doc: prefer 'stash push' over 'stash save'
[git/git.git] / builtin / pull.c
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"
24
25 enum rebase_type {
26 REBASE_INVALID = -1,
27 REBASE_FALSE = 0,
28 REBASE_TRUE,
29 REBASE_PRESERVE,
30 REBASE_INTERACTIVE
31 };
32
33 /**
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 */
39 static 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
44 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
53 if (fatal)
54 die(_("Invalid value for %s: %s"), key, value);
55 else
56 error(_("Invalid value for %s: %s"), key, value);
57
58 return REBASE_INVALID;
59 }
60
61 /**
62 * Callback for --rebase, which parses arg with parse_config_rebase().
63 */
64 static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
65 {
66 enum rebase_type *value = opt->value;
67
68 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 }
74
75 static const char * const pull_usage[] = {
76 N_("git pull [<options>] [<repository> [<refspec>...]]"),
77 NULL
78 };
79
80 /* Shared options */
81 static int opt_verbosity;
82 static char *opt_progress;
83 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
84
85 /* Options passed to git-merge or git-rebase */
86 static enum rebase_type opt_rebase = -1;
87 static char *opt_diffstat;
88 static char *opt_log;
89 static char *opt_squash;
90 static char *opt_commit;
91 static char *opt_edit;
92 static char *opt_ff;
93 static char *opt_verify_signatures;
94 static int opt_autostash = -1;
95 static int config_autostash;
96 static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
97 static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
98 static char *opt_gpg_sign;
99 static int opt_allow_unrelated_histories;
100
101 /* Options passed to git-fetch */
102 static char *opt_all;
103 static char *opt_append;
104 static char *opt_upload_pack;
105 static int opt_force;
106 static char *opt_tags;
107 static char *opt_prune;
108 static char *max_children;
109 static int opt_dry_run;
110 static char *opt_keep;
111 static char *opt_depth;
112 static char *opt_unshallow;
113 static char *opt_update_shallow;
114 static char *opt_refmap;
115
116 static 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
127 /* 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
179 /* 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
218 OPT_END()
219 };
220
221 /**
222 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
223 */
224 static void argv_push_verbosity(struct argv_array *arr)
225 {
226 int verbosity;
227
228 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
229 argv_array_push(arr, "-v");
230
231 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
232 argv_array_push(arr, "-q");
233 }
234
235 /**
236 * Pushes "-f" switches into arr to match the opt_force level.
237 */
238 static 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
245 /**
246 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
247 */
248 static void set_reflog_message(int argc, const char **argv)
249 {
250 int i;
251 struct strbuf msg = STRBUF_INIT;
252
253 for (i = 0; i < argc; i++) {
254 if (i)
255 strbuf_addch(&msg, ' ');
256 strbuf_addstr(&msg, argv[i]);
257 }
258
259 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
260
261 strbuf_release(&msg);
262 }
263
264 /**
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 */
270 static const char *config_get_ff(void)
271 {
272 const char *value;
273
274 if (git_config_get_value("pull.ff", &value))
275 return NULL;
276
277 switch (git_parse_maybe_bool(value)) {
278 case 0:
279 return "--no-ff";
280 case 1:
281 return "--ff";
282 }
283
284 if (!strcmp(value, "only"))
285 return "--ff-only";
286
287 die(_("Invalid value for pull.ff: %s"), value);
288 }
289
290 /**
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 */
297 static enum rebase_type config_get_rebase(void)
298 {
299 struct branch *curr_branch = branch_get("HEAD");
300 const char *value;
301
302 if (curr_branch) {
303 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
304
305 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
311 free(key);
312 }
313
314 if (!git_config_get_value("pull.rebase", &value))
315 return parse_config_rebase("pull.rebase", value, 1);
316
317 return REBASE_FALSE;
318 }
319
320 /**
321 * Read config variables.
322 */
323 static 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 } else if (!strcmp(var, "submodule.recurse")) {
329 recurse_submodules = git_config_bool(var, value) ?
330 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
331 return 0;
332 }
333 return git_default_config(var, value, cb);
334 }
335
336 /**
337 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
338 * into merge_heads.
339 */
340 static void get_merge_heads(struct oid_array *merge_heads)
341 {
342 const char *filename = git_path_fetch_head();
343 FILE *fp;
344 struct strbuf sb = STRBUF_INIT;
345 struct object_id oid;
346
347 fp = xfopen(filename, "r");
348 while (strbuf_getline_lf(&sb, fp) != EOF) {
349 if (get_oid_hex(sb.buf, &oid))
350 continue; /* invalid line: does not start with SHA1 */
351 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
352 continue; /* ref is not-for-merge */
353 oid_array_append(merge_heads, &oid);
354 }
355 fclose(fp);
356 strbuf_release(&sb);
357 }
358
359 /**
360 * Used by die_no_merge_candidates() as a for_each_remote() callback to
361 * retrieve the name of the remote if the repository only has one remote.
