Merge branch 'tb/ref-filter-multiple-patterns'
[git] / builtin / rebase.c
1 /*
2  * "git rebase" builtin command
3  *
4  * Copyright (c) 2018 Pratik Karki
5  */
6
7 #define USE_THE_INDEX_COMPATIBILITY_MACROS
8 #include "builtin.h"
9 #include "run-command.h"
10 #include "exec-cmd.h"
11 #include "argv-array.h"
12 #include "dir.h"
13 #include "packfile.h"
14 #include "refs.h"
15 #include "quote.h"
16 #include "config.h"
17 #include "cache-tree.h"
18 #include "unpack-trees.h"
19 #include "lockfile.h"
20 #include "parse-options.h"
21 #include "commit.h"
22 #include "diff.h"
23 #include "wt-status.h"
24 #include "revision.h"
25 #include "commit-reach.h"
26 #include "rerere.h"
27 #include "branch.h"
28 #include "sequencer.h"
29 #include "rebase-interactive.h"
30
31 static char const * const builtin_rebase_usage[] = {
32         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
33                 "[<upstream>] [<branch>]"),
34         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
35                 "--root [<branch>]"),
36         N_("git rebase --continue | --abort | --skip | --edit-todo"),
37         NULL
38 };
39
40 static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
41 static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
42 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
43 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
44
45 enum rebase_type {
46         REBASE_UNSPECIFIED = -1,
47         REBASE_AM,
48         REBASE_MERGE,
49         REBASE_INTERACTIVE,
50         REBASE_PRESERVE_MERGES
51 };
52
53 struct rebase_options {
54         enum rebase_type type;
55         const char *state_dir;
56         struct commit *upstream;
57         const char *upstream_name;
58         const char *upstream_arg;
59         char *head_name;
60         struct object_id orig_head;
61         struct commit *onto;
62         const char *onto_name;
63         const char *revisions;
64         const char *switch_to;
65         int root;
66         struct object_id *squash_onto;
67         struct commit *restrict_revision;
68         int dont_finish_rebase;
69         enum {
70                 REBASE_NO_QUIET = 1<<0,
71                 REBASE_VERBOSE = 1<<1,
72                 REBASE_DIFFSTAT = 1<<2,
73                 REBASE_FORCE = 1<<3,
74                 REBASE_INTERACTIVE_EXPLICIT = 1<<4,
75         } flags;
76         struct argv_array git_am_opts;
77         const char *action;
78         int signoff;
79         int allow_rerere_autoupdate;
80         int keep_empty;
81         int autosquash;
82         char *gpg_sign_opt;
83         int autostash;
84         char *cmd;
85         int allow_empty_message;
86         int rebase_merges, rebase_cousins;
87         char *strategy, *strategy_opts;
88         struct strbuf git_format_patch_opt;
89         int reschedule_failed_exec;
90         int use_legacy_rebase;
91 };
92
93 #define REBASE_OPTIONS_INIT {                           \
94                 .type = REBASE_UNSPECIFIED,             \
95                 .flags = REBASE_NO_QUIET,               \
96                 .git_am_opts = ARGV_ARRAY_INIT,         \
97                 .git_format_patch_opt = STRBUF_INIT     \
98         }
99
100 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
101 {
102         struct replay_opts replay = REPLAY_OPTS_INIT;
103
104         replay.action = REPLAY_INTERACTIVE_REBASE;
105         sequencer_init_config(&replay);
106
107         replay.signoff = opts->signoff;
108         replay.allow_ff = !(opts->flags & REBASE_FORCE);
109         if (opts->allow_rerere_autoupdate)
110                 replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
111         replay.allow_empty = 1;
112         replay.allow_empty_message = opts->allow_empty_message;
113         replay.verbose = opts->flags & REBASE_VERBOSE;
114         replay.reschedule_failed_exec = opts->reschedule_failed_exec;
115         replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
116         replay.strategy = opts->strategy;
117         if (opts->strategy_opts)
118                 parse_strategy_opts(&replay, opts->strategy_opts);
119
120         return replay;
121 }
122
123 enum action {
124         ACTION_NONE = 0,
125         ACTION_CONTINUE,
126         ACTION_SKIP,
127         ACTION_ABORT,
128         ACTION_QUIT,
129         ACTION_EDIT_TODO,
130         ACTION_SHOW_CURRENT_PATCH,
131         ACTION_SHORTEN_OIDS,
132         ACTION_EXPAND_OIDS,
133         ACTION_CHECK_TODO_LIST,
134         ACTION_REARRANGE_SQUASH,
135         ACTION_ADD_EXEC
136 };
137
138 static const char *action_names[] = { "undefined",
139                                       "continue",
140                                       "skip",
141                                       "abort",
142                                       "quit",
143                                       "edit_todo",
144                                       "show_current_patch" };
145
146 static int add_exec_commands(struct string_list *commands)
147 {
148         const char *todo_file = rebase_path_todo();
149         struct todo_list todo_list = TODO_LIST_INIT;
150         int res;
151
152         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
153                 return error_errno(_("could not read '%s'."), todo_file);
154
155         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
156                                         &todo_list)) {
157                 todo_list_release(&todo_list);
158                 return error(_("unusable todo list: '%s'"), todo_file);
159         }
160
161         todo_list_add_exec_commands(&todo_list, commands);
162         res = todo_list_write_to_file(the_repository, &todo_list,
163                                       todo_file, NULL, NULL, -1, 0);
164         todo_list_release(&todo_list);
165
166         if (res)
167                 return error_errno(_("could not write '%s'."), todo_file);
168         return 0;
169 }
170
171 static int rearrange_squash_in_todo_file(void)
172 {
173         const char *todo_file = rebase_path_todo();
174         struct todo_list todo_list = TODO_LIST_INIT;
175         int res = 0;
176
177         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
178                 return error_errno(_("could not read '%s'."), todo_file);
179         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
180                                         &todo_list)) {
181                 todo_list_release(&todo_list);
182                 return error(_("unusable todo list: '%s'"), todo_file);
183         }
184
185         res = todo_list_rearrange_squash(&todo_list);
186         if (!res)
187                 res = todo_list_write_to_file(the_repository, &todo_list,
188                                               todo_file, NULL, NULL, -1, 0);
189
190         todo_list_release(&todo_list);
191
192         if (res)
193                 return error_errno(_("could not write '%s'."), todo_file);
194         return 0;
195 }
196
197 static int transform_todo_file(unsigned flags)
198 {
199         const char *todo_file = rebase_path_todo();
200         struct todo_list todo_list = TODO_LIST_INIT;
201         int res;
202
203         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
204                 return error_errno(_("could not read '%s'."), todo_file);
205
206         if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
207                                         &todo_list)) {
208                 todo_list_release(&todo_list);
209                 return error(_("unusable todo list: '%s'"), todo_file);
210         }
211
212         res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
213                                       NULL, NULL, -1, flags);
214         todo_list_release(&todo_list);
215
216         if (res)
217                 return error_errno(_("could not write '%s'."), todo_file);
218         return 0;
219 }
220
221 static int edit_todo_file(unsigned flags)
222 {
223         const char *todo_file = rebase_path_todo();
224         struct todo_list todo_list = TODO_LIST_INIT,
225                 new_todo = TODO_LIST_INIT;
226         int res = 0;
227
228         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
229                 return error_errno(_("could not read '%s'."), todo_file);
230
231         strbuf_stripspace(&todo_list.buf, 1);
232         res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
233         if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
234                                             NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
235                 res = error_errno(_("could not write '%s'"), todo_file);
236
237         todo_list_release(&todo_list);
238         todo_list_release(&new_todo);
239
240         return res;
241 }
242
243 static int get_revision_ranges(struct commit *upstream, struct commit *onto,
244                                const char **head_hash,
245                                char **revisions, char **shortrevisions)
246 {
247         struct commit *base_rev = upstream ? upstream : onto;
248         const char *shorthead;
249         struct object_id orig_head;
250
251         if (get_oid("HEAD", &orig_head))
252                 return error(_("no HEAD?"));
253
254         *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
255         *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
256                                                    *head_hash);
257
258         shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
259
260         if (upstream) {
261                 const char *shortrev;
262
263                 shortrev = find_unique_abbrev(&base_rev->object.oid,
264                                               DEFAULT_ABBREV);
265
266                 *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
267         } else
268                 *shortrevisions = xstrdup(shorthead);
269
270         return 0;
271 }
272
273 static int init_basic_state(struct replay_opts *opts, const char *head_name,
274                             struct commit *onto, const char *orig_head)
275 {
276         FILE *interactive;
277
278         if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
279                 return error_errno(_("could not create temporary %s"), merge_dir());
280
281         delete_reflog("REBASE_HEAD");
282
283         interactive = fopen(path_interactive(), "w");
284         if (!interactive)
285                 return error_errno(_("could not mark as interactive"));
286         fclose(interactive);
287
288         return write_basic_state(opts, head_name, onto, orig_head);
289 }
290
291 static void split_exec_commands(const char *cmd, struct string_list *commands)
292 {
293         if (cmd && *cmd) {
294                 string_list_split(commands, cmd, '\n', -1);
295
296                 /* rebase.c adds a new line to cmd after every command,
297                  * so here the last command is always empty */
298                 string_list_remove_empty_items(commands, 0);
299         }
300 }
301
302 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
303 {
304         int ret;
305         const char *head_hash = NULL;
306         char *revisions = NULL, *shortrevisions = NULL;
307         struct argv_array make_script_args = ARGV_ARRAY_INIT;
308         struct todo_list todo_list = TODO_LIST_INIT;
309         struct replay_opts replay = get_replay_opts(opts);
310         struct string_list commands = STRING_LIST_INIT_DUP;
311
312         if (prepare_branch_to_be_rebased(the_repository, &replay,
313                                          opts->switch_to))
314                 return -1;
315
316         if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
317                                 &revisions, &shortrevisions))
318                 return -1;
319
320         if (init_basic_state(&replay,
321                              opts->head_name ? opts->head_name : "detached HEAD",
322                              opts->onto, head_hash)) {
323                 free(revisions);
