pull: configure --rebase via branch.<name>.rebase or pull.rebase
[git/git.git] / builtin / pull.c
CommitLineData
1e1ea69f
PT
1/*
2 * Builtin "git pull"
3 *
4 * Based on git-pull.sh by Junio C Hamano
5 *
6 * Fetch one or more remote refs and merge it/them into the current HEAD.
7 */
8#include "cache.h"
9#include "builtin.h"
10#include "parse-options.h"
11#include "exec_cmd.h"
f2c5baa1 12#include "run-command.h"
44c175c7
PT
13#include "sha1-array.h"
14#include "remote.h"
4a4cf9e8 15#include "dir.h"
49ec402d 16#include "refs.h"
1e1ea69f 17
1678b81e
PT
18enum rebase_type {
19 REBASE_INVALID = -1,
20 REBASE_FALSE = 0,
21 REBASE_TRUE,
22 REBASE_PRESERVE
23};
24
25/**
26 * Parses the value of --rebase. If value is a false value, returns
27 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
28 * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
29 * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
30 */
31static enum rebase_type parse_config_rebase(const char *key, const char *value,
32 int fatal)
33{
34 int v = git_config_maybe_bool("pull.rebase", value);
35
36 if (!v)
37 return REBASE_FALSE;
38 else if (v > 0)
39 return REBASE_TRUE;
40 else if (!strcmp(value, "preserve"))
41 return REBASE_PRESERVE;
42
43 if (fatal)
44 die(_("Invalid value for %s: %s"), key, value);
45 else
46 error(_("Invalid value for %s: %s"), key, value);
47
48 return REBASE_INVALID;
49}
50
51/**
52 * Callback for --rebase, which parses arg with parse_config_rebase().
53 */
54static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
55{
56 enum rebase_type *value = opt->value;
57
58 if (arg)
59 *value = parse_config_rebase("--rebase", arg, 0);
60 else
61 *value = unset ? REBASE_FALSE : REBASE_TRUE;
62 return *value == REBASE_INVALID ? -1 : 0;
63}
64
1e1ea69f 65static const char * const pull_usage[] = {
f2c5baa1 66 N_("git pull [options] [<repository> [<refspec>...]]"),
1e1ea69f
PT
67 NULL
68};
69
2a747902
PT
70/* Shared options */
71static int opt_verbosity;
72static char *opt_progress;
73
1678b81e 74/* Options passed to git-merge or git-rebase */
81dbd768 75static enum rebase_type opt_rebase = -1;
11b6d178
PT
76static char *opt_diffstat;
77static char *opt_log;
78static char *opt_squash;
79static char *opt_commit;
80static char *opt_edit;
81static char *opt_ff;
82static char *opt_verify_signatures;
83static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
84static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
85static char *opt_gpg_sign;
86
a32975f5
PT
87/* Options passed to git-fetch */
88static char *opt_all;
89static char *opt_append;
90static char *opt_upload_pack;
91static int opt_force;
92static char *opt_tags;
93static char *opt_prune;
94static char *opt_recurse_submodules;
95static int opt_dry_run;
96static char *opt_keep;
97static char *opt_depth;
98static char *opt_unshallow;
99static char *opt_update_shallow;
100static char *opt_refmap;
101
1e1ea69f 102static struct option pull_options[] = {
2a747902
PT
103 /* Shared options */
104 OPT__VERBOSITY(&opt_verbosity),
105 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
106 N_("force progress reporting"),
107 PARSE_OPT_NOARG),
108
1678b81e 109 /* Options passed to git-merge or git-rebase */
11b6d178 110 OPT_GROUP(N_("Options related to merging")),
1678b81e
PT
111 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
112 N_("false|true|preserve"),
113 N_("incorporate changes by rebasing rather than merging"),
114 PARSE_OPT_OPTARG, parse_opt_rebase },
11b6d178
PT
115 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
116 N_("do not show a diffstat at the end of the merge"),
117 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
118 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
119 N_("show a diffstat at the end of the merge"),
120 PARSE_OPT_NOARG),
121 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
122 N_("(synonym to --stat)"),
123 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
124 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
125 N_("add (at most <n>) entries from shortlog to merge commit message"),
126 PARSE_OPT_OPTARG),
127 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
128 N_("create a single commit instead of doing a merge"),
129 PARSE_OPT_NOARG),
130 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
131 N_("perform a commit if the merge succeeds (default)"),
132 PARSE_OPT_NOARG),
133 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
134 N_("edit message before committing"),