362 */
363 static int get_only_remote(struct remote *remote, void *cb_data)
364 {
365 const char **remote_name = cb_data;
366
367 if (*remote_name)
368 return -1;
369
370 *remote_name = remote->name;
371 return 0;
372 }
373
374 /**
375 * Dies with the appropriate reason for why there are no merge candidates:
376 *
377 * 1. We fetched from a specific remote, and a refspec was given, but it ended
378 * up not fetching anything. This is usually because the user provided a
379 * wildcard refspec which had no matches on the remote end.
380 *
381 * 2. We fetched from a non-default remote, but didn't specify a branch to
382 * merge. We can't use the configured one because it applies to the default
383 * remote, thus the user must specify the branches to merge.
384 *
385 * 3. We fetched from the branch's or repo's default remote, but:
386 *
387 * a. We are not on a branch, so there will never be a configured branch to
388 * merge with.
389 *
390 * b. We are on a branch, but there is no configured branch to merge with.
391 *
392 * 4. We fetched from the branch's or repo's default remote, but the configured
393 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
394 * part of the configured fetch refspec.)
395 */
396 static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
397 {
398 struct branch *curr_branch = branch_get("HEAD");
399 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
400
401 if (*refspecs) {
402 if (opt_rebase)
403 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
404 else
405 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
406 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
407 "matches on the remote end."));
408 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
409 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
410 "a branch. Because this is not the default configured remote\n"
411 "for your current branch, you must specify a branch on the command line."),
412 repo);
413 } else if (!curr_branch) {
414 fprintf_ln(stderr, _("You are not currently on a branch."));
415 if (opt_rebase)
416 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
417 else
418 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
419 fprintf_ln(stderr, _("See git-pull(1) for details."));
420 fprintf(stderr, "\n");
421 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
422 fprintf(stderr, "\n");
423 } else if (!curr_branch->merge_nr) {
424 const char *remote_name = NULL;
425
426 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
427 remote_name = _("<remote>");
428
429 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
430 if (opt_rebase)
431 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
432 else
433 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
434 fprintf_ln(stderr, _("See git-pull(1) for details."));
435 fprintf(stderr, "\n");
436 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
437 fprintf(stderr, "\n");
438 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
439 fprintf(stderr, "\n");
440 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
441 remote_name, _("<branch>"), curr_branch->name);
442 } else
443 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
444 "from the remote, but no such ref was fetched."),
445 *curr_branch->merge_name);
446 exit(1);
447 }
448
449 /**
450 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
451 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
452 * is not provided in argv, it is set to NULL.
453 */
454 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
455 const char ***refspecs)
456 {
457 if (argc > 0) {
458 *repo = *argv++;
459 argc--;
460 } else
461 *repo = NULL;
462 *refspecs = argv;
463 }
464
465 /**
466 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
467 * repository and refspecs to fetch, or NULL if they are not provided.
468 */
469 static int run_fetch(const char *repo, const char **refspecs)
470 {
471 struct argv_array args = ARGV_ARRAY_INIT;
472 int ret;
473
474 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
475
476 /* Shared options */
477 argv_push_verbosity(&args);
478 if (opt_progress)
479 argv_array_push(&args, opt_progress);
480
481 /* Options passed to git-fetch */
482 if (opt_all)
483 argv_array_push(&args, opt_all);
484 if (opt_append)
485 argv_array_push(&args, opt_append);
486 if (opt_upload_pack)
487 argv_array_push(&args, opt_upload_pack);
488 argv_push_force(&args);
489 if (opt_tags)
490 argv_array_push(&args, opt_tags);
491 if (opt_prune)
492 argv_array_push(&args, opt_prune);
493 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
494 switch (recurse_submodules) {
495 case RECURSE_SUBMODULES_ON:
496 argv_array_push(&args, "--recurse-submodules=on");
497 break;
498 case RECURSE_SUBMODULES_OFF:
499 argv_array_push(&args, "--recurse-submodules=no");
500 break;
501 case RECURSE_SUBMODULES_ON_DEMAND:
502 argv_array_push(&args, "--recurse-submodules=on-demand");
503 break;
504 default:
505 BUG("submodule recursion option not understood");
506 }
507 if (max_children)
508 argv_array_push(&args, max_children);
509 if (opt_dry_run)
510 argv_array_push(&args, "--dry-run");
511 if (opt_keep)
512 argv_array_push(&args, opt_keep);
513 if (opt_depth)
514 argv_array_push(&args, opt_depth);
515 if (opt_unshallow)
516 argv_array_push(&args, opt_unshallow);
517 if (opt_update_shallow)
518 argv_array_push(&args, opt_update_shallow);
519 if (opt_refmap)
520 argv_array_push(&args, opt_refmap);
521
522 if (repo) {
523 argv_array_push(&args, repo);
524 argv_array_pushv(&args, refspecs);
525 } else if (*refspecs)
526 die("BUG: refspecs without repo?");
527 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
528 argv_array_clear(&args);
529 return ret;
530 }
531
532 /**
533 * "Pulls into void" by branching off merge_head.