324                 free(shortrevisions);
325
326                 return -1;
327         }
328
329         if (!opts->upstream && opts->squash_onto)
330                 write_file(path_squash_onto(), "%s\n",
331                            oid_to_hex(opts->squash_onto));
332
333         argv_array_pushl(&make_script_args, "", revisions, NULL);
334         if (opts->restrict_revision)
335                 argv_array_push(&make_script_args,
336                                 oid_to_hex(&opts->restrict_revision->object.oid));
337
338         ret = sequencer_make_script(the_repository, &todo_list.buf,
339                                     make_script_args.argc, make_script_args.argv,
340                                     flags);
341
342         if (ret)
343                 error(_("could not generate todo list"));
344         else {
345                 discard_cache();
346                 if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
347                                                 &todo_list))
348                         BUG("unusable todo list");
349
350                 split_exec_commands(opts->cmd, &commands);
351                 ret = complete_action(the_repository, &replay, flags,
352                         shortrevisions, opts->onto_name, opts->onto, head_hash,
353                         &commands, opts->autosquash, &todo_list);
354         }
355
356         string_list_clear(&commands, 0);
357         free(revisions);
358         free(shortrevisions);
359         todo_list_release(&todo_list);
360         argv_array_clear(&make_script_args);
361
362         return ret;
363 }
364
365 static int run_rebase_interactive(struct rebase_options *opts,
366                                   enum action command)
367 {
368         unsigned flags = 0;
369         int abbreviate_commands = 0, ret = 0;
370
371         git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
372
373         flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
374         flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
375         flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
376         flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
377         flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
378
379         switch (command) {
380         case ACTION_NONE: {
381                 if (!opts->onto && !opts->upstream)
382                         die(_("a base commit must be provided with --upstream or --onto"));
383
384                 ret = do_interactive_rebase(opts, flags);
385                 break;
386         }
387         case ACTION_SKIP: {
388                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
389
390                 rerere_clear(the_repository, &merge_rr);
391         }
392                 /* fallthrough */
393         case ACTION_CONTINUE: {
394                 struct replay_opts replay_opts = get_replay_opts(opts);
395
396                 ret = sequencer_continue(the_repository, &replay_opts);
397                 break;
398         }
399         case ACTION_EDIT_TODO:
400                 ret = edit_todo_file(flags);
401                 break;
402         case ACTION_SHOW_CURRENT_PATCH: {
403                 struct child_process cmd = CHILD_PROCESS_INIT;
404
405                 cmd.git_cmd = 1;
406                 argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
407                 ret = run_command(&cmd);
408
409                 break;
410         }
411         case ACTION_SHORTEN_OIDS:
412         case ACTION_EXPAND_OIDS:
413                 ret = transform_todo_file(flags);
414                 break;
415         case ACTION_CHECK_TODO_LIST:
416                 ret = check_todo_list_from_file(the_repository);
417                 break;
418         case ACTION_REARRANGE_SQUASH:
419                 ret = rearrange_squash_in_todo_file();
420                 break;
421         case ACTION_ADD_EXEC: {
422                 struct string_list commands = STRING_LIST_INIT_DUP;
423
424                 split_exec_commands(opts->cmd, &commands);
425                 ret = add_exec_commands(&commands);
426                 string_list_clear(&commands, 0);
427                 break;
428         }
429         default:
430                 BUG("invalid command '%d'", command);
431         }
432
433         return ret;
434 }
435
436 static const char * const builtin_rebase_interactive_usage[] = {
437         N_("git rebase--interactive [<options>]"),
438         NULL
439 };
440
441 int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
442 {
443         struct rebase_options opts = REBASE_OPTIONS_INIT;
444         struct object_id squash_onto = null_oid;
445         enum action command = ACTION_NONE;
446         struct option options[] = {
447                 OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
448                            REBASE_FORCE),
449                 OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
450                 OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
451                          N_("allow commits with empty messages")),
452                 OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
453                 OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
454                          N_("keep original branch points of cousins")),
455                 OPT_BOOL(0, "autosquash", &opts.autosquash,
456                          N_("move commits that begin with squash!/fixup!")),
457                 OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
458                 OPT_BIT('v', "verbose", &opts.flags,
459                         N_("display a diffstat of what changed upstream"),
460                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
461                 OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
462                             ACTION_CONTINUE),
463                 OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
464                 OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
465                             ACTION_EDIT_TODO),
466                 OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
467                             ACTION_SHOW_CURRENT_PATCH),
468                 OPT_CMDMODE(0, "shorten-ids", &command,
469                         N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
470                 OPT_CMDMODE(0, "expand-ids", &command,
471                         N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
472                 OPT_CMDMODE(0, "check-todo-list", &command,
473                         N_("check the todo list"), ACTION_CHECK_TODO_LIST),
474                 OPT_CMDMODE(0, "rearrange-squash", &command,
475                         N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
476                 OPT_CMDMODE(0, "add-exec-commands", &command,
477                         N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
478                 { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
479                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
480                 { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
481                   N_("restrict-revision"), N_("restrict revision"),
482                   PARSE_OPT_NONEG, parse_opt_commit, 0 },
483                 { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
484                   N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
485                 { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
486                   N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
487                   0 },
488                 OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
489                 { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
490                         N_("GPG-sign commits"),
491                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
492                 OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
493                            N_("rebase strategy")),
494                 OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
495                            N_("strategy options")),
496                 OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
497                            N_("the branch or commit to checkout")),
498                 OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
499                 OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
500                 OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
501                 OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
502                          N_("automatically re-schedule any `exec` that fails")),
503                 OPT_END()
504         };
505
506         opts.rebase_cousins = -1;
507
508         if (argc == 1)
509                 usage_with_options(builtin_rebase_interactive_usage, options);
510
511         argc = parse_options(argc, argv, prefix, options,
512                         builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
513
514         if (!is_null_oid(&squash_onto))
515                 opts.squash_onto = &squash_onto;
516
517         if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
518                 warning(_("--[no-]rebase-cousins has no effect without "
519                           "--rebase-merges"));
520
521         return !!run_rebase_interactive(&opts, command);
522 }
523
524 static int is_interactive(struct rebase_options *opts)
525 {
526         return opts->type == REBASE_INTERACTIVE ||
527                 opts->type == REBASE_PRESERVE_MERGES;
528 }
529
530 static void imply_interactive(struct rebase_options *opts, const char *option)
531 {
532         switch (opts->type) {
533         case REBASE_AM:
534                 die(_("%s requires an interactive rebase"), option);
535                 break;
536         case REBASE_INTERACTIVE:
537         case REBASE_PRESERVE_MERGES:
538                 break;
539         case REBASE_MERGE:
540                 /* we now implement --merge via --interactive */
541         default:
542                 opts->type = REBASE_INTERACTIVE; /* implied */
543                 break;
544         }
545 }
546
547 /* Returns the filename prefixed by the state_dir */
548 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
549 {
550         static struct strbuf path = STRBUF_INIT;
551         static size_t prefix_len;
552
553         if (!prefix_len) {
554                 strbuf_addf(&path, "%s/", opts->state_dir);
555                 prefix_len = path.len;
556         }
557
558         strbuf_setlen(&path, prefix_len);
559         strbuf_addstr(&path, filename);
560         return path.buf;
561 }
562
563 /* Read one file, then strip line endings */
564 static int read_one(const char *path, struct strbuf *buf)
565 {
566         if (strbuf_read_file(buf, path, 0) < 0)
567                 return error_errno(_("could not read '%s'"), path);
568         strbuf_trim_trailing_newline(buf);
569         return 0;
570 }
571
572 /* Initialize the rebase options from the state directory. */
573 static int read_basic_state(struct rebase_options *opts)
574 {
575         struct strbuf head_name = STRBUF_INIT;
576         struct strbuf buf = STRBUF_INIT;
577         struct object_id oid;
578
579         if (read_one(state_dir_path("head-name", opts), &head_name) ||
580             read_one(state_dir_path("onto", opts), &buf))
581                 return -1;
582         opts->head_name = starts_with(head_name.buf, "refs/") ?
583                 xstrdup(head_name.buf) : NULL;
584         strbuf_release(&head_name);
585         if (get_oid(buf.buf, &oid))
586                 return error(_("could not get 'onto': '%s'"), buf.buf);
587         opts->onto = lookup_commit_or_die(&oid, buf.buf);
588
589         /*
590          * We always write to orig-head, but interactive rebase used to write to
591          * head. Fall back to reading from head to cover for the case that the
592          * user upgraded git with an ongoing interactive rebase.
