Merge branch 'es/worktree-repair-both-moved'
[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 "strvec.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 #include "sequencer.h"
29 #include "rebase-interactive.h"
30 #include "reset.h"
31
32 #define DEFAULT_REFLOG_ACTION "rebase"
33
34 static char const * const builtin_rebase_usage[] = {
35         N_("git rebase [-i] [options] [--exec <cmd>] "
36                 "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
37         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
38                 "--root [<branch>]"),
39         N_("git rebase --continue | --abort | --skip | --edit-todo"),
40         NULL
41 };
42
43 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
44 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
45 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
46 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
47
48 enum rebase_type {
49         REBASE_UNSPECIFIED = -1,
50         REBASE_APPLY,
51         REBASE_MERGE,
52         REBASE_PRESERVE_MERGES
53 };
54
55 enum empty_type {
56         EMPTY_UNSPECIFIED = -1,
57         EMPTY_DROP,
58         EMPTY_KEEP,
59         EMPTY_ASK
60 };
61
62 struct rebase_options {
63         enum rebase_type type;
64         enum empty_type empty;
65         const char *default_backend;
66         const char *state_dir;
67         struct commit *upstream;
68         const char *upstream_name;
69         const char *upstream_arg;
70         char *head_name;
71         struct object_id orig_head;
72         struct commit *onto;
73         const char *onto_name;
74         const char *revisions;
75         const char *switch_to;
76         int root, root_with_onto;
77         struct object_id *squash_onto;
78         struct commit *restrict_revision;
79         int dont_finish_rebase;
80         enum {
81                 REBASE_NO_QUIET = 1<<0,
82                 REBASE_VERBOSE = 1<<1,
83                 REBASE_DIFFSTAT = 1<<2,
84                 REBASE_FORCE = 1<<3,
85                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
86         } flags;
87         struct strvec git_am_opts;
88         const char *action;
89         int signoff;
90         int allow_rerere_autoupdate;
91         int keep_empty;
92         int autosquash;
93         char *gpg_sign_opt;
94         int autostash;
95         int committer_date_is_author_date;
96         int ignore_date;
97         char *cmd;
98         int allow_empty_message;
99         int rebase_merges, rebase_cousins;
100         char *strategy, *strategy_opts;
101         struct strbuf git_format_patch_opt;
102         int reschedule_failed_exec;
103         int use_legacy_rebase;
104         int reapply_cherry_picks;
105 };
106
107 #define REBASE_OPTIONS_INIT {                           \
108                 .type = REBASE_UNSPECIFIED,             \
109                 .empty = EMPTY_UNSPECIFIED,             \
110                 .keep_empty = 1,                        \
111                 .default_backend = "merge",             \
112                 .flags = REBASE_NO_QUIET,               \
113                 .git_am_opts = STRVEC_INIT,             \
114                 .git_format_patch_opt = STRBUF_INIT     \
115         }
116
117 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
118 {
119         struct replay_opts replay = REPLAY_OPTS_INIT;
120
121         replay.action = REPLAY_INTERACTIVE_REBASE;
122         replay.strategy = NULL;
123         sequencer_init_config(&replay);
124
125         replay.signoff = opts->signoff;
126         replay.allow_ff = !(opts->flags & REBASE_FORCE);
127         if (opts->allow_rerere_autoupdate)
128                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
129         replay.allow_empty = 1;
130         replay.allow_empty_message = opts->allow_empty_message;
131         replay.drop_redundant_commits = (opts->empty == EMPTY_DROP);
132         replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
133         replay.quiet = !(opts->flags & REBASE_NO_QUIET);
134         replay.verbose = opts->flags & REBASE_VERBOSE;
135         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
136         replay.committer_date_is_author_date =
137                                         opts->committer_date_is_author_date;
138         replay.ignore_date = opts->ignore_date;
139         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
140         if (opts->strategy)
141                 replay.strategy = opts->strategy;
142         else if (!replay.strategy && replay.default_strategy) {
143                 replay.strategy = replay.default_strategy;
144                 replay.default_strategy = NULL;
145         }
146
147         if (opts->strategy_opts)
148                 parse_strategy_opts(&replay, opts->strategy_opts);
149
150         if (opts->squash_onto) {
151                 oidcpy(&replay.squash_onto, opts->squash_onto);
152                 replay.have_squash_onto = 1;
153         }
154
155         return replay;
156 }
157
158 enum action {
159         ACTION_NONE = 0,
160         ACTION_CONTINUE,
161         ACTION_SKIP,
162         ACTION_ABORT,
163         ACTION_QUIT,
164         ACTION_EDIT_TODO,
165         ACTION_SHOW_CURRENT_PATCH,
166         ACTION_SHORTEN_OIDS,
167         ACTION_EXPAND_OIDS,
168         ACTION_CHECK_TODO_LIST,
169         ACTION_REARRANGE_SQUASH,
170         ACTION_ADD_EXEC
171 };
172
173 static const char *action_names[] = { "undefined",
174                                       "continue",
175                                       "skip",
176                                       "abort",
177                                       "quit",
178                                       "edit_todo",
179                                       "show_current_patch" };
180
181 static int add_exec_commands(struct string_list *commands)
182 {
183         const char *todo_file = rebase_path_todo();
184         struct todo_list todo_list = TODO_LIST_INIT;
185         int res;
186
187         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
188                 return error_errno(_("could not read '%s'."), todo_file);
189
190         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
191                                         &todo_list)) {
192                 todo_list_release(&todo_list);
193                 return error(_("unusable todo list: '%s'"), todo_file);
194         }
195
196         todo_list_add_exec_commands(&todo_list, commands);
197         res = todo_list_write_to_file(the_repository, &todo_list,
198                                       todo_file, NULL, NULL, -1, 0);
199         todo_list_release(&todo_list);
200
201         if (res)
202                 return error_errno(_("could not write '%s'."), todo_file);
203         return 0;
204 }
205
206 static int rearrange_squash_in_todo_file(void)
207 {
208         const char *todo_file = rebase_path_todo();
209         struct todo_list todo_list = TODO_LIST_INIT;
210         int res = 0;
211
212         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
213                 return error_errno(_("could not read '%s'."), todo_file);
214         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
215                                         &todo_list)) {
216                 todo_list_release(&todo_list);
217                 return error(_("unusable todo list: '%s'"), todo_file);
218         }
219
220         res = todo_list_rearrange_squash(&todo_list);
221         if (!res)
222                 res = todo_list_write_to_file(the_repository, &todo_list,
223                                               todo_file, NULL, NULL, -1, 0);
224
225         todo_list_release(&todo_list);
226
227         if (res)
228                 return error_errno(_("could not write '%s'."), todo_file);
229         return 0;
230 }
231
232 static int transform_todo_file(unsigned flags)
233 {
234         const char *todo_file = rebase_path_todo();
235         struct todo_list todo_list = TODO_LIST_INIT;
236         int res;
237
238         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
239                 return error_errno(_("could not read '%s'."), todo_file);
240
241         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
242                                         &todo_list)) {
243                 todo_list_release(&todo_list);
244                 return error(_("unusable todo list: '%s'"), todo_file);
245         }
246
247         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
248                                       NULL, NULL, -1, flags);
249         todo_list_release(&todo_list);
250
251         if (res)
252                 return error_errno(_("could not write '%s'."), todo_file);
253         return 0;
254 }
255
256 static int edit_todo_file(unsigned flags)
257 {
258         const char *todo_file = rebase_path_todo();
259         struct todo_list todo_list = TODO_LIST_INIT,
260                 new_todo = TODO_LIST_INIT;
261         int res = 0;
262
263         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
264                 return error_errno(_("could not read '%s'."), todo_file);
265
266         strbuf_stripspace(&todo_list.buf, 1);
267         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
268         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
269                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
270                 res = error_errno(_("could not write '%s'"), todo_file);
271
272         todo_list_release(&todo_list);
273         todo_list_release(&new_todo);
274
275         return res;
276 }
277
278 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
279                                struct object_id *orig_head, char **revisions,
280                                char **shortrevisions)
281 {
282         struct commit *base_rev = upstream ? upstream : onto;
283         const char *shorthead;
284
285         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
286                              oid_to_hex(orig_head));
287
288         shorthead = find_unique_abbrev(orig_head, DEFAULT_ABBREV);
289
290         if (upstream) {
291                 const char *shortrev;
292
293                 shortrev = find_unique_abbrev(&base_rev->object.oid,
294                                               DEFAULT_ABBREV);
295
296                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
297         } else
298                 *shortrevisions = xstrdup(shorthead);
299
300         return 0;
301 }
302
303 static int init_basic_state(struct replay_opts *opts, const char *head_name,
304                             struct commit *onto,
305                             const struct object_id *orig_head)
306 {
307         FILE *interactive;
308
309         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
310                 return error_errno(_("could not create temporary %s"), merge_dir());
311
312         delete_reflog("REBASE_HEAD");
313
314         interactive = fopen(path_interactive(), "w");
315         if (!interactive)
316                 return error_errno(_("could not mark as interactive"));
317         fclose(interactive);
318
319         return write_basic_state(opts, head_name, onto, orig_head);
320 }
321
322 static void split_exec_commands(const char *cmd, struct string_list *commands)
323 {
324         if (cmd && *cmd) {
325                 string_list_split(commands, cmd, '\n', -1);
326
327                 /* rebase.c adds a new line to cmd after every command,
328                  * so here the last command is always empty */
329                 string_list_remove_empty_items(commands, 0);
330         }
331 }
332
333 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
334 {
335         int ret;
336         char *revisions = NULL, *shortrevisions = NULL;
337         struct strvec make_script_args = STRVEC_INIT;
338         struct todo_list todo_list = TODO_LIST_INIT;
339         struct replay_opts replay = get_replay_opts(opts);
340         struct string_list commands = STRING_LIST_INIT_DUP;
341
342         if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head,
343                                 &revisions, &shortrevisions))
