refspec: rename struct refspec to struct refspec_item
[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 "refspec.h"
19 #include "revision.h"
20 #include "submodule.h"
21 #include "submodule-config.h"
22 #include "tempfile.h"
23 #include "lockfile.h"
24 #include "wt-status.h"
25
26 enum rebase_type {
27 REBASE_INVALID = -1,
28 REBASE_FALSE = 0,
29 REBASE_TRUE,
30 REBASE_PRESERVE,
31 REBASE_INTERACTIVE
32 };
33
34 /**
35 * Parses the value of --rebase. If value is a false value, returns
36 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
37 * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
38 * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
39 */
40 static enum rebase_type parse_config_rebase(const char *key, const char *value,
41 int fatal)
42 {
43 int v = git_parse_maybe_bool(value);
44
45 if (!v)
46 return REBASE_FALSE;
47 else if (v > 0)
48 return REBASE_TRUE;
49 else if (!strcmp(value, "preserve"))
50 return REBASE_PRESERVE;
51 else if (!strcmp(value, "interactive"))
52 return REBASE_INTERACTIVE;
53
54 if (fatal)
55 die(_("Invalid value for %s: %s"), key, value);
56 else
57 error(_("Invalid value for %s: %s"), key, value);
58
59 return REBASE_INVALID;
60 }
61
62 /**
63 * Callback for --rebase, which parses arg with parse_config_rebase().
64 */
65 static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
66 {
67 enum rebase_type *value = opt->value;
68
69 if (arg)
70 *value = parse_config_rebase("--rebase", arg, 0);
71 else
72 *value = unset ? REBASE_FALSE : REBASE_TRUE;
73 return *value == REBASE_INVALID ? -1 : 0;
74 }
75
76 static const char * const pull_usage[] = {
77 N_("git pull [<options>] [<repository> [<refspec>...]]"),
78 NULL
79 };
80
81 /* Shared options */
82 static int opt_verbosity;
83 static char *opt_progress;
84 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
85
86 /* Options passed to git-merge or git-rebase */
87 static enum rebase_type opt_rebase = -1;
88 static char *opt_diffstat;
89 static char *opt_log;
90 static char *opt_signoff;
91 static char *opt_squash;
92 static char *opt_commit;
93 static char *opt_edit;
94 static char *opt_ff;
95 static char *opt_verify_signatures;
96 static int opt_autostash = -1;
97 static int config_autostash;
98 static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
99 static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
100 static char *opt_gpg_sign;
101 static int opt_allow_unrelated_histories;
102
103 /* Options passed to git-fetch */
104 static char *opt_all;
105 static char *opt_append;
106 static char *opt_upload_pack;
107 static int opt_force;
108 static char *opt_tags;
109 static char *opt_prune;
110 static char *max_children;
111 static int opt_dry_run;
112 static char *opt_keep;
113 static char *opt_depth;
114 static char *opt_unshallow;
115 static char *opt_update_shallow;
116 static char *opt_refmap;
117 static char *opt_ipv4;
118 static char *opt_ipv6;
119
120 static struct option pull_options[] = {
121 /* Shared options */
122 OPT__VERBOSITY(&opt_verbosity),
123 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
124 N_("force progress reporting"),
125 PARSE_OPT_NOARG),
126 { OPTION_CALLBACK, 0, "recurse-submodules",
127 &recurse_submodules, N_("on-demand"),
128 N_("control for recursive fetching of submodules"),
129 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules },
130
131 /* Options passed to git-merge or git-rebase */
132 OPT_GROUP(N_("Options related to merging")),
133 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
134 "false|true|preserve|interactive",
135 N_("incorporate changes by rebasing rather than merging"),
136 PARSE_OPT_OPTARG, parse_opt_rebase },
137 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
138 N_("do not show a diffstat at the end of the merge"),
139 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
140 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
141 N_("show a diffstat at the end of the merge"),
142 PARSE_OPT_NOARG),
143 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
144 N_("(synonym to --stat)"),
145 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
146 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
147 N_("add (at most <n>) entries from shortlog to merge commit message"),
148 PARSE_OPT_OPTARG),
149 OPT_PASSTHRU(0, "signoff", &opt_signoff, NULL,
150 N_("add Signed-off-by:"),
151 PARSE_OPT_OPTARG),
152 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
