orig-head", opts), &buf))
184                         return -1;
185         } else if (read_one(state_dir_path("head", opts), &buf))
186                 return -1;
187         if (get_oid(buf.buf, &opts->orig_head))
188                 return error(_("invalid orig-head: '%s'"), buf.buf);
189
190         if (file_exists(state_dir_path("quiet", opts)))
191                 opts->flags &= ~REBASE_NO_QUIET;
192         else
193                 opts->flags |= REBASE_NO_QUIET;
194
195         if (file_exists(state_dir_path("verbose", opts)))
196                 opts->flags |= REBASE_VERBOSE;
197
198         if (file_exists(state_dir_path("signoff", opts))) {
199                 opts->signoff = 1;
200                 opts->flags |= REBASE_FORCE;
201         }
202
203         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
204                 strbuf_reset(&buf);
205                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
206                             &buf))
207                         return -1;
208                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
209                         opts->allow_rerere_autoupdate = 1;
210                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
211                         opts->allow_rerere_autoupdate = 0;
212                 else
213                         warning(_("ignoring invalid allow_rerere_autoupdate: "
214                                   "'%s'"), buf.buf);
215         } else
216                 opts->allow_rerere_autoupdate = -1;
217
218         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
219                 strbuf_reset(&buf);
220                 if (read_one(state_dir_path("gpg_sign_opt", opts),
221                             &buf))
222                         return -1;
223                 free(opts->gpg_sign_opt);
224                 opts->gpg_sign_opt = xstrdup(buf.buf);
225         }
226
227         if (file_exists(state_dir_path("strategy", opts))) {
228                 strbuf_reset(&buf);
229                 if (read_one(state_dir_path("strategy", opts), &buf))
230                         return -1;
231                 free(opts->strategy);
232                 opts->strategy = xstrdup(buf.buf);
233         }
234
235         if (file_exists(state_dir_path("strategy_opts", opts))) {
236                 strbuf_reset(&buf);
237                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
238                         return -1;
239                 free(opts->strategy_opts);
240                 opts->strategy_opts = xstrdup(buf.buf);
241         }
242
243         strbuf_release(&buf);
244
245         return 0;
246 }
247
248 static int write_basic_state(struct rebase_options *opts)
249 {
250         write_file(state_dir_path("head-name", opts), "%s",
251                    opts->head_name ? opts->head_name : "detached HEAD");
252         write_file(state_dir_path("onto", opts), "%s",
253                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
254         write_file(state_dir_path("orig-head", opts), "%s",
255                    oid_to_hex(&opts->orig_head));
256         write_file(state_dir_path("quiet", opts), "%s",
257                    opts->flags & REBASE_NO_QUIET ? "" : "t");
258         if (opts->flags & REBASE_VERBOSE)
259                 write_file(state_dir_path("verbose", opts), "%s", "");
260         if (opts->strategy)
261                 write_file(state_dir_path("strategy", opts), "%s",
262                            opts->strategy);
263         if (opts->strategy_opts)
264                 write_file(state_dir_path("strategy_opts", opts), "%s",
265                            opts->strategy_opts);
266         if (opts->allow_rerere_autoupdate >= 0)
267                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
268                            "-%s-rerere-autoupdate",
269                            opts->allow_rerere_autoupdate ? "" : "-no");
270         if (opts->gpg_sign_opt)
271                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
272                            opts->gpg_sign_opt);
273         if (opts->signoff)
274                 write_file(state_dir_path("strategy", opts), "--signoff");
275
276         return 0;
277 }
278
279 static int apply_autostash(struct rebase_options *opts)
280 {
281         const char *path = state_dir_path("autostash", opts);
282         struct strbuf autostash = STRBUF_INIT;
283         struct child_process stash_apply = CHILD_PROCESS_INIT;
284
285         if (!file_exists(path))
286                 return 0;
287
288         if (read_one(path, &autostash))
289                 return error(_("Could not read '%s'"), path);
290         /* Ensure that the hash is not mistaken for a number */
291         strbuf_addstr(&autostash, "^0");
292         argv_array_pushl(&stash_apply.args,
293                          "stash", "apply", autostash.buf, NULL);
294         stash_apply.git_cmd = 1;
295         stash_apply.no_stderr = stash_apply.no_stdout =
296                 stash_apply.no_stdin = 1;
297         if (!run_command(&stash_apply))
298                 printf(_("Applied autostash.\n"));
299         else {
300                 struct argv_array args = ARGV_ARRAY_INIT;
301                 int res = 0;
302
303                 argv_array_pushl(&args,
304                                  "stash", "store", "-m", "autostash", "-q",
305                                  autostash.buf, NULL);
306                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
307                         res = error(_("Cannot store %s"), autostash.buf);
308                 argv_array_clear(&args);
309                 strbuf_release(&autostash);
310                 if (res)
311                         return res;
312
313                 fprintf(stderr,
314                         _("Applying autostash resulted in conflicts.\n"
315                           "Your changes are safe in the stash.\n"
316                           "You can run \"git stash pop\" or \"git stash drop\" "
317                           "at any time.\n"));
318         }
319
320         strbuf_release(&autostash);
321         return 0;
322 }
323
324 static int finish_rebase(struct rebase_options *opts)
325 {
326         struct strbuf dir = STRBUF_INIT;
327         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
328
329         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
330         apply_autostash(opts);
331         close_all_packs(the_repository->objects);
332         /*
333          * We ignore errors in 'gc --auto', since the
334          * user should see them.
