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 "config.h"
10#include "builtin.h"
11#include "parse-options.h"
12#include "exec_cmd.h"
13#include "run-command.h"
14#include "sha1-array.h"
15#include "remote.h"
16#include "dir.h"
17#include "refs.h"
18#include "revision.h"
19#include "submodule.h"
20#include "submodule-config.h"
21#include "tempfile.h"
22#include "lockfile.h"
23#include "wt-status.h"
24enum rebase_type {
26 REBASE_INVALID = -1,
27 REBASE_FALSE = 0,
28 REBASE_TRUE,
29 REBASE_PRESERVE,
30 REBASE_INTERACTIVE
31};
32/**
34 * Parses the value of --rebase. If value is a false value, returns
35 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
36 * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
37 * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
38 */
39static enum rebase_type parse_config_rebase(const char *key, const char *value,
40 int fatal)
41{
42 int v = git_parse_maybe_bool(value);
43 if (!v)
45 return REBASE_FALSE;
46 else if (v > 0)
47 return REBASE_TRUE;
48 else if (!strcmp(value, "preserve"))
49 return REBASE_PRESERVE;
50 else if (!strcmp(value, "interactive"))
51 return REBASE_INTERACTIVE;
52 if (fatal)
54 die(_("Invalid value for %s: %s"), key, value);
55 else
56 error(_("Invalid value for %s: %s"), key, value);
57 return REBASE_INVALID;
59}
60/**
62 * Callback for --rebase, which parses arg with parse_config_rebase().
63 */
64static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
65{
66 enum rebase_type *value = opt->value;
67 if (arg)
69 *value = parse_config_rebase("--rebase", arg, 0);
70 else
71 *value = unset ? REBASE_FALSE : REBASE_TRUE;
72 return *value == REBASE_INVALID ? -1 : 0;
73}
74static const char * const pull_usage[] = {
76 N_("git pull [<options>] [<repository> [<refspec>...]]"),
77 NULL
78};
79/* Shared options */
81static int opt_verbosity;
82static char *opt_progress;
83static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
84/* Options passed to git-merge or git-rebase */
86static enum rebase_type opt_rebase = -1;
87static char *opt_diffstat;
88static char *opt_log;
89static char *opt_squash;
90static char *opt_commit;
91static char *opt_edit;
92static char *opt_ff;
93static char *opt_verify_signatures;
94static int opt_autostash = -1;
95static int config_autostash;
96static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
97static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
98static char *opt_gpg_sign;
99static int opt_allow_unrelated_histories;
100/* Options passed to git-fetch */
102static char *opt_all;
103static char *opt_append;
104static char *opt_upload_pack;
105static int opt_force;
106static char *opt_tags;
107static char *opt_prune;
108static char *max_children;
109static int opt_dry_run;
110static char *opt_keep;
111static char *opt_depth;
112static char *opt_unshallow;
113static char *opt_update_shallow;
114static char *opt_refmap;
115static struct option pull_options[] = {
117 /* Shared options */
118 OPT__VERBOSITY(&opt_verbosity),
119 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
120 N_("force progress reporting"),
121 PARSE_OPT_NOARG),
122 { OPTION_CALLBACK, 0, "recurse-submodules",
123 &recurse_submodules, N_("on-demand"),
124 N_("control for recursive fetching of submodules"),
125 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules },
126 /* Options passed to git-merge or git-rebase */
128 OPT_GROUP(N_("Options related to merging")),
129 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
130 "false|true|preserve|interactive",
131 N_("incorporate changes by rebasing rather than merging"),
132 PARSE_OPT_OPTARG, parse_opt_rebase },
133 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
134 N_("do not show a diffstat at the end of the merge"),
135 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
136 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
137 N_("show a diffstat at the end of the merge"),
138 PARSE_OPT_NOARG),
139 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
140 N_("(synonym to --stat)"),
141 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
142 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
143 N_("add (at most <n>) entries from shortlog to merge commit message"),
144 PARSE_OPT_OPTARG),
145 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
146 N_("create a single commit instead of doing a merge"),
147 PARSE_OPT_NOARG),
148 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
149 N_("perform a commit if the merge succeeds (default)"),
150 PARSE_OPT_NOARG),
151 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