593          */
594         strbuf_reset(&buf);
595         if (file_exists(state_dir_path("orig-head", opts))) {
596                 if (read_one(state_dir_path("orig-head", opts), &buf))
597                         return -1;
598         } else if (read_one(state_dir_path("head", opts), &buf))
599                 return -1;
600         if (get_oid(buf.buf, &opts->orig_head))
601                 return error(_("invalid orig-head: '%s'"), buf.buf);
602
603         if (file_exists(state_dir_path("quiet", opts)))
604                 opts->flags &= ~REBASE_NO_QUIET;
605         else
606                 opts->flags |= REBASE_NO_QUIET;
607
608         if (file_exists(state_dir_path("verbose", opts)))
609                 opts->flags |= REBASE_VERBOSE;
610
611         if (file_exists(state_dir_path("signoff", opts))) {
612                 opts->signoff = 1;
613                 opts->flags |= REBASE_FORCE;
614         }
615
616         if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
617                 strbuf_reset(&buf);
618                 if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
619                             &buf))
620                         return -1;
621                 if (!strcmp(buf.buf, "--rerere-autoupdate"))
622                         opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
623                 else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
624                         opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
625                 else
626                         warning(_("ignoring invalid allow_rerere_autoupdate: "
627                                   "'%s'"), buf.buf);
628         }
629
630         if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
631                 strbuf_reset(&buf);
632                 if (read_one(state_dir_path("gpg_sign_opt", opts),
633                             &buf))
634                         return -1;
635                 free(opts->gpg_sign_opt);
636                 opts->gpg_sign_opt = xstrdup(buf.buf);
637         }
638
639         if (file_exists(state_dir_path("strategy", opts))) {
640                 strbuf_reset(&buf);
641                 if (read_one(state_dir_path("strategy", opts), &buf))
642                         return -1;
643                 free(opts->strategy);
644                 opts->strategy = xstrdup(buf.buf);
645         }
646
647         if (file_exists(state_dir_path("strategy_opts", opts))) {
648                 strbuf_reset(&buf);
649                 if (read_one(state_dir_path("strategy_opts", opts), &buf))
650                         return -1;
651                 free(opts->strategy_opts);
652                 opts->strategy_opts = xstrdup(buf.buf);
653         }
654
655         strbuf_release(&buf);
656
657         return 0;
658 }
659
660 static int rebase_write_basic_state(struct rebase_options *opts)
661 {
662         write_file(state_dir_path("head-name", opts), "%s",
663                    opts->head_name ? opts->head_name : "detached HEAD");
664         write_file(state_dir_path("onto", opts), "%s",
665                    opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
666         write_file(state_dir_path("orig-head", opts), "%s",
667                    oid_to_hex(&opts->orig_head));
668         write_file(state_dir_path("quiet", opts), "%s",
669                    opts->flags & REBASE_NO_QUIET ? "" : "t");
670         if (opts->flags & REBASE_VERBOSE)
671                 write_file(state_dir_path("verbose", opts), "%s", "");
672         if (opts->strategy)
673                 write_file(state_dir_path("strategy", opts), "%s",
674                            opts->strategy);
675         if (opts->strategy_opts)
676                 write_file(state_dir_path("strategy_opts", opts), "%s",
677                            opts->strategy_opts);
678         if (opts->allow_rerere_autoupdate > 0)
679                 write_file(state_dir_path("allow_rerere_autoupdate", opts),
680                            "-%s-rerere-autoupdate",
681                            opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
682                                 "" : "-no");
683         if (opts->gpg_sign_opt)
684                 write_file(state_dir_path("gpg_sign_opt", opts), "%s",
685                            opts->gpg_sign_opt);
686         if (opts->signoff)
687                 write_file(state_dir_path("strategy", opts), "--signoff");
688
689         return 0;
690 }
691
692 static int apply_autostash(struct rebase_options *opts)
693 {
694         const char *path = state_dir_path("autostash", opts);
695         struct strbuf autostash = STRBUF_INIT;
696         struct child_process stash_apply = CHILD_PROCESS_INIT;
697
698         if (!file_exists(path))
699                 return 0;
700
701         if (read_one(path, &autostash))
702                 return error(_("Could not read '%s'"), path);
703         /* Ensure that the hash is not mistaken for a number */
704         strbuf_addstr(&autostash, "^0");
705         argv_array_pushl(&stash_apply.args,
706                          "stash", "apply", autostash.buf, NULL);
707         stash_apply.git_cmd = 1;
708         stash_apply.no_stderr = stash_apply.no_stdout =
709                 stash_apply.no_stdin = 1;
710         if (!run_command(&stash_apply))
711                 printf(_("Applied autostash.\n"));
712         else {
713                 struct argv_array args = ARGV_ARRAY_INIT;
714                 int res = 0;
715
716                 argv_array_pushl(&args,
717                                  "stash", "store", "-m", "autostash", "-q",
718                                  autostash.buf, NULL);
719                 if (run_command_v_opt(args.argv, RUN_GIT_CMD))
720                         res = error(_("Cannot store %s"), autostash.buf);
721                 argv_array_clear(&args);
722                 strbuf_release(&autostash);
723                 if (res)
724                         return res;
725
726                 fprintf(stderr,
727                         _("Applying autostash resulted in conflicts.\n"
728                           "Your changes are safe in the stash.\n"
729                           "You can run \"git stash pop\" or \"git stash drop\" "
730                           "at any time.\n"));
731         }
732
733         strbuf_release(&autostash);
734         return 0;
735 }
736
737 static int finish_rebase(struct rebase_options *opts)
738 {
739         struct strbuf dir = STRBUF_INIT;
740         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
741         int ret = 0;
742
743         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
744         apply_autostash(opts);
745         close_object_store(the_repository->objects);
746         /*
747          * We ignore errors in 'gc --auto', since the
748          * user should see them.
749          */
750         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
751         if (opts->type == REBASE_INTERACTIVE) {
752                 struct replay_opts replay = REPLAY_OPTS_INIT;
753
754                 replay.action = REPLAY_INTERACTIVE_REBASE;
755                 ret = sequencer_remove_state(&replay);
756         } else {
757                 strbuf_addstr(&dir, opts->state_dir);
758                 if (remove_dir_recursively(&dir, 0))
759                         ret = error(_("could not remove '%s'"),
760                                     opts->state_dir);
761                 strbuf_release(&dir);
762         }
763
764         return ret;
765 }
766
767 static struct commit *peel_committish(const char *name)
768 {
769         struct object *obj;
770         struct object_id oid;
771
772         if (get_oid(name, &oid))
773                 return NULL;
774         obj = parse_object(the_repository, &oid);
775         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
776 }
777
778 static void add_var(struct strbuf *buf, const char *name, const char *value)
779 {
780         if (!value)
781                 strbuf_addf(buf, "unset %s; ", name);
782         else {
783                 strbuf_addf(buf, "%s=", name);
784                 sq_quote_buf(buf, value);
785                 strbuf_addstr(buf, "; ");
786         }
787 }
788
789 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
790
791 #define RESET_HEAD_DETACH (1<<0)
792 #define RESET_HEAD_HARD (1<<1)
793 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
794 #define RESET_HEAD_REFS_ONLY (1<<3)
795 #define RESET_ORIG_HEAD (1<<4)
796
797 static int reset_head(struct object_id *oid, const char *action,
798                       const char *switch_to_branch, unsigned flags,
799                       const char *reflog_orig_head, const char *reflog_head)
800 {
801         unsigned detach_head = flags & RESET_HEAD_DETACH;
802         unsigned reset_hard = flags & RESET_HEAD_HARD;
803         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
804         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
805         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
806         struct object_id head_oid;
807         struct tree_desc desc[2] = { { NULL }, { NULL } };
808         struct lock_file lock = LOCK_INIT;
809         struct unpack_trees_options unpack_tree_opts;
810         struct tree *tree;
811         const char *reflog_action;
812         struct strbuf msg = STRBUF_INIT;
813         size_t prefix_len;
814         struct object_id *orig = NULL, oid_orig,
815                 *old_orig = NULL, oid_old_orig;
816         int ret = 0, nr = 0;
817
818         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
819                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
820
821         if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
822                 ret = -1;
823                 goto leave_reset_head;
824         }
825
826         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
827                 ret = error(_("could not determine HEAD revision"));
828                 goto leave_reset_head;
829         }
830
831         if (!oid)
832                 oid = &head_oid;
833
834         if (refs_only)
835                 goto reset_head_refs;
836
837         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
838         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
839         unpack_tree_opts.head_idx = 1;
840         unpack_tree_opts.src_index = the_repository->index;
841         unpack_tree_opts.dst_index = the_repository->index;
842         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
843         unpack_tree_opts.update = 1;
844         unpack_tree_opts.merge = 1;
845         if (!detach_head)
846                 unpack_tree_opts.reset = 1;
847
848         if (repo_read_index_unmerged(the_repository) < 0) {
849                 ret = error(_("could not read index"));
850                 goto leave_reset_head;
851         }
852
853         if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
854                 ret = error(_("failed to find tree of %s"),
855                             oid_to_hex(&head_oid));
856                 goto leave_reset_head;
857         }
858
859         if (!fill_tree_descriptor(&desc[nr++], oid)) {
860                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
861                 goto leave_reset_head;
862         }
863
864         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
865                 ret = -1;
866                 goto leave_reset_head;
867         }
868
869         tree = parse_tree_indirect(oid);
870         prime_cache_tree(the_repository, the_repository->index, tree);
871
872         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
873                 ret = error(_("could not write index"));
874                 goto leave_reset_head;
875         }
876
877 reset_head_refs:
878         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
879         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