335          */
336         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
337         strbuf_addstr(&dir, opts->state_dir);
338         remove_dir_recursively(&dir, 0);
339         strbuf_release(&dir);
340
341         return 0;
342 }
343
344 static struct commit *peel_committish(const char *name)
345 {
346         struct object *obj;
347         struct object_id oid;
348
349         if (get_oid(name, &oid))
350                 return NULL;
351         obj = parse_object(the_repository, &oid);
352         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
353 }
354
355 static void add_var(struct strbuf *buf, const char *name, const char *value)
356 {
357         if (!value)
358                 strbuf_addf(buf, "unset %s; ", name);
359         else {
360                 strbuf_addf(buf, "%s=", name);
361                 sq_quote_buf(buf, value);
362                 strbuf_addstr(buf, "; ");
363         }
364 }
365
366 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
367
368 #define RESET_HEAD_DETACH (1<<0)
369 #define RESET_HEAD_HARD (1<<1)
370 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
371 #define RESET_HEAD_REFS_ONLY (1<<3)
372
373 static int reset_head(struct object_id *oid, const char *action,
374                       const char *switch_to_branch, unsigned flags,
375                       const char *reflog_orig_head, const char *reflog_head)
376 {
377         unsigned detach_head = flags & RESET_HEAD_DETACH;
378         unsigned reset_hard = flags & RESET_HEAD_HARD;
379         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
380         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
381         struct object_id head_oid;
382         struct tree_desc desc[2] = { { NULL }, { NULL } };
383         struct lock_file lock = LOCK_INIT;
384         struct unpack_trees_options unpack_tree_opts;
385         struct tree *tree;
386         const char *reflog_action;
387         struct strbuf msg = STRBUF_INIT;
388         size_t prefix_len;
389         struct object_id *orig = NULL, oid_orig,
390                 *old_orig = NULL, oid_old_orig;
391         int ret = 0, nr = 0;
392
393         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
394                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
395
396         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
397                 ret = -1;
398                 goto leave_reset_head;
399         }
400
401         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
402                 ret = error(_("could not determine HEAD revision"));
403                 goto leave_reset_head;
404         }
405
406         if (!oid)
407                 oid = &head_oid;
408
409         if (refs_only)
410                 goto reset_head_refs;
411
412         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
413         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
414         unpack_tree_opts.head_idx = 1;
415         unpack_tree_opts.src_index = the_repository->index;
416         unpack_tree_opts.dst_index = the_repository->index;
417         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
418         unpack_tree_opts.update = 1;
419         unpack_tree_opts.merge = 1;
420         if (!detach_head)
421                 unpack_tree_opts.reset = 1;
422
423         if (repo_read_index_unmerged(the_repository) < 0) {
424                 ret = error(_("could not read index"));
425                 goto leave_reset_head;
426         }
427
428         if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
429                 ret = error(_("failed to find tree of %s"),
430                             oid_to_hex(&head_oid));
431                 goto leave_reset_head;
432         }
433
434         if (!fill_tree_descriptor(&desc[nr++], oid)) {
435                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
436                 goto leave_reset_head;
437         }
438
439         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
440                 ret = -1;
441                 goto leave_reset_head;
442         }
443
444         tree = parse_tree_indirect(oid);
445         prime_cache_tree(the_repository, the_repository->index, tree);
446
447         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
448                 ret = error(_("could not write index"));
449                 goto leave_reset_head;
450         }
451
452 reset_head_refs:
453         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
454         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
455         prefix_len = msg.len;
456
457         if (!get_oid("ORIG_HEAD", &oid_old_orig))
458                 old_orig = &oid_old_orig;
459         if (!get_oid("HEAD", &oid_orig)) {
460                 orig = &oid_orig;
461                 if (!reflog_orig_head) {
462                         strbuf_addstr(&msg, "updating ORIG_HEAD");
463                         reflog_orig_head = msg.buf;
464                 }
465                 update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
466                            UPDATE_REFS_MSG_ON_ERR);
467         } else if (old_orig)
468                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
469         if (!reflog_head) {
470                 strbuf_setlen(&msg, prefix_len);
471                 strbuf_addstr(&msg, "updating HEAD");
472                 reflog_head = msg.buf;
473         }
474         if (!switch_to_branch)
475                 ret = update_ref(reflog_head, "HEAD", oid, orig,
476                                  detach_head ? REF_NO_DEREF : 0,
477                                  UPDATE_REFS_MSG_ON_ERR);
478         else {
479                 ret = update_ref(reflog_orig_head, switch_to_branch, oid,
480                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
481                 if (!ret)
482                         ret = create_symref("HEAD", switch_to_branch,
483                                             reflog_head);
484         }
485         if (run_hook)
486                 run_hook_le(NULL, "post-checkout",
487                             oid_to_hex(orig ? orig : &null_oid),
488                             oid_to_hex(oid), "1", NULL);
489
490 leave_reset_head:
491         strbuf_release(&msg);
492         rollback_lock_file(&lock);
493         while (nr)
494                 free((void *)desc[--nr].buffer);
495         return ret;
496 }
497
498 static int move_to_original_branch(struct rebase_options *opts)
499 {
500         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
501         int ret;
502
503         if (!opts->head_name)
504                 return 0; /* nothing to move back to */
505
506         if (!opts->onto)
507                 BUG("move_to_original_branch without onto");
508
509         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
510                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
511         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
512                     opts->head_name);
513         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
514                          orig_head_reflog.buf, head_reflog.buf);
515
516         strbuf_release(&orig_head_reflog);
517         strbuf_release(&head_reflog);
518         return ret;
519 }
520
521 static const char *resolvemsg =
522 N_("Resolve all conflicts manually, mark them as resolved with\n"
523 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
524 "You can instead skip this commit: run \"git rebase --skip\".\n"
525 "To abort and get back to the state before \"git rebase\", run "
526 "\"git rebase --abort\".");
527
528 static int run_am(struct rebase_options *opts)
529 {
530         struct child_process am = CHILD_PROCESS_INIT;
531         struct child_process format_patch = CHILD_PROCESS_INIT;
532         struct strbuf revisions = STRBUF_INIT;
533         int status;
534         char *rebased_patches;
535
536         am.git_cmd = 1;
537         argv_array_push(&am.args, "am");
538
539         if (opts->action && !strcmp("continue", opts->action)) {
540                 argv_array_push(&am.args, "--resolved");
541                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
542                 if (opts->gpg_sign_opt)
543                         argv_array_push(&am.args, opts->gpg_sign_opt);
544                 status = run_command(&am);
545                 if (status)
546                         return status;
547
548                 return move_to_original_branch(opts);
549         }
550         if (opts->action && !strcmp("skip", opts->action)) {
551                 argv_array_push(&am.args, "--skip");
552                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
553                 status = run_command(&am);
554                 if (status)
555                         return status;
556
557                 return move_to_original_branch(opts);
558         }
559         if (opts->action && !strcmp("show-current-patch", opts->action)) {
560                 argv_array_push(&am.args, "--show-current-patch");
561                 return run_command(&am);
562         }
563
564         strbuf_addf(&revisions, "%s...%s",
565                     oid_to_hex(opts->root ?