153 N_("create a single commit instead of doing a merge"),
154 PARSE_OPT_NOARG),
155 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
156 N_("perform a commit if the merge succeeds (default)"),
157 PARSE_OPT_NOARG),
158 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
159 N_("edit message before committing"),
160 PARSE_OPT_NOARG),
161 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
162 N_("allow fast-forward"),
163 PARSE_OPT_NOARG),
164 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
165 N_("abort if fast-forward is not possible"),
166 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
167 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
168 N_("verify that the named commit has a valid GPG signature"),
169 PARSE_OPT_NOARG),
170 OPT_BOOL(0, "autostash", &opt_autostash,
171 N_("automatically stash/stash pop before and after rebase")),
172 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
173 N_("merge strategy to use"),
174 0),
175 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
176 N_("option=value"),
177 N_("option for selected merge strategy"),
178 0),
179 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
180 N_("GPG sign commit"),
181 PARSE_OPT_OPTARG),
182 OPT_SET_INT(0, "allow-unrelated-histories",
183 &opt_allow_unrelated_histories,
184 N_("allow merging unrelated histories"), 1),
185
186 /* Options passed to git-fetch */
187 OPT_GROUP(N_("Options related to fetching")),
188 OPT_PASSTHRU(0, "all", &opt_all, NULL,
189 N_("fetch from all remotes"),
190 PARSE_OPT_NOARG),
191 OPT_PASSTHRU('a', "append", &opt_append, NULL,
192 N_("append to .git/FETCH_HEAD instead of overwriting"),
193 PARSE_OPT_NOARG),
194 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
195 N_("path to upload pack on remote end"),
196 0),
197 OPT__FORCE(&opt_force, N_("force overwrite of local branch"), 0),
198 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
199 N_("fetch all tags and associated objects"),
200 PARSE_OPT_NOARG),
201 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
202 N_("prune remote-tracking branches no longer on remote"),
203 PARSE_OPT_NOARG),
204 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
205 N_("number of submodules pulled in parallel"),
206 PARSE_OPT_OPTARG),
207 OPT_BOOL(0, "dry-run", &opt_dry_run,
208 N_("dry run")),
209 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
210 N_("keep downloaded pack"),
211 PARSE_OPT_NOARG),
212 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
213 N_("deepen history of shallow clone"),
214 0),
215 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
216 N_("convert to a complete repository"),
217 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
218 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
219 N_("accept refs that update .git/shallow"),
220 PARSE_OPT_NOARG),
221 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
222 N_("specify fetch refmap"),
223 PARSE_OPT_NONEG),
224 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
225 N_("use IPv4 addresses only"),
226 PARSE_OPT_NOARG),
227 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
228 N_("use IPv6 addresses only"),
229 PARSE_OPT_NOARG),
230
231 OPT_END()
232 };
233
234 /**
235 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
236 */
237 static void argv_push_verbosity(struct argv_array *arr)
238 {
239 int verbosity;
240
241 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
242 argv_array_push(arr, "-v");
243
244 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
245 argv_array_push(arr, "-q");
246 }
247
248 /**
249 * Pushes "-f" switches into arr to match the opt_force level.
250 */
251 static void argv_push_force(struct argv_array *arr)
252 {
253 int force = opt_force;
254 while (force-- > 0)
255 argv_array_push(arr, "-f");
256 }
257
258 /**
259 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
260 */
261 static void set_reflog_message(int argc, const char **argv)
262 {
263 int i;
264 struct strbuf msg = STRBUF_INIT;
265
266 for (i = 0; i < argc; i++) {
267 if (i)
268 strbuf_addch(&msg, ' ');
269 strbuf_addstr(&msg, argv[i]);
270 }
271
272 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
273
274 strbuf_release(&msg);
275 }
276
277 /**
278 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
279 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
280 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
281 * error.