880         prefix_len = msg.len;
881
882         if (update_orig_head) {
883                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
884                         old_orig = &oid_old_orig;
885                 if (!get_oid("HEAD", &oid_orig)) {
886                         orig = &oid_orig;
887                         if (!reflog_orig_head) {
888                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
889                                 reflog_orig_head = msg.buf;
890                         }
891                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
892                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
893                 } else if (old_orig)
894                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
895         }
896
897         if (!reflog_head) {
898                 strbuf_setlen(&msg, prefix_len);
899                 strbuf_addstr(&msg, "updating HEAD");
900                 reflog_head = msg.buf;
901         }
902         if (!switch_to_branch)
903                 ret = update_ref(reflog_head, "HEAD", oid, orig,
904                                  detach_head ? REF_NO_DEREF : 0,
905                                  UPDATE_REFS_MSG_ON_ERR);
906         else {
907                 ret = update_ref(reflog_head, switch_to_branch, oid,
908                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
909                 if (!ret)
910                         ret = create_symref("HEAD", switch_to_branch,
911                                             reflog_head);
912         }
913         if (run_hook)
914                 run_hook_le(NULL, "post-checkout",
915                             oid_to_hex(orig ? orig : &null_oid),
916                             oid_to_hex(oid), "1", NULL);
917
918 leave_reset_head:
919         strbuf_release(&msg);
920         rollback_lock_file(&lock);
921         while (nr)
922                 free((void *)desc[--nr].buffer);
923         return ret;
924 }
925
926 static int move_to_original_branch(struct rebase_options *opts)
927 {
928         struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
929         int ret;
930
931         if (!opts->head_name)
932                 return 0; /* nothing to move back to */
933
934         if (!opts->onto)
935                 BUG("move_to_original_branch without onto");
936
937         strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
938                     opts->head_name, oid_to_hex(&opts->onto->object.oid));
939         strbuf_addf(&head_reflog, "rebase finished: returning to %s",
940                     opts->head_name);
941         ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
942                          orig_head_reflog.buf, head_reflog.buf);
943
944         strbuf_release(&orig_head_reflog);
945         strbuf_release(&head_reflog);
946         return ret;
947 }
948
949 static const char *resolvemsg =
950 N_("Resolve all conflicts manually, mark them as resolved with\n"
951 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
952 "You can instead skip this commit: run \"git rebase --skip\".\n"
953 "To abort and get back to the state before \"git rebase\", run "
954 "\"git rebase --abort\".");
955
956 static int run_am(struct rebase_options *opts)
957 {
958         struct child_process am = CHILD_PROCESS_INIT;
959         struct child_process format_patch = CHILD_PROCESS_INIT;
960         struct strbuf revisions = STRBUF_INIT;
961         int status;
962         char *rebased_patches;
963
964         am.git_cmd = 1;
965         argv_array_push(&am.args, "am");
966
967         if (opts->action && !strcmp("continue", opts->action)) {
968                 argv_array_push(&am.args, "--resolved");
969                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
970                 if (opts->gpg_sign_opt)
971                         argv_array_push(&am.args, opts->gpg_sign_opt);
972                 status = run_command(&am);
973                 if (status)
974                         return status;
975
976                 return move_to_original_branch(opts);
977         }
978         if (opts->action && !strcmp("skip", opts->action)) {
979                 argv_array_push(&am.args, "--skip");
980                 argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
981                 status = run_command(&am);
982                 if (status)
983                         return status;
984
985                 return move_to_original_branch(opts);
986         }
987         if (opts->action && !strcmp("show-current-patch", opts->action)) {
988                 argv_array_push(&am.args, "--show-current-patch");
989                 return run_command(&am);
990         }
991
992         strbuf_addf(&revisions, "%s...%s",
993                     oid_to_hex(opts->root ?
994                                /* this is now equivalent to !opts->upstream */
995                                &opts->onto->object.oid :
996                                &opts->upstream->object.oid),
997                     oid_to_hex(&opts->orig_head));
998
999         rebased_patches = xstrdup(git_path("rebased-patches"));
1000         format_patch.out = open(rebased_patches,
1001                                 O_WRONLY | O_CREAT | O_TRUNC, 0666);
1002         if (format_patch.out < 0) {
1003                 status = error_errno(_("could not open '%s' for writing"),
1004                                      rebased_patches);
1005                 free(rebased_patches);
1006                 argv_array_clear(&am.args);
1007                 return status;
1008         }
1009
1010         format_patch.git_cmd = 1;
1011         argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1012                          "--full-index", "--cherry-pick", "--right-only",
1013                          "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1014                          "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
1015         if (opts->git_format_patch_opt.len)
1016                 argv_array_split(&format_patch.args,
1017                                  opts->git_format_patch_opt.buf);
1018         argv_array_push(&format_patch.args, revisions.buf);
1019         if (opts->restrict_revision)
1020                 argv_array_pushf(&format_patch.args, "^%s",
1021                                  oid_to_hex(&opts->restrict_revision->object.oid));
1022
1023         status = run_command(&format_patch);
1024         if (status) {
1025                 unlink(rebased_patches);
1026                 free(rebased_patches);
1027                 argv_array_clear(&am.args);
1028
1029                 reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1030                            "HEAD", NULL);
1031                 error(_("\ngit encountered an error while preparing the "
1032                         "patches to replay\n"
1033                         "these revisions:\n"
1034                         "\n    %s\n\n"
1035                         "As a result, git cannot rebase them."),
1036                       opts->revisions);
1037
1038                 strbuf_release(&revisions);
1039                 return status;
1040         }
1041         strbuf_release(&revisions);
1042
1043         am.in = open(rebased_patches, O_RDONLY);
1044         if (am.in < 0) {
1045                 status = error_errno(_("could not open '%s' for reading"),
1046                                      rebased_patches);
1047                 free(rebased_patches);
1048                 argv_array_clear(&am.args);
1049                 return status;
1050         }
1051
1052         argv_array_pushv(&am.args, opts->git_am_opts.argv);
1053         argv_array_push(&am.args, "--rebasing");
1054         argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1055         argv_array_push(&am.args, "--patch-format=mboxrd");
1056         if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1057                 argv_array_push(&am.args, "--rerere-autoupdate");
1058         else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1059                 argv_array_push(&am.args, "--no-rerere-autoupdate");
1060         if (opts->gpg_sign_opt)
1061                 argv_array_push(&am.args, opts->gpg_sign_opt);
1062         status = run_command(&am);
1063         unlink(rebased_patches);
1064         free(rebased_patches);
1065
1066         if (!status) {
1067                 return move_to_original_branch(opts);
1068         }
1069
1070         if (is_directory(opts->state_dir))
1071                 rebase_write_basic_state(opts);
1072
1073         return status;
1074 }
1075
1076 static int run_specific_rebase(struct rebase_options *opts, enum action action)
1077 {
1078         const char *argv[] = { NULL, NULL };
1079         struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1080         int status;
1081         const char *backend, *backend_func;
1082
1083         if (opts->type == REBASE_INTERACTIVE) {
1084                 /* Run builtin interactive rebase */
1085                 setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1086                 if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1087                         setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1088                         opts->autosquash = 0;
1089                 }
1090                 if (opts->gpg_sign_opt) {
1091                         /* remove the leading "-S" */
1092                         char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1093                         free(opts->gpg_sign_opt);
1094                         opts->gpg_sign_opt = tmp;
1095                 }
1096
1097                 status = run_rebase_interactive(opts, action);
1098                 goto finished_rebase;
1099         }
1100
1101         if (opts->type == REBASE_AM) {
1102                 status = run_am(opts);
1103                 goto finished_rebase;
1104         }
1105
1106         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1107         add_var(&script_snippet, "state_dir", opts->state_dir);
1108
1109         add_var(&script_snippet, "upstream_name", opts->upstream_name);
1110         add_var(&script_snippet, "upstream", opts->upstream ?
1111                 oid_to_hex(&opts->upstream->object.oid) : NULL);
1112         add_var(&script_snippet, "head_name",
1113                 opts->head_name ? opts->head_name : "detached HEAD");
1114         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1115         add_var(&script_snippet, "onto", opts->onto ?
1116                 oid_to_hex(&opts->onto->object.oid) : NULL);
1117         add_var(&script_snippet, "onto_name", opts->onto_name);
1118         add_var(&script_snippet, "revisions", opts->revisions);
1119         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1120                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1121         add_var(&script_snippet, "GIT_QUIET",
1122                 opts->flags & REBASE_NO_QUIET ? "" : "t");
1123         sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1124         add_var(&script_snippet, "git_am_opt", buf.buf);
1125         strbuf_release(&buf);
1126         add_var(&script_snippet, "verbose",
1127                 opts->flags & REBASE_VERBOSE ? "t" : "");
1128         add_var(&script_snippet, "diffstat",
1129                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
1130         add_var(&script_snippet, "force_rebase",
1131                 opts->flags & REBASE_FORCE ? "t" : "");
1132         if (opts->switch_to)
1133                 add_var(&script_snippet, "switch_to", opts->switch_to);
1134         add_var(&script_snippet, "action", opts->action ? opts->action : "");
1135         add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1136         add_var(&script_snippet, "allow_rerere_autoupdate",
1137                 opts->allow_rerere_autoupdate ?