566                                /* this is now equivalent to !opts->upstream */
567                                &opts->onto->object.oid :
568                                &opts->upstream->object.oid),
569                     oid_to_hex(&opts->orig_head));
570
571         rebased_patches = xstrdup(git_path("rebased-patches"));
572         format_patch.out = open(rebased_patches,
573                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
574         if (format_patch.out < 0) {
575                 status = error_errno(_("could not open '%s' for writing"),
576                                      rebased_patches);
577                 free(rebased_patches);
578                 argv_array_clear(&am.args);
579                 return status;
580         }
581
582         format_patch.git_cmd = 1;
583         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
584                          "--full-index", "--cherry-pick", "--right-only",
585                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
586                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
587         if (opts->git_format_patch_opt.len)
588                 argv_array_split(&format_patch.args,
589                                  opts->git_format_patch_opt.buf);
590         argv_array_push(&format_patch.args, revisions.buf);
591         if (opts->restrict_revision)
592                 argv_array_pushf(&format_patch.args, "^%s",
593                                  oid_to_hex(&opts->restrict_revision->object.oid));
594
595         status = run_command(&format_patch);
596         if (status) {
597                 unlink(rebased_patches);
598                 free(rebased_patches);
599                 argv_array_clear(&am.args);
600
601                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
602                            "HEAD", NULL);
603                 error(_("\ngit encountered an error while preparing the "
604                         "patches to replay\n"
605                         "these revisions:\n"
606                         "\n    %s\n\n"
607                         "As a result, git cannot rebase them."),
608                       opts->revisions);
609
610                 strbuf_release(&revisions);
611                 return status;
612         }
613         strbuf_release(&revisions);
614
615         am.in = open(rebased_patches, O_RDONLY);
616         if (am.in < 0) {
617                 status = error_errno(_("could not open '%s' for reading"),
618                                      rebased_patches);
619                 free(rebased_patches);
620                 argv_array_clear(&am.args);
621                 return status;
622         }
623
624         argv_array_pushv(&am.args, opts->git_am_opts.argv);
625         argv_array_push(&am.args, "--rebasing");
626         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
627         argv_array_push(&am.args, "--patch-format=mboxrd");
628         if (opts->allow_rerere_autoupdate > 0)
629                 argv_array_push(&am.args, "--rerere-autoupdate");
630         else if (opts->allow_rerere_autoupdate == 0)
631                 argv_array_push(&am.args, "--no-rerere-autoupdate");
632         if (opts->gpg_sign_opt)
633                 argv_array_push(&am.args, opts->gpg_sign_opt);
634         status = run_command(&am);
635         unlink(rebased_patches);
636         free(rebased_patches);
637
638         if (!status) {
639                 return move_to_original_branch(opts);
640         }
641
642         if (is_directory(opts->state_dir))
643                 write_basic_state(opts);
644
645         return status;
646 }
647
648 static int run_specific_rebase(struct rebase_options *opts)
649 {
650         const char *argv[] = { NULL, NULL };
651         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
652         int status;
653         const char *backend, *backend_func;
654
655         if (opts->type == REBASE_INTERACTIVE) {
656                 /* Run builtin interactive rebase */
657                 struct child_process child = CHILD_PROCESS_INIT;
658
659                 argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
660                                  resolvemsg);
661                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
662                         argv_array_push(&child.env_array,
663                                         "GIT_SEQUENCE_EDITOR=:");
664                         opts->autosquash = 0;
665                 }
666
667                 child.git_cmd = 1;
668                 argv_array_push(&child.args, "rebase--interactive");
669
670                 if (opts->action)
671                         argv_array_pushf(&child.args, "--%s", opts->action);
672                 if (opts->keep_empty)
673                         argv_array_push(&child.args, "--keep-empty");
674                 if (opts->rebase_merges)
675                         argv_array_push(&child.args, "--rebase-merges");
676                 if (opts->rebase_cousins)
677                         argv_array_push(&child.args, "--rebase-cousins");
678                 if (opts->autosquash)
679                         argv_array_push(&child.args, "--autosquash");
680                 if (opts->flags & REBASE_VERBOSE)
681                         argv_array_push(&child.args, "--verbose");
682                 if (opts->flags & REBASE_FORCE)
683                         argv_array_push(&child.args, "--no-ff");
684                 if (opts->restrict_revision)
685                         argv_array_pushf(&child.args,
686                                          "--restrict-revision=^%s",
687                                          oid_to_hex(&opts->restrict_revision->object.oid));
688                 if (opts->upstream)
689                         argv_array_pushf(&child.args, "--upstream=%s",
690                                          oid_to_hex(&opts->upstream->object.oid));
691                 if (opts->onto)
692                         argv_array_pushf(&child.args, "--onto=%s",
693                                          oid_to_hex(&opts->onto->object.oid));
694                 if (opts->squash_onto)
695                         argv_array_pushf(&child.args, "--squash-onto=%s",
696                                          oid_to_hex(opts->squash_onto));
697                 if (opts->onto_name)
698                         argv_array_pushf(&child.args, "--onto-name=%s",
699                                          opts->onto_name);
700                 argv_array_pushf(&child.args, "--head-name=%s",
701                                  opts->head_name ?
702                                  opts->head_name : "detached HEAD");
703                 if (opts->strategy)
704                         argv_array_pushf(&child.args, "--strategy=%s",
705                                          opts->strategy);
706                 if (opts->strategy_opts)
707                         argv_array_pushf(&child.args, "--strategy-opts=%s",
708                                          opts->strategy_opts);
709                 if (opts->switch_to)
710                         argv_array_pushf(&child.args, "--switch-to=%s",
711                                          opts->switch_to);
712                 if (opts->cmd)
713                         argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
714                 if (opts->allow_empty_message)
715                         argv_array_push(&child.args, "--allow-empty-message");
716                 if (opts->allow_rerere_autoupdate > 0)
717                         argv_array_push(&child.args, "--rerere-autoupdate");
718                 else if (opts->allow_rerere_autoupdate == 0)
719                         argv_array_push(&child.args, "--no-rerere-autoupdate");
720                 if (opts->gpg_sign_opt)
721                         argv_array_push(&child.args, opts->gpg_sign_opt);
722                 if (opts->signoff)
723                         argv_array_push(&child.args, "--signoff");
724                 if (opts->reschedule_failed_exec)
725                         argv_array_push(&child.args, "--reschedule-failed-exec");
726
727                 status = run_command(&child);
728                 goto finished_rebase;
729         }
730
731         if (opts->type == REBASE_AM) {
732                 status = run_am(opts);
733                 goto finished_rebase;
734         }
735
736         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
737         add_var(&script_snippet, "state_dir", opts->state_dir);
738
739         add_var(&script_snippet, "upstream_name", opts->upstream_name);
740         add_var(&script_snippet, "upstream", opts->upstream ?
741                 oid_to_hex(&opts->upstream->object.oid) : NULL);
742         add_var(&script_snippet, "head_name",
743                 opts->head_name ? opts->head_name : "detached HEAD");
744         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
745         add_var(&script_snippet, "onto", opts->onto ?
746                 oid_to_hex(&opts->onto->object.oid) : NULL);
747         add_var(&script_snippet, "onto_name", opts->onto_name);
748         add_var(&script_snippet, "revisions", opts->revisions);
749         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
750                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
751         add_var(&script_snippet, "GIT_QUIET",
752                 opts->flags & REBASE_NO_QUIET ? "" : "t");
753         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
754         add_var(&script_snippet, "git_am_opt", buf.buf);
755         strbuf_release(&buf);
756         add_var(&script_snippet, "verbose",
757                 opts->flags & REBASE_VERBOSE ? "t" : "");
758         add_var(&script_snippet, "diffstat",
759                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
760         add_var(&script_snippet, "force_rebase",
761                 opts->flags & REBASE_FORCE ? "t" : "");
762         if (opts->switch_to)
763                 add_var(&script_snippet, "switch_to", opts->switch_to);
764         add_var(&script_snippet, "action", opts->action ? opts->action : "");
765         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
766         add_var(&script_snippet, "allow_rerere_autoupdate",
767                 opts->allow_rerere_autoupdate < 0 ? "" :
768                 opts->allow_rerere_autoupdate ?