282 */
283 static const char *config_get_ff(void)
284 {
285 const char *value;
286
287 if (git_config_get_value("pull.ff", &value))
288 return NULL;
289
290 switch (git_parse_maybe_bool(value)) {
291 case 0:
292 return "--no-ff";
293 case 1:
294 return "--ff";
295 }
296
297 if (!strcmp(value, "only"))
298 return "--ff-only";
299
300 die(_("Invalid value for pull.ff: %s"), value);
301 }
302
303 /**
304 * Returns the default configured value for --rebase. It first looks for the
305 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
306 * branch, and if HEAD is detached or the configuration key does not exist,
307 * looks for the value of "pull.rebase". If both configuration keys do not
308 * exist, returns REBASE_FALSE.
309 */
310 static enum rebase_type config_get_rebase(void)
311 {
312 struct branch *curr_branch = branch_get("HEAD");
313 const char *value;
314
315 if (curr_branch) {
316 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
317
318 if (!git_config_get_value(key, &value)) {
319 enum rebase_type ret = parse_config_rebase(key, value, 1);
320 free(key);
321 return ret;
322 }
323
324 free(key);
325 }
326
327 if (!git_config_get_value("pull.rebase", &value))
328 return parse_config_rebase("pull.rebase", value, 1);
329
330 return REBASE_FALSE;
331 }
332
333 /**
334 * Read config variables.
335 */
336 static int git_pull_config(const char *var, const char *value, void *cb)
337 {
338 if (!strcmp(var, "rebase.autostash")) {
339 config_autostash = git_config_bool(var, value);
340 return 0;
341 } else if (!strcmp(var, "submodule.recurse")) {
342 recurse_submodules = git_config_bool(var, value) ?
343 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
344 return 0;
345 }
346 return git_default_config(var, value, cb);
347 }
348
349 /**
350 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
351 * into merge_heads.
352 */
353 static void get_merge_heads(struct oid_array *merge_heads)
354 {
355 const char *filename = git_path_fetch_head();
356 FILE *fp;
357 struct strbuf sb = STRBUF_INIT;
358 struct object_id oid;
359
360 fp = xfopen(filename, "r");
361 while (strbuf_getline_lf(&sb, fp) != EOF) {
362 if (get_oid_hex(sb.buf, &oid))
363 continue; /* invalid line: does not start with SHA1 */
364 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
365 continue; /* ref is not-for-merge */
366 oid_array_append(merge_heads, &oid);
367 }
368 fclose(fp);
369 strbuf_release(&sb);
370 }
371
372 /**
373 * Used by die_no_merge_candidates() as a for_each_remote() callback to
374 * retrieve the name of the remote if the repository only has one remote.
375 */
376 static int get_only_remote(struct remote *remote, void *cb_data)
377 {
378 const char **remote_name = cb_data;
379
380 if (*remote_name)
381 return -1;
382
383 *remote_name = remote->name;
384 return 0;
385 }
386
387 /**
388 * Dies with the appropriate reason for why there are no merge candidates:
389 *
390 * 1. We fetched from a specific remote, and a refspec was given, but it ended
391 * up not fetching anything. This is usually because the user provided a
392 * wildcard refspec which had no matches on the remote end.
393 *
394 * 2. We fetched from a non-default remote, but didn't specify a branch to
395 * merge. We can't use the configured one because it applies to the default
396 * remote, thus the user must specify the branches to merge.
397 *
398 * 3. We fetched from the branch's or repo's default remote, but:
399 *
400 * a. We are not on a branch, so there will never be a configured branch to
401 * merge with.
402 *
403 * b. We are on a branch, but there is no configured branch to merge with.
404 *
405 * 4. We fetched from the branch's or repo's default remote, but the configured
406 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
407 * part of the configured fetch refspec.)