152 N_("edit message before committing"),
153 PARSE_OPT_NOARG),
154 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
155 N_("allow fast-forward"),
156 PARSE_OPT_NOARG),
157 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
158 N_("abort if fast-forward is not possible"),
159 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
160 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
161 N_("verify that the named commit has a valid GPG signature"),
162 PARSE_OPT_NOARG),
163 OPT_BOOL(0, "autostash", &opt_autostash,
164 N_("automatically stash/stash pop before and after rebase")),
165 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
166 N_("merge strategy to use"),
167 0),
168 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
169 N_("option=value"),
170 N_("option for selected merge strategy"),
171 0),
172 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
173 N_("GPG sign commit"),
174 PARSE_OPT_OPTARG),
175 OPT_SET_INT(0, "allow-unrelated-histories",
176 &opt_allow_unrelated_histories,
177 N_("allow merging unrelated histories"), 1),
178 /* Options passed to git-fetch */
180 OPT_GROUP(N_("Options related to fetching")),
181 OPT_PASSTHRU(0, "all", &opt_all, NULL,
182 N_("fetch from all remotes"),
183 PARSE_OPT_NOARG),
184 OPT_PASSTHRU('a', "append", &opt_append, NULL,
185 N_("append to .git/FETCH_HEAD instead of overwriting"),
186 PARSE_OPT_NOARG),
187 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
188 N_("path to upload pack on remote end"),
189 0),
190 OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
191 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
192 N_("fetch all tags and associated objects"),
193 PARSE_OPT_NOARG),
194 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
195 N_("prune remote-tracking branches no longer on remote"),
196 PARSE_OPT_NOARG),
197 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
198 N_("number of submodules pulled in parallel"),
199 PARSE_OPT_OPTARG),
200 OPT_BOOL(0, "dry-run", &opt_dry_run,
201 N_("dry run")),
202 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
203 N_("keep downloaded pack"),
204 PARSE_OPT_NOARG),
205 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
206 N_("deepen history of shallow clone"),
207 0),
208 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
209 N_("convert to a complete repository"),
210 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
211 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
212 N_("accept refs that update .git/shallow"),
213 PARSE_OPT_NOARG),
214 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
215 N_("specify fetch refmap"),
216 PARSE_OPT_NONEG),
217 OPT_END()
219};
220/**
222 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
223 */
224static void argv_push_verbosity(struct argv_array *arr)
225{
226 int verbosity;
227 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
229 argv_array_push(arr, "-v");
230 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
232 argv_array_push(arr, "-q");
233}
234/**
236 * Pushes "-f" switches into arr to match the opt_force level.
237 */
238static void argv_push_force(struct argv_array *arr)
239{
240 int force = opt_force;
241 while (force-- > 0)
242 argv_array_push(arr, "-f");
243}
244/**
246 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
247 */
248static void set_reflog_message(int argc, const char **argv)
249{
250 int i;
251 struct strbuf msg = STRBUF_INIT;
252 for (i = 0; i < argc; i++) {
254 if (i)
255 strbuf_addch(&msg, ' ');
256 strbuf_addstr(&msg, argv[i]);
257 }
258 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
260 strbuf_release(&msg);
262}
263/**
265 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
266 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
267 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
268 * error.
269 */
270static const char *config_get_ff(void)
271{
272 const char *value;
273 if (git_config_get_value("pull.ff", &value))
275 return NULL;
276 switch (git_parse_maybe_bool(value)) {
278 case 0:
279 return "--no-ff";
280 case 1:
281 return "--ff";
282 }
283 if (!strcmp(value, "only"))
285 return "--ff-only";
286 die(_("Invalid value for pull.ff: %s"), value);
288}
289/**
291 * Returns the default configured value for --rebase. It first looks for the
292 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
293 * branch, and if HEAD is detached or the configuration key does not exist,
294 * looks for the value of "pull.rebase". If both configuration keys do not
295 * exist, returns REBASE_FALSE.