135 PARSE_OPT_NOARG),
136 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
137 N_("allow fast-forward"),
138 PARSE_OPT_NOARG),
139 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
140 N_("abort if fast-forward is not possible"),
141 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
142 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
143 N_("verify that the named commit has a valid GPG signature"),
144 PARSE_OPT_NOARG),
145 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
146 N_("merge strategy to use"),
147 0),
148 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
149 N_("option=value"),
150 N_("option for selected merge strategy"),
151 0),
152 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
153 N_("GPG sign commit"),
154 PARSE_OPT_OPTARG),
155
a32975f5
PT
156 /* Options passed to git-fetch */
157 OPT_GROUP(N_("Options related to fetching")),
158 OPT_PASSTHRU(0, "all", &opt_all, NULL,
159 N_("fetch from all remotes"),
160 PARSE_OPT_NOARG),
161 OPT_PASSTHRU('a', "append", &opt_append, NULL,
162 N_("append to .git/FETCH_HEAD instead of overwriting"),
163 PARSE_OPT_NOARG),
164 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
165 N_("path to upload pack on remote end"),
166 0),
167 OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
168 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
169 N_("fetch all tags and associated objects"),
170 PARSE_OPT_NOARG),
171 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
172 N_("prune remote-tracking branches no longer on remote"),
173 PARSE_OPT_NOARG),
174 OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules,
175 N_("on-demand"),
176 N_("control recursive fetching of submodules"),
177 PARSE_OPT_OPTARG),
178 OPT_BOOL(0, "dry-run", &opt_dry_run,
179 N_("dry run")),
180 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
181 N_("keep downloaded pack"),
182 PARSE_OPT_NOARG),
183 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
184 N_("deepen history of shallow clone"),
185 0),
186 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
187 N_("convert to a complete repository"),
188 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
189 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
190 N_("accept refs that update .git/shallow"),
191 PARSE_OPT_NOARG),
192 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
193 N_("specify fetch refmap"),
194 PARSE_OPT_NONEG),
195
1e1ea69f
PT
196 OPT_END()
197};
198
2a747902
PT
199/**
200 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
201 */
202static void argv_push_verbosity(struct argv_array *arr)
203{
204 int verbosity;
205
206 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
207 argv_array_push(arr, "-v");
208
209 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
210 argv_array_push(arr, "-q");
211}
212
a32975f5
PT
213/**
214 * Pushes "-f" switches into arr to match the opt_force level.
215 */
216static void argv_push_force(struct argv_array *arr)
217{
218 int force = opt_force;
219 while (force-- > 0)
220 argv_array_push(arr, "-f");
221}
222
41fca098
PT
223/**
224 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
225 */
226static void set_reflog_message(int argc, const char **argv)
227{
228 int i;
229 struct strbuf msg = STRBUF_INIT;
230
231 for (i = 0; i < argc; i++) {
232 if (i)
233 strbuf_addch(&msg, ' ');
234 strbuf_addstr(&msg, argv[i]);
235 }
236
237 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
238
239 strbuf_release(&msg);
240}
241
a9de9897
PT
242/**
243 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
244 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
245 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
246 * error.
247 */
248static const char *config_get_ff(void)
249{
250 const char *value;
251
252 if (git_config_get_value("pull.ff", &value))
253 return NULL;
254
255 switch (git_config_maybe_bool("pull.ff", value)) {
256 case 0:
257 return "--no-ff";
258 case 1:
259 return "--ff";
260 }
261
262 if (!strcmp(value, "only"))
263 return "--ff-only";
264
265 die(_("Invalid value for pull.ff: %s"), value);
266}
267
81dbd768
PT
268/**
269 * Returns the default configured value for --rebase. It first looks for the
270 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
271 * branch, and if HEAD is detached or the configuration key does not exist,
272 * looks for the value of "pull.rebase". If both configuration keys do not
273 * exist, returns REBASE_FALSE.
