The eighth batch
[git.git] / builtin / pull.c
blob3e13f8108432fe03b6cb5e10b4b3fe737e9db0f4
1 /*
2 * Builtin "git pull"
4 * Based on git-pull.sh by Junio C Hamano
6 * Fetch one or more remote refs and merge it/them into the current HEAD.
7 */
8 #define USE_THE_INDEX_COMPATIBILITY_MACROS
9 #include "cache.h"
10 #include "config.h"
11 #include "builtin.h"
12 #include "parse-options.h"
13 #include "exec-cmd.h"
14 #include "run-command.h"
15 #include "oid-array.h"
16 #include "remote.h"
17 #include "dir.h"
18 #include "rebase.h"
19 #include "refs.h"
20 #include "refspec.h"
21 #include "revision.h"
22 #include "submodule.h"
23 #include "submodule-config.h"
24 #include "tempfile.h"
25 #include "lockfile.h"
26 #include "wt-status.h"
27 #include "commit-reach.h"
28 #include "sequencer.h"
30 /**
31 * Parses the value of --rebase. If value is a false value, returns
32 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
33 * "merges", returns REBASE_MERGES. If value is "preserve", returns
34 * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if
35 * fatal is true, otherwise returns REBASE_INVALID.
37 static enum rebase_type parse_config_rebase(const char *key, const char *value,
38 int fatal)
40 enum rebase_type v = rebase_parse_value(value);
41 if (v != REBASE_INVALID)
42 return v;
44 if (fatal)
45 die(_("Invalid value for %s: %s"), key, value);
46 else
47 error(_("Invalid value for %s: %s"), key, value);
49 return REBASE_INVALID;
52 /**
53 * Callback for --rebase, which parses arg with parse_config_rebase().
55 static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
57 enum rebase_type *value = opt->value;
59 if (arg)
60 *value = parse_config_rebase("--rebase", arg, 0);
61 else
62 *value = unset ? REBASE_FALSE : REBASE_TRUE;
63 return *value == REBASE_INVALID ? -1 : 0;
66 static const char * const pull_usage[] = {
67 N_("git pull [<options>] [<repository> [<refspec>...]]"),
68 NULL
71 /* Shared options */
72 static int opt_verbosity;
73 static char *opt_progress;
74 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
76 /* Options passed to git-merge or git-rebase */
77 static enum rebase_type opt_rebase = -1;
78 static char *opt_diffstat;
79 static char *opt_log;
80 static char *opt_signoff;
81 static char *opt_squash;
82 static char *opt_commit;
83 static char *opt_edit;
84 static char *cleanup_arg;
85 static char *opt_ff;
86 static char *opt_verify_signatures;
87 static int opt_autostash = -1;
88 static int config_autostash;
89 static int check_trust_level = 1;
90 static struct strvec opt_strategies = STRVEC_INIT;
91 static struct strvec opt_strategy_opts = STRVEC_INIT;
92 static char *opt_gpg_sign;
93 static int opt_allow_unrelated_histories;
95 /* Options passed to git-fetch */
96 static char *opt_all;
97 static char *opt_append;
98 static char *opt_upload_pack;
99 static int opt_force;
100 static char *opt_tags;
101 static char *opt_prune;
102 static char *max_children;
103 static int opt_dry_run;
104 static char *opt_keep;
105 static char *opt_depth;
106 static char *opt_unshallow;
107 static char *opt_update_shallow;
108 static char *opt_refmap;
109 static char *opt_ipv4;
110 static char *opt_ipv6;
111 static int opt_show_forced_updates = -1;
112 static char *set_upstream;
113 static struct strvec opt_fetch = STRVEC_INIT;
115 static struct option pull_options[] = {
116 /* Shared options */
117 OPT__VERBOSITY(&opt_verbosity),
118 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
119 N_("force progress reporting"),
120 PARSE_OPT_NOARG),
121 OPT_CALLBACK_F(0, "recurse-submodules",
122 &recurse_submodules, N_("on-demand"),
123 N_("control for recursive fetching of submodules"),
124 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules),
126 /* Options passed to git-merge or git-rebase */
127 OPT_GROUP(N_("Options related to merging")),
128 OPT_CALLBACK_F('r', "rebase", &opt_rebase,
129 "(false|true|merges|preserve|interactive)",
130 N_("incorporate changes by rebasing rather than merging"),
131 PARSE_OPT_OPTARG, parse_opt_rebase),
132 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
133 N_("do not show a diffstat at the end of the merge"),
134 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
135 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
136 N_("show a diffstat at the end of the merge"),
137 PARSE_OPT_NOARG),
138 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
139 N_("(synonym to --stat)"),
140 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
141 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
142 N_("add (at most <n>) entries from shortlog to merge commit message"),