296 */
297static enum rebase_type config_get_rebase(void)
298{
299 struct branch *curr_branch = branch_get("HEAD");
300 const char *value;
301 if (curr_branch) {
303 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
304 if (!git_config_get_value(key, &value)) {
306 enum rebase_type ret = parse_config_rebase(key, value, 1);
307 free(key);
308 return ret;
309 }
310 free(key);
312 }
313 if (!git_config_get_value("pull.rebase", &value))
315 return parse_config_rebase("pull.rebase", value, 1);
316 return REBASE_FALSE;
318}
319/**
321 * Read config variables.
322 */
323static int git_pull_config(const char *var, const char *value, void *cb)
324{
325 if (!strcmp(var, "rebase.autostash")) {
326 config_autostash = git_config_bool(var, value);
327 return 0;
328 }
329 return git_default_config(var, value, cb);
330}
331/**
333 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
334 * into merge_heads.
335 */
336static void get_merge_heads(struct oid_array *merge_heads)
337{
338 const char *filename = git_path_fetch_head();
339 FILE *fp;
340 struct strbuf sb = STRBUF_INIT;
341 struct object_id oid;
342 fp = xfopen(filename, "r");
344 while (strbuf_getline_lf(&sb, fp) != EOF) {
345 if (get_oid_hex(sb.buf, &oid))
346 continue; /* invalid line: does not start with SHA1 */
347 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
348 continue; /* ref is not-for-merge */
349 oid_array_append(merge_heads, &oid);
350 }
351 fclose(fp);
352 strbuf_release(&sb);
353}
354/**
356 * Used by die_no_merge_candidates() as a for_each_remote() callback to
357 * retrieve the name of the remote if the repository only has one remote.
358 */
359static int get_only_remote(struct remote *remote, void *cb_data)
360{
361 const char **remote_name = cb_data;
362 if (*remote_name)
364 return -1;
365 *remote_name = remote->name;
367 return 0;
368}
369/**
371 * Dies with the appropriate reason for why there are no merge candidates:
372 *
373 * 1. We fetched from a specific remote, and a refspec was given, but it ended
374 * up not fetching anything. This is usually because the user provided a
375 * wildcard refspec which had no matches on the remote end.
376 *
377 * 2. We fetched from a non-default remote, but didn't specify a branch to
378 * merge. We can't use the configured one because it applies to the default
379 * remote, thus the user must specify the branches to merge.
380 *
381 * 3. We fetched from the branch's or repo's default remote, but:
382 *
383 * a. We are not on a branch, so there will never be a configured branch to
384 * merge with.
385 *
386 * b. We are on a branch, but there is no configured branch to merge with.
387 *
388 * 4. We fetched from the branch's or repo's default remote, but the configured
389 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
390 * part of the configured fetch refspec.)
391 */
392static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
393{
394 struct branch *curr_branch = branch_get("HEAD");
395 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
396 if (*refspecs) {
398 if (opt_rebase)
399 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
400 else
401 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
402 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
403 "matches on the remote end."));
404 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
405 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
406 "a branch. Because this is not the default configured remote\n"
407 "for your current branch, you must specify a branch on the command line."),
408 repo);
409 } else if (!curr_branch) {
410 fprintf_ln(stderr, _("You are not currently on a branch."));
411 if (opt_rebase)
412 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
413 else
414 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
415 fprintf_ln(stderr, _("See git-pull(1) for details."));
416 fprintf(stderr, "\n");
417 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
418 fprintf(stderr, "\n");
419 } else if (!curr_branch->merge_nr) {
420 const char *remote_name = NULL;
421 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
423 remote_name = _("<remote>");
424 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
426 if (opt_rebase)
427 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
428 else
429 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
430 fprintf_ln(stderr, _("See git-pull(1) for details."));
431 fprintf(stderr, "\n");
432 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
433 fprintf(stderr, "\n");
434 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
435 fprintf(stderr, "\n");
436 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
437 remote_name, _("<branch>"), curr_branch->name);
438 } else
439 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
440 "from the remote, but no such ref was fetched."),
441 *curr_branch->merge_name);
442 exit(1);
443}
444/**
446 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
447 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
448 * is not provided in argv, it is set to NULL.