534 */
535 static int pull_into_void(const struct object_id *merge_head,
536 const struct object_id *curr_head)
537 {
538 /*
539 * Two-way merge: we treat the index as based on an empty tree,
540 * and try to fast-forward to HEAD. This ensures we will not lose
541 * index/worktree changes that the user already made on the unborn
542 * branch.
543 */
544 if (checkout_fast_forward(&empty_tree_oid, merge_head, 0))
545 return 1;
546
547 if (update_ref("initial pull", "HEAD", merge_head->hash, curr_head->hash, 0, UPDATE_REFS_DIE_ON_ERR))
548 return 1;
549
550 return 0;
551 }
552
553 static int rebase_submodules(void)
554 {
555 struct child_process cp = CHILD_PROCESS_INIT;
556
557 cp.git_cmd = 1;
558 cp.no_stdin = 1;
559 argv_array_pushl(&cp.args, "submodule", "update",
560 "--recursive", "--rebase", NULL);
561
562 return run_command(&cp);
563 }
564
565 static int update_submodules(void)
566 {
567 struct child_process cp = CHILD_PROCESS_INIT;
568
569 cp.git_cmd = 1;
570 cp.no_stdin = 1;
571 argv_array_pushl(&cp.args, "submodule", "update",
572 "--recursive", "--checkout", NULL);
573
574 return run_command(&cp);
575 }
576
577 /**
578 * Runs git-merge, returning its exit status.
579 */
580 static int run_merge(void)
581 {
582 int ret;
583 struct argv_array args = ARGV_ARRAY_INIT;
584
585 argv_array_pushl(&args, "merge", NULL);
586
587 /* Shared options */
588 argv_push_verbosity(&args);
589 if (opt_progress)
590 argv_array_push(&args, opt_progress);
591
592 /* Options passed to git-merge */
593 if (opt_diffstat)
594 argv_array_push(&args, opt_diffstat);
595 if (opt_log)
596 argv_array_push(&args, opt_log);
597 if (opt_squash)
598 argv_array_push(&args, opt_squash);
599 if (opt_commit)
600 argv_array_push(&args, opt_commit);
601 if (opt_edit)
602 argv_array_push(&args, opt_edit);
603 if (opt_ff)
604 argv_array_push(&args, opt_ff);
605 if (opt_verify_signatures)
606 argv_array_push(&args, opt_verify_signatures);
607 argv_array_pushv(&args, opt_strategies.argv);
608 argv_array_pushv(&args, opt_strategy_opts.argv);
609 if (opt_gpg_sign)
610 argv_array_push(&args, opt_gpg_sign);
611 if (opt_allow_unrelated_histories > 0)
612 argv_array_push(&args, "--allow-unrelated-histories");
613
614 argv_array_push(&args, "FETCH_HEAD");
615 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
616 argv_array_clear(&args);
617 return ret;
618 }
619
620 /**
621 * Returns remote's upstream branch for the current branch. If remote is NULL,
622 * the current branch's configured default remote is used. Returns NULL if
623 * `remote` does not name a valid remote, HEAD does not point to a branch,
624 * remote is not the branch's configured remote or the branch does not have any
625 * configured upstream branch.
626 */
627 static const char *get_upstream_branch(const char *remote)
628 {
629 struct remote *rm;
630 struct branch *curr_branch;
631 const char *curr_branch_remote;
632
633 rm = remote_get(remote);
634 if (!rm)
635 return NULL;
636
637 curr_branch = branch_get("HEAD");
638 if (!curr_branch)
639 return NULL;
640
641 curr_branch_remote = remote_for_branch(curr_branch, NULL);
642 assert(curr_branch_remote);
643
644 if (strcmp(curr_branch_remote, rm->name))
645 return NULL;
646
647 return branch_get_upstream(curr_branch, NULL);
648 }
649
650 /**
651 * Derives the remote tracking branch from the remote and refspec.