274 */
275static enum rebase_type config_get_rebase(void)
276{
277 struct branch *curr_branch = branch_get("HEAD");
278 const char *value;
279
280 if (curr_branch) {
281 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
282
283 if (!git_config_get_value(key, &value)) {
284 enum rebase_type ret = parse_config_rebase(key, value, 1);
285 free(key);
286 return ret;
287 }
288
289 free(key);
290 }
291
292 if (!git_config_get_value("pull.rebase", &value))
293 return parse_config_rebase("pull.rebase", value, 1);
294
295 return REBASE_FALSE;
296}
297
44c175c7
PT
298/**
299 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
300 * into merge_heads.
301 */
302static void get_merge_heads(struct sha1_array *merge_heads)
303{
304 const char *filename = git_path("FETCH_HEAD");
305 FILE *fp;
306 struct strbuf sb = STRBUF_INIT;
307 unsigned char sha1[GIT_SHA1_RAWSZ];
308
309 if (!(fp = fopen(filename, "r")))
310 die_errno(_("could not open '%s' for reading"), filename);
311 while (strbuf_getline(&sb, fp, '\n') != EOF) {
312 if (get_sha1_hex(sb.buf, sha1))
313 continue; /* invalid line: does not start with SHA1 */
314 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
315 continue; /* ref is not-for-merge */
316 sha1_array_append(merge_heads, sha1);
317 }
318 fclose(fp);
319 strbuf_release(&sb);
320}
321
322/**
323 * Used by die_no_merge_candidates() as a for_each_remote() callback to
324 * retrieve the name of the remote if the repository only has one remote.
325 */
326static int get_only_remote(struct remote *remote, void *cb_data)
327{
328 const char **remote_name = cb_data;
329
330 if (*remote_name)
331 return -1;
332
333 *remote_name = remote->name;
334 return 0;
335}
336
337/**
338 * Dies with the appropriate reason for why there are no merge candidates:
339 *
340 * 1. We fetched from a specific remote, and a refspec was given, but it ended
341 * up not fetching anything. This is usually because the user provided a
342 * wildcard refspec which had no matches on the remote end.
343 *
344 * 2. We fetched from a non-default remote, but didn't specify a branch to
345 * merge. We can't use the configured one because it applies to the default
346 * remote, thus the user must specify the branches to merge.
347 *
348 * 3. We fetched from the branch's or repo's default remote, but:
349 *
350 * a. We are not on a branch, so there will never be a configured branch to
351 * merge with.
352 *
353 * b. We are on a branch, but there is no configured branch to merge with.
354 *
355 * 4. We fetched from the branch's or repo's default remote, but the configured
356 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
357 * part of the configured fetch refspec.)
358 */
359static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
360{
361 struct branch *curr_branch = branch_get("HEAD");
362 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
363
364 if (*refspecs) {
365 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
366 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
367 "matches on the remote end."));
368 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
369 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
370 "a branch. Because this is not the default configured remote\n"
371 "for your current branch, you must specify a branch on the command line."),
372 repo);
373 } else if (!curr_branch) {
374 fprintf_ln(stderr, _("You are not currently on a branch."));
375 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
376 fprintf_ln(stderr, _("See git-pull(1) for details."));
377 fprintf(stderr, "\n");
378 fprintf_ln(stderr, " git pull <remote> <branch>");
379 fprintf(stderr, "\n");
380 } else if (!curr_branch->merge_nr) {
381 const char *remote_name = NULL;
382
383 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
384 remote_name = "<remote>";
385
386 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
387 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
388 fprintf_ln(stderr, _("See git-pull(1) for details."));
389 fprintf(stderr, "\n");
390 fprintf_ln(stderr, " git pull <remote> <branch>");
391 fprintf(stderr, "\n");
392 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:\n"
393 "\n"
394 " git branch --set-upstream-to=%s/<branch> %s\n"),
395 remote_name, curr_branch->name);
396 } else
397 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
398 "from the remote, but no such ref was fetched."),
399 *curr_branch->merge_name);
400 exit(1);
401}
402
f2c5baa1
PT
403/**
404 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
405 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
406 * is not provided in argv, it is set to NULL.
407 */
408static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
409 const char ***refspecs)
410{
411 if (argc > 0) {
412 *repo = *argv++;
413 argc--;
414 } else
415 *repo = NULL;
416 *refspecs = argv;
417}
418
419/**
420 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
421 * repository and refspecs to fetch, or NULL if they are not provided.