449 */
450static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
451 const char ***refspecs)
452{
453 if (argc > 0) {
454 *repo = *argv++;
455 argc--;
456 } else
457 *repo = NULL;
458 *refspecs = argv;
459}
460/**
462 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
463 * repository and refspecs to fetch, or NULL if they are not provided.
464 */
465static int run_fetch(const char *repo, const char **refspecs)
466{
467 struct argv_array args = ARGV_ARRAY_INIT;
468 int ret;
469 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
471 /* Shared options */
473 argv_push_verbosity(&args);
474 if (opt_progress)
475 argv_array_push(&args, opt_progress);
476 /* Options passed to git-fetch */
478 if (opt_all)
479 argv_array_push(&args, opt_all);
480 if (opt_append)
481 argv_array_push(&args, opt_append);
482 if (opt_upload_pack)
483 argv_array_push(&args, opt_upload_pack);
484 argv_push_force(&args);
485 if (opt_tags)
486 argv_array_push(&args, opt_tags);
487 if (opt_prune)
488 argv_array_push(&args, opt_prune);
489 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
490 switch (recurse_submodules) {
491 case RECURSE_SUBMODULES_ON:
492 argv_array_push(&args, "--recurse-submodules=on");
493 break;
494 case RECURSE_SUBMODULES_OFF:
495 argv_array_push(&args, "--recurse-submodules=no");
496 break;
497 case RECURSE_SUBMODULES_ON_DEMAND:
498 argv_array_push(&args, "--recurse-submodules=on-demand");
499 break;
500 default:
501 BUG("submodule recursion option not understood");
502 }
503 if (max_children)
504 argv_array_push(&args, max_children);
505 if (opt_dry_run)
506 argv_array_push(&args, "--dry-run");
507 if (opt_keep)
508 argv_array_push(&args, opt_keep);
509 if (opt_depth)
510 argv_array_push(&args, opt_depth);
511 if (opt_unshallow)
512 argv_array_push(&args, opt_unshallow);
513 if (opt_update_shallow)
514 argv_array_push(&args, opt_update_shallow);
515 if (opt_refmap)
516 argv_array_push(&args, opt_refmap);
517 if (repo) {
519 argv_array_push(&args, repo);
520 argv_array_pushv(&args, refspecs);
521 } else if (*refspecs)
522 die("BUG: refspecs without repo?");
523 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
524 argv_array_clear(&args);
525 return ret;
526}
527/**
529 * "Pulls into void" by branching off merge_head.
530 */
531static int pull_into_void(const struct object_id *merge_head,
532 const struct object_id *curr_head)
533{
534 /*
535 * Two-way merge: we treat the index as based on an empty tree,
536 * and try to fast-forward to HEAD. This ensures we will not lose
537 * index/worktree changes that the user already made on the unborn
538 * branch.