143 PARSE_OPT_OPTARG),
144 OPT_PASSTHRU(0, "signoff", &opt_signoff, NULL,
145 N_("add a Signed-off-by trailer"),
146 PARSE_OPT_OPTARG),
147 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
148 N_("create a single commit instead of doing a merge"),
149 PARSE_OPT_NOARG),
150 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
151 N_("perform a commit if the merge succeeds (default)"),
152 PARSE_OPT_NOARG),
153 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
154 N_("edit message before committing"),
155 PARSE_OPT_NOARG),
156 OPT_CLEANUP(&cleanup_arg),
157 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
158 N_("allow fast-forward"),
159 PARSE_OPT_NOARG),
160 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
161 N_("abort if fast-forward is not possible"),
162 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
163 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
164 N_("verify that the named commit has a valid GPG signature"),
165 PARSE_OPT_NOARG),
166 OPT_BOOL(0, "autostash", &opt_autostash,
167 N_("automatically stash/stash pop before and after")),
168 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
169 N_("merge strategy to use"),
171 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
172 N_("option=value"),
173 N_("option for selected merge strategy"),
175 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
176 N_("GPG sign commit"),
177 PARSE_OPT_OPTARG),
178 OPT_SET_INT(0, "allow-unrelated-histories",
179 &opt_allow_unrelated_histories,
180 N_("allow merging unrelated histories"), 1),
182 /* Options passed to git-fetch */
183 OPT_GROUP(N_("Options related to fetching")),
184 OPT_PASSTHRU(0, "all", &opt_all, NULL,
185 N_("fetch from all remotes"),
186 PARSE_OPT_NOARG),
187 OPT_PASSTHRU('a', "append", &opt_append, NULL,
188 N_("append to .git/FETCH_HEAD instead of overwriting"),
189 PARSE_OPT_NOARG),
190 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
191 N_("path to upload pack on remote end"),
193 OPT__FORCE(&opt_force, N_("force overwrite of local branch"), 0),
194 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
195 N_("fetch all tags and associated objects"),
196 PARSE_OPT_NOARG),
197 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
198 N_("prune remote-tracking branches no longer on remote"),
199 PARSE_OPT_NOARG),
200 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
201 N_("number of submodules pulled in parallel"),
202 PARSE_OPT_OPTARG),
203 OPT_BOOL(0, "dry-run", &opt_dry_run,
204 N_("dry run")),
205 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
206 N_("keep downloaded pack"),
207 PARSE_OPT_NOARG),
208 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
209 N_("deepen history of shallow clone"),
211 OPT_PASSTHRU_ARGV(0, "shallow-since", &opt_fetch, N_("time"),
212 N_("deepen history of shallow repository based on time"),
214 OPT_PASSTHRU_ARGV(0, "shallow-exclude", &opt_fetch, N_("revision"),
215 N_("deepen history of shallow clone, excluding rev"),
217 OPT_PASSTHRU_ARGV(0, "deepen", &opt_fetch, N_("n"),
218 N_("deepen history of shallow clone"),
220 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
221 N_("convert to a complete repository"),
222 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
223 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
224 N_("accept refs that update .git/shallow"),
225 PARSE_OPT_NOARG),
226 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
227 N_("specify fetch refmap"),
228 PARSE_OPT_NONEG),
229 OPT_PASSTHRU_ARGV('o', "server-option", &opt_fetch,
230 N_("server-specific"),
231 N_("option to transmit"),
233 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
234 N_("use IPv4 addresses only"),
235 PARSE_OPT_NOARG),
236 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
237 N_("use IPv6 addresses only"),
238 PARSE_OPT_NOARG),
239 OPT_PASSTHRU_ARGV(0, "negotiation-tip", &opt_fetch, N_("revision"),
240 N_("report that we have only objects reachable from this object"),
242 OPT_BOOL(0, "show-forced-updates", &opt_show_forced_updates,
243 N_("check for forced-updates on all updated branches")),
244 OPT_PASSTHRU(0, "set-upstream", &set_upstream, NULL,
245 N_("set upstream for git pull/fetch"),
246 PARSE_OPT_NOARG),
248 OPT_END()
252 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
254 static void argv_push_verbosity(struct strvec *arr)
256 int verbosity;
258 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
259 strvec_push(arr, "-v");
261 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
262 strvec_push(arr, "-q");
266 * Pushes "-f" switches into arr to match the opt_force level.