1138                         opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1139                         "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1140         add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1141         add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1142         add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1143         add_var(&script_snippet, "cmd", opts->cmd);
1144         add_var(&script_snippet, "allow_empty_message",
1145                 opts->allow_empty_message ?  "--allow-empty-message" : "");
1146         add_var(&script_snippet, "rebase_merges",
1147                 opts->rebase_merges ? "t" : "");
1148         add_var(&script_snippet, "rebase_cousins",
1149                 opts->rebase_cousins ? "t" : "");
1150         add_var(&script_snippet, "strategy", opts->strategy);
1151         add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1152         add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1153         add_var(&script_snippet, "squash_onto",
1154                 opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1155         add_var(&script_snippet, "git_format_patch_opt",
1156                 opts->git_format_patch_opt.buf);
1157
1158         if (is_interactive(opts) &&
1159             !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1160                 strbuf_addstr(&script_snippet,
1161                               "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1162                 opts->autosquash = 0;
1163         }
1164
1165         switch (opts->type) {
1166         case REBASE_PRESERVE_MERGES:
1167                 backend = "git-rebase--preserve-merges";
1168                 backend_func = "git_rebase__preserve_merges";
1169                 break;
1170         default:
1171                 BUG("Unhandled rebase type %d", opts->type);
1172                 break;
1173         }
1174
1175         strbuf_addf(&script_snippet,
1176                     ". git-sh-setup && . %s && %s", backend, backend_func);
1177         argv[0] = script_snippet.buf;
1178
1179         status = run_command_v_opt(argv, RUN_USING_SHELL);
1180 finished_rebase:
1181         if (opts->dont_finish_rebase)
1182                 ; /* do nothing */
1183         else if (opts->type == REBASE_INTERACTIVE)
1184                 ; /* interactive rebase cleans up after itself */
1185         else if (status == 0) {
1186                 if (!file_exists(state_dir_path("stopped-sha", opts)))
1187                         finish_rebase(opts);
1188         } else if (status == 2) {
1189                 struct strbuf dir = STRBUF_INIT;
1190
1191                 apply_autostash(opts);
1192                 strbuf_addstr(&dir, opts->state_dir);
1193                 remove_dir_recursively(&dir, 0);
1194                 strbuf_release(&dir);
1195                 die("Nothing to do");
1196         }
1197
1198         strbuf_release(&script_snippet);
1199
1200         return status ? -1 : 0;
1201 }
1202
1203 static int rebase_config(const char *var, const char *value, void *data)
1204 {
1205         struct rebase_options *opts = data;
1206
1207         if (!strcmp(var, "rebase.stat")) {
1208                 if (git_config_bool(var, value))
1209                         opts->flags |= REBASE_DIFFSTAT;
1210                 else
1211                         opts->flags &= ~REBASE_DIFFSTAT;
1212                 return 0;
1213         }
1214
1215         if (!strcmp(var, "rebase.autosquash")) {
1216                 opts->autosquash = git_config_bool(var, value);
1217                 return 0;
1218         }
1219
1220         if (!strcmp(var, "commit.gpgsign")) {
1221                 free(opts->gpg_sign_opt);
1222                 opts->gpg_sign_opt = git_config_bool(var, value) ?
1223                         xstrdup("-S") : NULL;
1224                 return 0;
1225         }
1226
1227         if (!strcmp(var, "rebase.autostash")) {
1228                 opts->autostash = git_config_bool(var, value);
1229                 return 0;
1230         }
1231
1232         if (!strcmp(var, "rebase.reschedulefailedexec")) {
1233                 opts->reschedule_failed_exec = git_config_bool(var, value);
1234                 return 0;
1235         }
1236
1237         if (!strcmp(var, "rebase.usebuiltin")) {
1238                 opts->use_legacy_rebase = !git_config_bool(var, value);
1239                 return 0;
1240         }
1241
1242         return git_default_config(var, value, data);
1243 }
1244
1245 /*
1246  * Determines whether the commits in from..to are linear, i.e. contain
1247  * no merge commits. This function *expects* `from` to be an ancestor of
1248  * `to`.
1249  */
1250 static int is_linear_history(struct commit *from, struct commit *to)
1251 {
1252         while (to && to != from) {
1253                 parse_commit(to);
1254                 if (!to->parents)
1255                         return 1;
1256                 if (to->parents->next)
1257                         return 0;
1258                 to = to->parents->item;
1259         }
1260         return 1;
1261 }
1262
1263 static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
1264                             struct object_id *merge_base)
1265 {
1266         struct commit *head = lookup_commit(the_repository, head_oid);
1267         struct commit_list *merge_bases;
1268         int res;
1269
1270         if (!head)
1271                 return 0;
1272
1273         merge_bases = get_merge_bases(onto, head);
1274         if (merge_bases && !merge_bases->next) {
1275                 oidcpy(merge_base, &merge_bases->item->object.oid);
1276                 res = oideq(merge_base, &onto->object.oid);
1277         } else {
1278                 oidcpy(merge_base, &null_oid);
1279                 res = 0;
1280         }
1281         free_commit_list(merge_bases);
1282         return res && is_linear_history(onto, head);
1283 }
1284
1285 /* -i followed by -m is still -i */
1286 static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1287 {
1288         struct rebase_options *opts = opt->value;
1289
1290         BUG_ON_OPT_NEG(unset);
1291         BUG_ON_OPT_ARG(arg);
1292
1293         if (!is_interactive(opts))
1294                 opts->type = REBASE_MERGE;
1295
1296         return 0;
1297 }
1298
1299 /* -i followed by -p is still explicitly interactive, but -p alone is not */
1300 static int parse_opt_interactive(const struct option *opt, const char *arg,
1301                                  int unset)
1302 {
1303         struct rebase_options *opts = opt->value;
1304
1305         BUG_ON_OPT_NEG(unset);
1306         BUG_ON_OPT_ARG(arg);
1307
1308         opts->type = REBASE_INTERACTIVE;
1309         opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1310
1311         return 0;
1312 }
1313
1314 static void NORETURN error_on_missing_default_upstream(void)
1315 {
1316         struct branch *current_branch = branch_get(NULL);
1317
1318         printf(_("%s\n"
1319                  "Please specify which branch you want to rebase against.\n"
1320                  "See git-rebase(1) for details.\n"
1321                  "\n"
1322                  "    git rebase '<branch>'\n"
1323                  "\n"),
1324                 current_branch ? _("There is no tracking information for "
1325                         "the current branch.") :
1326                         _("You are not currently on a branch."));
1327
1328         if (current_branch) {
1329                 const char *remote = current_branch->remote_name;
1330
1331                 if (!remote)
1332                         remote = _("<remote>");
1333
1334                 printf(_("If you wish to set tracking information for this "
1335                          "branch you can do so with:\n"
1336                          "\n"
1337                          "    git branch --set-upstream-to=%s/<branch> %s\n"
1338                          "\n"),
1339                        remote, current_branch->name);
1340         }
1341         exit(1);
1342 }
1343
1344 static void set_reflog_action(struct rebase_options *options)
1345 {
1346         const char *env;
1347         struct strbuf buf = STRBUF_INIT;
1348
1349         if (!is_interactive(options))
1350                 return;
1351
1352         env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1353         if (env && strcmp("rebase", env))
1354                 return; /* only override it if it is "rebase" */
1355
1356         strbuf_addf(&buf, "rebase -i (%s)", options->action);
1357         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1358         strbuf_release(&buf);
1359 }
1360
1361 static int check_exec_cmd(const char *cmd)
1362 {
1363         if (strchr(cmd, '\n'))
1364                 return error(_("exec commands cannot contain newlines"));
1365
1366         /* Does the command consist purely of whitespace? */
1367         if (!cmd[strspn(cmd, " \t\r\f\v")])
1368                 return error(_("empty exec command"));
1369
1370         return 0;
1371 }
1372
1373
1374 int cmd_rebase(int argc, const char **argv, const char *prefix)
1375 {
1376         struct rebase_options options = REBASE_OPTIONS_INIT;
1377         const char *branch_name;
1378         int ret, flags, total_argc, in_progress = 0;
1379         int ok_to_skip_pre_rebase = 0;
1380         struct strbuf msg = STRBUF_INIT;
1381         struct strbuf revisions = STRBUF_INIT;
1382         struct strbuf buf = STRBUF_INIT;
1383         struct object_id merge_base;
1384         enum action action = ACTION_NONE;
1385         const char *gpg_sign = NULL;
1386         struct string_list exec = STRING_LIST_INIT_NODUP;
1387         const char *rebase_merges = NULL;
1388         int fork_point = -1;
1389         struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1390         struct object_id squash_onto;
1391         char *squash_onto_name = NULL;
1392         int reschedule_failed_exec = -1;
1393         struct option builtin_rebase_options[] = {
1394                 OPT_STRING(0, "onto", &options.onto_name,
1395                            N_("revision"),
1396                            N_("rebase onto given branch instead of upstream")),
1397                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1398                          N_("allow pre-rebase hook to run")),
1399                 OPT_NEGBIT('q', "quiet", &options.flags,
1400                            N_("be quiet. implies --no-stat"),
1401                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1402                 OPT_BIT('v', "verbose", &options.flags,
1403                         N_("display a diffstat of what changed upstream"),
1404                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1405                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1406                         N_("do not show diffstat of what changed upstream"),
1407                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1408                 OPT_BOOL(0, "signoff", &options.signoff,
1409                          N_("add a Signed-off-by: line to each commit")),
1410                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1411                                   NULL, N_("passed to 'git am'"),
1412                                   PARSE_OPT_NOARG),
1413                 OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1414                                   &options.git_am_opts, NULL,
1415                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1416                 OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1417                                   N_("passed to 'git am'"), PARSE_OPT_NOARG),
1418                 OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1419                                   N_("passed to 'git apply'"), 0),
1420                 OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1421                                   N_("action"), N_("passed to 'git apply'"), 0),
1422                 OPT_BIT('f', "force-rebase", &options.flags,
1423                         N_("cherry-pick all commits, even if unchanged"),
1424                         REBASE_FORCE),
1425                 OPT_BIT(0, "no-ff", &options.flags,
1426                         N_("cherry-pick all commits, even if unchanged"),
1427                         REBASE_FORCE),
1428                 OPT_CMDMODE(0, "continue", &action, N_("continue"),
1429                             ACTION_CONTINUE),