539 */
540 if (checkout_fast_forward(&empty_tree_oid, merge_head, 0))
541 return 1;
542 if (update_ref("initial pull", "HEAD", merge_head->hash, curr_head->hash, 0, UPDATE_REFS_DIE_ON_ERR))
544 return 1;
545 return 0;
547}
548static int rebase_submodules(void)
550{
551 struct child_process cp = CHILD_PROCESS_INIT;
552 cp.git_cmd = 1;
554 cp.no_stdin = 1;
555 argv_array_pushl(&cp.args, "submodule", "update",
556 "--recursive", "--rebase", NULL);
557 return run_command(&cp);
559}
560static int update_submodules(void)
562{
563 struct child_process cp = CHILD_PROCESS_INIT;
564 cp.git_cmd = 1;
566 cp.no_stdin = 1;
567 argv_array_pushl(&cp.args, "submodule", "update",
568 "--recursive", "--checkout", NULL);
569 return run_command(&cp);
571}
572/**
574 * Runs git-merge, returning its exit status.
575 */
576static int run_merge(void)
577{
578 int ret;
579 struct argv_array args = ARGV_ARRAY_INIT;
580 argv_array_pushl(&args, "merge", NULL);
582 /* Shared options */
584 argv_push_verbosity(&args);
585 if (opt_progress)
586 argv_array_push(&args, opt_progress);
587 /* Options passed to git-merge */
589 if (opt_diffstat)
590 argv_array_push(&args, opt_diffstat);
591 if (opt_log)
592 argv_array_push(&args, opt_log);
593 if (opt_squash)
594 argv_array_push(&args, opt_squash);
595 if (opt_commit)
596 argv_array_push(&args, opt_commit);
597 if (opt_edit)
598 argv_array_push(&args, opt_edit);
599 if (opt_ff)
600 argv_array_push(&args, opt_ff);
601 if (opt_verify_signatures)
602 argv_array_push(&args, opt_verify_signatures);
603 argv_array_pushv(&args, opt_strategies.argv);
604 argv_array_pushv(&args, opt_strategy_opts.argv);
605 if (opt_gpg_sign)
606 argv_array_push(&args, opt_gpg_sign);
607 if (opt_allow_unrelated_histories > 0)
608 argv_array_push(&args, "--allow-unrelated-histories");
609 argv_array_push(&args, "FETCH_HEAD");
611 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
612 argv_array_clear(&args);
613 return ret;
614}
615/**
617 * Returns remote's upstream branch for the current branch. If remote is NULL,
618 * the current branch's configured default remote is used. Returns NULL if
619 * `remote` does not name a valid remote, HEAD does not point to a branch,
620 * remote is not the branch's configured remote or the branch does not have any
621 * configured upstream branch.
622 */
623static const char *get_upstream_branch(const char *remote)
624{
625 struct remote *rm;
626 struct branch *curr_branch;
627 const char *curr_branch_remote;
628 rm = remote_get(remote);
630 if (!rm)
631 return NULL;
632 curr_branch = branch_get("HEAD");
634 if (!curr_branch)
635 return NULL;
636 curr_branch_remote = remote_for_branch(curr_branch, NULL);
638 assert(curr_branch_remote);
639 if (strcmp(curr_branch_remote, rm->name))
641 return NULL;
642 return branch_get_upstream(curr_branch, NULL);
644}
645/**
647 * Derives the remote tracking branch from the remote and refspec.
648 *
649 * FIXME: The current implementation assumes the default mapping of
650 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
651 */
652static const char *get_tracking_branch(const char *remote, const char *refspec)
653{
654 struct refspec *spec;
655 const char *spec_src;
656 const char *merge_branch;
657 spec = parse_fetch_refspec(1, &refspec);
659 spec_src = spec->src;
660 if (!*spec_src || !strcmp(spec_src, "HEAD"))
661 spec_src = "HEAD";
662 else if (skip_prefix(spec_src, "heads/", &spec_src))
663 ;
664 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
665 ;
666 else if (starts_with(spec_src, "refs/") ||
667 starts_with(spec_src, "tags/") ||
668 starts_with(spec_src, "remotes/"))
669 spec_src = "";
670 if (*spec_src) {
672 if (!strcmp(remote, "."))