268 static void argv_push_force(struct strvec *arr)
270 int force = opt_force;
271 while (force-- > 0)
272 strvec_push(arr, "-f");
276 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
278 static void set_reflog_message(int argc, const char **argv)
280 int i;
281 struct strbuf msg = STRBUF_INIT;
283 for (i = 0; i < argc; i++) {
284 if (i)
285 strbuf_addch(&msg, ' ');
286 strbuf_addstr(&msg, argv[i]);
289 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
291 strbuf_release(&msg);
295 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
296 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
297 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
298 * error.
300 static const char *config_get_ff(void)
302 const char *value;
304 if (git_config_get_value("pull.ff", &value))
305 return NULL;
307 switch (git_parse_maybe_bool(value)) {
308 case 0:
309 return "--no-ff";
310 case 1:
311 return "--ff";
314 if (!strcmp(value, "only"))
315 return "--ff-only";
317 die(_("Invalid value for pull.ff: %s"), value);
321 * Returns the default configured value for --rebase. It first looks for the
322 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
323 * branch, and if HEAD is detached or the configuration key does not exist,
324 * looks for the value of "pull.rebase". If both configuration keys do not
325 * exist, returns REBASE_FALSE.
327 static enum rebase_type config_get_rebase(int *rebase_unspecified)
329 struct branch *curr_branch = branch_get("HEAD");
330 const char *value;
332 if (curr_branch) {
333 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
335 if (!git_config_get_value(key, &value)) {
336 enum rebase_type ret = parse_config_rebase(key, value, 1);
337 free(key);
338 return ret;
341 free(key);
344 if (!git_config_get_value("pull.rebase", &value))
345 return parse_config_rebase("pull.rebase", value, 1);
347 *rebase_unspecified = 1;
349 return REBASE_FALSE;
353 * Read config variables.
355 static int git_pull_config(const char *var, const char *value, void *cb)
357 int status;
359 if (!strcmp(var, "rebase.autostash")) {
360 config_autostash = git_config_bool(var, value);
361 return 0;
362 } else if (!strcmp(var, "submodule.recurse")) {
363 recurse_submodules = git_config_bool(var, value) ?
364 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
365 return 0;
366 } else if (!strcmp(var, "gpg.mintrustlevel")) {
367 check_trust_level = 0;
370 status = git_gpg_config(var, value, cb);
371 if (status)
372 return status;
374 return git_default_config(var, value, cb);
378 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
379 * into merge_heads.
381 static void get_merge_heads(struct oid_array *merge_heads)
383 const char *filename = git_path_fetch_head(the_repository);
384 FILE *fp;
385 struct strbuf sb = STRBUF_INIT;
386 struct object_id oid;
388 fp = xfopen(filename, "r");
389 while (strbuf_getline_lf(&sb, fp) != EOF) {
390 const char *p;
391 if (parse_oid_hex(sb.buf, &oid, &p))
392 continue; /* invalid line: does not start with object ID */
393 if (starts_with(p, "\tnot-for-merge\t"))
394 continue; /* ref is not-for-merge */
395 oid_array_append(merge_heads, &oid);
397 fclose(fp);
398 strbuf_release(&sb);
402 * Used by die_no_merge_candidates() as a for_each_remote() callback to
403 * retrieve the name of the remote if the repository only has one remote.