344                 return -1;
345
346         if (init_basic_state(&replay,
347                              opts->head_name ? opts->head_name : "detached HEAD",
348                              opts->onto, &opts->orig_head)) {
349                 free(revisions);
350                 free(shortrevisions);
351
352                 return -1;
353         }
354
355         if (!opts->upstream && opts->squash_onto)
356                 write_file(path_squash_onto(), "%s\n",
357                            oid_to_hex(opts->squash_onto));
358
359         strvec_pushl(&make_script_args, "", revisions, NULL);
360         if (opts->restrict_revision)
361                 strvec_pushf(&make_script_args, "^%s",
362                              oid_to_hex(&opts->restrict_revision->object.oid));
363
364         ret = sequencer_make_script(the_repository, &todo_list.buf,
365                                     make_script_args.nr, make_script_args.v,
366                                     flags);
367
368         if (ret)
369                 error(_("could not generate todo list"));
370         else {
371                 discard_cache();
372                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
373                                                 &todo_list))
374                         BUG("unusable todo list");
375
376                 split_exec_commands(opts->cmd, &commands);
377                 ret = complete_action(the_repository, &replay, flags,
378                         shortrevisions, opts->onto_name, opts->onto,
379                         &opts->orig_head, &commands, opts->autosquash,
380                         &todo_list);
381         }
382
383         string_list_clear(&commands, 0);
384         free(revisions);
385         free(shortrevisions);
386         todo_list_release(&todo_list);
387         strvec_clear(&make_script_args);
388
389         return ret;
390 }
391
392 static int run_sequencer_rebase(struct rebase_options *opts,
393                                   enum action command)
394 {
395         unsigned flags = 0;
396         int abbreviate_commands = 0, ret = 0;
397
398         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
399
400         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
401         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
402         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
403         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
404         flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
405         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
406         flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
407
408         switch (command) {
409         case ACTION_NONE: {
410                 if (!opts->onto && !opts->upstream)
411                         die(_("a base commit must be provided with --upstream or --onto"));
412
413                 ret = do_interactive_rebase(opts, flags);
414                 break;
415         }
416         case ACTION_SKIP: {
417                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
418
419                 rerere_clear(the_repository, &merge_rr);
420         }
421                 /* fallthrough */
422         case ACTION_CONTINUE: {
423                 struct replay_opts replay_opts = get_replay_opts(opts);
424
425                 ret = sequencer_continue(the_repository, &replay_opts);
426                 break;
427         }
428         case ACTION_EDIT_TODO:
429                 ret = edit_todo_file(flags);
430                 break;
431         case ACTION_SHOW_CURRENT_PATCH: {
432                 struct child_process cmd = CHILD_PROCESS_INIT;
433
434                 cmd.git_cmd = 1;
435                 strvec_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
436                 ret = run_command(&cmd);
437
438                 break;
439         }
440         case ACTION_SHORTEN_OIDS:
441         case ACTION_EXPAND_OIDS:
442                 ret = transform_todo_file(flags);
443                 break;
444         case ACTION_CHECK_TODO_LIST:
445                 ret = check_todo_list_from_file(the_repository);
446                 break;
447         case ACTION_REARRANGE_SQUASH:
448                 ret = rearrange_squash_in_todo_file();
449                 break;
450         case ACTION_ADD_EXEC: {
451                 struct string_list commands = STRING_LIST_INIT_DUP;
452
453                 split_exec_commands(opts->cmd, &commands);
454                 ret = add_exec_commands(&commands);
455                 string_list_clear(&commands, 0);
456                 break;
457         }
458         default:
459                 BUG("invalid command '%d'", command);
460         }
461
462         return ret;
463 }
464
465 static void imply_merge(struct rebase_options *opts, const char *option);
466 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
467                                 int unset)
468 {
469         struct rebase_options *opts = opt->value;
470
471         BUG_ON_OPT_ARG(arg);
472
473         imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
474         opts->keep_empty = !unset;
475         opts->type = REBASE_MERGE;
476         return 0;
477 }
478
479 static const char * const builtin_rebase_interactive_usage[] = {
480         N_("git rebase--interactive [<options>]"),
481         NULL
482 };
483
484 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
485 {
486         struct rebase_options opts = REBASE_OPTIONS_INIT;
487         struct object_id squash_onto = null_oid;
488         enum action command = ACTION_NONE;
489         struct option options[] = {
490                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
491                            REBASE_FORCE),
492                 OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
493                         N_("keep commits which start empty"),
494                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
495                         parse_opt_keep_empty),
496                 OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
497                            N_("allow commits with empty messages"),
498                            PARSE_OPT_HIDDEN),
499                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
500                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
501                          N_("keep original branch points of cousins")),
502                 OPT_BOOL(0, "autosquash", &opts.autosquash,
503                          N_("move commits that begin with squash!/fixup!")),
504                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
505                 OPT_BIT('v', "verbose", &opts.flags,
506                         N_("display a diffstat of what changed upstream"),
507                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
508                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
509                             ACTION_CONTINUE),
510                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
511                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
512                             ACTION_EDIT_TODO),
513                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
514                             ACTION_SHOW_CURRENT_PATCH),
515                 OPT_CMDMODE(0, "shorten-ids", &command,
516                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
517                 OPT_CMDMODE(0, "expand-ids", &command,
518                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
519                 OPT_CMDMODE(0, "check-todo-list", &command,
520                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
521                 OPT_CMDMODE(0, "rearrange-squash", &command,
522                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
523                 OPT_CMDMODE(0, "add-exec-commands", &command,
524                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
525                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
526                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
527                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
528                   N_("restrict-revision"), N_("restrict revision"),
529                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
530                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
531                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
532                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
533                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
534                   0 },
535                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
536                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
537                         N_("GPG-sign commits"),
538                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
539                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
540                            N_("rebase strategy")),
541                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
542                            N_("strategy options")),
543                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
544                            N_("the branch or commit to checkout")),
545                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
546                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
547                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
548                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
549                          N_("automatically re-schedule any `exec` that fails")),
550                 OPT_END()
551         };
552
553         opts.rebase_cousins = -1;
554
555         if (argc == 1)
556                 usage_with_options(builtin_rebase_interactive_usage, options);
557
558         argc = parse_options(argc, argv, prefix, options,
559                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
560
561         if (!is_null_oid(&squash_onto))
562                 opts.squash_onto = &squash_onto;
563
564         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
565                 warning(_("--[no-]rebase-cousins has no effect without "
566                           "--rebase-merges"));
567
568         return !!run_sequencer_rebase(&opts, command);
569 }
570
571 static int is_merge(struct rebase_options *opts)
572 {
573         return opts->type == REBASE_MERGE ||
574                 opts->type == REBASE_PRESERVE_MERGES;
575 }
576
577 static void imply_merge(struct rebase_options *opts, const char *option)
578 {
579         switch (opts->type) {
580         case REBASE_APPLY:
581                 die(_("%s requires the merge backend"), option);
582                 break;
583         case REBASE_MERGE:
584         case REBASE_PRESERVE_MERGES:
585                 break;
586         default:
587                 opts->type = REBASE_MERGE; /* implied */
588                 break;
589         }
590 }
591
592 /* Returns the filename prefixed by the state_dir */
593 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
594 {
595         static struct strbuf path = STRBUF_INIT;
596         static size_t prefix_len;
597
598         if (!prefix_len) {
599                 strbuf_addf(&path, "%s/", opts->state_dir);
600                 prefix_len = path.len;
601         }
602
603         strbuf_setlen(&path, prefix_len);
604         strbuf_addstr(&path, filename);
605         return path.buf;
606 }
607
608 /* Initialize the rebase options from the state directory. */
609 static int read_basic_state(struct rebase_options *opts)
610 {
611         struct strbuf head_name = STRBUF_INIT;
612         struct strbuf buf = STRBUF_INIT;
613         struct object_id oid;
614
615         if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
616                            READ_ONELINER_WARN_MISSING) ||
617             !read_oneliner(&buf, state_dir_path("onto", opts),
618                            READ_ONELINER_WARN_MISSING))
619                 return -1;
620         opts->head_name = starts_with(head_name.buf, "refs/") ?