422 */
423static int run_fetch(const char *repo, const char **refspecs)
424{
425 struct argv_array args = ARGV_ARRAY_INIT;
426 int ret;
427
428 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
2a747902
PT
429
430 /* Shared options */
431 argv_push_verbosity(&args);
432 if (opt_progress)
433 argv_array_push(&args, opt_progress);
434
a32975f5
PT
435 /* Options passed to git-fetch */
436 if (opt_all)
437 argv_array_push(&args, opt_all);
438 if (opt_append)
439 argv_array_push(&args, opt_append);
440 if (opt_upload_pack)
441 argv_array_push(&args, opt_upload_pack);
442 argv_push_force(&args);
443 if (opt_tags)
444 argv_array_push(&args, opt_tags);
445 if (opt_prune)
446 argv_array_push(&args, opt_prune);
447 if (opt_recurse_submodules)
448 argv_array_push(&args, opt_recurse_submodules);
449 if (opt_dry_run)
450 argv_array_push(&args, "--dry-run");
451 if (opt_keep)
452 argv_array_push(&args, opt_keep);
453 if (opt_depth)
454 argv_array_push(&args, opt_depth);
455 if (opt_unshallow)
456 argv_array_push(&args, opt_unshallow);
457 if (opt_update_shallow)
458 argv_array_push(&args, opt_update_shallow);
459 if (opt_refmap)
460 argv_array_push(&args, opt_refmap);
461
f2c5baa1
PT
462 if (repo) {
463 argv_array_push(&args, repo);
464 argv_array_pushv(&args, refspecs);
465 } else if (*refspecs)
466 die("BUG: refspecs without repo?");
467 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
468 argv_array_clear(&args);
469 return ret;
470}
471
49ec402d
PT
472/**
473 * "Pulls into void" by branching off merge_head.
474 */
475static int pull_into_void(const unsigned char *merge_head,
476 const unsigned char *curr_head)
477{
478 /*
479 * Two-way merge: we treat the index as based on an empty tree,
480 * and try to fast-forward to HEAD. This ensures we will not lose
481 * index/worktree changes that the user already made on the unborn
482 * branch.
483 */
484 if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0))
485 return 1;
486
487 if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
488 return 1;
489
490 return 0;
491}
492
f2c5baa1
PT
493/**
494 * Runs git-merge, returning its exit status.
495 */
496static int run_merge(void)
497{
498 int ret;
499 struct argv_array args = ARGV_ARRAY_INIT;
500
501 argv_array_pushl(&args, "merge", NULL);
2a747902
PT
502
503 /* Shared options */
504 argv_push_verbosity(&args);
505 if (opt_progress)
506 argv_array_push(&args, opt_progress);
507
11b6d178
PT
508 /* Options passed to git-merge */
509 if (opt_diffstat)
510 argv_array_push(&args, opt_diffstat);
511 if (opt_log)
512 argv_array_push(&args, opt_log);
513 if (opt_squash)
514 argv_array_push(&args, opt_squash);
515 if (opt_commit)
516 argv_array_push(&args, opt_commit);
517 if (opt_edit)
518 argv_array_push(&args, opt_edit);
519 if (opt_ff)
520 argv_array_push(&args, opt_ff);
521 if (opt_verify_signatures)
522 argv_array_push(&args, opt_verify_signatures);
523 argv_array_pushv(&args, opt_strategies.argv);
524 argv_array_pushv(&args, opt_strategy_opts.argv);
525 if (opt_gpg_sign)
526 argv_array_push(&args, opt_gpg_sign);
527
f2c5baa1
PT
528 argv_array_push(&args, "FETCH_HEAD");
529 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
530 argv_array_clear(&args);
531 return ret;
532}
533
1678b81e
PT
534/**
535 * Returns remote's upstream branch for the current branch. If remote is NULL,
536 * the current branch's configured default remote is used. Returns NULL if
537 * `remote` does not name a valid remote, HEAD does not point to a branch,
538 * remote is not the branch's configured remote or the branch does not have any
539 * configured upstream branch.