673 merge_branch = mkpath("refs/heads/%s", spec_src);
674 else
675 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
676 } else
677 merge_branch = NULL;
678 free_refspec(1, spec);
680 return merge_branch;
681}
682/**
684 * Given the repo and refspecs, sets fork_point to the point at which the
685 * current branch forked from its remote tracking branch. Returns 0 on success,
686 * -1 on failure.
687 */
688static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
689 const char *refspec)
690{
691 int ret;
692 struct branch *curr_branch;
693 const char *remote_branch;
694 struct child_process cp = CHILD_PROCESS_INIT;
695 struct strbuf sb = STRBUF_INIT;
696 curr_branch = branch_get("HEAD");
698 if (!curr_branch)
699 return -1;
700 if (refspec)
702 remote_branch = get_tracking_branch(repo, refspec);
703 else
704 remote_branch = get_upstream_branch(repo);
705 if (!remote_branch)
707 return -1;
708 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
710 remote_branch, curr_branch->name, NULL);
711 cp.no_stdin = 1;
712 cp.no_stderr = 1;
713 cp.git_cmd = 1;
714 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
716 if (ret)
717 goto cleanup;
718 ret = get_oid_hex(sb.buf, fork_point);
720 if (ret)
721 goto cleanup;
722cleanup:
724 strbuf_release(&sb);
725 return ret ? -1 : 0;
726}
727/**
729 * Sets merge_base to the octopus merge base of curr_head, merge_head and
730 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
731 */
732static int get_octopus_merge_base(struct object_id *merge_base,
733 const struct object_id *curr_head,
734 const struct object_id *merge_head,
735 const struct object_id *fork_point)
736{
737 struct commit_list *revs = NULL, *result;
738 commit_list_insert(lookup_commit_reference(curr_head), &revs);
740 commit_list_insert(lookup_commit_reference(merge_head), &revs);
741 if (!is_null_oid(fork_point))
742 commit_list_insert(lookup_commit_reference(fork_point), &revs);
743 result = reduce_heads(get_octopus_merge_bases(revs));
745 free_commit_list(revs);
746 if (!result)
747 return 1;
748 oidcpy(merge_base, &result->item->object.oid);
750 return 0;
751}
752/**
754 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
755 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
756 * appropriate arguments and returns its exit status.
757 */
758static int run_rebase(const struct object_id *curr_head,
759 const struct object_id *merge_head,
760 const struct object_id *fork_point)
761{
762 int ret;
763 struct object_id oct_merge_base;
764 struct argv_array args = ARGV_ARRAY_INIT;
765 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
767 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
768 fork_point = NULL;
769 argv_array_push(&args, "rebase");
771 /* Shared options */
773 argv_push_verbosity(&args);
774 /* Options passed to git-rebase */
776 if (opt_rebase == REBASE_PRESERVE)
777 argv_array_push(&args, "--preserve-merges");
778 else if (opt_rebase == REBASE_INTERACTIVE)
779 argv_array_push(&args, "--interactive");
780 if (opt_diffstat)
781 argv_array_push(&args, opt_diffstat);
782 argv_array_pushv(&args, opt_strategies.argv);
783 argv_array_pushv(&args, opt_strategy_opts.argv);
784 if (opt_gpg_sign)
785 argv_array_push(&args, opt_gpg_sign);
786 if (opt_autostash == 0)
787 argv_array_push(&args, "--no-autostash");
788 else if (opt_autostash == 1)
789 argv_array_push(&args, "--autostash");
790 if (opt_verify_signatures &&
791 !strcmp(opt_verify_signatures, "--verify-signatures"))
792 warning(_("ignoring --verify-signatures for rebase"));
793 argv_array_push(&args, "--onto");
795 argv_array_push(&args, oid_to_hex(merge_head));
796 if (fork_point && !is_null_oid(fork_point))
798 argv_array_push(&args, oid_to_hex(fork_point));
799 else
800 argv_array_push(&args, oid_to_hex(merge_head));
801 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
803 argv_array_clear(&args);