405 static int get_only_remote(struct remote *remote, void *cb_data)
407 const char **remote_name = cb_data;
409 if (*remote_name)
410 return -1;
412 *remote_name = remote->name;
413 return 0;
417 * Dies with the appropriate reason for why there are no merge candidates:
419 * 1. We fetched from a specific remote, and a refspec was given, but it ended
420 * up not fetching anything. This is usually because the user provided a
421 * wildcard refspec which had no matches on the remote end.
423 * 2. We fetched from a non-default remote, but didn't specify a branch to
424 * merge. We can't use the configured one because it applies to the default
425 * remote, thus the user must specify the branches to merge.
427 * 3. We fetched from the branch's or repo's default remote, but:
429 * a. We are not on a branch, so there will never be a configured branch to
430 * merge with.
432 * b. We are on a branch, but there is no configured branch to merge with.
434 * 4. We fetched from the branch's or repo's default remote, but the configured
435 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
436 * part of the configured fetch refspec.)
438 static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
440 struct branch *curr_branch = branch_get("HEAD");
441 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
443 if (*refspecs) {
444 if (opt_rebase)
445 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
446 else
447 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
448 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
449 "matches on the remote end."));
450 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
451 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
452 "a branch. Because this is not the default configured remote\n"
453 "for your current branch, you must specify a branch on the command line."),
454 repo);
455 } else if (!curr_branch) {
456 fprintf_ln(stderr, _("You are not currently on a branch."));
457 if (opt_rebase)
458 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
459 else
460 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
461 fprintf_ln(stderr, _("See git-pull(1) for details."));
462 fprintf(stderr, "\n");
463 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
464 fprintf(stderr, "\n");
465 } else if (!curr_branch->merge_nr) {
466 const char *remote_name = NULL;
468 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
469 remote_name = _("<remote>");
471 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
472 if (opt_rebase)
473 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
474 else
475 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
476 fprintf_ln(stderr, _("See git-pull(1) for details."));
477 fprintf(stderr, "\n");
478 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
479 fprintf(stderr, "\n");
480 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
481 fprintf(stderr, "\n");
482 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
483 remote_name, _("<branch>"), curr_branch->name);
484 } else
485 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
486 "from the remote, but no such ref was fetched."),
487 *curr_branch->merge_name);
488 exit(1);
492 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
493 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
494 * is not provided in argv, it is set to NULL.
496 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
497 const char ***refspecs)
499 if (argc > 0) {
500 *repo = *argv++;
501 argc--;
502 } else
503 *repo = NULL;
504 *refspecs = argv;
508 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
509 * repository and refspecs to fetch, or NULL if they are not provided.
511 static int run_fetch(const char *repo, const char **refspecs)
513 struct strvec args = STRVEC_INIT;
514 int ret;
516 strvec_pushl(&args, "fetch", "--update-head-ok", NULL);
518 /* Shared options */
519 argv_push_verbosity(&args);
520 if (opt_progress)
521 strvec_push(&args, opt_progress);
523 /* Options passed to git-fetch */
524 if (opt_all)
525 strvec_push(&args, opt_all);
526 if (opt_append)
527 strvec_push(&args, opt_append);
528 if (opt_upload_pack)
529 strvec_push(&args, opt_upload_pack);
530 argv_push_force(&args);
531 if (opt_tags)
532 strvec_push(&args, opt_tags);
533 if (opt_prune)
534 strvec_push(&args, opt_prune);
535 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
536 switch (recurse_submodules) {
537 case RECURSE_SUBMODULES_ON:
538 strvec_push(&args, "--recurse-submodules=on");
539 break;
540 case RECURSE_SUBMODULES_OFF:
541 strvec_push(&args, "--recurse-submodules=no");
542 break;
543 case RECURSE_SUBMODULES_ON_DEMAND:
544 strvec_push(&args, "--recurse-submodules=on-demand");
545 break;
546 default:
547 BUG("submodule recursion option not understood");
549 if (max_children)
550 strvec_push(&args, max_children);
551 if (opt_dry_run)
552 strvec_push(&args, "--dry-run");
553 if (opt_keep)
554 strvec_push(&args, opt_keep);
555 if (opt_depth)
556 strvec_push(&args, opt_depth);
557 if (opt_unshallow)
558 strvec_push(&args, opt_unshallow);
559 if (opt_update_shallow)
560 strvec_push(&args, opt_update_shallow);
561 if (opt_refmap)
562 strvec_push(&args, opt_refmap);
563 if (opt_ipv4)
564 strvec_push(&args, opt_ipv4);
565 if (opt_ipv6)
566 strvec_push(&args, opt_ipv6);
567 if (opt_show_forced_updates > 0)
568 strvec_push(&args, "--show-forced-updates");
569 else if (opt_show_forced_updates == 0)
570 strvec_push(&args, "--no-show-forced-updates");
571 if (set_upstream)
572 strvec_push(&args, set_upstream);
573 strvec_pushv(&args, opt_fetch.v);
575 if (repo) {
576 strvec_push(&args, repo);
577 strvec_pushv(&args, refspecs);
578 } else if (*refspecs)
579 BUG("refspecs without repo?");
580 ret = run_command_v_opt(args.v, RUN_GIT_CMD);
581 strvec_clear(&args);
582 return ret;
586 * "Pulls into void" by branching off merge_head.