621                 xstrdup(head_name.buf) : NULL;
622         strbuf_release(&head_name);
623         if (get_oid(buf.buf, &oid))
624                 return error(_("could not get 'onto': '%s'"), buf.buf);
625         opts->onto = lookup_commit_or_die(&oid, buf.buf);
626
627         /*
628          * We always write to orig-head, but interactive rebase used to write to
629          * head. Fall back to reading from head to cover for the case that the
630          * user upgraded git with an ongoing interactive rebase.
631          */
632         strbuf_reset(&buf);
633         if (file_exists(state_dir_path("orig-head", opts))) {
634                 if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
635                                    READ_ONELINER_WARN_MISSING))
636                         return -1;
637         } else if (!read_oneliner(&buf, state_dir_path("head", opts),
638                                   READ_ONELINER_WARN_MISSING))
639                 return -1;
640         if (get_oid(buf.buf, &opts->orig_head))
641                 return error(_("invalid orig-head: '%s'"), buf.buf);
642
643         if (file_exists(state_dir_path("quiet", opts)))
644                 opts->flags &= ~REBASE_NO_QUIET;
645         else
646                 opts->flags |= REBASE_NO_QUIET;
647
648         if (file_exists(state_dir_path("verbose", opts)))
649                 opts->flags |= REBASE_VERBOSE;
650
651         if (file_exists(state_dir_path("signoff", opts))) {
652                 opts->signoff = 1;
653                 opts->flags |= REBASE_FORCE;
654         }
655
656         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
657                 strbuf_reset(&buf);
658                 if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
659                                    READ_ONELINER_WARN_MISSING))
660                         return -1;
661                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
662                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
663                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
664                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
665                 else
666                         warning(_("ignoring invalid allow_rerere_autoupdate: "
667                                   "'%s'"), buf.buf);
668         }
669
670         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
671                 strbuf_reset(&buf);
672                 if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
673                                    READ_ONELINER_WARN_MISSING))
674                         return -1;
675                 free(opts->gpg_sign_opt);
676                 opts->gpg_sign_opt = xstrdup(buf.buf);
677         }
678
679         if (file_exists(state_dir_path("strategy", opts))) {
680                 strbuf_reset(&buf);
681                 if (!read_oneliner(&buf, state_dir_path("strategy", opts),
682                                    READ_ONELINER_WARN_MISSING))
683                         return -1;
684                 free(opts->strategy);
685                 opts->strategy = xstrdup(buf.buf);
686         }
687
688         if (file_exists(state_dir_path("strategy_opts", opts))) {
689                 strbuf_reset(&buf);
690                 if (!read_oneliner(&buf, state_dir_path("strategy_opts", opts),
691                                    READ_ONELINER_WARN_MISSING))
692                         return -1;
693                 free(opts->strategy_opts);
694                 opts->strategy_opts = xstrdup(buf.buf);
695         }
696
697         strbuf_release(&buf);
698
699         return 0;
700 }
701
702 static int rebase_write_basic_state(struct rebase_options *opts)
703 {
704         write_file(state_dir_path("head-name", opts), "%s",
705                    opts->head_name ? opts->head_name : "detached HEAD");
706         write_file(state_dir_path("onto", opts), "%s",
707                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
708         write_file(state_dir_path("orig-head", opts), "%s",
709                    oid_to_hex(&opts->orig_head));
710         if (!(opts->flags & REBASE_NO_QUIET))
711                 write_file(state_dir_path("quiet", opts), "%s", "");
712         if (opts->flags & REBASE_VERBOSE)
713                 write_file(state_dir_path("verbose", opts), "%s", "");
714         if (opts->strategy)
715                 write_file(state_dir_path("strategy", opts), "%s",
716                            opts->strategy);
717         if (opts->strategy_opts)
718                 write_file(state_dir_path("strategy_opts", opts), "%s",
719                            opts->strategy_opts);
720         if (opts->allow_rerere_autoupdate > 0)
721                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
722                            "-%s-rerere-autoupdate",
723                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
724                                 "" : "-no");
725         if (opts->gpg_sign_opt)
726                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
727                            opts->gpg_sign_opt);
728         if (opts->signoff)
729                 write_file(state_dir_path("signoff", opts), "--signoff");
730
731         return 0;
732 }
733
734 static int finish_rebase(struct rebase_options *opts)
735 {
736         struct strbuf dir = STRBUF_INIT;
737         int ret = 0;
738
739         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
740         apply_autostash(state_dir_path("autostash", opts));
741         close_object_store(the_repository->objects);
742         /*
743          * We ignore errors in 'git maintenance run --auto', since the
744          * user should see them.
745          */
746         run_auto_maintenance(!(opts->flags & (REBASE_NO_QUIET|REBASE_VERBOSE)));
747         if (opts->type == REBASE_MERGE) {
748                 struct replay_opts replay = REPLAY_OPTS_INIT;
749
750                 replay.action = REPLAY_INTERACTIVE_REBASE;
751                 ret = sequencer_remove_state(&replay);
752         } else {
753                 strbuf_addstr(&dir, opts->state_dir);
754                 if (remove_dir_recursively(&dir, 0))
755                         ret = error(_("could not remove '%s'"),
756                                     opts->state_dir);
757                 strbuf_release(&dir);
758         }
759
760         return ret;
761 }
762
763 static struct commit *peel_committish(const char *name)
764 {
765         struct object *obj;
766         struct object_id oid;
767
768         if (get_oid(name, &oid))
769                 return NULL;
770         obj = parse_object(the_repository, &oid);
771         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
772 }
773
774 static void add_var(struct strbuf *buf, const char *name, const char *value)
775 {
776         if (!value)
777                 strbuf_addf(buf, "unset %s; ", name);
778         else {
779                 strbuf_addf(buf, "%s=", name);
780                 sq_quote_buf(buf, value);
781                 strbuf_addstr(buf, "; ");
782         }
783 }
784
785 static int move_to_original_branch(struct rebase_options *opts)
786 {
787         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
788         int ret;
789
790         if (!opts->head_name)
791                 return 0; /* nothing to move back to */
792
793         if (!opts->onto)
794                 BUG("move_to_original_branch without onto");
795
796         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
797                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
798         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
799                     opts->head_name);
800         ret = reset_head(the_repository, NULL, "", opts->head_name,
801                          RESET_HEAD_REFS_ONLY,
802                          orig_head_reflog.buf, head_reflog.buf,
803                          DEFAULT_REFLOG_ACTION);
804
805         strbuf_release(&orig_head_reflog);
806         strbuf_release(&head_reflog);
807         return ret;
808 }
809
810 static const char *resolvemsg =
811 N_("Resolve all conflicts manually, mark them as resolved with\n"
812 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
813 "You can instead skip this commit: run \"git rebase --skip\".\n"
814 "To abort and get back to the state before \"git rebase\", run "
815 "\"git rebase --abort\".");
816
817 static int run_am(struct rebase_options *opts)
818 {
819         struct child_process am = CHILD_PROCESS_INIT;
820         struct child_process format_patch = CHILD_PROCESS_INIT;
821         struct strbuf revisions = STRBUF_INIT;
822         int status;
823         char *rebased_patches;
824
825         am.git_cmd = 1;
826         strvec_push(&am.args, "am");
827
828         if (opts->action && !strcmp("continue", opts->action)) {
829                 strvec_push(&am.args, "--resolved");
830                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
831                 if (opts->gpg_sign_opt)
832                         strvec_push(&am.args, opts->gpg_sign_opt);
833                 status = run_command(&am);
834                 if (status)
835                         return status;
836
837                 return move_to_original_branch(opts);
838         }
839         if (opts->action && !strcmp("skip", opts->action)) {
840                 strvec_push(&am.args, "--skip");
841                 strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
842                 status = run_command(&am);
843                 if (status)
844                         return status;
845
846                 return move_to_original_branch(opts);
847         }
848         if (opts->action && !strcmp("show-current-patch", opts->action)) {
849                 strvec_push(&am.args, "--show-current-patch");
850                 return run_command(&am);
851         }
852
853         strbuf_addf(&revisions, "%s...%s",
854                     oid_to_hex(opts->root ?