540 */
541static const char *get_upstream_branch(const char *remote)
542{
543 struct remote *rm;
544 struct branch *curr_branch;
545 const char *curr_branch_remote;
546
547 rm = remote_get(remote);
548 if (!rm)
549 return NULL;
550
551 curr_branch = branch_get("HEAD");
552 if (!curr_branch)
553 return NULL;
554
555 curr_branch_remote = remote_for_branch(curr_branch, NULL);
556 assert(curr_branch_remote);
557
558 if (strcmp(curr_branch_remote, rm->name))
559 return NULL;
560
561 return branch_get_upstream(curr_branch, NULL);
562}
563
564/**
565 * Derives the remote tracking branch from the remote and refspec.
566 *
567 * FIXME: The current implementation assumes the default mapping of
568 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
569 */
570static const char *get_tracking_branch(const char *remote, const char *refspec)
571{
572 struct refspec *spec;
573 const char *spec_src;
574 const char *merge_branch;
575
576 spec = parse_fetch_refspec(1, &refspec);
577 spec_src = spec->src;
578 if (!*spec_src || !strcmp(spec_src, "HEAD"))
579 spec_src = "HEAD";
580 else if (skip_prefix(spec_src, "heads/", &spec_src))
581 ;
582 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
583 ;
584 else if (starts_with(spec_src, "refs/") ||
585 starts_with(spec_src, "tags/") ||
586 starts_with(spec_src, "remotes/"))
587 spec_src = "";
588
589 if (*spec_src) {
590 if (!strcmp(remote, "."))
591 merge_branch = mkpath("refs/heads/%s", spec_src);
592 else
593 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
594 } else
595 merge_branch = NULL;
596
597 free_refspec(1, spec);
598 return merge_branch;
599}
600
601/**
602 * Given the repo and refspecs, sets fork_point to the point at which the
603 * current branch forked from its remote tracking branch. Returns 0 on success,
604 * -1 on failure.
605 */
606static int get_rebase_fork_point(unsigned char *fork_point, const char *repo,
607 const char *refspec)
608{
609 int ret;
610 struct branch *curr_branch;
611 const char *remote_branch;
612 struct child_process cp = CHILD_PROCESS_INIT;
613 struct strbuf sb = STRBUF_INIT;
614
615 curr_branch = branch_get("HEAD");
616 if (!curr_branch)
617 return -1;
618
619 if (refspec)
620 remote_branch = get_tracking_branch(repo, refspec);
621 else
622 remote_branch = get_upstream_branch(repo);
623
624 if (!remote_branch)
625 return -1;
626
627 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
628 remote_branch, curr_branch->name, NULL);
629 cp.no_stdin = 1;
630 cp.no_stderr = 1;
631 cp.git_cmd = 1;
632
633 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
634 if (ret)
635 goto cleanup;
636
637 ret = get_sha1_hex(sb.buf, fork_point);
638 if (ret)
639 goto cleanup;
640
641cleanup:
642 strbuf_release(&sb);
643 return ret ? -1 : 0;
644}
645
646/**
647 * Sets merge_base to the octopus merge base of curr_head, merge_head and
648 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
649 */
650static int get_octopus_merge_base(unsigned char *merge_base,
651 const unsigned char *curr_head,
652 const unsigned char *merge_head,
653 const unsigned char *fork_point)
654{
655 struct commit_list *revs = NULL, *result;
656
657 commit_list_insert(lookup_commit_reference(curr_head), &revs);
658 commit_list_insert(lookup_commit_reference(merge_head), &revs);
659 if (!is_null_sha1(fork_point))
660 commit_list_insert(lookup_commit_reference(fork_point), &revs);
661
662 result = reduce_heads(get_octopus_merge_bases(revs));
663 free_commit_list(revs);
664 if (!result)
665 return 1;
666
667 hashcpy(merge_base, result->item->object.sha1);
668 return 0;
669}
670
671/**
672 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
673 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
674 * appropriate arguments and returns its exit status.