588 static int pull_into_void(const struct object_id *merge_head,
589 const struct object_id *curr_head)
591 if (opt_verify_signatures) {
592 struct commit *commit;
594 commit = lookup_commit(the_repository, merge_head);
595 if (!commit)
596 die(_("unable to access commit %s"),
597 oid_to_hex(merge_head));
599 verify_merge_signature(commit, opt_verbosity,
600 check_trust_level);
604 * Two-way merge: we treat the index as based on an empty tree,
605 * and try to fast-forward to HEAD. This ensures we will not lose
606 * index/worktree changes that the user already made on the unborn
607 * branch.
609 if (checkout_fast_forward(the_repository,
610 the_hash_algo->empty_tree,
611 merge_head, 0))
612 return 1;
614 if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
615 return 1;
617 return 0;
620 static int rebase_submodules(void)
622 struct child_process cp = CHILD_PROCESS_INIT;
624 cp.git_cmd = 1;
625 cp.no_stdin = 1;
626 strvec_pushl(&cp.args, "submodule", "update",
627 "--recursive", "--rebase", NULL);
628 argv_push_verbosity(&cp.args);
630 return run_command(&cp);
633 static int update_submodules(void)
635 struct child_process cp = CHILD_PROCESS_INIT;
637 cp.git_cmd = 1;
638 cp.no_stdin = 1;
639 strvec_pushl(&cp.args, "submodule", "update",
640 "--recursive", "--checkout", NULL);
641 argv_push_verbosity(&cp.args);
643 return run_command(&cp);
647 * Runs git-merge, returning its exit status.
649 static int run_merge(void)
651 int ret;
652 struct strvec args = STRVEC_INIT;
654 strvec_pushl(&args, "merge", NULL);
656 /* Shared options */
657 argv_push_verbosity(&args);
658 if (opt_progress)
659 strvec_push(&args, opt_progress);
661 /* Options passed to git-merge */
662 if (opt_diffstat)
663 strvec_push(&args, opt_diffstat);
664 if (opt_log)
665 strvec_push(&args, opt_log);
666 if (opt_signoff)
667 strvec_push(&args, opt_signoff);
668 if (opt_squash)
669 strvec_push(&args, opt_squash);
670 if (opt_commit)
671 strvec_push(&args, opt_commit);
672 if (opt_edit)
673 strvec_push(&args, opt_edit);
674 if (cleanup_arg)
675 strvec_pushf(&args, "--cleanup=%s", cleanup_arg);
676 if (opt_ff)
677 strvec_push(&args, opt_ff);
678 if (opt_verify_signatures)
679 strvec_push(&args, opt_verify_signatures);
680 strvec_pushv(&args, opt_strategies.v);
681 strvec_pushv(&args, opt_strategy_opts.v);
682 if (opt_gpg_sign)
683 strvec_push(&args, opt_gpg_sign);
684 if (opt_autostash == 0)
685 strvec_push(&args, "--no-autostash");
686 else if (opt_autostash == 1)
687 strvec_push(&args, "--autostash");
688 if (opt_allow_unrelated_histories > 0)
689 strvec_push(&args, "--allow-unrelated-histories");
691 strvec_push(&args, "FETCH_HEAD");
692 ret = run_command_v_opt(args.v, RUN_GIT_CMD);
693 strvec_clear(&args);
694 return ret;
698 * Returns remote's upstream branch for the current branch. If remote is NULL,
699 * the current branch's configured default remote is used. Returns NULL if
700 * `remote` does not name a valid remote, HEAD does not point to a branch,
701 * remote is not the branch's configured remote or the branch does not have any
702 * configured upstream branch.