408 */
409 static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
410 {
411 struct branch *curr_branch = branch_get("HEAD");
412 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
413
414 if (*refspecs) {
415 if (opt_rebase)
416 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
417 else
418 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
419 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
420 "matches on the remote end."));
421 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
422 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
423 "a branch. Because this is not the default configured remote\n"
424 "for your current branch, you must specify a branch on the command line."),
425 repo);
426 } else if (!curr_branch) {
427 fprintf_ln(stderr, _("You are not currently on a branch."));
428 if (opt_rebase)
429 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
430 else
431 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
432 fprintf_ln(stderr, _("See git-pull(1) for details."));
433 fprintf(stderr, "\n");
434 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
435 fprintf(stderr, "\n");
436 } else if (!curr_branch->merge_nr) {
437 const char *remote_name = NULL;
438
439 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
440 remote_name = _("<remote>");
441
442 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
443 if (opt_rebase)
444 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
445 else
446 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
447 fprintf_ln(stderr, _("See git-pull(1) for details."));
448 fprintf(stderr, "\n");
449 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
450 fprintf(stderr, "\n");
451 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
452 fprintf(stderr, "\n");
453 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
454 remote_name, _("<branch>"), curr_branch->name);
455 } else
456 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
457 "from the remote, but no such ref was fetched."),
458 *curr_branch->merge_name);
459 exit(1);
460 }
461
462 /**
463 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
464 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
465 * is not provided in argv, it is set to NULL.
466 */
467 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
468 const char ***refspecs)
469 {
470 if (argc > 0) {
471 *repo = *argv++;
472 argc--;
473 } else
474 *repo = NULL;
475 *refspecs = argv;
476 }
477
478 /**
479 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
480 * repository and refspecs to fetch, or NULL if they are not provided.
481 */
482 static int run_fetch(const char *repo, const char **refspecs)
483 {
484 struct argv_array args = ARGV_ARRAY_INIT;
485 int ret;
486
487 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
488
489 /* Shared options */
490 argv_push_verbosity(&args);
491 if (opt_progress)
492 argv_array_push(&args, opt_progress);
493
494 /* Options passed to git-fetch */
495 if (opt_all)
496 argv_array_push(&args, opt_all);
497 if (opt_append)
498 argv_array_push(&args, opt_append);
499 if (opt_upload_pack)
500 argv_array_push(&args, opt_upload_pack);
501 argv_push_force(&args);
502 if (opt_tags)
503 argv_array_push(&args, opt_tags);
504 if (opt_prune)
505 argv_array_push(&args, opt_prune);
506 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
507 switch (recurse_submodules) {
508 case RECURSE_SUBMODULES_ON:
509 argv_array_push(&args, "--recurse-submodules=on");
510 break;
511 case RECURSE_SUBMODULES_OFF:
512 argv_array_push(&args, "--recurse-submodules=no");
513 break;
514 case RECURSE_SUBMODULES_ON_DEMAND:
515 argv_array_push(&args, "--recurse-submodules=on-demand");
516 break;
517 default:
518 BUG("submodule recursion option not understood");
519 }
520 if (max_children)
521 argv_array_push(&args, max_children);
522 if (opt_dry_run)
523 argv_array_push(&args, "--dry-run");
524 if (opt_keep)
525 argv_array_push(&args, opt_keep);
526 if (opt_depth)
527 argv_array_push(&args, opt_depth);
528 if (opt_unshallow)
529 argv_array_push(&args, opt_unshallow);
530 if (opt_update_shallow)
531 argv_array_push(&args, opt_update_shallow);
532 if (opt_refmap)
533 argv_array_push(&args, opt_refmap);
534 if (opt_ipv4)
535 argv_array_push(&args, opt_ipv4);
536 if (opt_ipv6)
537 argv_array_push(&args, opt_ipv6);
538
539 if (repo) {
540 argv_array_push(&args, repo);
541 argv_array_pushv(&args, refspecs);
542 } else if (*refspecs)
543 die("BUG: refspecs without repo?");
544 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
545 argv_array_clear(&args);
546 return ret;
547 }
548
549 /**
550 * "Pulls into void" by branching off merge_head.
551 */
552 static int pull_into_void(const struct object_id *merge_head,
553 const struct object_id *curr_head)
554 {
555 /*
556 * Two-way merge: we treat the index as based on an empty tree,
557 * and try to fast-forward to HEAD. This ensures we will not lose
558 * index/worktree changes that the user already made on the unborn
559 * branch.