855                                /* this is now equivalent to !opts->upstream */
856                                &opts->onto->object.oid :
857                                &opts->upstream->object.oid),
858                     oid_to_hex(&opts->orig_head));
859
860         rebased_patches = xstrdup(git_path("rebased-patches"));
861         format_patch.out = open(rebased_patches,
862                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
863         if (format_patch.out < 0) {
864                 status = error_errno(_("could not open '%s' for writing"),
865                                      rebased_patches);
866                 free(rebased_patches);
867                 strvec_clear(&am.args);
868                 return status;
869         }
870
871         format_patch.git_cmd = 1;
872         strvec_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
873                      "--full-index", "--cherry-pick", "--right-only",
874                      "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
875                      "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
876                      "--no-base", NULL);
877         if (opts->git_format_patch_opt.len)
878                 strvec_split(&format_patch.args,
879                              opts->git_format_patch_opt.buf);
880         strvec_push(&format_patch.args, revisions.buf);
881         if (opts->restrict_revision)
882                 strvec_pushf(&format_patch.args, "^%s",
883                              oid_to_hex(&opts->restrict_revision->object.oid));
884
885         status = run_command(&format_patch);
886         if (status) {
887                 unlink(rebased_patches);
888                 free(rebased_patches);
889                 strvec_clear(&am.args);
890
891                 reset_head(the_repository, &opts->orig_head, "checkout",
892                            opts->head_name, 0,
893                            "HEAD", NULL, DEFAULT_REFLOG_ACTION);
894                 error(_("\ngit encountered an error while preparing the "
895                         "patches to replay\n"
896                         "these revisions:\n"
897                         "\n    %s\n\n"
898                         "As a result, git cannot rebase them."),
899                       opts->revisions);
900
901                 strbuf_release(&revisions);
902                 return status;
903         }
904         strbuf_release(&revisions);
905
906         am.in = open(rebased_patches, O_RDONLY);
907         if (am.in < 0) {
908                 status = error_errno(_("could not open '%s' for reading"),
909                                      rebased_patches);
910                 free(rebased_patches);
911                 strvec_clear(&am.args);
912                 return status;
913         }
914
915         strvec_pushv(&am.args, opts->git_am_opts.v);
916         strvec_push(&am.args, "--rebasing");
917         strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
918         strvec_push(&am.args, "--patch-format=mboxrd");
919         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
920                 strvec_push(&am.args, "--rerere-autoupdate");
921         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
922                 strvec_push(&am.args, "--no-rerere-autoupdate");
923         if (opts->gpg_sign_opt)
924                 strvec_push(&am.args, opts->gpg_sign_opt);
925         status = run_command(&am);
926         unlink(rebased_patches);
927         free(rebased_patches);
928
929         if (!status) {
930                 return move_to_original_branch(opts);
931         }
932
933         if (is_directory(opts->state_dir))
934                 rebase_write_basic_state(opts);
935
936         return status;
937 }
938
939 static int run_specific_rebase(struct rebase_options *opts, enum action action)
940 {
941         const char *argv[] = { NULL, NULL };
942         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
943         int status;
944         const char *backend, *backend_func;
945
946         if (opts->type == REBASE_MERGE) {
947                 /* Run sequencer-based rebase */
948                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
949                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
950                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
951                         opts->autosquash = 0;
952                 }
953                 if (opts->gpg_sign_opt) {
954                         /* remove the leading "-S" */
955                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
956                         free(opts->gpg_sign_opt);
957                         opts->gpg_sign_opt = tmp;
958                 }
959
960                 status = run_sequencer_rebase(opts, action);
961                 goto finished_rebase;
962         }
963
964         if (opts->type == REBASE_APPLY) {
965                 status = run_am(opts);
966                 goto finished_rebase;
967         }
968
969         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
970         add_var(&script_snippet, "state_dir", opts->state_dir);
971
972         add_var(&script_snippet, "upstream_name", opts->upstream_name);
973         add_var(&script_snippet, "upstream", opts->upstream ?
974                 oid_to_hex(&opts->upstream->object.oid) : NULL);
975         add_var(&script_snippet, "head_name",
976                 opts->head_name ? opts->head_name : "detached HEAD");
977         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
978         add_var(&script_snippet, "onto", opts->onto ?
979                 oid_to_hex(&opts->onto->object.oid) : NULL);
980         add_var(&script_snippet, "onto_name", opts->onto_name);
981         add_var(&script_snippet, "revisions", opts->revisions);
982         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
983                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
984         sq_quote_argv_pretty(&buf, opts->git_am_opts.v);
985         add_var(&script_snippet, "git_am_opt", buf.buf);
986         strbuf_release(&buf);
987         add_var(&script_snippet, "verbose",
988                 opts->flags & REBASE_VERBOSE ? "t" : "");
989         add_var(&script_snippet, "diffstat",
990                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
991         add_var(&script_snippet, "force_rebase",
992                 opts->flags & REBASE_FORCE ? "t" : "");
993         if (opts->switch_to)
994                 add_var(&script_snippet, "switch_to", opts->switch_to);
995         add_var(&script_snippet, "action", opts->action ? opts->action : "");
996         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
997         add_var(&script_snippet, "allow_rerere_autoupdate",
998                 opts->allow_rerere_autoupdate ?
999                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1000                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1001         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1002         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1003         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1004         add_var(&script_snippet, "cmd", opts->cmd);
1005         add_var(&script_snippet, "allow_empty_message",
1006                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1007         add_var(&script_snippet, "rebase_merges",
1008                 opts->rebase_merges ? "t" : "");
1009         add_var(&script_snippet, "rebase_cousins",
1010                 opts->rebase_cousins ? "t" : "");
1011         add_var(&script_snippet, "strategy", opts->strategy);
1012         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1013         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1014         add_var(&script_snippet, "squash_onto",
1015                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1016         add_var(&script_snippet, "git_format_patch_opt",
1017                 opts->git_format_patch_opt.buf);
1018
1019         if (is_merge(opts) &&
1020             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1021                 strbuf_addstr(&script_snippet,
1022                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1023                 opts->autosquash = 0;
1024         }
1025
1026         switch (opts->type) {
1027         case REBASE_PRESERVE_MERGES:
1028                 backend = "git-rebase--preserve-merges";
1029                 backend_func = "git_rebase__preserve_merges";
1030                 break;
1031         default:
1032                 BUG("Unhandled rebase type %d", opts->type);
1033                 break;
1034         }
1035
1036         strbuf_addf(&script_snippet,
1037                     ". git-sh-setup && . %s && %s", backend, backend_func);
1038         argv[0] = script_snippet.buf;
1039
1040         status = run_command_v_opt(argv, RUN_USING_SHELL);
1041 finished_rebase:
1042         if (opts->dont_finish_rebase)
1043                 ; /* do nothing */
1044         else if (opts->type == REBASE_MERGE)
1045                 ; /* merge backend cleans up after itself */
1046         else if (status == 0) {
1047                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1048                         finish_rebase(opts);
1049         } else if (status == 2) {
1050                 struct strbuf dir = STRBUF_INIT;
1051
1052                 apply_autostash(state_dir_path("autostash", opts));
1053                 strbuf_addstr(&dir, opts->state_dir);
1054                 remove_dir_recursively(&dir, 0);
1055                 strbuf_release(&dir);
1056                 die("Nothing to do");
1057         }
1058
1059         strbuf_release(&script_snippet);
1060
1061         return status ? -1 : 0;
1062 }
1063
1064 static int rebase_config(const char *var, const char *value, void *data)
1065 {
1066         struct rebase_options *opts = data;
1067
1068         if (!strcmp(var, "rebase.stat")) {
1069                 if (git_config_bool(var, value))
1070                         opts->flags |= REBASE_DIFFSTAT;
1071                 else
1072                         opts->flags &= ~REBASE_DIFFSTAT;
1073                 return 0;
1074         }
1075
1076         if (!strcmp(var, "rebase.autosquash")) {
1077                 opts->autosquash = git_config_bool(var, value);
1078                 return 0;
1079         }
1080
1081         if (!strcmp(var, "commit.gpgsign")) {
1082                 free(opts->gpg_sign_opt);
1083                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1084                         xstrdup("-S") : NULL;
1085                 return 0;
1086         }
1087
1088         if (!strcmp(var, "rebase.autostash")) {
1089                 opts->autostash = git_config_bool(var, value);
1090                 return 0;
1091         }
1092
1093         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1094                 opts->reschedule_failed_exec = git_config_bool(var, value);
1095                 return 0;
1096         }
1097
1098         if (!strcmp(var, "rebase.usebuiltin")) {
1099                 opts->use_legacy_rebase = !git_config_bool(var, value);
1100                 return 0;
1101         }
1102
1103         if (!strcmp(var, "rebase.backend")) {
1104                 return git_config_string(&opts->default_backend, var, value);
1105         }
1106
1107         return git_default_config(var, value, data);
1108 }
1109
1110 /*
1111  * Determines whether the commits in from..to are linear, i.e. contain
1112  * no merge commits. This function *expects* `from` to be an ancestor of
1113  * `to`.