1430                 OPT_CMDMODE(0, "skip", &action,
1431                             N_("skip current patch and continue"), ACTION_SKIP),
1432                 OPT_CMDMODE(0, "abort", &action,
1433                             N_("abort and check out the original branch"),
1434                             ACTION_ABORT),
1435                 OPT_CMDMODE(0, "quit", &action,
1436                             N_("abort but keep HEAD where it is"), ACTION_QUIT),
1437                 OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1438                             "during an interactive rebase"), ACTION_EDIT_TODO),
1439                 OPT_CMDMODE(0, "show-current-patch", &action,
1440                             N_("show the patch file being applied or merged"),
1441                             ACTION_SHOW_CURRENT_PATCH),
1442                 { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1443                         N_("use merging strategies to rebase"),
1444                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1445                         parse_opt_merge },
1446                 { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1447                         N_("let the user edit the list of commits to rebase"),
1448                         PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1449                         parse_opt_interactive },
1450                 OPT_SET_INT('p', "preserve-merges", &options.type,
1451                             N_("(DEPRECATED) try to recreate merges instead of "
1452                                "ignoring them"), REBASE_PRESERVE_MERGES),
1453                 OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1454                 OPT_BOOL('k', "keep-empty", &options.keep_empty,
1455                          N_("preserve empty commits during rebase")),
1456                 OPT_BOOL(0, "autosquash", &options.autosquash,
1457                          N_("move commits that begin with "
1458                             "squash!/fixup! under -i")),
1459                 { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1460                         N_("GPG-sign commits"),
1461                         PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1462                 OPT_BOOL(0, "autostash", &options.autostash,
1463                          N_("automatically stash/stash pop before and after")),
1464                 OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1465                                 N_("add exec lines after each commit of the "
1466                                    "editable list")),
1467                 OPT_BOOL(0, "allow-empty-message",
1468                          &options.allow_empty_message,
1469                          N_("allow rebasing commits with empty messages")),
1470                 {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1471                         N_("mode"),
1472                         N_("try to rebase merges instead of skipping them"),
1473                         PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1474                 OPT_BOOL(0, "fork-point", &fork_point,
1475                          N_("use 'merge-base --fork-point' to refine upstream")),
1476                 OPT_STRING('s', "strategy", &options.strategy,
1477                            N_("strategy"), N_("use the given merge strategy")),
1478                 OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1479                                 N_("option"),
1480                                 N_("pass the argument through to the merge "
1481                                    "strategy")),
1482                 OPT_BOOL(0, "root", &options.root,
1483                          N_("rebase all reachable commits up to the root(s)")),
1484                 OPT_BOOL(0, "reschedule-failed-exec",
1485                          &reschedule_failed_exec,
1486                          N_("automatically re-schedule any `exec` that fails")),
1487                 OPT_END(),
1488         };
1489         int i;
1490
1491         if (argc == 2 && !strcmp(argv[1], "-h"))
1492                 usage_with_options(builtin_rebase_usage,
1493                                    builtin_rebase_options);
1494
1495         prefix = setup_git_directory();
1496         trace_repo_setup(prefix);
1497         setup_work_tree();
1498
1499         options.allow_empty_message = 1;
1500         git_config(rebase_config, &options);
1501
1502         if (options.use_legacy_rebase ||
1503             !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1504                 warning(_("the rebase.useBuiltin support has been removed!\n"
1505                           "See its entry in 'git help config' for details."));
1506
1507         strbuf_reset(&buf);
1508         strbuf_addf(&buf, "%s/applying", apply_dir());
1509         if(file_exists(buf.buf))
1510                 die(_("It looks like 'git am' is in progress. Cannot rebase."));
1511
1512         if (is_directory(apply_dir())) {
1513                 options.type = REBASE_AM;
1514                 options.state_dir = apply_dir();
1515         } else if (is_directory(merge_dir())) {
1516                 strbuf_reset(&buf);
1517                 strbuf_addf(&buf, "%s/rewritten", merge_dir());
1518                 if (is_directory(buf.buf)) {
1519                         options.type = REBASE_PRESERVE_MERGES;
1520                         options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1521                 } else {
1522                         strbuf_reset(&buf);
1523                         strbuf_addf(&buf, "%s/interactive", merge_dir());
1524                         if(file_exists(buf.buf)) {
1525                                 options.type = REBASE_INTERACTIVE;
1526                                 options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1527                         } else
1528                                 options.type = REBASE_MERGE;
1529                 }
1530                 options.state_dir = merge_dir();
1531         }
1532
1533         if (options.type != REBASE_UNSPECIFIED)
1534                 in_progress = 1;
1535
1536         total_argc = argc;
1537         argc = parse_options(argc, argv, prefix,
1538                              builtin_rebase_options,
1539                              builtin_rebase_usage, 0);
1540
1541         if (action != ACTION_NONE && total_argc != 2) {
1542                 usage_with_options(builtin_rebase_usage,
1543                                    builtin_rebase_options);
1544         }
1545
1546         if (argc > 2)
1547                 usage_with_options(builtin_rebase_usage,
1548                                    builtin_rebase_options);
1549
1550         if (options.type == REBASE_PRESERVE_MERGES)
1551                 warning(_("git rebase --preserve-merges is deprecated. "
1552                           "Use --rebase-merges instead."));
1553
1554         if (action != ACTION_NONE && !in_progress)
1555                 die(_("No rebase in progress?"));
1556         setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1557
1558         if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1559                 die(_("The --edit-todo action can only be used during "
1560                       "interactive rebase."));
1561
1562         if (trace2_is_enabled()) {
1563                 if (is_interactive(&options))
1564                         trace2_cmd_mode("interactive");
1565                 else if (exec.nr)
1566                         trace2_cmd_mode("interactive-exec");
1567                 else
1568                         trace2_cmd_mode(action_names[action]);
1569         }
1570
1571         switch (action) {
1572         case ACTION_CONTINUE: {
1573                 struct object_id head;
1574                 struct lock_file lock_file = LOCK_INIT;
1575                 int fd;
1576
1577                 options.action = "continue";
1578                 set_reflog_action(&options);
1579
1580                 /* Sanity check */
1581                 if (get_oid("HEAD", &head))
1582                         die(_("Cannot read HEAD"));
1583
1584                 fd = hold_locked_index(&lock_file, 0);
1585                 if (repo_read_index(the_repository) < 0)
1586                         die(_("could not read index"));
1587                 refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1588                               NULL);
1589                 if (0 <= fd)
1590                         repo_update_index_if_able(the_repository, &lock_file);
1591                 rollback_lock_file(&lock_file);
1592
1593                 if (has_unstaged_changes(the_repository, 1)) {
1594                         puts(_("You must edit all merge conflicts and then\n"
1595                                "mark them as resolved using git add"));
1596                         exit(1);
1597                 }
1598                 if (read_basic_state(&options))
1599                         exit(1);
1600                 goto run_rebase;
1601         }
1602         case ACTION_SKIP: {
1603                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1604
1605                 options.action = "skip";
1606                 set_reflog_action(&options);
1607
1608                 rerere_clear(the_repository, &merge_rr);
1609                 string_list_clear(&merge_rr, 1);
1610
1611                 if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1612                                NULL, NULL) < 0)
1613                         die(_("could not discard worktree changes"));
1614                 remove_branch_state(the_repository, 0);
1615                 if (read_basic_state(&options))
1616                         exit(1);
1617                 goto run_rebase;
1618         }
1619         case ACTION_ABORT: {
1620                 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1621                 options.action = "abort";
1622                 set_reflog_action(&options);
1623
1624                 rerere_clear(the_repository, &merge_rr);
1625                 string_list_clear(&merge_rr, 1);
1626
1627                 if (read_basic_state(&options))
1628                         exit(1);
1629                 if (reset_head(&options.orig_head, "reset",
1630                                options.head_name, RESET_HEAD_HARD,
1631                                NULL, NULL) < 0)
1632                         die(_("could not move back to %s"),
1633                             oid_to_hex(&options.orig_head));
1634                 remove_branch_state(the_repository, 0);
1635                 ret = !!finish_rebase(&options);
1636                 goto cleanup;
1637         }
1638         case ACTION_QUIT: {
1639                 if (options.type == REBASE_INTERACTIVE) {
1640                         struct replay_opts replay = REPLAY_OPTS_INIT;
1641
1642                         replay.action = REPLAY_INTERACTIVE_REBASE;
1643                         ret = !!sequencer_remove_state(&replay);
1644                 } else {
1645                         strbuf_reset(&buf);
1646                         strbuf_addstr(&buf, options.state_dir);
1647                         ret = !!remove_dir_recursively(&buf, 0);
1648                         if (ret)
1649                                 error(_("could not remove '%s'"),
1650                                        options.state_dir);
1651                 }
1652                 goto cleanup;
1653         }
1654         case ACTION_EDIT_TODO:
1655                 options.action = "edit-todo";
1656                 options.dont_finish_rebase = 1;
1657                 goto run_rebase;
1658         case ACTION_SHOW_CURRENT_PATCH:
1659                 options.action = "show-current-patch";
1660                 options.dont_finish_rebase = 1;
1661                 goto run_rebase;
1662         case ACTION_NONE:
1663                 break;
1664         default:
1665                 BUG("action: %d", action);
1666         }
1667
1668         /* Make sure no rebase is in progress */
1669         if (in_progress) {
1670                 const char *last_slash = strrchr(options.state_dir, '/');
1671                 const char *state_dir_base =
1672                         last_slash ? last_slash + 1 : options.state_dir;
1673                 const char *cmd_live_rebase =
1674                         "git rebase (--continue | --abort | --skip)";