675 */
676static int run_rebase(const unsigned char *curr_head,
677 const unsigned char *merge_head,
678 const unsigned char *fork_point)
679{
680 int ret;
681 unsigned char oct_merge_base[GIT_SHA1_RAWSZ];
682 struct argv_array args = ARGV_ARRAY_INIT;
683
684 if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point))
685 if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point))
686 fork_point = NULL;
687
688 argv_array_push(&args, "rebase");
689
690 /* Shared options */
691 argv_push_verbosity(&args);
692
693 /* Options passed to git-rebase */
694 if (opt_rebase == REBASE_PRESERVE)
695 argv_array_push(&args, "--preserve-merges");
696 if (opt_diffstat)
697 argv_array_push(&args, opt_diffstat);
698 argv_array_pushv(&args, opt_strategies.argv);
699 argv_array_pushv(&args, opt_strategy_opts.argv);
700 if (opt_gpg_sign)
701 argv_array_push(&args, opt_gpg_sign);
702
703 argv_array_push(&args, "--onto");
704 argv_array_push(&args, sha1_to_hex(merge_head));
705
706 if (fork_point && !is_null_sha1(fork_point))
707 argv_array_push(&args, sha1_to_hex(fork_point));
708 else
709 argv_array_push(&args, sha1_to_hex(merge_head));
710
711 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
712 argv_array_clear(&args);
713 return ret;
714}
715
1e1ea69f
PT
716int cmd_pull(int argc, const char **argv, const char *prefix)
717{
f2c5baa1 718 const char *repo, **refspecs;
44c175c7 719 struct sha1_array merge_heads = SHA1_ARRAY_INIT;
fe911b8c 720 unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
1678b81e 721 unsigned char rebase_fork_point[GIT_SHA1_RAWSZ];
f2c5baa1 722
1e1ea69f
PT
723 if (!getenv("_GIT_USE_BUILTIN_PULL")) {
724 const char *path = mkpath("%s/git-pull", git_exec_path());
725
726 if (sane_execvp(path, (char **)argv) < 0)
727 die_errno("could not exec %s", path);
728 }
729
41fca098
PT
730 if (!getenv("GIT_REFLOG_ACTION"))
731 set_reflog_message(argc, argv);
732
1e1ea69f
PT
733 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
734
f2c5baa1
PT
735 parse_repo_refspecs(argc, argv, &repo, &refspecs);
736
a9de9897
PT
737 if (!opt_ff)
738 opt_ff = xstrdup_or_null(config_get_ff());
739
81dbd768
PT
740 if (opt_rebase < 0)
741 opt_rebase = config_get_rebase();
742
4a4cf9e8
PT
743 git_config(git_default_config, NULL);
744
745 if (read_cache_unmerged())
746 die_resolve_conflict("Pull");
747
748 if (file_exists(git_path("MERGE_HEAD")))
749 die_conclude_merge();
750
fe911b8c
PT
751 if (get_sha1("HEAD", orig_head))
752 hashclr(orig_head);
753
1678b81e
PT
754 if (opt_rebase)
755 if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
756 hashclr(rebase_fork_point);
757
f2c5baa1
PT
758 if (run_fetch(repo, refspecs))
759 return 1;
760
a32975f5
PT
761 if (opt_dry_run)
762 return 0;
763
fe911b8c
PT
764 if (get_sha1("HEAD", curr_head))
765 hashclr(curr_head);
766
767 if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
768 hashcmp(orig_head, curr_head)) {
769 /*
770 * The fetch involved updating the current branch.
771 *
772 * The working tree and the index file are still based on
773 * orig_head commit, but we are merging into curr_head.
774 * Update the working tree to match curr_head.
775 */
776
777 warning(_("fetch updated the current branch head.\n"
778 "fast-forwarding your working tree from\n"
779 "commit %s."), sha1_to_hex(orig_head));
780
781 if (checkout_fast_forward(orig_head, curr_head, 0))
782 die(_("Cannot fast-forward your working tree.\n"
783 "After making sure that you saved anything precious from\n"
784 "$ git diff %s\n"
785 "output, run\n"
786 "$ git reset --hard\n"
787 "to recover."), sha1_to_hex(orig_head));
788 }
789
44c175c7
PT
790 get_merge_heads(&merge_heads);
791
792 if (!merge_heads.nr)
793 die_no_merge_candidates(repo, refspecs);
794
49ec402d
PT
795 if (is_null_sha1(orig_head)) {
796 if (merge_heads.nr > 1)
797 die(_("Cannot merge multiple branches into empty head."));
798 return pull_into_void(*merge_heads.sha1, curr_head);
1678b81e
PT
799 } else if (opt_rebase) {
800 if (merge_heads.nr > 1)
801 die(_("Cannot rebase onto multiple branches."));
802 return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
49ec402d
PT
803 } else
804 return run_merge();
1e1ea69f 805}