1114  */
1115 static int is_linear_history(struct commit *from, struct commit *to)
1116 {
1117         while (to && to != from) {
1118                 parse_commit(to);
1119                 if (!to->parents)
1120                         return 1;
1121                 if (to->parents->next)
1122                         return 0;
1123                 to = to->parents->item;
1124         }
1125         return 1;
1126 }
1127
1128 static int can_fast_forward(struct commit *onto, struct commit *upstream,
1129                             struct commit *restrict_revision,
1130                             struct object_id *head_oid, struct object_id *merge_base)
1131 {
1132         struct commit *head = lookup_commit(the_repository, head_oid);
1133         struct commit_list *merge_bases = NULL;
1134         int res = 0;
1135
1136         if (!head)
1137                 goto done;
1138
1139         merge_bases = get_merge_bases(onto, head);
1140         if (!merge_bases || merge_bases->next) {
1141                 oidcpy(merge_base, &null_oid);
1142                 goto done;
1143         }
1144
1145         oidcpy(merge_base, &merge_bases->item->object.oid);
1146         if (!oideq(merge_base, &onto->object.oid))
1147                 goto done;
1148
1149         if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
1150                 goto done;
1151
1152         if (!upstream)
1153                 goto done;
1154
1155         free_commit_list(merge_bases);
1156         merge_bases = get_merge_bases(upstream, head);
1157         if (!merge_bases || merge_bases->next)
1158                 goto done;
1159
1160         if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
1161                 goto done;
1162
1163         res = 1;
1164
1165 done:
1166         free_commit_list(merge_bases);
1167         return res && is_linear_history(onto, head);
1168 }
1169
1170 static int parse_opt_am(const struct option *opt, const char *arg, int unset)
1171 {
1172         struct rebase_options *opts = opt->value;
1173
1174         BUG_ON_OPT_NEG(unset);
1175         BUG_ON_OPT_ARG(arg);
1176
1177         opts->type = REBASE_APPLY;
1178
1179         return 0;
1180 }
1181
1182 /* -i followed by -m is still -i */
1183 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1184 {
1185         struct rebase_options *opts = opt->value;
1186
1187         BUG_ON_OPT_NEG(unset);
1188         BUG_ON_OPT_ARG(arg);
1189
1190         if (!is_merge(opts))
1191                 opts->type = REBASE_MERGE;
1192
1193         return 0;
1194 }
1195
1196 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1197 static int parse_opt_interactive(const struct option *opt, const char *arg,
1198                                  int unset)
1199 {
1200         struct rebase_options *opts = opt->value;
1201
1202         BUG_ON_OPT_NEG(unset);
1203         BUG_ON_OPT_ARG(arg);
1204
1205         opts->type = REBASE_MERGE;
1206         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1207
1208         return 0;
1209 }
1210
1211 static enum empty_type parse_empty_value(const char *value)
1212 {
1213         if (!strcasecmp(value, "drop"))
1214                 return EMPTY_DROP;
1215         else if (!strcasecmp(value, "keep"))
1216                 return EMPTY_KEEP;
1217         else if (!strcasecmp(value, "ask"))
1218                 return EMPTY_ASK;
1219
1220         die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
1221 }
1222
1223 static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
1224 {
1225         struct rebase_options *options = opt->value;
1226         enum empty_type value = parse_empty_value(arg);
1227
1228         BUG_ON_OPT_NEG(unset);
1229
1230         options->empty = value;
1231         return 0;
1232 }
1233
1234 static void NORETURN error_on_missing_default_upstream(void)
1235 {
1236         struct branch *current_branch = branch_get(NULL);
1237
1238         printf(_("%s\n"
1239                  "Please specify which branch you want to rebase against.\n"
1240                  "See git-rebase(1) for details.\n"
1241                  "\n"
1242                  "    git rebase '<branch>'\n"
1243                  "\n"),
1244                 current_branch ? _("There is no tracking information for "
1245                         "the current branch.") :
1246                         _("You are not currently on a branch."));
1247
1248         if (current_branch) {
1249                 const char *remote = current_branch->remote_name;
1250
1251                 if (!remote)
1252                         remote = _("<remote>");
1253
1254                 printf(_("If you wish to set tracking information for this "
1255                          "branch you can do so with:\n"
1256                          "\n"
1257                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1258                          "\n"),
1259                        remote, current_branch->name);
1260         }
1261         exit(1);
1262 }
1263
1264 static void set_reflog_action(struct rebase_options *options)
1265 {
1266         const char *env;
1267         struct strbuf buf = STRBUF_INIT;
1268
1269         if (!is_merge(options))
1270                 return;
1271
1272         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1273         if (env && strcmp("rebase", env))
1274                 return; /* only override it if it is "rebase" */
1275
1276         strbuf_addf(&buf, "rebase (%s)", options->action);
1277         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1278         strbuf_release(&buf);
1279 }
1280
1281 static int check_exec_cmd(const char *cmd)
1282 {
1283         if (strchr(cmd, '\n'))
1284                 return error(_("exec commands cannot contain newlines"));
1285
1286         /* Does the command consist purely of whitespace? */
1287         if (!cmd[strspn(cmd, " \t\r\f\v")])
1288                 return error(_("empty exec command"));
1289
1290         return 0;
1291 }
1292
1293 int cmd_rebase(int argc, const char **argv, const char *prefix)
1294 {
1295         struct rebase_options options = REBASE_OPTIONS_INIT;
1296         const char *branch_name;
1297         int ret, flags, total_argc, in_progress = 0;
1298         int keep_base = 0;
1299         int ok_to_skip_pre_rebase = 0;
1300         struct strbuf msg = STRBUF_INIT;
1301         struct strbuf revisions = STRBUF_INIT;
1302         struct strbuf buf = STRBUF_INIT;
1303         struct object_id merge_base;
1304         int ignore_whitespace = 0;
1305         enum action action = ACTION_NONE;
1306         const char *gpg_sign = NULL;
1307         struct string_list exec = STRING_LIST_INIT_NODUP;
1308         const char *rebase_merges = NULL;
1309         int fork_point = -1;
1310         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1311         struct object_id squash_onto;
1312         char *squash_onto_name = NULL;
1313         int reschedule_failed_exec = -1;
1314         int allow_preemptive_ff = 1;
1315         struct option builtin_rebase_options[] = {
1316                 OPT_STRING(0, "onto", &options.onto_name,
1317                            N_("revision"),
1318                            N_("rebase onto given branch instead of upstream")),
1319                 OPT_BOOL(0, "keep-base", &keep_base,
1320                          N_("use the merge-base of upstream and branch as the current base")),
1321                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1322                          N_("allow pre-rebase hook to run")),
1323                 OPT_NEGBIT('q', "quiet", &options.flags,
1324                            N_("be quiet. implies --no-stat"),
1325                            REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1326                 OPT_BIT('v', "verbose", &options.flags,
1327                         N_("display a diffstat of what changed upstream"),
1328                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1329                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1330                         N_("do not show diffstat of what changed upstream"),
1331                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1332                 OPT_BOOL(0, "signoff", &options.signoff,
1333                          N_("add a Signed-off-by trailer to each commit")),
1334                 OPT_BOOL(0, "committer-date-is-author-date",
1335                          &options.committer_date_is_author_date,
1336                          N_("make committer date match author date")),
1337                 OPT_BOOL(0, "reset-author-date", &options.ignore_date,
1338                          N_("ignore author date and use current date")),
1339                 OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
1340                                 N_("synonym of --reset-author-date")),
1341                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1342                                   N_("passed to 'git apply'"), 0),
1343                 OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
1344                          N_("ignore changes in whitespace")),
1345                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1346                                   N_("action"), N_("passed to 'git apply'"), 0),
1347                 OPT_BIT('f', "force-rebase", &options.flags,
1348                         N_("cherry-pick all commits, even if unchanged"),
1349                         REBASE_FORCE),
1350                 OPT_BIT(0, "no-ff", &options.flags,
1351                         N_("cherry-pick all commits, even if unchanged"),
1352                         REBASE_FORCE),
1353                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1354                             ACTION_CONTINUE),
1355                 OPT_CMDMODE(0, "skip", &action,
1356                             N_("skip current patch and continue"), ACTION_SKIP),
1357                 OPT_CMDMODE(0, "abort", &action,
1358                             N_("abort and check out the original branch"),
1359                             ACTION_ABORT),
1360                 OPT_CMDMODE(0, "quit", &action,
1361                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1362                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1363                             "during an interactive rebase"), ACTION_EDIT_TODO),
1364                 OPT_CMDMODE(0, "show-current-patch", &action,
1365                             N_("show the patch file being applied or merged"),
1366                             ACTION_SHOW_CURRENT_PATCH),
1367                 OPT_CALLBACK_F(0, "apply", &options, NULL,
1368                         N_("use apply strategies to rebase"),
1369                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1370                         parse_opt_am),
1371                 OPT_CALLBACK_F('m', "merge", &options, NULL,
1372                         N_("use merging strategies to rebase"),
1373                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1374                         parse_opt_merge),
1375                 OPT_CALLBACK_F('i', "interactive", &options, NULL,
1376                         N_("let the user edit the list of commits to rebase"),
1377                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1378                         parse_opt_interactive),
1379                 OPT_SET_INT_F('p', "preserve-merges", &options.type,
1380                               N_("(DEPRECATED) try to recreate merges instead of "
1381                                  "ignoring them"),
1382                               REBASE_PRESERVE_MERGES, PARSE_OPT_HIDDEN),
1383                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1384                 OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
1385                                N_("how to handle commits that become empty"),