769                 "--rerere-autoupdate" : "--no-rerere-autoupdate");
770         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
771         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
772         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
773         add_var(&script_snippet, "cmd", opts->cmd);
774         add_var(&script_snippet, "allow_empty_message",
775                 opts->allow_empty_message ?  "--allow-empty-message" : "");
776         add_var(&script_snippet, "rebase_merges",
777                 opts->rebase_merges ? "t" : "");
778         add_var(&script_snippet, "rebase_cousins",
779                 opts->rebase_cousins ? "t" : "");
780         add_var(&script_snippet, "strategy", opts->strategy);
781         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
782         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
783         add_var(&script_snippet, "squash_onto",
784                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
785         add_var(&script_snippet, "git_format_patch_opt",
786                 opts->git_format_patch_opt.buf);
787
788         if (is_interactive(opts) &&
789             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
790                 strbuf_addstr(&script_snippet,
791                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
792                 opts->autosquash = 0;
793         }
794
795         switch (opts->type) {
796         case REBASE_AM:
797                 backend = "git-rebase--am";
798                 backend_func = "git_rebase__am";
799                 break;
800         case REBASE_PRESERVE_MERGES:
801                 backend = "git-rebase--preserve-merges";
802                 backend_func = "git_rebase__preserve_merges";
803                 break;
804         default:
805                 BUG("Unhandled rebase type %d", opts->type);
806                 break;
807         }
808
809         strbuf_addf(&script_snippet,
810                     ". git-sh-setup && . git-rebase--common &&"
811                     " . %s && %s", backend, backend_func);
812         argv[0] = script_snippet.buf;
813
814         status = run_command_v_opt(argv, RUN_USING_SHELL);
815 finished_rebase:
816         if (opts->dont_finish_rebase)
817                 ; /* do nothing */
818         else if (opts->type == REBASE_INTERACTIVE)
819                 ; /* interactive rebase cleans up after itself */
820         else if (status == 0) {
821                 if (!file_exists(state_dir_path("stopped-sha", opts)))
822                         finish_rebase(opts);
823         } else if (status == 2) {
824                 struct strbuf dir = STRBUF_INIT;
825
826                 apply_autostash(opts);
827                 strbuf_addstr(&dir, opts->state_dir);
828                 remove_dir_recursively(&dir, 0);
829                 strbuf_release(&dir);
830                 die("Nothing to do");
831         }
832
833         strbuf_release(&script_snippet);
834
835         return status ? -1 : 0;
836 }
837
838 static int rebase_config(const char *var, const char *value, void *data)
839 {
840         struct rebase_options *opts = data;
841
842         if (!strcmp(var, "rebase.stat")) {
843                 if (git_config_bool(var, value))
844                         opts->flags |= REBASE_DIFFSTAT;
845                 else
846                         opts->flags &= !REBASE_DIFFSTAT;
847                 return 0;
848         }
849
850         if (!strcmp(var, "rebase.autosquash")) {
851                 opts->autosquash = git_config_bool(var, value);
852                 return 0;
853         }
854
855         if (!strcmp(var, "commit.gpgsign")) {
856                 free(opts->gpg_sign_opt);
857                 opts->gpg_sign_opt = git_config_bool(var, value) ?
858                         xstrdup("-S") : NULL;
859                 return 0;
860         }
861
862         if (!strcmp(var, "rebase.autostash")) {
863                 opts->autostash = git_config_bool(var, value);
864                 return 0;
865         }
866
867         if (!strcmp(var, "rebase.reschedulefailedexec")) {
868                 opts->reschedule_failed_exec = git_config_bool(var, value);
869                 return 0;
870         }
871
872         return git_default_config(var, value, data);
873 }
874
875 /*
876  * Determines whether the commits in from..to are linear, i.e. contain
877  * no merge commits. This function *expects* `from` to be an ancestor of
878  * `to`.
879  */
880 static int is_linear_history(struct commit *from, struct commit *to)
881 {
882         while (to && to != from) {
883                 parse_commit(to);
884                 if (!to->parents)
885                         return 1;
886                 if (to->parents->next)
887                         return 0;
888                 to = to->parents->item;
889         }
890         return 1;
891 }
892
893 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
894                             struct object_id *merge_base)
895 {
896         struct commit *head = lookup_commit(the_repository, head_oid);
897         struct commit_list *merge_bases;
898         int res;
899
900         if (!head)
901                 return 0;
902
903         merge_bases = get_merge_bases(onto, head);
904         if (merge_bases && !merge_bases->next) {
905                 oidcpy(merge_base, &merge_bases->item->object.oid);
906                 res = oideq(merge_base, &onto->object.oid);
907         } else {
908                 oidcpy(merge_base, &null_oid);
909                 res = 0;
910         }
911         free_commit_list(merge_bases);
912         return res && is_linear_history(onto, head);
913 }
914
915 /* -i followed by -m is still -i */
916 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
917 {
918         struct rebase_options *opts = opt->value;
919
920         BUG_ON_OPT_NEG(unset);
921         BUG_ON_OPT_ARG(arg);
922
923         if (!is_interactive(opts))
924                 opts->type = REBASE_MERGE;
925
926         return 0;
927 }
928
929 /* -i followed by -p is still explicitly interactive, but -p alone is not */
930 static int parse_opt_interactive(const struct option *opt, const char *arg,
931                                  int unset)
932 {
933         struct rebase_options *opts = opt->value;
934
935         BUG_ON_OPT_NEG(unset);
936         BUG_ON_OPT_ARG(arg);
937
938         opts->type = REBASE_INTERACTIVE;
939         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
940
941         return 0;
942 }
943
944 static void NORETURN error_on_missing_default_upstream(void)
945 {
946         struct branch *current_branch = branch_get(NULL);
947
948         printf(_("%s\n"
949                  "Please specify which branch you want to rebase against.\n"
950                  "See git-rebase(1) for details.\n"
951                  "\n"
952                  "    git rebase '<branch>'\n"
953                  "\n"),
954                 current_branch ? _("There is no tracking information for "
955                         "the current branch.") :
956                         _("You are not currently on a branch."));
957
958         if (current_branch) {
959                 const char *remote = current_branch->remote_name;
960
961                 if (!remote)
962                         remote = _("<remote>");
963
964                 printf(_("If you wish to set tracking information for this "
965                          "branch you can do so with:\n"
966                          "\n"
967                          "    git branch --set-upstream-to=%s/<branch> %s\n"
968                          "\n"),
969                        remote, current_branch->name);
970         }
971         exit(1);
972 }
973
974 static void set_reflog_action(struct rebase_options *options)
975 {
976         const char *env;
977         struct strbuf buf = STRBUF_INIT;
978
979         if (!is_interactive(options))
980                 return;
981
982         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
983         if (env && strcmp("rebase", env))
984                 return; /* only override it if it is "rebase" */
985
986         strbuf_addf(&buf, "rebase -i (%s)", options->action);
987         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
988         strbuf_release(&buf);
989 }
990
991 static int check_exec_cmd(const char *cmd)
992 {
993         if (strchr(cmd, '\n'))
994                 return error(_("exec commands cannot contain newlines"));
995
996         /* Does the command consist purely of whitespace? */
997         if (!cmd[strspn(cmd, " \t\r\f\v")])
998                 return error(_("empty exec command"));
999
1000         return 0;
1001 }
1002
1003
1004 int cmd_rebase(int argc, const char **argv, const char *prefix)
1005 {
1006         struct rebase_options options = {
1007                 .type = REBASE_UNSPECIFIED,
1008                 .flags = REBASE_NO_QUIET,
1009                 .git_am_opts = ARGV_ARRAY_INIT,
1010                 .allow_rerere_autoupdate  = -1,
1011                 .allow_empty_message = 1,
1012                 .git_format_patch_opt = STRBUF_INIT,
1013         };
1014         const char *branch_name;
1015         int ret, flags, total_argc, in_progress = 0;
1016         int ok_to_skip_pre_rebase = 0;
1017         struct strbuf msg = STRBUF_INIT;
1018         struct strbuf revisions = STRBUF_INIT;
1019         struct strbuf buf = STRBUF_INIT;
1020         struct object_id merge_base;
1021         enum {
1022                 NO_ACTION,
1023                 ACTION_CONTINUE,
1024                 ACTION_SKIP,
1025                 ACTION_ABORT,
1026                 ACTION_QUIT,
1027                 ACTION_EDIT_TODO,
1028                 ACTION_SHOW_CURRENT_PATCH,
1029         } action = NO_ACTION;
1030         const char *gpg_sign = NULL;
1031         struct string_list exec = STRING_LIST_INIT_NODUP;
1032         const char *rebase_merges = NULL;
1033         int fork_point = -1;
1034         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1035         struct object_id squash_onto;
1036         char *squash_onto_name = NULL;
1037         struct option builtin_rebase_options[] = {
1038                 OPT_STRING(0, "onto", &options.onto_name,
1039                            N_("revision"),
1040                            N_("rebase onto given branch instead of upstream")),