560 */
561 if (checkout_fast_forward(the_hash_algo->empty_tree, merge_head, 0))
562 return 1;
563
564 if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
565 return 1;
566
567 return 0;
568 }
569
570 static int rebase_submodules(void)
571 {
572 struct child_process cp = CHILD_PROCESS_INIT;
573
574 cp.git_cmd = 1;
575 cp.no_stdin = 1;
576 argv_array_pushl(&cp.args, "submodule", "update",
577 "--recursive", "--rebase", NULL);
578 argv_push_verbosity(&cp.args);
579
580 return run_command(&cp);
581 }
582
583 static int update_submodules(void)
584 {
585 struct child_process cp = CHILD_PROCESS_INIT;
586
587 cp.git_cmd = 1;
588 cp.no_stdin = 1;
589 argv_array_pushl(&cp.args, "submodule", "update",
590 "--recursive", "--checkout", NULL);
591 argv_push_verbosity(&cp.args);
592
593 return run_command(&cp);
594 }
595
596 /**
597 * Runs git-merge, returning its exit status.
598 */
599 static int run_merge(void)
600 {
601 int ret;
602 struct argv_array args = ARGV_ARRAY_INIT;
603
604 argv_array_pushl(&args, "merge", NULL);
605
606 /* Shared options */
607 argv_push_verbosity(&args);
608 if (opt_progress)
609 argv_array_push(&args, opt_progress);
610
611 /* Options passed to git-merge */
612 if (opt_diffstat)
613 argv_array_push(&args, opt_diffstat);
614 if (opt_log)
615 argv_array_push(&args, opt_log);
616 if (opt_signoff)
617 argv_array_push(&args, opt_signoff);
618 if (opt_squash)
619 argv_array_push(&args, opt_squash);
620 if (opt_commit)
621 argv_array_push(&args, opt_commit);
622 if (opt_edit)
623 argv_array_push(&args, opt_edit);
624 if (opt_ff)
625 argv_array_push(&args, opt_ff);
626 if (opt_verify_signatures)
627 argv_array_push(&args, opt_verify_signatures);
628 argv_array_pushv(&args, opt_strategies.argv);
629 argv_array_pushv(&args, opt_strategy_opts.argv);
630 if (opt_gpg_sign)
631 argv_array_push(&args, opt_gpg_sign);
632 if (opt_allow_unrelated_histories > 0)
633 argv_array_push(&args, "--allow-unrelated-histories");
634
635 argv_array_push(&args, "FETCH_HEAD");
636 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
637 argv_array_clear(&args);
638 return ret;
639 }
640
641 /**
642 * Returns remote's upstream branch for the current branch. If remote is NULL,
643 * the current branch's configured default remote is used. Returns NULL if
644 * `remote` does not name a valid remote, HEAD does not point to a branch,
645 * remote is not the branch's configured remote or the branch does not have any
646 * configured upstream branch.
647 */
648 static const char *get_upstream_branch(const char *remote)
649 {
650 struct remote *rm;
651 struct branch *curr_branch;
652 const char *curr_branch_remote;
653
654 rm = remote_get(remote);
655 if (!rm)
656 return NULL;
657
658 curr_branch = branch_get("HEAD");
659 if (!curr_branch)
660 return NULL;
661
662 curr_branch_remote = remote_for_branch(curr_branch, NULL);
663 assert(curr_branch_remote);
664
665 if (strcmp(curr_branch_remote, rm->name))
666 return NULL;
667
668 return branch_get_upstream(curr_branch, NULL);
669 }
670
671 /**
672 * Derives the remote tracking branch from the remote and refspec.
673 *
674 * FIXME: The current implementation assumes the default mapping of
675 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
676 */
677 static const char *get_tracking_branch(const char *remote, const char *refspec)
678 {
679 struct refspec_item *spec;
680 const char *spec_src;
681 const char *merge_branch;
682
683 spec = parse_fetch_refspec(1, &refspec);
684 spec_src = spec->src;
685 if (!*spec_src || !strcmp(spec_src, "HEAD"))
686 spec_src = "HEAD";
687 else if (skip_prefix(spec_src, "heads/", &spec_src))
688 ;
689 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
690 ;
691 else if (starts_with(spec_src, "refs/") ||
692 starts_with(spec_src, "tags/") ||
693 starts_with(spec_src, "remotes/"))
694 spec_src = "";
695
696 if (*spec_src) {
697 if (!strcmp(remote, "."))