1386                                PARSE_OPT_NONEG, parse_opt_empty),
1387                 OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
1388                         N_("keep commits which start empty"),
1389                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
1390                         parse_opt_keep_empty),
1391                 OPT_BOOL(0, "autosquash", &options.autosquash,
1392                          N_("move commits that begin with "
1393                             "squash!/fixup! under -i")),
1394                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1395                         N_("GPG-sign commits"),
1396                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1397                 OPT_AUTOSTASH(&options.autostash),
1398                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1399                                 N_("add exec lines after each commit of the "
1400                                    "editable list")),
1401                 OPT_BOOL_F(0, "allow-empty-message",
1402                            &options.allow_empty_message,
1403                            N_("allow rebasing commits with empty messages"),
1404                            PARSE_OPT_HIDDEN),
1405                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1406                         N_("mode"),
1407                         N_("try to rebase merges instead of skipping them"),
1408                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1409                 OPT_BOOL(0, "fork-point", &fork_point,
1410                          N_("use 'merge-base --fork-point' to refine upstream")),
1411                 OPT_STRING('s', "strategy", &options.strategy,
1412                            N_("strategy"), N_("use the given merge strategy")),
1413                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1414                                 N_("option"),
1415                                 N_("pass the argument through to the merge "
1416                                    "strategy")),
1417                 OPT_BOOL(0, "root", &options.root,
1418                          N_("rebase all reachable commits up to the root(s)")),
1419                 OPT_BOOL(0, "reschedule-failed-exec",
1420                          &reschedule_failed_exec,
1421                          N_("automatically re-schedule any `exec` that fails")),
1422                 OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
1423                          N_("apply all changes, even those already present upstream")),
1424                 OPT_END(),
1425         };
1426         int i;
1427
1428         if (argc == 2 && !strcmp(argv[1], "-h"))
1429                 usage_with_options(builtin_rebase_usage,
1430                                    builtin_rebase_options);
1431
1432         options.allow_empty_message = 1;
1433         git_config(rebase_config, &options);
1434         /* options.gpg_sign_opt will be either "-S" or NULL */
1435         gpg_sign = options.gpg_sign_opt ? "" : NULL;
1436         FREE_AND_NULL(options.gpg_sign_opt);
1437
1438         if (options.use_legacy_rebase ||
1439             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1440                 warning(_("the rebase.useBuiltin support has been removed!\n"
1441                           "See its entry in 'git help config' for details."));
1442
1443         strbuf_reset(&buf);
1444         strbuf_addf(&buf, "%s/applying", apply_dir());
1445         if(file_exists(buf.buf))
1446                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1447
1448         if (is_directory(apply_dir())) {
1449                 options.type = REBASE_APPLY;
1450                 options.state_dir = apply_dir();
1451         } else if (is_directory(merge_dir())) {
1452                 strbuf_reset(&buf);
1453                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1454                 if (is_directory(buf.buf)) {
1455                         options.type = REBASE_PRESERVE_MERGES;
1456                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1457                 } else {
1458                         strbuf_reset(&buf);
1459                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1460                         if(file_exists(buf.buf)) {
1461                                 options.type = REBASE_MERGE;
1462                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1463                         } else
1464                                 options.type = REBASE_MERGE;
1465                 }
1466                 options.state_dir = merge_dir();
1467         }
1468
1469         if (options.type != REBASE_UNSPECIFIED)
1470                 in_progress = 1;
1471
1472         total_argc = argc;
1473         argc = parse_options(argc, argv, prefix,
1474                              builtin_rebase_options,
1475                              builtin_rebase_usage, 0);
1476
1477         if (action != ACTION_NONE && total_argc != 2) {
1478                 usage_with_options(builtin_rebase_usage,
1479                                    builtin_rebase_options);
1480         }
1481
1482         if (argc > 2)
1483                 usage_with_options(builtin_rebase_usage,
1484                                    builtin_rebase_options);
1485
1486         if (options.type == REBASE_PRESERVE_MERGES)
1487                 warning(_("git rebase --preserve-merges is deprecated. "
1488                           "Use --rebase-merges instead."));
1489
1490         if (keep_base) {
1491                 if (options.onto_name)
1492                         die(_("cannot combine '--keep-base' with '--onto'"));
1493                 if (options.root)
1494                         die(_("cannot combine '--keep-base' with '--root'"));
1495         }
1496
1497         if (options.root && fork_point > 0)
1498                 die(_("cannot combine '--root' with '--fork-point'"));
1499
1500         if (action != ACTION_NONE && !in_progress)
1501                 die(_("No rebase in progress?"));
1502         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1503
1504         if (action == ACTION_EDIT_TODO && !is_merge(&options))
1505                 die(_("The --edit-todo action can only be used during "
1506                       "interactive rebase."));
1507
1508         if (trace2_is_enabled()) {
1509                 if (is_merge(&options))
1510                         trace2_cmd_mode("interactive");
1511                 else if (exec.nr)
1512                         trace2_cmd_mode("interactive-exec");
1513                 else
1514                         trace2_cmd_mode(action_names[action]);
1515         }
1516
1517         switch (action) {
1518         case ACTION_CONTINUE: {
1519                 struct object_id head;
1520                 struct lock_file lock_file = LOCK_INIT;
1521                 int fd;
1522
1523                 options.action = "continue";
1524                 set_reflog_action(&options);
1525
1526                 /* Sanity check */
1527                 if (get_oid("HEAD", &head))
1528                         die(_("Cannot read HEAD"));
1529
1530                 fd = hold_locked_index(&lock_file, 0);
1531                 if (repo_read_index(the_repository) < 0)
1532                         die(_("could not read index"));
1533                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1534                               NULL);
1535                 if (0 <= fd)
1536                         repo_update_index_if_able(the_repository, &lock_file);
1537                 rollback_lock_file(&lock_file);
1538
1539                 if (has_unstaged_changes(the_repository, 1)) {
1540                         puts(_("You must edit all merge conflicts and then\n"
1541                                "mark them as resolved using git add"));
1542                         exit(1);
1543                 }
1544                 if (read_basic_state(&options))
1545                         exit(1);
1546                 goto run_rebase;
1547         }
1548         case ACTION_SKIP: {
1549                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1550
1551                 options.action = "skip";
1552                 set_reflog_action(&options);
1553
1554                 rerere_clear(the_repository, &merge_rr);
1555                 string_list_clear(&merge_rr, 1);
1556
1557                 if (reset_head(the_repository, NULL, "reset", NULL, RESET_HEAD_HARD,
1558                                NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
1559                         die(_("could not discard worktree changes"));
1560                 remove_branch_state(the_repository, 0);
1561                 if (read_basic_state(&options))
1562                         exit(1);
1563                 goto run_rebase;
1564         }
1565         case ACTION_ABORT: {
1566                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1567                 options.action = "abort";
1568                 set_reflog_action(&options);
1569
1570                 rerere_clear(the_repository, &merge_rr);
1571                 string_list_clear(&merge_rr, 1);
1572
1573                 if (read_basic_state(&options))
1574                         exit(1);
1575                 if (reset_head(the_repository, &options.orig_head, "reset",
1576                                options.head_name, RESET_HEAD_HARD,
1577                                NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
1578                         die(_("could not move back to %s"),
1579                             oid_to_hex(&options.orig_head));
1580                 remove_branch_state(the_repository, 0);
1581                 ret = !!finish_rebase(&options);
1582                 goto cleanup;
1583         }
1584         case ACTION_QUIT: {
1585                 save_autostash(state_dir_path("autostash", &options));
1586                 if (options.type == REBASE_MERGE) {
1587                         struct replay_opts replay = REPLAY_OPTS_INIT;
1588
1589                         replay.action = REPLAY_INTERACTIVE_REBASE;
1590                         ret = !!sequencer_remove_state(&replay);
1591                 } else {
1592                         strbuf_reset(&buf);
1593                         strbuf_addstr(&buf, options.state_dir);
1594                         ret = !!remove_dir_recursively(&buf, 0);
1595                         if (ret)
1596                                 error(_("could not remove '%s'"),
1597                                        options.state_dir);
1598                 }
1599                 goto cleanup;
1600         }
1601         case ACTION_EDIT_TODO:
1602                 options.action = "edit-todo";
1603                 options.dont_finish_rebase = 1;
1604                 goto run_rebase;
1605         case ACTION_SHOW_CURRENT_PATCH:
1606                 options.action = "show-current-patch";
1607                 options.dont_finish_rebase = 1;
1608                 goto run_rebase;
1609         case ACTION_NONE:
1610                 break;
1611         default:
1612                 BUG("action: %d", action);
1613         }
1614
1615         /* Make sure no rebase is in progress */
1616         if (in_progress) {
1617                 const char *last_slash = strrchr(options.state_dir, '/');
1618                 const char *state_dir_base =
1619                         last_slash ? last_slash + 1 : options.state_dir;
1620                 const char *cmd_live_rebase =
1621                         "git rebase (--continue | --abort | --skip)";
1622                 strbuf_reset(&buf);
1623                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1624                 die(_("It seems that there is already a %s directory, and\n"
1625                       "I wonder if you are in the middle of another rebase.  "
1626                       "If that is the\n"