1041                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1042                          N_("allow pre-rebase hook to run")),
1043                 OPT_NEGBIT('q', "quiet", &options.flags,
1044                            N_("be quiet. implies --no-stat"),
1045                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1046                 OPT_BIT('v', "verbose", &options.flags,
1047                         N_("display a diffstat of what changed upstream"),
1048                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1049                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1050                         N_("do not show diffstat of what changed upstream"),
1051                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1052                 OPT_BOOL(0, "signoff", &options.signoff,
1053                          N_("add a Signed-off-by: line to each commit")),
1054                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1055                                   NULL, N_("passed to 'git am'"),
1056                                   PARSE_OPT_NOARG),
1057                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1058                                   &options.git_am_opts, NULL,
1059                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1060                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1061                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1062                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1063                                   N_("passed to 'git apply'"), 0),
1064                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1065                                   N_("action"), N_("passed to 'git apply'"), 0),
1066                 OPT_BIT('f', "force-rebase", &options.flags,
1067                         N_("cherry-pick all commits, even if unchanged"),
1068                         REBASE_FORCE),
1069                 OPT_BIT(0, "no-ff", &options.flags,
1070                         N_("cherry-pick all commits, even if unchanged"),
1071                         REBASE_FORCE),
1072                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1073                             ACTION_CONTINUE),
1074                 OPT_CMDMODE(0, "skip", &action,
1075                             N_("skip current patch and continue"), ACTION_SKIP),
1076                 OPT_CMDMODE(0, "abort", &action,
1077                             N_("abort and check out the original branch"),
1078                             ACTION_ABORT),
1079                 OPT_CMDMODE(0, "quit", &action,
1080                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1081                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1082                             "during an interactive rebase"), ACTION_EDIT_TODO),
1083                 OPT_CMDMODE(0, "show-current-patch", &action,
1084                             N_("show the patch file being applied or merged"),
1085                             ACTION_SHOW_CURRENT_PATCH),
1086                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1087                         N_("use merging strategies to rebase"),
1088                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1089                         parse_opt_merge },
1090                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1091                         N_("let the user edit the list of commits to rebase"),
1092                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1093                         parse_opt_interactive },
1094                 OPT_SET_INT('p', "preserve-merges", &options.type,
1095                             N_("try to recreate merges instead of ignoring "
1096                                "them"), REBASE_PRESERVE_MERGES),
1097                 OPT_BOOL(0, "rerere-autoupdate",
1098                          &options.allow_rerere_autoupdate,
1099                          N_("allow rerere to update index with resolved "
1100                             "conflict")),
1101                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1102                          N_("preserve empty commits during rebase")),
1103                 OPT_BOOL(0, "autosquash", &options.autosquash,
1104                          N_("move commits that begin with "
1105                             "squash!/fixup! under -i")),
1106                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1107                         N_("GPG-sign commits"),
1108                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1109                 OPT_BOOL(0, "autostash", &options.autostash,
1110                          N_("automatically stash/stash pop before and after")),
1111                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1112                                 N_("add exec lines after each commit of the "
1113                                    "editable list")),
1114                 OPT_BOOL(0, "allow-empty-message",
1115                          &options.allow_empty_message,
1116                          N_("allow rebasing commits with empty messages")),
1117                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1118                         N_("mode"),
1119                         N_("try to rebase merges instead of skipping them"),
1120                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1121                 OPT_BOOL(0, "fork-point", &fork_point,
1122                          N_("use 'merge-base --fork-point' to refine upstream")),
1123                 OPT_STRING('s', "strategy", &options.strategy,
1124                            N_("strategy"), N_("use the given merge strategy")),
1125                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1126                                 N_("option"),
1127                                 N_("pass the argument through to the merge "
1128                                    "strategy")),
1129                 OPT_BOOL(0, "root", &options.root,
1130                          N_("rebase all reachable commits up to the root(s)")),
1131                 OPT_BOOL(0, "reschedule-failed-exec",
1132                          &options.reschedule_failed_exec,
1133                          N_("automatically re-schedule any `exec` that fails")),
1134                 OPT_END(),
1135         };
1136         int i;
1137
1138         /*
1139          * NEEDSWORK: Once the builtin rebase has been tested enough
1140          * and git-legacy-rebase.sh is retired to contrib/, this preamble
1141          * can be removed.
1142          */
1143
1144         if (!use_builtin_rebase()) {
1145                 const char *path = mkpath("%s/git-legacy-rebase",
1146                                           git_exec_path());
1147
1148                 if (sane_execvp(path, (char **)argv) < 0)
1149                         die_errno(_("could not exec %s"), path);
1150                 else
1151                         BUG("sane_execvp() returned???");
1152         }
1153
1154         if (argc == 2 && !strcmp(argv[1], "-h"))
1155                 usage_with_options(builtin_rebase_usage,
1156                                    builtin_rebase_options);
1157
1158         prefix = setup_git_directory();
1159         trace_repo_setup(prefix);
1160         setup_work_tree();
1161
1162         git_config(rebase_config, &options);
1163
1164         strbuf_reset(&buf);
1165         strbuf_addf(&buf, "%s/applying", apply_dir());
1166         if(file_exists(buf.buf))
1167                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1168
1169         if (is_directory(apply_dir())) {
1170                 options.type = REBASE_AM;
1171                 options.state_dir = apply_dir();
1172         } else if (is_directory(merge_dir())) {
1173                 strbuf_reset(&buf);
1174                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1175                 if (is_directory(buf.buf)) {
1176                         options.type = REBASE_PRESERVE_MERGES;
1177                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1178                 } else {
1179                         strbuf_reset(&buf);
1180                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1181                         if(file_exists(buf.buf)) {
1182                                 options.type = REBASE_INTERACTIVE;
1183                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1184                         } else
1185                                 options.type = REBASE_MERGE;
1186                 }
1187                 options.state_dir = merge_dir();
1188         }
1189
1190         if (options.type != REBASE_UNSPECIFIED)
1191                 in_progress = 1;
1192
1193         total_argc = argc;
1194         argc = parse_options(argc, argv, prefix,
1195                              builtin_rebase_options,
1196                              builtin_rebase_usage, 0);
1197
1198         if (action != NO_ACTION && total_argc != 2) {
1199                 usage_with_options(builtin_rebase_usage,
1200                                    builtin_rebase_options);
1201         }
1202
1203         if (argc > 2)
1204                 usage_with_options(builtin_rebase_usage,
1205                                    builtin_rebase_options);
1206
1207         if (action != NO_ACTION && !in_progress)
1208                 die(_("No rebase in progress?"));
1209         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1210
1211         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1212                 die(_("The --edit-todo action can only be used during "
1213                       "interactive rebase."));
1214
1215         switch (action) {
1216         case ACTION_CONTINUE: {
1217                 struct object_id head;
1218                 struct lock_file lock_file = LOCK_INIT;
1219                 int fd;
1220
1221                 options.action = "continue";
1222                 set_reflog_action(&options);
1223
1224                 /* Sanity check */
1225                 if (get_oid("HEAD", &head))
1226                         die(_("Cannot read HEAD"));
1227
1228                 fd = hold_locked_index(&lock_file, 0);
1229                 if (repo_read_index(the_repository) < 0)
1230                         die(_("could not read index"));