804 return ret;
805}
806int cmd_pull(int argc, const char **argv, const char *prefix)
808{
809 const char *repo, **refspecs;
810 struct oid_array merge_heads = OID_ARRAY_INIT;
811 struct object_id orig_head, curr_head;
812 struct object_id rebase_fork_point;
813 int autostash;
814 if (!getenv("GIT_REFLOG_ACTION"))
816 set_reflog_message(argc, argv);
817 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
819 parse_repo_refspecs(argc, argv, &repo, &refspecs);
821 if (!opt_ff)
823 opt_ff = xstrdup_or_null(config_get_ff());
824 if (opt_rebase < 0)
826 opt_rebase = config_get_rebase();
827 git_config(git_pull_config, NULL);
829 if (read_cache_unmerged())
831 die_resolve_conflict("pull");
832 if (file_exists(git_path_merge_head()))
834 die_conclude_merge();
835 if (get_oid("HEAD", &orig_head))
837 oidclr(&orig_head);
838 if (!opt_rebase && opt_autostash != -1)
840 die(_("--[no-]autostash option is only valid with --rebase."));
841 autostash = config_autostash;
843 if (opt_rebase) {
844 if (opt_autostash != -1)
845 autostash = opt_autostash;
846 if (is_null_oid(&orig_head) && !is_cache_unborn())
848 die(_("Updating an unborn branch with changes added to the index."));
849 if (!autostash)
851 require_clean_work_tree(N_("pull with rebase"),
852 _("please commit or stash them."), 1, 0);
853 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
855 oidclr(&rebase_fork_point);
856 }
857 if (run_fetch(repo, refspecs))
859 return 1;
860 if (opt_dry_run)
862 return 0;
863 if (get_oid("HEAD", &curr_head))
865 oidclr(&curr_head);
866 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
868 oidcmp(&orig_head, &curr_head)) {
869 /*
870 * The fetch involved updating the current branch.
871 *
872 * The working tree and the index file are still based on
873 * orig_head commit, but we are merging into curr_head.
874 * Update the working tree to match curr_head.
875 */
876 warning(_("fetch updated the current branch head.\n"
878 "fast-forwarding your working tree from\n"
879 "commit %s."), oid_to_hex(&orig_head));
880 if (checkout_fast_forward(&orig_head, &curr_head, 0))
882 die(_("Cannot fast-forward your working tree.\n"
883 "After making sure that you saved anything precious from\n"
884 "$ git diff %s\n"
885 "output, run\n"
886 "$ git reset --hard\n"
887 "to recover."), oid_to_hex(&orig_head));
888 }
889 get_merge_heads(&merge_heads);
891 if (!merge_heads.nr)
893 die_no_merge_candidates(repo, refspecs);
894 if (is_null_oid(&orig_head)) {
896 if (merge_heads.nr > 1)
897 die(_("Cannot merge multiple branches into empty head."));
898 return pull_into_void(merge_heads.oid, &curr_head);
899 }
900 if (opt_rebase && merge_heads.nr > 1)
901 die(_("Cannot rebase onto multiple branches."));
902 if (opt_rebase) {
904 int ret = 0;
905 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
906 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
907 submodule_touches_in_range(&rebase_fork_point, &curr_head))
908 die(_("cannot rebase with locally recorded submodule modifications"));
909 if (!autostash) {
910 struct commit_list *list = NULL;
911 struct commit *merge_head, *head;
912 head = lookup_commit_reference(&orig_head);
914 commit_list_insert(head, &list);
915 merge_head = lookup_commit_reference(&merge_heads.oid[0]);
916 if (is_descendant_of(merge_head, list)) {
917 /* we can fast-forward this without invoking rebase */
918 opt_ff = "--ff-only";
919 ret = run_merge();
920 }
921 }
922 ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
923 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
925 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
926 ret = rebase_submodules();
927 return ret;
929 } else {
930 int ret = run_merge();
931 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
932 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
933 ret = update_submodules();
934 return ret;
935 }
936}