1627                       "case, please try\n\t%s\n"
1628                       "If that is not the case, please\n\t%s\n"
1629                       "and run me again.  I am stopping in case you still "
1630                       "have something\n"
1631                       "valuable there.\n"),
1632                     state_dir_base, cmd_live_rebase, buf.buf);
1633         }
1634
1635         if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
1636             (action != ACTION_NONE) ||
1637             (exec.nr > 0) ||
1638             options.autosquash) {
1639                 allow_preemptive_ff = 0;
1640         }
1641         if (options.committer_date_is_author_date || options.ignore_date)
1642                 options.flags |= REBASE_FORCE;
1643
1644         for (i = 0; i < options.git_am_opts.nr; i++) {
1645                 const char *option = options.git_am_opts.v[i], *p;
1646                 if (!strcmp(option, "--whitespace=fix") ||
1647                     !strcmp(option, "--whitespace=strip"))
1648                         allow_preemptive_ff = 0;
1649                 else if (skip_prefix(option, "-C", &p)) {
1650                         while (*p)
1651                                 if (!isdigit(*(p++)))
1652                                         die(_("switch `C' expects a "
1653                                               "numerical value"));
1654                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1655                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1656                             strcmp(p, "error") && strcmp(p, "error-all"))
1657                                 die("Invalid whitespace option: '%s'", p);
1658                 }
1659         }
1660
1661         for (i = 0; i < exec.nr; i++)
1662                 if (check_exec_cmd(exec.items[i].string))
1663                         exit(1);
1664
1665         if (!(options.flags & REBASE_NO_QUIET))
1666                 strvec_push(&options.git_am_opts, "-q");
1667
1668         if (options.empty != EMPTY_UNSPECIFIED)
1669                 imply_merge(&options, "--empty");
1670
1671         if (options.reapply_cherry_picks)
1672                 imply_merge(&options, "--reapply-cherry-picks");
1673
1674         if (gpg_sign)
1675                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1676
1677         if (exec.nr) {
1678                 int i;
1679
1680                 imply_merge(&options, "--exec");
1681
1682                 strbuf_reset(&buf);
1683                 for (i = 0; i < exec.nr; i++)
1684                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1685                 options.cmd = xstrdup(buf.buf);
1686         }
1687
1688         if (rebase_merges) {
1689                 if (!*rebase_merges)
1690                         ; /* default mode; do nothing */
1691                 else if (!strcmp("rebase-cousins", rebase_merges))
1692                         options.rebase_cousins = 1;
1693                 else if (strcmp("no-rebase-cousins", rebase_merges))
1694                         die(_("Unknown mode: %s"), rebase_merges);
1695                 options.rebase_merges = 1;
1696                 imply_merge(&options, "--rebase-merges");
1697         }
1698
1699         if (options.type == REBASE_APPLY) {
1700                 if (ignore_whitespace)
1701                         strvec_push(&options.git_am_opts,
1702                                     "--ignore-whitespace");
1703                 if (options.committer_date_is_author_date)
1704                         strvec_push(&options.git_am_opts,
1705                                     "--committer-date-is-author-date");
1706                 if (options.ignore_date)
1707                         strvec_push(&options.git_am_opts, "--ignore-date");
1708         } else {
1709                 /* REBASE_MERGE and PRESERVE_MERGES */
1710                 if (ignore_whitespace) {
1711                         string_list_append(&strategy_options,
1712                                            "ignore-space-change");
1713                 }
1714         }
1715
1716         if (strategy_options.nr) {
1717                 int i;
1718
1719                 if (!options.strategy)
1720                         options.strategy = "recursive";
1721
1722                 strbuf_reset(&buf);
1723                 for (i = 0; i < strategy_options.nr; i++)
1724                         strbuf_addf(&buf, " --%s",
1725                                     strategy_options.items[i].string);
1726                 options.strategy_opts = xstrdup(buf.buf);
1727         }
1728
1729         if (options.strategy) {
1730                 options.strategy = xstrdup(options.strategy);
1731                 switch (options.type) {
1732                 case REBASE_APPLY:
1733                         die(_("--strategy requires --merge or --interactive"));
1734                 case REBASE_MERGE:
1735                 case REBASE_PRESERVE_MERGES:
1736                         /* compatible */
1737                         break;
1738                 case REBASE_UNSPECIFIED:
1739                         options.type = REBASE_MERGE;
1740                         break;
1741                 default:
1742                         BUG("unhandled rebase type (%d)", options.type);
1743                 }
1744         }
1745
1746         if (options.type == REBASE_MERGE)
1747                 imply_merge(&options, "--merge");
1748
1749         if (options.root && !options.onto_name)
1750                 imply_merge(&options, "--root without --onto");
1751
1752         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1753                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1754
1755         if (options.git_am_opts.nr || options.type == REBASE_APPLY) {
1756                 /* all am options except -q are compatible only with --apply */
1757                 for (i = options.git_am_opts.nr - 1; i >= 0; i--)
1758                         if (strcmp(options.git_am_opts.v[i], "-q"))
1759                                 break;
1760
1761                 if (i >= 0) {
1762                         if (is_merge(&options))
1763                                 die(_("cannot combine apply options with "
1764                                       "merge options"));
1765                         else
1766                                 options.type = REBASE_APPLY;
1767                 }
1768         }
1769
1770         if (options.type == REBASE_UNSPECIFIED) {
1771                 if (!strcmp(options.default_backend, "merge"))
1772                         imply_merge(&options, "--merge");
1773                 else if (!strcmp(options.default_backend, "apply"))
1774                         options.type = REBASE_APPLY;
1775                 else
1776                         die(_("Unknown rebase backend: %s"),
1777                             options.default_backend);
1778         }
1779
1780         if (options.type == REBASE_MERGE &&
1781             !options.strategy &&
1782             getenv("GIT_TEST_MERGE_ALGORITHM"))
1783                 options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
1784
1785         switch (options.type) {
1786         case REBASE_MERGE:
1787         case REBASE_PRESERVE_MERGES:
1788                 options.state_dir = merge_dir();
1789                 break;
1790         case REBASE_APPLY:
1791                 options.state_dir = apply_dir();
1792                 break;
1793         default:
1794                 BUG("options.type was just set above; should be unreachable.");
1795         }
1796
1797         if (options.empty == EMPTY_UNSPECIFIED) {
1798                 if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
1799                         options.empty = EMPTY_ASK;
1800                 else if (exec.nr > 0)
1801                         options.empty = EMPTY_KEEP;
1802                 else
1803                         options.empty = EMPTY_DROP;
1804         }
1805         if (reschedule_failed_exec > 0 && !is_merge(&options))
1806                 die(_("--reschedule-failed-exec requires "
1807                       "--exec or --interactive"));
1808         if (reschedule_failed_exec >= 0)
1809                 options.reschedule_failed_exec = reschedule_failed_exec;
1810
1811         if (options.signoff) {
1812                 if (options.type == REBASE_PRESERVE_MERGES)
1813                         die("cannot combine '--signoff' with "
1814                             "'--preserve-merges'");
1815                 strvec_push(&options.git_am_opts, "--signoff");
1816                 options.flags |= REBASE_FORCE;
1817         }
1818
1819         if (options.type == REBASE_PRESERVE_MERGES) {
1820                 /*
1821                  * Note: incompatibility with --signoff handled in signoff block above
1822                  * Note: incompatibility with --interactive is just a strong warning;
1823                  *       git-rebase.txt caveats with "unless you know what you are doing"
1824                  */
1825                 if (options.rebase_merges)
1826                         die(_("cannot combine '--preserve-merges' with "
1827                               "'--rebase-merges'"));
1828
1829                 if (options.reschedule_failed_exec)
1830                         die(_("error: cannot combine '--preserve-merges' with "
1831                               "'--reschedule-failed-exec'"));
1832         }
1833
1834         if (!options.root) {
1835                 if (argc < 1) {
1836                         struct branch *branch;
1837
1838                         branch = branch_get(NULL);
1839                         options.upstream_name = branch_get_upstream(branch,
1840                                                                     NULL);
1841                         if (!options.upstream_name)
1842                                 error_on_missing_default_upstream();
1843                         if (fork_point < 0)
1844                                 fork_point = 1;
1845                 } else {
1846                         options.upstream_name = argv[0];
1847                         argc--;
1848                         argv++;
1849                         if (!strcmp(options.upstream_name, "-"))
1850                                 options.upstream_name = "@{-1}";
1851                 }
1852                 options.upstream = peel_committish(options.upstream_name);
1853                 if (!options.upstream)
1854                         die(_("invalid upstream '%s'"), options.upstream_name);
1855                 options.upstream_arg = options.upstream_name;
1856         } else {
1857                 if (!options.onto_name) {
1858                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1859                                         &squash_onto, NULL, NULL) < 0)
1860                                 die(_("Could not create new root commit"));
1861                         options.squash_onto = &squash_onto;
1862                         options.onto_name = squash_onto_name =
1863                                 xstrdup(oid_to_hex(&squash_onto));
1864                 } else
1865                         options.root_with_onto = 1;
1866
1867                 options.upstream_name = NULL;
1868                 options.upstream = NULL;
1869                 if (argc > 1)
1870                         usage_with_options(builtin_rebase_usage,
1871                                            builtin_rebase_options);
1872                 options.upstream_arg = "--root";
1873         }
1874
1875         /* Make sure the branch to rebase onto is valid. */
1876         if (keep_base) {
1877                 strbuf_reset(&buf);
1878                 strbuf_addstr(&buf, options.upstream_name);
1879                 strbuf_addstr(&buf, "...");
1880                 options.onto_name = xstrdup(buf.buf);
1881         } else if (!options.onto_name)