1231                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1232                               NULL);
1233                 if (0 <= fd)
1234                         repo_update_index_if_able(the_repository, &lock_file);
1235                 rollback_lock_file(&lock_file);
1236
1237                 if (has_unstaged_changes(the_repository, 1)) {
1238                         puts(_("You must edit all merge conflicts and then\n"
1239                                "mark them as resolved using git add"));
1240                         exit(1);
1241                 }
1242                 if (read_basic_state(&options))
1243                         exit(1);
1244                 goto run_rebase;
1245         }
1246         case ACTION_SKIP: {
1247                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1248
1249                 options.action = "skip";
1250                 set_reflog_action(&options);
1251
1252                 rerere_clear(the_repository, &merge_rr);
1253                 string_list_clear(&merge_rr, 1);
1254
1255                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1256                                NULL, NULL) < 0)
1257                         die(_("could not discard worktree changes"));
1258                 remove_branch_state(the_repository);
1259                 if (read_basic_state(&options))
1260                         exit(1);
1261                 goto run_rebase;
1262         }
1263         case ACTION_ABORT: {
1264                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1265                 options.action = "abort";
1266                 set_reflog_action(&options);
1267
1268                 rerere_clear(the_repository, &merge_rr);
1269                 string_list_clear(&merge_rr, 1);
1270
1271                 if (read_basic_state(&options))
1272                         exit(1);
1273                 if (reset_head(&options.orig_head, "reset",
1274                                options.head_name, RESET_HEAD_HARD,
1275                                NULL, NULL) < 0)
1276                         die(_("could not move back to %s"),
1277                             oid_to_hex(&options.orig_head));
1278                 remove_branch_state(the_repository);
1279                 ret = finish_rebase(&options);
1280                 goto cleanup;
1281         }
1282         case ACTION_QUIT: {
1283                 strbuf_reset(&buf);
1284                 strbuf_addstr(&buf, options.state_dir);
1285                 ret = !!remove_dir_recursively(&buf, 0);
1286                 if (ret)
1287                         die(_("could not remove '%s'"), options.state_dir);
1288                 goto cleanup;
1289         }
1290         case ACTION_EDIT_TODO:
1291                 options.action = "edit-todo";
1292                 options.dont_finish_rebase = 1;
1293                 goto run_rebase;
1294         case ACTION_SHOW_CURRENT_PATCH:
1295                 options.action = "show-current-patch";
1296                 options.dont_finish_rebase = 1;
1297                 goto run_rebase;
1298         case NO_ACTION:
1299                 break;
1300         default:
1301                 BUG("action: %d", action);
1302         }
1303
1304         /* Make sure no rebase is in progress */
1305         if (in_progress) {
1306                 const char *last_slash = strrchr(options.state_dir, '/');
1307                 const char *state_dir_base =
1308                         last_slash ? last_slash + 1 : options.state_dir;
1309                 const char *cmd_live_rebase =
1310                         "git rebase (--continue | --abort | --skip)";
1311                 strbuf_reset(&buf);
1312                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1313                 die(_("It seems that there is already a %s directory, and\n"
1314                       "I wonder if you are in the middle of another rebase.  "
1315                       "If that is the\n"
1316                       "case, please try\n\t%s\n"
1317                       "If that is not the case, please\n\t%s\n"
1318                       "and run me again.  I am stopping in case you still "
1319                       "have something\n"
1320                       "valuable there.\n"),
1321                     state_dir_base, cmd_live_rebase, buf.buf);
1322         }
1323
1324         for (i = 0; i < options.git_am_opts.argc; i++) {
1325                 const char *option = options.git_am_opts.argv[i], *p;
1326                 if (!strcmp(option, "--committer-date-is-author-date") ||
1327                     !strcmp(option, "--ignore-date") ||
1328                     !strcmp(option, "--whitespace=fix") ||
1329                     !strcmp(option, "--whitespace=strip"))
1330                         options.flags |= REBASE_FORCE;
1331                 else if (skip_prefix(option, "-C", &p)) {
1332                         while (*p)
1333                                 if (!isdigit(*(p++)))
1334                                         die(_("switch `C' expects a "
1335                                               "numerical value"));
1336                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1337                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1338                             strcmp(p, "error") && strcmp(p, "error-all"))
1339                                 die("Invalid whitespace option: '%s'", p);
1340                 }
1341         }
1342
1343         for (i = 0; i < exec.nr; i++)
1344                 if (check_exec_cmd(exec.items[i].string))
1345                         exit(1);
1346
1347         if (!(options.flags & REBASE_NO_QUIET))
1348                 argv_array_push(&options.git_am_opts, "-q");
1349
1350         if (options.keep_empty)
1351                 imply_interactive(&options, "--keep-empty");
1352
1353         if (gpg_sign) {
1354                 free(options.gpg_sign_opt);
1355                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1356         }
1357
1358         if (exec.nr) {
1359                 int i;
1360
1361                 imply_interactive(&options, "--exec");
1362
1363                 strbuf_reset(&buf);
1364                 for (i = 0; i < exec.nr; i++)
1365                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1366                 options.cmd = xstrdup(buf.buf);
1367         }
1368
1369         if (rebase_merges) {
1370                 if (!*rebase_merges)
1371                         ; /* default mode; do nothing */
1372                 else if (!strcmp("rebase-cousins", rebase_merges))
1373                         options.rebase_cousins = 1;
1374                 else if (strcmp("no-rebase-cousins", rebase_merges))
1375                         die(_("Unknown mode: %s"), rebase_merges);
1376                 options.rebase_merges = 1;
1377                 imply_interactive(&options, "--rebase-merges");
1378         }
1379
1380         if (strategy_options.nr) {
1381                 int i;
1382
1383                 if (!options.strategy)
1384                         options.strategy = "recursive";
1385
1386                 strbuf_reset(&buf);
1387                 for (i = 0; i < strategy_options.nr; i++)
1388                         strbuf_addf(&buf, " --%s",
1389                                     strategy_options.items[i].string);
1390                 options.strategy_opts = xstrdup(buf.buf);
1391         }
1392
1393         if (options.strategy) {
1394                 options.strategy = xstrdup(options.strategy);
1395                 switch (options.type) {
1396                 case REBASE_AM:
1397                         die(_("--strategy requires --merge or --interactive"));
1398                 case REBASE_MERGE:
1399                 case REBASE_INTERACTIVE:
1400                 case REBASE_PRESERVE_MERGES:
1401                         /* compatible */
1402                         break;
1403                 case REBASE_UNSPECIFIED:
1404                         options.type = REBASE_MERGE;
1405                         break;
1406                 default:
1407                         BUG("unhandled rebase type (%d)", options.type);
1408                 }
1409         }
1410
1411         if (options.type == REBASE_MERGE)
1412                 imply_interactive(&options, "--merge");
1413
1414         if (options.root && !options.onto_name)
1415                 imply_interactive(&options, "--root without --onto");
1416
1417         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1418                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1419
1420         switch (options.type) {
1421         case REBASE_MERGE:
1422         case REBASE_INTERACTIVE:
1423         case REBASE_PRESERVE_MERGES:
1424                 options.state_dir = merge_dir();
1425                 break;
1426         case REBASE_AM:
1427                 options.state_dir = apply_dir();
1428                 break;
1429         default:
1430                 /* the default rebase backend is `--am` */
1431                 options.type = REBASE_AM;
1432                 options.state_dir = apply_dir();
1433                 break;
1434         }
1435
1436         if (options.reschedule_failed_exec && !is_interactive(&options))
1437                 die(_("%s requires an interactive rebase"), "--reschedule-failed-exec");
1438
1439         if (options.git_am_opts.argc) {
1440                 /* all am options except -q are compatible only with --am */
1441                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1442                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1443                                 break;
1444
1445                 if (is_interactive(&options) && i >= 0)
1446                         die(_("cannot combine am options with either "
1447                               "interactive or merge options"));
1448         }
1449
1450         if (options.signoff) {
1451                 if (options.type == REBASE_PRESERVE_MERGES)
1452                         die("cannot combine '--signoff' with "
1453                             "'--preserve-merges'");
1454                 argv_array_push(&options.git_am_opts, "--signoff");
1455                 options.flags |= REBASE_FORCE;
1456         }
1457
1458         if (options.type == REBASE_PRESERVE_MERGES) {
1459                 /*