652 *
653 * FIXME: The current implementation assumes the default mapping of
654 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
655 */
656 static const char *get_tracking_branch(const char *remote, const char *refspec)
657 {
658 struct refspec *spec;
659 const char *spec_src;
660 const char *merge_branch;
661
662 spec = parse_fetch_refspec(1, &refspec);
663 spec_src = spec->src;
664 if (!*spec_src || !strcmp(spec_src, "HEAD"))
665 spec_src = "HEAD";
666 else if (skip_prefix(spec_src, "heads/", &spec_src))
667 ;
668 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
669 ;
670 else if (starts_with(spec_src, "refs/") ||
671 starts_with(spec_src, "tags/") ||
672 starts_with(spec_src, "remotes/"))
673 spec_src = "";
674
675 if (*spec_src) {
676 if (!strcmp(remote, "."))
677 merge_branch = mkpath("refs/heads/%s", spec_src);
678 else
679 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
680 } else
681 merge_branch = NULL;
682
683 free_refspec(1, spec);
684 return merge_branch;
685 }
686
687 /**
688 * Given the repo and refspecs, sets fork_point to the point at which the
689 * current branch forked from its remote tracking branch. Returns 0 on success,
690 * -1 on failure.
691 */
692 static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
693 const char *refspec)
694 {
695 int ret;
696 struct branch *curr_branch;
697 const char *remote_branch;
698 struct child_process cp = CHILD_PROCESS_INIT;
699 struct strbuf sb = STRBUF_INIT;
700
701 curr_branch = branch_get("HEAD");
702 if (!curr_branch)
703 return -1;
704
705 if (refspec)
706 remote_branch = get_tracking_branch(repo, refspec);
707 else
708 remote_branch = get_upstream_branch(repo);
709
710 if (!remote_branch)
711 return -1;
712
713 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
714 remote_branch, curr_branch->name, NULL);
715 cp.no_stdin = 1;
716 cp.no_stderr = 1;
717 cp.git_cmd = 1;
718
719 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
720 if (ret)
721 goto cleanup;
722
723 ret = get_oid_hex(sb.buf, fork_point);
724 if (ret)
725 goto cleanup;
726
727 cleanup:
728 strbuf_release(&sb);
729 return ret ? -1 : 0;
730 }
731
732 /**
733 * Sets merge_base to the octopus merge base of curr_head, merge_head and
734 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
735 */
736 static int get_octopus_merge_base(struct object_id *merge_base,
737 const struct object_id *curr_head,
738 const struct object_id *merge_head,
739 const struct object_id *fork_point)
740 {
741 struct commit_list *revs = NULL, *result;
742
743 commit_list_insert(lookup_commit_reference(curr_head), &revs);
744 commit_list_insert(lookup_commit_reference(merge_head), &revs);
745 if (!is_null_oid(fork_point))
746 commit_list_insert(lookup_commit_reference(fork_point), &revs);
747
748 result = reduce_heads(get_octopus_merge_bases(revs));
749 free_commit_list(revs);
750 if (!result)
751 return 1;
752
753 oidcpy(merge_base, &result->item->object.oid);
754 return 0;
755 }
756
757 /**
758 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
759 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
760 * appropriate arguments and returns its exit status.