698 merge_branch = mkpath("refs/heads/%s", spec_src);
699 else
700 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
701 } else
702 merge_branch = NULL;
703
704 free_refspec(1, spec);
705 return merge_branch;
706 }
707
708 /**
709 * Given the repo and refspecs, sets fork_point to the point at which the
710 * current branch forked from its remote tracking branch. Returns 0 on success,
711 * -1 on failure.
712 */
713 static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
714 const char *refspec)
715 {
716 int ret;
717 struct branch *curr_branch;
718 const char *remote_branch;
719 struct child_process cp = CHILD_PROCESS_INIT;
720 struct strbuf sb = STRBUF_INIT;
721
722 curr_branch = branch_get("HEAD");
723 if (!curr_branch)
724 return -1;
725
726 if (refspec)
727 remote_branch = get_tracking_branch(repo, refspec);
728 else
729 remote_branch = get_upstream_branch(repo);
730
731 if (!remote_branch)
732 return -1;
733
734 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
735 remote_branch, curr_branch->name, NULL);
736 cp.no_stdin = 1;
737 cp.no_stderr = 1;
738 cp.git_cmd = 1;
739
740 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
741 if (ret)
742 goto cleanup;
743
744 ret = get_oid_hex(sb.buf, fork_point);
745 if (ret)
746 goto cleanup;
747
748 cleanup:
749 strbuf_release(&sb);
750 return ret ? -1 : 0;
751 }
752
753 /**
754 * Sets merge_base to the octopus merge base of curr_head, merge_head and
755 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
756 */
757 static int get_octopus_merge_base(struct object_id *merge_base,
758 const struct object_id *curr_head,
759 const struct object_id *merge_head,
760 const struct object_id *fork_point)
761 {
762 struct commit_list *revs = NULL, *result;
763
764 commit_list_insert(lookup_commit_reference(curr_head), &revs);
765 commit_list_insert(lookup_commit_reference(merge_head), &revs);
766 if (!is_null_oid(fork_point))
767 commit_list_insert(lookup_commit_reference(fork_point), &revs);
768
769 result = get_octopus_merge_bases(revs);
770 free_commit_list(revs);
771 reduce_heads_replace(&result);
772
773 if (!result)
774 return 1;
775
776 oidcpy(merge_base, &result->item->object.oid);
777 free_commit_list(result);
778 return 0;
779 }
780
781 /**
782 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
783 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
784 * appropriate arguments and returns its exit status.
785 */
786 static int run_rebase(const struct object_id *curr_head,
787 const struct object_id *merge_head,
788 const struct object_id *fork_point)
789 {
790 int ret;
791 struct object_id oct_merge_base;
792 struct argv_array args = ARGV_ARRAY_INIT;
793
794 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
795 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
796 fork_point = NULL;
797
798 argv_array_push(&args, "rebase");
799
800 /* Shared options */
801 argv_push_verbosity(&args);
802
803 /* Options passed to git-rebase */
804 if (opt_rebase == REBASE_PRESERVE)
805 argv_array_push(&args, "--preserve-merges");
806 else if (opt_rebase == REBASE_INTERACTIVE)
807 argv_array_push(&args, "--interactive");
808 if (opt_diffstat)
809 argv_array_push(&args, opt_diffstat);
810 argv_array_pushv(&args, opt_strategies.argv);
811 argv_array_pushv(&args, opt_strategy_opts.argv);
812 if (opt_gpg_sign)
813 argv_array_push(&args, opt_gpg_sign);
814 if (opt_autostash == 0)
815 argv_array_push(&args, "--no-autostash");
816 else if (opt_autostash == 1)
817 argv_array_push(&args, "--autostash");
818 if (opt_verify_signatures &&
819 !strcmp(opt_verify_signatures, "--verify-signatures"))
820 warning(_("ignoring --verify-signatures for rebase"));
821
822 argv_array_push(&args, "--onto");
823 argv_array_push(&args, oid_to_hex(merge_head));
824
825 if (fork_point && !is_null_oid(fork_point))
826 argv_array_push(&args, oid_to_hex(fork_point));
827 else
828 argv_array_push(&args, oid_to_hex(merge_head));
829
830 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