1460                  * Note: incompatibility with --signoff handled in signoff block above
1461                  * Note: incompatibility with --interactive is just a strong warning;
1462                  *       git-rebase.txt caveats with "unless you know what you are doing"
1463                  */
1464                 if (options.rebase_merges)
1465                         die(_("cannot combine '--preserve-merges' with "
1466                               "'--rebase-merges'"));
1467
1468                 if (options.reschedule_failed_exec)
1469                         die(_("error: cannot combine '--preserve-merges' with "
1470                               "'--reschedule-failed-exec'"));
1471         }
1472
1473         if (options.rebase_merges) {
1474                 if (strategy_options.nr)
1475                         die(_("cannot combine '--rebase-merges' with "
1476                               "'--strategy-option'"));
1477                 if (options.strategy)
1478                         die(_("cannot combine '--rebase-merges' with "
1479                               "'--strategy'"));
1480         }
1481
1482         if (!options.root) {
1483                 if (argc < 1) {
1484                         struct branch *branch;
1485
1486                         branch = branch_get(NULL);
1487                         options.upstream_name = branch_get_upstream(branch,
1488                                                                     NULL);
1489                         if (!options.upstream_name)
1490                                 error_on_missing_default_upstream();
1491                         if (fork_point < 0)
1492                                 fork_point = 1;
1493                 } else {
1494                         options.upstream_name = argv[0];
1495                         argc--;
1496                         argv++;
1497                         if (!strcmp(options.upstream_name, "-"))
1498                                 options.upstream_name = "@{-1}";
1499                 }
1500                 options.upstream = peel_committish(options.upstream_name);
1501                 if (!options.upstream)
1502                         die(_("invalid upstream '%s'"), options.upstream_name);
1503                 options.upstream_arg = options.upstream_name;
1504         } else {
1505                 if (!options.onto_name) {
1506                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1507                                         &squash_onto, NULL, NULL) < 0)
1508                                 die(_("Could not create new root commit"));
1509                         options.squash_onto = &squash_onto;
1510                         options.onto_name = squash_onto_name =
1511                                 xstrdup(oid_to_hex(&squash_onto));
1512                 }
1513                 options.upstream_name = NULL;
1514                 options.upstream = NULL;
1515                 if (argc > 1)
1516                         usage_with_options(builtin_rebase_usage,
1517                                            builtin_rebase_options);
1518                 options.upstream_arg = "--root";
1519         }
1520
1521         /* Make sure the branch to rebase onto is valid. */
1522         if (!options.onto_name)
1523                 options.onto_name = options.upstream_name;
1524         if (strstr(options.onto_name, "...")) {
1525                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1526                         die(_("'%s': need exactly one merge base"),
1527                             options.onto_name);
1528                 options.onto = lookup_commit_or_die(&merge_base,
1529                                                     options.onto_name);
1530         } else {
1531                 options.onto = peel_committish(options.onto_name);
1532                 if (!options.onto)
1533                         die(_("Does not point to a valid commit '%s'"),
1534                                 options.onto_name);
1535         }
1536
1537         /*
1538          * If the branch to rebase is given, that is the branch we will rebase
1539          * branch_name -- branch/commit being rebased, or
1540          *                HEAD (already detached)
1541          * orig_head -- commit object name of tip of the branch before rebasing
1542          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1543          */
1544         if (argc == 1) {
1545                 /* Is it "rebase other branchname" or "rebase other commit"? */
1546                 branch_name = argv[0];
1547                 options.switch_to = argv[0];
1548
1549                 /* Is it a local branch? */
1550                 strbuf_reset(&buf);
1551                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1552                 if (!read_ref(buf.buf, &options.orig_head))
1553                         options.head_name = xstrdup(buf.buf);
1554                 /* If not is it a valid ref (branch or commit)? */
1555                 else if (!get_oid(branch_name, &options.orig_head))
1556                         options.head_name = NULL;
1557                 else
1558                         die(_("fatal: no such branch/commit '%s'"),
1559                             branch_name);
1560         } else if (argc == 0) {
1561                 /* Do not need to switch branches, we are already on it. */
1562                 options.head_name =
1563                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1564                                          &flags));
1565                 if (!options.head_name)
1566                         die(_("No such ref: %s"), "HEAD");
1567                 if (flags & REF_ISSYMREF) {
1568                         if (!skip_prefix(options.head_name,
1569                                          "refs/heads/", &branch_name))
1570                                 branch_name = options.head_name;
1571
1572                 } else {
1573                         free(options.head_name);
1574                         options.head_name = NULL;
1575                         branch_name = "HEAD";
1576                 }
1577                 if (get_oid("HEAD", &options.orig_head))
1578                         die(_("Could not resolve HEAD to a revision"));
1579         } else
1580                 BUG("unexpected number of arguments left to parse");
1581
1582         if (fork_point > 0) {
1583                 struct commit *head =
1584                         lookup_commit_reference(the_repository,
1585                                                 &options.orig_head);
1586                 options.restrict_revision =
1587                         get_fork_point(options.upstream_name, head);
1588         }
1589
1590         if (repo_read_index(the_repository) < 0)
1591                 die(_("could not read index"));
1592
1593         if (options.autostash) {
1594                 struct lock_file lock_file = LOCK_INIT;
1595                 int fd;
1596
1597                 fd = hold_locked_index(&lock_file, 0);
1598                 refresh_cache(REFRESH_QUIET);
1599                 if (0 <= fd)
1600                         repo_update_index_if_able(the_repository, &lock_file);
1601                 rollback_lock_file(&lock_file);
1602
1603                 if (has_unstaged_changes(the_repository, 1) ||
1604                     has_uncommitted_changes(the_repository, 1)) {
1605                         const char *autostash =
1606                                 state_dir_path("autostash", &options);
1607                         struct child_process stash = CHILD_PROCESS_INIT;
1608                         struct object_id oid;
1609                         struct commit *head =
1610                                 lookup_commit_reference(the_repository,
1611                                                         &options.orig_head);
1612
1613                         argv_array_pushl(&stash.args,
1614                                          "stash", "create", "autostash", NULL);
1615                         stash.git_cmd = 1;
1616                         stash.no_stdin = 1;
1617                         strbuf_reset(&buf);
1618                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1619                                 die(_("Cannot autostash"));
1620                         strbuf_trim_trailing_newline(&buf);
1621                         if (get_oid(buf.buf, &oid))
1622                                 die(_("Unexpected stash response: '%s'"),
1623                                     buf.buf);
1624                         strbuf_reset(&buf);
1625                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1626
1627                         if (safe_create_leading_directories_const(autostash))
1628                                 die(_("Could not create directory for '%s'"),
1629                                     options.state_dir);
1630                         write_file(autostash, "%s", oid_to_hex(&oid));
1631                         printf(_("Created autostash: %s\n"), buf.buf);
1632                         if (reset_head(&head->object.oid, "reset --hard",
1633                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1634                                 die(_("could not reset --hard"));
1635                         printf(_("HEAD is now at %s"),
1636                                find_unique_abbrev(&head->object.oid,
1637                                                   DEFAULT_ABBREV));
1638                         strbuf_reset(&buf);
1639                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1640                         if (buf.len > 0)
1641                                 printf(" %s", buf.buf);
1642                         putchar('\n');
1643
1644                         if (discard_index(the_repository->index) < 0 ||
1645                                 repo_read_index(the_repository) < 0)
1646                                 die(_("could not read index"));
1647                 }
1648         }
1649
1650         if (require_clean_work_tree(the_repository, "rebase",
1651                                     _("Please commit or stash them."), 1, 1)) {
1652                 ret = 1;
1653                 goto cleanup;
1654         }
1655
1656         /*
1657          * Now we are rebasing commits upstream..orig_head (or with --root,
1658          * everything leading up to orig_head) on top of onto.