704 static const char *get_upstream_branch(const char *remote)
706 struct remote *rm;
707 struct branch *curr_branch;
708 const char *curr_branch_remote;
710 rm = remote_get(remote);
711 if (!rm)
712 return NULL;
714 curr_branch = branch_get("HEAD");
715 if (!curr_branch)
716 return NULL;
718 curr_branch_remote = remote_for_branch(curr_branch, NULL);
719 assert(curr_branch_remote);
721 if (strcmp(curr_branch_remote, rm->name))
722 return NULL;
724 return branch_get_upstream(curr_branch, NULL);
728 * Derives the remote-tracking branch from the remote and refspec.
730 * FIXME: The current implementation assumes the default mapping of
731 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
733 static const char *get_tracking_branch(const char *remote, const char *refspec)
735 struct refspec_item spec;
736 const char *spec_src;
737 const char *merge_branch;
739 refspec_item_init_or_die(&spec, refspec, REFSPEC_FETCH);
740 spec_src = spec.src;
741 if (!*spec_src || !strcmp(spec_src, "HEAD"))
742 spec_src = "HEAD";
743 else if (skip_prefix(spec_src, "heads/", &spec_src))
745 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
747 else if (starts_with(spec_src, "refs/") ||
748 starts_with(spec_src, "tags/") ||
749 starts_with(spec_src, "remotes/"))
750 spec_src = "";
752 if (*spec_src) {
753 if (!strcmp(remote, "."))
754 merge_branch = mkpath("refs/heads/%s", spec_src);
755 else
756 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
757 } else
758 merge_branch = NULL;
760 refspec_item_clear(&spec);
761 return merge_branch;
765 * Given the repo and refspecs, sets fork_point to the point at which the
766 * current branch forked from its remote-tracking branch. Returns 0 on success,
767 * -1 on failure.
769 static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
770 const char *refspec)
772 int ret;
773 struct branch *curr_branch;
774 const char *remote_branch;
775 struct child_process cp = CHILD_PROCESS_INIT;
776 struct strbuf sb = STRBUF_INIT;
778 curr_branch = branch_get("HEAD");
779 if (!curr_branch)
780 return -1;
782 if (refspec)
783 remote_branch = get_tracking_branch(repo, refspec);
784 else
785 remote_branch = get_upstream_branch(repo);
787 if (!remote_branch)
788 return -1;
790 strvec_pushl(&cp.args, "merge-base", "--fork-point",
791 remote_branch, curr_branch->name, NULL);
792 cp.no_stdin = 1;
793 cp.no_stderr = 1;
794 cp.git_cmd = 1;
796 ret = capture_command(&cp, &sb, GIT_MAX_HEXSZ);
797 if (ret)
798 goto cleanup;
800 ret = get_oid_hex(sb.buf, fork_point);
801 if (ret)
802 goto cleanup;
804 cleanup:
805 strbuf_release(&sb);
806 return ret ? -1 : 0;
810 * Sets merge_base to the octopus merge base of curr_head, merge_head and
811 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
813 static int get_octopus_merge_base(struct object_id *merge_base,
814 const struct object_id *curr_head,
815 const struct object_id *merge_head,
816 const struct object_id *fork_point)
818 struct commit_list *revs = NULL, *result;
820 commit_list_insert(lookup_commit_reference(the_repository, curr_head),
821 &revs);
822 commit_list_insert(lookup_commit_reference(the_repository, merge_head),
823 &revs);
824 if (!is_null_oid(fork_point))
825 commit_list_insert(lookup_commit_reference(the_repository, fork_point),
826 &revs);
828 result = get_octopus_merge_bases(revs);
829 free_commit_list(revs);
830 reduce_heads_replace(&result);
832 if (!result)
833 return 1;
835 oidcpy(merge_base, &result->item->object.oid);
836 free_commit_list(result);
837 return 0;
841 * Given the current HEAD oid, the merge head returned from git-fetch and the
842 * fork point calculated by get_rebase_fork_point(), compute the <newbase> and
843 * <upstream> arguments to use for the upcoming git-rebase invocation.