1675                 strbuf_reset(&buf);
1676                 strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1677                 die(_("It seems that there is already a %s directory, and\n"
1678                       "I wonder if you are in the middle of another rebase.  "
1679                       "If that is the\n"
1680                       "case, please try\n\t%s\n"
1681                       "If that is not the case, please\n\t%s\n"
1682                       "and run me again.  I am stopping in case you still "
1683                       "have something\n"
1684                       "valuable there.\n"),
1685                     state_dir_base, cmd_live_rebase, buf.buf);
1686         }
1687
1688         for (i = 0; i < options.git_am_opts.argc; i++) {
1689                 const char *option = options.git_am_opts.argv[i], *p;
1690                 if (!strcmp(option, "--committer-date-is-author-date") ||
1691                     !strcmp(option, "--ignore-date") ||
1692                     !strcmp(option, "--whitespace=fix") ||
1693                     !strcmp(option, "--whitespace=strip"))
1694                         options.flags |= REBASE_FORCE;
1695                 else if (skip_prefix(option, "-C", &p)) {
1696                         while (*p)
1697                                 if (!isdigit(*(p++)))
1698                                         die(_("switch `C' expects a "
1699                                               "numerical value"));
1700                 } else if (skip_prefix(option, "--whitespace=", &p)) {
1701                         if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1702                             strcmp(p, "error") && strcmp(p, "error-all"))
1703                                 die("Invalid whitespace option: '%s'", p);
1704                 }
1705         }
1706
1707         for (i = 0; i < exec.nr; i++)
1708                 if (check_exec_cmd(exec.items[i].string))
1709                         exit(1);
1710
1711         if (!(options.flags & REBASE_NO_QUIET))
1712                 argv_array_push(&options.git_am_opts, "-q");
1713
1714         if (options.keep_empty)
1715                 imply_interactive(&options, "--keep-empty");
1716
1717         if (gpg_sign) {
1718                 free(options.gpg_sign_opt);
1719                 options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1720         }
1721
1722         if (exec.nr) {
1723                 int i;
1724
1725                 imply_interactive(&options, "--exec");
1726
1727                 strbuf_reset(&buf);
1728                 for (i = 0; i < exec.nr; i++)
1729                         strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1730                 options.cmd = xstrdup(buf.buf);
1731         }
1732
1733         if (rebase_merges) {
1734                 if (!*rebase_merges)
1735                         ; /* default mode; do nothing */
1736                 else if (!strcmp("rebase-cousins", rebase_merges))
1737                         options.rebase_cousins = 1;
1738                 else if (strcmp("no-rebase-cousins", rebase_merges))
1739                         die(_("Unknown mode: %s"), rebase_merges);
1740                 options.rebase_merges = 1;
1741                 imply_interactive(&options, "--rebase-merges");
1742         }
1743
1744         if (strategy_options.nr) {
1745                 int i;
1746
1747                 if (!options.strategy)
1748                         options.strategy = "recursive";
1749
1750                 strbuf_reset(&buf);
1751                 for (i = 0; i < strategy_options.nr; i++)
1752                         strbuf_addf(&buf, " --%s",
1753                                     strategy_options.items[i].string);
1754                 options.strategy_opts = xstrdup(buf.buf);
1755         }
1756
1757         if (options.strategy) {
1758                 options.strategy = xstrdup(options.strategy);
1759                 switch (options.type) {
1760                 case REBASE_AM:
1761                         die(_("--strategy requires --merge or --interactive"));
1762                 case REBASE_MERGE:
1763                 case REBASE_INTERACTIVE:
1764                 case REBASE_PRESERVE_MERGES:
1765                         /* compatible */
1766                         break;
1767                 case REBASE_UNSPECIFIED:
1768                         options.type = REBASE_MERGE;
1769                         break;
1770                 default:
1771                         BUG("unhandled rebase type (%d)", options.type);
1772                 }
1773         }
1774
1775         if (options.type == REBASE_MERGE)
1776                 imply_interactive(&options, "--merge");
1777
1778         if (options.root && !options.onto_name)
1779                 imply_interactive(&options, "--root without --onto");
1780
1781         if (isatty(2) && options.flags & REBASE_NO_QUIET)
1782                 strbuf_addstr(&options.git_format_patch_opt, " --progress");
1783
1784         switch (options.type) {
1785         case REBASE_MERGE:
1786         case REBASE_INTERACTIVE:
1787         case REBASE_PRESERVE_MERGES:
1788                 options.state_dir = merge_dir();
1789                 break;
1790         case REBASE_AM:
1791                 options.state_dir = apply_dir();
1792                 break;
1793         default:
1794                 /* the default rebase backend is `--am` */
1795                 options.type = REBASE_AM;
1796                 options.state_dir = apply_dir();
1797                 break;
1798         }
1799
1800         if (reschedule_failed_exec > 0 && !is_interactive(&options))
1801                 die(_("--reschedule-failed-exec requires "
1802                       "--exec or --interactive"));
1803         if (reschedule_failed_exec >= 0)
1804                 options.reschedule_failed_exec = reschedule_failed_exec;
1805
1806         if (options.git_am_opts.argc) {
1807                 /* all am options except -q are compatible only with --am */
1808                 for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1809                         if (strcmp(options.git_am_opts.argv[i], "-q"))
1810                                 break;
1811
1812                 if (is_interactive(&options) && i >= 0)
1813                         die(_("cannot combine am options with either "
1814                               "interactive or merge options"));
1815         }
1816
1817         if (options.signoff) {
1818                 if (options.type == REBASE_PRESERVE_MERGES)
1819                         die("cannot combine '--signoff' with "
1820                             "'--preserve-merges'");
1821                 argv_array_push(&options.git_am_opts, "--signoff");
1822                 options.flags |= REBASE_FORCE;
1823         }
1824
1825         if (options.type == REBASE_PRESERVE_MERGES) {
1826                 /*
1827                  * Note: incompatibility with --signoff handled in signoff block above
1828                  * Note: incompatibility with --interactive is just a strong warning;
1829                  *       git-rebase.txt caveats with "unless you know what you are doing"
1830                  */
1831                 if (options.rebase_merges)
1832                         die(_("cannot combine '--preserve-merges' with "
1833                               "'--rebase-merges'"));
1834
1835                 if (options.reschedule_failed_exec)
1836                         die(_("error: cannot combine '--preserve-merges' with "
1837                               "'--reschedule-failed-exec'"));
1838         }
1839
1840         if (options.rebase_merges) {
1841                 if (strategy_options.nr)
1842                         die(_("cannot combine '--rebase-merges' with "
1843                               "'--strategy-option'"));
1844                 if (options.strategy)
1845                         die(_("cannot combine '--rebase-merges' with "
1846                               "'--strategy'"));
1847         }
1848
1849         if (!options.root) {
1850                 if (argc < 1) {
1851                         struct branch *branch;
1852
1853                         branch = branch_get(NULL);
1854                         options.upstream_name = branch_get_upstream(branch,
1855                                                                     NULL);
1856                         if (!options.upstream_name)
1857                                 error_on_missing_default_upstream();
1858                         if (fork_point < 0)
1859                                 fork_point = 1;
1860                 } else {
1861                         options.upstream_name = argv[0];
1862                         argc--;
1863                         argv++;
1864                         if (!strcmp(options.upstream_name, "-"))
1865                                 options.upstream_name = "@{-1}";
1866                 }
1867                 options.upstream = peel_committish(options.upstream_name);
1868                 if (!options.upstream)
1869                         die(_("invalid upstream '%s'"), options.upstream_name);
1870                 options.upstream_arg = options.upstream_name;
1871         } else {
1872                 if (!options.onto_name) {
1873                         if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1874                                         &squash_onto, NULL, NULL) < 0)
1875                                 die(_("Could not create new root commit"));
1876                         options.squash_onto = &squash_onto;
1877                         options.onto_name = squash_onto_name =
1878                                 xstrdup(oid_to_hex(&squash_onto));
1879                 }
1880                 options.upstream_name = NULL;
1881                 options.upstream = NULL;
1882                 if (argc > 1)
1883                         usage_with_options(builtin_rebase_usage,
1884                                            builtin_rebase_options);
1885                 options.upstream_arg = "--root";
1886         }
1887
1888         /* Make sure the branch to rebase onto is valid. */
1889         if (!options.onto_name)
1890                 options.onto_name = options.upstream_name;
1891         if (strstr(options.onto_name, "...")) {
1892                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
1893                         die(_("'%s': need exactly one merge base"),
1894                             options.onto_name);
1895                 options.onto = lookup_commit_or_die(&merge_base,
1896                                                     options.onto_name);
1897         } else {
1898                 options.onto = peel_committish(options.onto_name);
1899                 if (!options.onto)
1900                         die(_("Does not point to a valid commit '%s'"),
1901                                 options.onto_name);
1902         }
1903
1904         /*
1905          * If the branch to rebase is given, that is the branch we will rebase
1906          * branch_name -- branch/commit being rebased, or
1907          *                HEAD (already detached)
1908          * orig_head -- commit object name of tip of the branch before rebasing
1909          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1910          */
1911         if (argc == 1) {
1912                 /* Is it "rebase other branchname" or "rebase other commit"? */
1913                 branch_name = argv[0];
1914                 options.switch_to = argv[0];
1915
1916                 /* Is it a local branch? */
1917                 strbuf_reset(&buf);
1918                 strbuf_addf(&buf, "refs/heads/%s", branch_name);
1919                 if (!read_ref(buf.buf, &options.orig_head))
1920                         options.head_name = xstrdup(buf.buf);
1921                 /* If not is it a valid ref (branch or commit)? */
1922                 else if (!get_oid(branch_name, &options.orig_head))
1923                         options.head_name = NULL;
1924                 else
1925                         die(_("fatal: no such branch/commit '%s'"),
1926                             branch_name);
1927         } else if (argc == 0) {
1928                 /* Do not need to switch branches, we are already on it. */
1929                 options.head_name =
1930                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1931                                          &flags));