1659          */
1660
1661         /*
1662          * Check if we are already based on onto with linear history,
1663          * but this should be done only when upstream and onto are the same
1664          * and if this is not an interactive rebase.
1665          */
1666         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1667             !is_interactive(&options) && !options.restrict_revision &&
1668             options.upstream &&
1669             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1670                 int flag;
1671
1672                 if (!(options.flags & REBASE_FORCE)) {
1673                         /* Lazily switch to the target branch if needed... */
1674                         if (options.switch_to) {
1675                                 struct object_id oid;
1676
1677                                 if (get_oid(options.switch_to, &oid) < 0) {
1678                                         ret = !!error(_("could not parse '%s'"),
1679                                                       options.switch_to);
1680                                         goto cleanup;
1681                                 }
1682
1683                                 strbuf_reset(&buf);
1684                                 strbuf_addf(&buf, "%s: checkout %s",
1685                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1686                                             options.switch_to);
1687                                 if (reset_head(&oid, "checkout",
1688                                                options.head_name,
1689                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1690                                                NULL, buf.buf) < 0) {
1691                                         ret = !!error(_("could not switch to "
1692                                                         "%s"),
1693                                                       options.switch_to);
1694                                         goto cleanup;
1695                                 }
1696                         }
1697
1698                         if (!(options.flags & REBASE_NO_QUIET))
1699                                 ; /* be quiet */
1700                         else if (!strcmp(branch_name, "HEAD") &&
1701                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1702                                 puts(_("HEAD is up to date."));
1703                         else
1704                                 printf(_("Current branch %s is up to date.\n"),
1705                                        branch_name);
1706                         ret = !!finish_rebase(&options);
1707                         goto cleanup;
1708                 } else if (!(options.flags & REBASE_NO_QUIET))
1709                         ; /* be quiet */
1710                 else if (!strcmp(branch_name, "HEAD") &&
1711                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1712                         puts(_("HEAD is up to date, rebase forced."));
1713                 else
1714                         printf(_("Current branch %s is up to date, rebase "
1715                                  "forced.\n"), branch_name);
1716         }
1717
1718         /* If a hook exists, give it a chance to interrupt*/
1719         if (!ok_to_skip_pre_rebase &&
1720             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1721                         argc ? argv[0] : NULL, NULL))
1722                 die(_("The pre-rebase hook refused to rebase."));
1723
1724         if (options.flags & REBASE_DIFFSTAT) {
1725                 struct diff_options opts;
1726
1727                 if (options.flags & REBASE_VERBOSE) {
1728                         if (is_null_oid(&merge_base))
1729                                 printf(_("Changes to %s:\n"),
1730                                        oid_to_hex(&options.onto->object.oid));
1731                         else
1732                                 printf(_("Changes from %s to %s:\n"),
1733                                        oid_to_hex(&merge_base),
1734                                        oid_to_hex(&options.onto->object.oid));
1735                 }
1736
1737                 /* We want color (if set), but no pager */
1738                 diff_setup(&opts);
1739                 opts.stat_width = -1; /* use full terminal width */
1740                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1741                 opts.output_format |=
1742                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1743                 opts.detect_rename = DIFF_DETECT_RENAME;
1744                 diff_setup_done(&opts);
1745                 diff_tree_oid(is_null_oid(&merge_base) ?
1746                               the_hash_algo->empty_tree : &merge_base,
1747                               &options.onto->object.oid, "", &opts);
1748                 diffcore_std(&opts);
1749                 diff_flush(&opts);
1750         }
1751
1752         if (is_interactive(&options))
1753                 goto run_rebase;
1754
1755         /* Detach HEAD and reset the tree */
1756         if (options.flags & REBASE_NO_QUIET)
1757                 printf(_("First, rewinding head to replay your work on top of "
1758                          "it...\n"));
1759
1760         strbuf_addf(&msg, "%s: checkout %s",
1761                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1762         if (reset_head(&options.onto->object.oid, "checkout", NULL,
1763                        RESET_HEAD_DETACH | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1764                        NULL, msg.buf))
1765                 die(_("Could not detach HEAD"));
1766         strbuf_release(&msg);
1767
1768         /*
1769          * If the onto is a proper descendant of the tip of the branch, then
1770          * we just fast-forwarded.
1771          */
1772         strbuf_reset(&msg);
1773         if (!oidcmp(&merge_base, &options.orig_head)) {
1774                 printf(_("Fast-forwarded %s to %s.\n"),
1775                         branch_name, options.onto_name);
1776                 strbuf_addf(&msg, "rebase finished: %s onto %s",
1777                         options.head_name ? options.head_name : "detached HEAD",
1778                         oid_to_hex(&options.onto->object.oid));
1779                 reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1780                            "HEAD", msg.buf);
1781                 strbuf_release(&msg);
1782                 ret = !!finish_rebase(&options);
1783                 goto cleanup;
1784         }
1785
1786         strbuf_addf(&revisions, "%s..%s",
1787                     options.root ? oid_to_hex(&options.onto->object.oid) :
1788                     (options.restrict_revision ?
1789                      oid_to_hex(&options.restrict_revision->object.oid) :
1790                      oid_to_hex(&options.upstream->object.oid)),
1791                     oid_to_hex(&options.orig_head));
1792
1793         options.revisions = revisions.buf;
1794
1795 run_rebase:
1796         ret = !!run_specific_rebase(&options);
1797
1798 cleanup:
1799         strbuf_release(&revisions);
1800         free(options.head_name);
1801         free(options.gpg_sign_opt);
1802         free(options.cmd);
1803         free(squash_onto_name);
1804         return ret;
1805 }