845 static int get_rebase_newbase_and_upstream(struct object_id *newbase,
846 struct object_id *upstream,
847 const struct object_id *curr_head,
848 const struct object_id *merge_head,
849 const struct object_id *fork_point)
851 struct object_id oct_merge_base;
853 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
854 if (!is_null_oid(fork_point) && oideq(&oct_merge_base, fork_point))
855 fork_point = NULL;
857 if (fork_point && !is_null_oid(fork_point))
858 oidcpy(upstream, fork_point);
859 else
860 oidcpy(upstream, merge_head);
862 oidcpy(newbase, merge_head);
864 return 0;
868 * Given the <newbase> and <upstream> calculated by
869 * get_rebase_newbase_and_upstream(), runs git-rebase with the
870 * appropriate arguments and returns its exit status.
872 static int run_rebase(const struct object_id *newbase,
873 const struct object_id *upstream)
875 int ret;
876 struct strvec args = STRVEC_INIT;
878 strvec_push(&args, "rebase");
880 /* Shared options */
881 argv_push_verbosity(&args);
883 /* Options passed to git-rebase */
884 if (opt_rebase == REBASE_MERGES)
885 strvec_push(&args, "--rebase-merges");
886 else if (opt_rebase == REBASE_PRESERVE)
887 strvec_push(&args, "--preserve-merges");
888 else if (opt_rebase == REBASE_INTERACTIVE)
889 strvec_push(&args, "--interactive");
890 if (opt_diffstat)
891 strvec_push(&args, opt_diffstat);
892 strvec_pushv(&args, opt_strategies.v);
893 strvec_pushv(&args, opt_strategy_opts.v);
894 if (opt_gpg_sign)
895 strvec_push(&args, opt_gpg_sign);
896 if (opt_autostash == 0)
897 strvec_push(&args, "--no-autostash");
898 else if (opt_autostash == 1)
899 strvec_push(&args, "--autostash");
900 if (opt_verify_signatures &&
901 !strcmp(opt_verify_signatures, "--verify-signatures"))
902 warning(_("ignoring --verify-signatures for rebase"));
904 strvec_push(&args, "--onto");
905 strvec_push(&args, oid_to_hex(newbase));
907 strvec_push(&args, oid_to_hex(upstream));
909 ret = run_command_v_opt(args.v, RUN_GIT_CMD);
910 strvec_clear(&args);
911 return ret;
914 static int get_can_ff(struct object_id *orig_head, struct object_id *orig_merge_head)
916 int ret;
917 struct commit_list *list = NULL;
918 struct commit *merge_head, *head;
920 head = lookup_commit_reference(the_repository, orig_head);
921 commit_list_insert(head, &list);
922 merge_head = lookup_commit_reference(the_repository, orig_merge_head);
923 ret = repo_is_descendant_of(the_repository, merge_head, list);
924 free_commit_list(list);
925 return ret;
928 static void show_advice_pull_non_ff(void)
930 advise(_("Pulling without specifying how to reconcile divergent branches is\n"
931 "discouraged. You can squelch this message by running one of the following\n"
932 "commands sometime before your next pull:\n"
933 "\n"
934 " git config pull.rebase false # merge (the default strategy)\n"
935 " git config pull.rebase true # rebase\n"
936 " git config pull.ff only # fast-forward only\n"
937 "\n"
938 "You can replace \"git config\" with \"git config --global\" to set a default\n"
939 "preference for all repositories. You can also pass --rebase, --no-rebase,\n"
940 "or --ff-only on the command line to override the configured default per\n"
941 "invocation.\n"));
944 int cmd_pull(int argc, const char **argv, const char *prefix)
946 const char *repo, **refspecs;
947 struct oid_array merge_heads = OID_ARRAY_INIT;
948 struct object_id orig_head, curr_head;
949 struct object_id rebase_fork_point;
950 int rebase_unspecified = 0;
951 int can_ff;
953 if (!getenv("GIT_REFLOG_ACTION"))
954 set_reflog_message(argc, argv);
956 git_config(git_pull_config, NULL);
958 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