761 */
762 static int run_rebase(const struct object_id *curr_head,
763 const struct object_id *merge_head,
764 const struct object_id *fork_point)
765 {
766 int ret;
767 struct object_id oct_merge_base;
768 struct argv_array args = ARGV_ARRAY_INIT;
769
770 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
771 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
772 fork_point = NULL;
773
774 argv_array_push(&args, "rebase");
775
776 /* Shared options */
777 argv_push_verbosity(&args);
778
779 /* Options passed to git-rebase */
780 if (opt_rebase == REBASE_PRESERVE)
781 argv_array_push(&args, "--preserve-merges");
782 else if (opt_rebase == REBASE_INTERACTIVE)
783 argv_array_push(&args, "--interactive");
784 if (opt_diffstat)
785 argv_array_push(&args, opt_diffstat);
786 argv_array_pushv(&args, opt_strategies.argv);
787 argv_array_pushv(&args, opt_strategy_opts.argv);
788 if (opt_gpg_sign)
789 argv_array_push(&args, opt_gpg_sign);
790 if (opt_autostash == 0)
791 argv_array_push(&args, "--no-autostash");
792 else if (opt_autostash == 1)
793 argv_array_push(&args, "--autostash");
794 if (opt_verify_signatures &&
795 !strcmp(opt_verify_signatures, "--verify-signatures"))
796 warning(_("ignoring --verify-signatures for rebase"));
797
798 argv_array_push(&args, "--onto");
799 argv_array_push(&args, oid_to_hex(merge_head));
800
801 if (fork_point && !is_null_oid(fork_point))
802 argv_array_push(&args, oid_to_hex(fork_point));
803 else
804 argv_array_push(&args, oid_to_hex(merge_head));
805
806 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
807 argv_array_clear(&args);
808 return ret;
809 }
810
811 int cmd_pull(int argc, const char **argv, const char *prefix)
812 {
813 const char *repo, **refspecs;
814 struct oid_array merge_heads = OID_ARRAY_INIT;
815 struct object_id orig_head, curr_head;
816 struct object_id rebase_fork_point;
817 int autostash;
818
819 if (!getenv("GIT_REFLOG_ACTION"))
820 set_reflog_message(argc, argv);
821
822 git_config(git_pull_config, NULL);
823
824 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
825
826 parse_repo_refspecs(argc, argv, &repo, &refspecs);
827
828 if (!opt_ff)
829 opt_ff = xstrdup_or_null(config_get_ff());
830
831 if (opt_rebase < 0)
832 opt_rebase = config_get_rebase();
833
834 if (read_cache_unmerged())
835 die_resolve_conflict("pull");
836
837 if (file_exists(git_path_merge_head()))
838 die_conclude_merge();
839
840 if (get_oid("HEAD", &orig_head))
841 oidclr(&orig_head);
842
843 if (!opt_rebase && opt_autostash != -1)
844 die(_("--[no-]autostash option is only valid with --rebase."));
845
846 autostash = config_autostash;
847 if (opt_rebase) {
848 if (opt_autostash != -1)
849 autostash = opt_autostash;
850
851 if (is_null_oid(&orig_head) && !is_cache_unborn())
852 die(_("Updating an unborn branch with changes added to the index."));
853
854 if (!autostash)
855 require_clean_work_tree(N_("pull with rebase"),
856 _("please commit or stash them."), 1, 0);
857
858 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
859 oidclr(&rebase_fork_point);
860 }
861
862 if (run_fetch(repo, refspecs))
863 return 1;
864
865 if (opt_dry_run)
866 return 0;
867
868 if (get_oid("HEAD", &curr_head))
869 oidclr(&curr_head);
870
871 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
872 oidcmp(&orig_head, &curr_head)) {
873 /*
874 * The fetch involved updating the current branch.
875 *
876 * The working tree and the index file are still based on
877 * orig_head commit, but we are merging into curr_head.
878 * Update the working tree to match curr_head.
879 */
880
881 warning(_("fetch updated the current branch head.\n"
882 "fast-forwarding your working tree from\n"
883 "commit %s."), oid_to_hex(&orig_head));
884
885 if (checkout_fast_forward(&orig_head, &curr_head, 0))
886 die(_("Cannot fast-forward your working tree.\n"
887 "After making sure that you saved anything precious from\n"
888 "$ git diff %s\n"
889 "output, run\n"
890 "$ git reset --hard\n"
891 "to recover."), oid_to_hex(&orig_head));
892 }
893
894 get_merge_heads(&merge_heads);
895
896 if (!merge_heads.nr)
897 die_no_merge_candidates(repo, refspecs);
898
899 if (is_null_oid(&orig_head)) {
900 if (merge_heads.nr > 1)
901 die(_("Cannot merge multiple branches into empty head."));
902 return pull_into_void(merge_heads.oid, &curr_head);
903 }
904 if (opt_rebase && merge_heads.nr > 1)
905 die(_("Cannot rebase onto multiple branches."));
906
907 if (opt_rebase) {
908 int ret = 0;
909 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
910 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
911 submodule_touches_in_range(&rebase_fork_point, &curr_head))
912 die(_("cannot rebase with locally recorded submodule modifications"));
913 if (!autostash) {
914 struct commit_list *list = NULL;
915 struct commit *merge_head, *head;
916
917 head = lookup_commit_reference(&orig_head);
918 commit_list_insert(head, &list);
919 merge_head = lookup_commit_reference(&merge_heads.oid[0]);
920 if (is_descendant_of(merge_head, list)) {
921 /* we can fast-forward this without invoking rebase */
922 opt_ff = "--ff-only";
923 ret = run_merge();
924 }
925 }
926 ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
927
928 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
929 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
930 ret = rebase_submodules();
931
932 return ret;
933 } else {
934 int ret = run_merge();
935 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
936 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
937 ret = update_submodules();
938 return ret;
939 }
940 }