831 argv_array_clear(&args);
832 return ret;
833 }
834
835 int cmd_pull(int argc, const char **argv, const char *prefix)
836 {
837 const char *repo, **refspecs;
838 struct oid_array merge_heads = OID_ARRAY_INIT;
839 struct object_id orig_head, curr_head;
840 struct object_id rebase_fork_point;
841 int autostash;
842
843 if (!getenv("GIT_REFLOG_ACTION"))
844 set_reflog_message(argc, argv);
845
846 git_config(git_pull_config, NULL);
847
848 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
849
850 parse_repo_refspecs(argc, argv, &repo, &refspecs);
851
852 if (!opt_ff)
853 opt_ff = xstrdup_or_null(config_get_ff());
854
855 if (opt_rebase < 0)
856 opt_rebase = config_get_rebase();
857
858 if (read_cache_unmerged())
859 die_resolve_conflict("pull");
860
861 if (file_exists(git_path_merge_head()))
862 die_conclude_merge();
863
864 if (get_oid("HEAD", &orig_head))
865 oidclr(&orig_head);
866
867 if (!opt_rebase && opt_autostash != -1)
868 die(_("--[no-]autostash option is only valid with --rebase."));
869
870 autostash = config_autostash;
871 if (opt_rebase) {
872 if (opt_autostash != -1)
873 autostash = opt_autostash;
874
875 if (is_null_oid(&orig_head) && !is_cache_unborn())
876 die(_("Updating an unborn branch with changes added to the index."));
877
878 if (!autostash)
879 require_clean_work_tree(N_("pull with rebase"),
880 _("please commit or stash them."), 1, 0);
881
882 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
883 oidclr(&rebase_fork_point);
884 }
885
886 if (run_fetch(repo, refspecs))
887 return 1;
888
889 if (opt_dry_run)
890 return 0;
891
892 if (get_oid("HEAD", &curr_head))
893 oidclr(&curr_head);
894
895 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
896 oidcmp(&orig_head, &curr_head)) {
897 /*
898 * The fetch involved updating the current branch.
899 *
900 * The working tree and the index file are still based on
901 * orig_head commit, but we are merging into curr_head.
902 * Update the working tree to match curr_head.
903 */
904
905 warning(_("fetch updated the current branch head.\n"
906 "fast-forwarding your working tree from\n"
907 "commit %s."), oid_to_hex(&orig_head));
908
909 if (checkout_fast_forward(&orig_head, &curr_head, 0))
910 die(_("Cannot fast-forward your working tree.\n"
911 "After making sure that you saved anything precious from\n"
912 "$ git diff %s\n"
913 "output, run\n"
914 "$ git reset --hard\n"
915 "to recover."), oid_to_hex(&orig_head));
916 }
917
918 get_merge_heads(&merge_heads);
919
920 if (!merge_heads.nr)
921 die_no_merge_candidates(repo, refspecs);
922
923 if (is_null_oid(&orig_head)) {
924 if (merge_heads.nr > 1)
925 die(_("Cannot merge multiple branches into empty head."));
926 return pull_into_void(merge_heads.oid, &curr_head);
927 }
928 if (opt_rebase && merge_heads.nr > 1)
929 die(_("Cannot rebase onto multiple branches."));
930
931 if (opt_rebase) {
932 int ret = 0;
933 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
934 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
935 submodule_touches_in_range(&rebase_fork_point, &curr_head))
936 die(_("cannot rebase with locally recorded submodule modifications"));
937 if (!autostash) {
938 struct commit_list *list = NULL;
939 struct commit *merge_head, *head;
940
941 head = lookup_commit_reference(&orig_head);
942 commit_list_insert(head, &list);
943 merge_head = lookup_commit_reference(&merge_heads.oid[0]);
944 if (is_descendant_of(merge_head, list)) {
945 /* we can fast-forward this without invoking rebase */
946 opt_ff = "--ff-only";
947 ret = run_merge();
948 }
949 }
950 ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
951
952 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
953 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
954 ret = rebase_submodules();
955
956 return ret;
957 } else {
958 int ret = run_merge();
959 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
960 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
961 ret = update_submodules();
962 return ret;
963 }
964 }