960 if (cleanup_arg)
962 * this only checks the validity of cleanup_arg; we don't need
963 * a valid value for use_editor
965 get_cleanup_mode(cleanup_arg, 0);
967 parse_repo_refspecs(argc, argv, &repo, &refspecs);
969 if (!opt_ff)
970 opt_ff = xstrdup_or_null(config_get_ff());
972 if (opt_rebase < 0)
973 opt_rebase = config_get_rebase(&rebase_unspecified);
975 if (read_cache_unmerged())
976 die_resolve_conflict("pull");
978 if (file_exists(git_path_merge_head(the_repository)))
979 die_conclude_merge();
981 if (get_oid("HEAD", &orig_head))
982 oidclr(&orig_head);
984 if (opt_rebase) {
985 int autostash = config_autostash;
986 if (opt_autostash != -1)
987 autostash = opt_autostash;
989 if (is_null_oid(&orig_head) && !is_cache_unborn())
990 die(_("Updating an unborn branch with changes added to the index."));
992 if (!autostash)
993 require_clean_work_tree(the_repository,
994 N_("pull with rebase"),
995 _("please commit or stash them."), 1, 0);
997 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
998 oidclr(&rebase_fork_point);
1001 if (run_fetch(repo, refspecs))
1002 return 1;
1004 if (opt_dry_run)
1005 return 0;
1007 if (get_oid("HEAD", &curr_head))
1008 oidclr(&curr_head);
1010 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
1011 !oideq(&orig_head, &curr_head)) {
1013 * The fetch involved updating the current branch.
1015 * The working tree and the index file are still based on
1016 * orig_head commit, but we are merging into curr_head.
1017 * Update the working tree to match curr_head.
1020 warning(_("fetch updated the current branch head.\n"
1021 "fast-forwarding your working tree from\n"
1022 "commit %s."), oid_to_hex(&orig_head));
1024 if (checkout_fast_forward(the_repository, &orig_head,
1025 &curr_head, 0))
1026 die(_("Cannot fast-forward your working tree.\n"
1027 "After making sure that you saved anything precious from\n"
1028 "$ git diff %s\n"
1029 "output, run\n"
1030 "$ git reset --hard\n"
1031 "to recover."), oid_to_hex(&orig_head));
1034 get_merge_heads(&merge_heads);
1036 if (!merge_heads.nr)
1037 die_no_merge_candidates(repo, refspecs);
1039 if (is_null_oid(&orig_head)) {
1040 if (merge_heads.nr > 1)
1041 die(_("Cannot merge multiple branches into empty head."));
1042 return pull_into_void(merge_heads.oid, &curr_head);
1044 if (opt_rebase && merge_heads.nr > 1)
1045 die(_("Cannot rebase onto multiple branches."));
1047 can_ff = get_can_ff(&orig_head, &merge_heads.oid[0]);
1049 if (rebase_unspecified && !opt_ff && !can_ff) {
1050 if (opt_verbosity >= 0)
1051 show_advice_pull_non_ff();
1054 if (opt_rebase) {
1055 int ret = 0;
1057 struct object_id newbase;
1058 struct object_id upstream;
1059 get_rebase_newbase_and_upstream(&newbase, &upstream, &curr_head,
1060 merge_heads.oid, &rebase_fork_point);
1062 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
1063 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
1064 submodule_touches_in_range(the_repository, &upstream, &curr_head))
1065 die(_("cannot rebase with locally recorded submodule modifications"));
1067 if (can_ff) {
1068 /* we can fast-forward this without invoking rebase */
1069 opt_ff = "--ff-only";
1070 ret = run_merge();
1071 } else {
1072 ret = run_rebase(&newbase, &upstream);
1075 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
1076 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
1077 ret = rebase_submodules();
1079 return ret;
1080 } else {
1081 int ret = run_merge();
1082 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
1083 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
1084 ret = update_submodules();
1085 return ret;