1932                 if (!options.head_name)
1933                         die(_("No such ref: %s"), "HEAD");
1934                 if (flags & REF_ISSYMREF) {
1935                         if (!skip_prefix(options.head_name,
1936                                          "refs/heads/", &branch_name))
1937                                 branch_name = options.head_name;
1938
1939                 } else {
1940                         FREE_AND_NULL(options.head_name);
1941                         branch_name = "HEAD";
1942                 }
1943                 if (get_oid("HEAD", &options.orig_head))
1944                         die(_("Could not resolve HEAD to a revision"));
1945         } else
1946                 BUG("unexpected number of arguments left to parse");
1947
1948         if (fork_point > 0) {
1949                 struct commit *head =
1950                         lookup_commit_reference(the_repository,
1951                                                 &options.orig_head);
1952                 options.restrict_revision =
1953                         get_fork_point(options.upstream_name, head);
1954         }
1955
1956         if (repo_read_index(the_repository) < 0)
1957                 die(_("could not read index"));
1958
1959         if (options.autostash) {
1960                 struct lock_file lock_file = LOCK_INIT;
1961                 int fd;
1962
1963                 fd = hold_locked_index(&lock_file, 0);
1964                 refresh_cache(REFRESH_QUIET);
1965                 if (0 <= fd)
1966                         repo_update_index_if_able(the_repository, &lock_file);
1967                 rollback_lock_file(&lock_file);
1968
1969                 if (has_unstaged_changes(the_repository, 1) ||
1970                     has_uncommitted_changes(the_repository, 1)) {
1971                         const char *autostash =
1972                                 state_dir_path("autostash", &options);
1973                         struct child_process stash = CHILD_PROCESS_INIT;
1974                         struct object_id oid;
1975                         struct commit *head =
1976                                 lookup_commit_reference(the_repository,
1977                                                         &options.orig_head);
1978
1979                         argv_array_pushl(&stash.args,
1980                                          "stash", "create", "autostash", NULL);
1981                         stash.git_cmd = 1;
1982                         stash.no_stdin = 1;
1983                         strbuf_reset(&buf);
1984                         if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1985                                 die(_("Cannot autostash"));
1986                         strbuf_trim_trailing_newline(&buf);
1987                         if (get_oid(buf.buf, &oid))
1988                                 die(_("Unexpected stash response: '%s'"),
1989                                     buf.buf);
1990                         strbuf_reset(&buf);
1991                         strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1992
1993                         if (safe_create_leading_directories_const(autostash))
1994                                 die(_("Could not create directory for '%s'"),
1995                                     options.state_dir);
1996                         write_file(autostash, "%s", oid_to_hex(&oid));
1997                         printf(_("Created autostash: %s\n"), buf.buf);
1998                         if (reset_head(&head->object.oid, "reset --hard",
1999                                        NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2000                                 die(_("could not reset --hard"));
2001                         printf(_("HEAD is now at %s"),
2002                                find_unique_abbrev(&head->object.oid,
2003                                                   DEFAULT_ABBREV));
2004                         strbuf_reset(&buf);
2005                         pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
2006                         if (buf.len > 0)
2007                                 printf(" %s", buf.buf);
2008                         putchar('\n');
2009
2010                         if (discard_index(the_repository->index) < 0 ||
2011                                 repo_read_index(the_repository) < 0)
2012                                 die(_("could not read index"));
2013                 }
2014         }
2015
2016         if (require_clean_work_tree(the_repository, "rebase",
2017                                     _("Please commit or stash them."), 1, 1)) {
2018                 ret = 1;
2019                 goto cleanup;
2020         }
2021
2022         /*
2023          * Now we are rebasing commits upstream..orig_head (or with --root,
2024          * everything leading up to orig_head) on top of onto.
2025          */
2026
2027         /*
2028          * Check if we are already based on onto with linear history,
2029          * but this should be done only when upstream and onto are the same
2030          * and if this is not an interactive rebase.
2031          */
2032         if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
2033             !is_interactive(&options) && !options.restrict_revision &&
2034             options.upstream &&
2035             !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
2036                 int flag;
2037
2038                 if (!(options.flags & REBASE_FORCE)) {
2039                         /* Lazily switch to the target branch if needed... */
2040                         if (options.switch_to) {
2041                                 struct object_id oid;
2042
2043                                 if (get_oid(options.switch_to, &oid) < 0) {
2044                                         ret = !!error(_("could not parse '%s'"),
2045                                                       options.switch_to);
2046                                         goto cleanup;
2047                                 }
2048
2049                                 strbuf_reset(&buf);
2050                                 strbuf_addf(&buf, "%s: checkout %s",
2051                                             getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2052                                             options.switch_to);
2053                                 if (reset_head(&oid, "checkout",
2054                                                options.head_name,
2055                                                RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2056                                                NULL, buf.buf) < 0) {
2057                                         ret = !!error(_("could not switch to "
2058                                                         "%s"),
2059                                                       options.switch_to);
2060                                         goto cleanup;
2061                                 }
2062                         }
2063
2064                         if (!(options.flags & REBASE_NO_QUIET))
2065                                 ; /* be quiet */
2066                         else if (!strcmp(branch_name, "HEAD") &&
2067                                  resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2068                                 puts(_("HEAD is up to date."));
2069                         else
2070                                 printf(_("Current branch %s is up to date.\n"),
2071                                        branch_name);
2072                         ret = !!finish_rebase(&options);
2073                         goto cleanup;
2074                 } else if (!(options.flags & REBASE_NO_QUIET))
2075                         ; /* be quiet */
2076                 else if (!strcmp(branch_name, "HEAD") &&
2077                          resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2078                         puts(_("HEAD is up to date, rebase forced."));
2079                 else
2080                         printf(_("Current branch %s is up to date, rebase "
2081                                  "forced.\n"), branch_name);
2082         }
2083
2084         /* If a hook exists, give it a chance to interrupt*/
2085         if (!ok_to_skip_pre_rebase &&
2086             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2087                         argc ? argv[0] : NULL, NULL))
2088                 die(_("The pre-rebase hook refused to rebase."));
2089
2090         if (options.flags & REBASE_DIFFSTAT) {
2091                 struct diff_options opts;
2092
2093                 if (options.flags & REBASE_VERBOSE) {
2094                         if (is_null_oid(&merge_base))
2095                                 printf(_("Changes to %s:\n"),
2096                                        oid_to_hex(&options.onto->object.oid));
2097                         else
2098                                 printf(_("Changes from %s to %s:\n"),
2099                                        oid_to_hex(&merge_base),
2100                                        oid_to_hex(&options.onto->object.oid));
2101                 }
2102
2103                 /* We want color (if set), but no pager */
2104                 diff_setup(&opts);
2105                 opts.stat_width = -1; /* use full terminal width */
2106                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
2107                 opts.output_format |=
2108                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2109                 opts.detect_rename = DIFF_DETECT_RENAME;
2110                 diff_setup_done(&opts);
2111                 diff_tree_oid(is_null_oid(&merge_base) ?
2112                               the_hash_algo->empty_tree : &merge_base,
2113                               &options.onto->object.oid, "", &opts);
2114                 diffcore_std(&opts);
2115                 diff_flush(&opts);
2116         }
2117
2118         if (is_interactive(&options))
2119                 goto run_rebase;
2120
2121         /* Detach HEAD and reset the tree */
2122         if (options.flags & REBASE_NO_QUIET)
2123                 printf(_("First, rewinding head to replay your work on top of "
2124                          "it...\n"));
2125
2126         strbuf_addf(&msg, "%s: checkout %s",
2127                     getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2128         if (reset_head(&options.onto->object.oid, "checkout", NULL,
2129                        RESET_HEAD_DETACH | RESET_ORIG_HEAD | 
2130                        RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2131                        NULL, msg.buf))
2132                 die(_("Could not detach HEAD"));
2133         strbuf_release(&msg);
2134
2135         /*
2136          * If the onto is a proper descendant of the tip of the branch, then
2137          * we just fast-forwarded.
2138          */
2139         strbuf_reset(&msg);
2140         if (oideq(&merge_base, &options.orig_head)) {
2141                 printf(_("Fast-forwarded %s to %s.\n"),
2142                         branch_name, options.onto_name);
2143                 strbuf_addf(&msg, "rebase finished: %s onto %s",
2144                         options.head_name ? options.head_name : "detached HEAD",
2145                         oid_to_hex(&options.onto->object.oid));
2146                 reset_head(NULL, "Fast-forwarded", options.head_name,
2147                            RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2148                 strbuf_release(&msg);
2149                 ret = !!finish_rebase(&options);
2150                 goto cleanup;
2151         }
2152
2153         strbuf_addf(&revisions, "%s..%s",
2154                     options.root ? oid_to_hex(&options.onto->object.oid) :
2155                     (options.restrict_revision ?
2156                      oid_to_hex(&options.restrict_revision->object.oid) :
2157                      oid_to_hex(&options.upstream->object.oid)),
2158                     oid_to_hex(&options.orig_head));
2159
2160         options.revisions = revisions.buf;
2161
2162 run_rebase:
2163         ret = !!run_specific_rebase(&options, action);
2164
2165 cleanup:
2166         strbuf_release(&buf);
2167         strbuf_release(&revisions);
2168         free(options.head_name);
2169         free(options.gpg_sign_opt);
2170         free(options.cmd);
2171         free(squash_onto_name);
2172         return ret;
2173 }