1882                 options.onto_name = options.upstream_name;
1883         if (strstr(options.onto_name, "...")) {
1884                 if (get_oid_mb(options.onto_name, &merge_base) < 0) {
1885                         if (keep_base)
1886                                 die(_("'%s': need exactly one merge base with branch"),
1887                                     options.upstream_name);
1888                         else
1889                                 die(_("'%s': need exactly one merge base"),
1890                                     options.onto_name);
1891                 }
1892                 options.onto = lookup_commit_or_die(&merge_base,
1893                                                     options.onto_name);
1894         } else {
1895                 options.onto = peel_committish(options.onto_name);
1896                 if (!options.onto)
1897                         die(_("Does not point to a valid commit '%s'"),
1898                                 options.onto_name);
1899         }
1900
1901         /*
1902          * If the branch to rebase is given, that is the branch we will rebase
1903          * branch_name -- branch/commit being rebased, or
1904          *                HEAD (already detached)
1905          * orig_head -- commit object name of tip of the branch before rebasing
1906          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1907          */
1908         if (argc == 1) {
1909                 /* Is it "rebase other branchname" or "rebase other commit"? */
1910                 branch_name = argv[0];
1911                 options.switch_to = argv[0];
1912
1913                 /* Is it a local branch? */
1914                 strbuf_reset(&buf);
1915                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1916                 if (!read_ref(buf.buf, &options.orig_head)) {
1917                         die_if_checked_out(buf.buf, 1);
1918                         options.head_name = xstrdup(buf.buf);
1919                 /* If not is it a valid ref (branch or commit)? */
1920                 } else if (!get_oid(branch_name, &options.orig_head))
1921                         options.head_name = NULL;
1922                 else
1923                         die(_("fatal: no such branch/commit '%s'"),
1924                             branch_name);
1925         } else if (argc == 0) {
1926                 /* Do not need to switch branches, we are already on it. */
1927                 options.head_name =
1928                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1929                                          &flags));
1930                 if (!options.head_name)
1931                         die(_("No such ref: %s"), "HEAD");
1932                 if (flags & REF_ISSYMREF) {
1933                         if (!skip_prefix(options.head_name,
1934                                          "refs/heads/", &branch_name))
1935                                 branch_name = options.head_name;
1936
1937                 } else {
1938                         FREE_AND_NULL(options.head_name);
1939                         branch_name = "HEAD";
1940                 }
1941                 if (get_oid("HEAD", &options.orig_head))
1942                         die(_("Could not resolve HEAD to a revision"));
1943         } else
1944                 BUG("unexpected number of arguments left to parse");
1945
1946         if (fork_point > 0) {
1947                 struct commit *head =
1948                         lookup_commit_reference(the_repository,
1949                                                 &options.orig_head);
1950                 options.restrict_revision =
1951                         get_fork_point(options.upstream_name, head);
1952         }
1953
1954         if (repo_read_index(the_repository) < 0)
1955                 die(_("could not read index"));
1956
1957         if (options.autostash) {
1958                 create_autostash(the_repository, state_dir_path("autostash", &options),
1959                                  DEFAULT_REFLOG_ACTION);
1960         }
1961
1962         if (require_clean_work_tree(the_repository, "rebase",
1963                                     _("Please commit or stash them."), 1, 1)) {
1964                 ret = 1;
1965                 goto cleanup;
1966         }
1967
1968         /*
1969          * Now we are rebasing commits upstream..orig_head (or with --root,
1970          * everything leading up to orig_head) on top of onto.
1971          */
1972
1973         /*
1974          * Check if we are already based on onto with linear history,
1975          * in which case we could fast-forward without replacing the commits
1976          * with new commits recreated by replaying their changes.
1977          *
1978          * Note that can_fast_forward() initializes merge_base, so we have to
1979          * call it before checking allow_preemptive_ff.
1980          */
1981         if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
1982                     &options.orig_head, &merge_base) &&
1983             allow_preemptive_ff) {
1984                 int flag;
1985
1986                 if (!(options.flags & REBASE_FORCE)) {
1987                         /* Lazily switch to the target branch if needed... */
1988                         if (options.switch_to) {
1989                                 strbuf_reset(&buf);
1990                                 strbuf_addf(&buf, "%s: checkout %s",
1991                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1992                                             options.switch_to);
1993                                 if (reset_head(the_repository,
1994                                                &options.orig_head, "checkout",
1995                                                options.head_name,
1996                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1997                                                NULL, buf.buf,
1998                                                DEFAULT_REFLOG_ACTION) < 0) {
1999                                         ret = !!error(_("could not switch to "
2000                                                         "%s"),
2001                                                       options.switch_to);
2002                                         goto cleanup;
2003                                 }
2004                         }
2005
2006                         if (!(options.flags & REBASE_NO_QUIET))
2007                                 ; /* be quiet */
2008                         else if (!strcmp(branch_name, "HEAD") &&
2009                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2010                                 puts(_("HEAD is up to date."));
2011                         else
2012                                 printf(_("Current branch %s is up to date.\n"),
2013                                        branch_name);
2014                         ret = !!finish_rebase(&options);
2015                         goto cleanup;
2016                 } else if (!(options.flags & REBASE_NO_QUIET))
2017                         ; /* be quiet */
2018                 else if (!strcmp(branch_name, "HEAD") &&
2019                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2020                         puts(_("HEAD is up to date, rebase forced."));
2021                 else
2022                         printf(_("Current branch %s is up to date, rebase "
2023                                  "forced.\n"), branch_name);
2024         }
2025
2026         /* If a hook exists, give it a chance to interrupt*/
2027         if (!ok_to_skip_pre_rebase &&
2028             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2029                         argc ? argv[0] : NULL, NULL))
2030                 die(_("The pre-rebase hook refused to rebase."));
2031
2032         if (options.flags & REBASE_DIFFSTAT) {
2033                 struct diff_options opts;
2034
2035                 if (options.flags & REBASE_VERBOSE) {
2036                         if (is_null_oid(&merge_base))
2037                                 printf(_("Changes to %s:\n"),
2038                                        oid_to_hex(&options.onto->object.oid));
2039                         else
2040                                 printf(_("Changes from %s to %s:\n"),
2041                                        oid_to_hex(&merge_base),
2042                                        oid_to_hex(&options.onto->object.oid));
2043                 }
2044
2045                 /* We want color (if set), but no pager */
2046                 diff_setup(&opts);
2047                 opts.stat_width = -1; /* use full terminal width */
2048                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2049                 opts.output_format |=
2050                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2051                 opts.detect_rename = DIFF_DETECT_RENAME;
2052                 diff_setup_done(&opts);
2053                 diff_tree_oid(is_null_oid(&merge_base) ?
2054                               the_hash_algo->empty_tree : &merge_base,
2055                               &options.onto->object.oid, "", &opts);
2056                 diffcore_std(&opts);
2057                 diff_flush(&opts);
2058         }
2059
2060         if (is_merge(&options))
2061                 goto run_rebase;
2062
2063         /* Detach HEAD and reset the tree */
2064         if (options.flags & REBASE_NO_QUIET)
2065                 printf(_("First, rewinding head to replay your work on top of "
2066                          "it...\n"));
2067
2068         strbuf_addf(&msg, "%s: checkout %s",
2069                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2070         if (reset_head(the_repository, &options.onto->object.oid, "checkout", NULL,
2071                        RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2072                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2073                        NULL, msg.buf, DEFAULT_REFLOG_ACTION))
2074                 die(_("Could not detach HEAD"));
2075         strbuf_release(&msg);
2076
2077         /*
2078          * If the onto is a proper descendant of the tip of the branch, then
2079          * we just fast-forwarded.
2080          */
2081         strbuf_reset(&msg);
2082         if (oideq(&merge_base, &options.orig_head)) {
2083                 printf(_("Fast-forwarded %s to %s.\n"),
2084                         branch_name, options.onto_name);
2085                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2086                         options.head_name ? options.head_name : "detached HEAD",
2087                         oid_to_hex(&options.onto->object.oid));
2088                 reset_head(the_repository, NULL, "Fast-forwarded", options.head_name,
2089                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf,
2090                            DEFAULT_REFLOG_ACTION);
2091                 strbuf_release(&msg);
2092                 ret = !!finish_rebase(&options);
2093                 goto cleanup;
2094         }
2095
2096         strbuf_addf(&revisions, "%s..%s",
2097                     options.root ? oid_to_hex(&options.onto->object.oid) :
2098                     (options.restrict_revision ?
2099                      oid_to_hex(&options.restrict_revision->object.oid) :
2100                      oid_to_hex(&options.upstream->object.oid)),
2101                     oid_to_hex(&options.orig_head));
2102
2103         options.revisions = revisions.buf;
2104
2105 run_rebase:
2106         ret = !!run_specific_rebase(&options, action);
2107
2108 cleanup:
2109         strbuf_release(&buf);
2110         strbuf_release(&revisions);
2111         free(options.head_name);
2112         free(options.gpg_sign_opt);
2113         free(options.cmd);
2114         free(squash_onto_name);
2115         return ret;
2116 }