merge.c: remove implicit dependency on the_index
[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_MERGES,
32 REBASE_INTERACTIVE
33 };
34
35 /**
36 * Parses the value of --rebase. If value is a false value, returns
37 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
38 * "merges", returns REBASE_MERGES. If value is "preserve", returns
39 * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if
40 * fatal is true, otherwise returns REBASE_INVALID.
41 */
42 static enum rebase_type parse_config_rebase(const char *key, const char *value,
43 int fatal)
44 {
45 int v = git_parse_maybe_bool(value);
46
47 if (!v)
48 return REBASE_FALSE;
49 else if (v > 0)
50 return REBASE_TRUE;
51 else if (!strcmp(value, "preserve") || !strcmp(value, "p"))
52 return REBASE_PRESERVE;
53 else if (!strcmp(value, "merges") || !strcmp(value, "m"))
54 return REBASE_MERGES;
55 else if (!strcmp(value, "interactive") || !strcmp(value, "i"))
56 return REBASE_INTERACTIVE;
57
58 if (fatal)
59 die(_("Invalid value for %s: %s"), key, value);
60 else
61 error(_("Invalid value for %s: %s"), key, value);
62
63 return REBASE_INVALID;
64 }
65
66 /**
67 * Callback for --rebase, which parses arg with parse_config_rebase().
68 */
69 static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
70 {
71 enum rebase_type *value = opt->value;
72
73 if (arg)
74 *value = parse_config_rebase("--rebase", arg, 0);
75 else
76 *value = unset ? REBASE_FALSE : REBASE_TRUE;
77 return *value == REBASE_INVALID ? -1 : 0;
78 }
79
80 static const char * const pull_usage[] = {
81 N_("git pull [<options>] [<repository> [<refspec>...]]"),
82 NULL
83 };
84
85 /* Shared options */
86 static int opt_verbosity;
87 static char *opt_progress;
88 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
89
90 /* Options passed to git-merge or git-rebase */
91 static enum rebase_type opt_rebase = -1;
92 static char *opt_diffstat;
93 static char *opt_log;
94 static char *opt_signoff;
95 static char *opt_squash;
96 static char *opt_commit;
97 static char *opt_edit;
98 static char *opt_ff;
99 static char *opt_verify_signatures;
100 static int opt_autostash = -1;
101 static int config_autostash;
102 static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
103 static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
104 static char *opt_gpg_sign;
105 static int opt_allow_unrelated_histories;
106
107 /* Options passed to git-fetch */
108 static char *opt_all;
109 static char *opt_append;
110 static char *opt_upload_pack;
111 static int opt_force;
112 static char *opt_tags;
113 static char *opt_prune;
114 static char *max_children;
115 static int opt_dry_run;
116 static char *opt_keep;
117 static char *opt_depth;
118 static char *opt_unshallow;
119 static char *opt_update_shallow;
120 static char *opt_refmap;
121 static char *opt_ipv4;
122 static char *opt_ipv6;
123
124 static struct option pull_options[] = {
125 /* Shared options */
126 OPT__VERBOSITY(&opt_verbosity),
127 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
128 N_("force progress reporting"),
129 PARSE_OPT_NOARG),
130 { OPTION_CALLBACK, 0, "recurse-submodules",
131 &recurse_submodules, N_("on-demand"),
132 N_("control for recursive fetching of submodules"),
133 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules },
134
135 /* Options passed to git-merge or git-rebase */
136 OPT_GROUP(N_("Options related to merging")),
137 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
138 "(false|true|merges|preserve|interactive)",
139 N_("incorporate changes by rebasing rather than merging"),
140 PARSE_OPT_OPTARG, parse_opt_rebase },
141 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
142 N_("do not show a diffstat at the end of the merge"),
143 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
144 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
145 N_("show a diffstat at the end of the merge"),
146 PARSE_OPT_NOARG),
147 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
148 N_("(synonym to --stat)"),
149 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
150 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
151 N_("add (at most <n>) entries from shortlog to merge commit message"),
152 PARSE_OPT_OPTARG),
153 OPT_PASSTHRU(0, "signoff", &opt_signoff, NULL,
154 N_("add Signed-off-by:"),
155 PARSE_OPT_OPTARG),
156 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
157 N_("create a single commit instead of doing a merge"),
158 PARSE_OPT_NOARG),
159 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
160 N_("perform a commit if the merge succeeds (default)"),
161 PARSE_OPT_NOARG),
162 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
163 N_("edit message before committing"),
164 PARSE_OPT_NOARG),
165 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
166 N_("allow fast-forward"),
167 PARSE_OPT_NOARG),
168 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
169 N_("abort if fast-forward is not possible"),
170 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
171 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
172 N_("verify that the named commit has a valid GPG signature"),
173 PARSE_OPT_NOARG),
174 OPT_BOOL(0, "autostash", &opt_autostash,
175 N_("automatically stash/stash pop before and after rebase")),
176 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
177 N_("merge strategy to use"),
178 0),
179 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
180 N_("option=value"),
181 N_("option for selected merge strategy"),
182 0),
183 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
184 N_("GPG sign commit"),
185 PARSE_OPT_OPTARG),
186 OPT_SET_INT(0, "allow-unrelated-histories",
187 &opt_allow_unrelated_histories,
188 N_("allow merging unrelated histories"), 1),
189
190 /* Options passed to git-fetch */
191 OPT_GROUP(N_("Options related to fetching")),
192 OPT_PASSTHRU(0, "all", &opt_all, NULL,
193 N_("fetch from all remotes"),
194 PARSE_OPT_NOARG),
195 OPT_PASSTHRU('a', "append", &opt_append, NULL,
196 N_("append to .git/FETCH_HEAD instead of overwriting"),
197 PARSE_OPT_NOARG),
198 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
199 N_("path to upload pack on remote end"),
200 0),
201 OPT__FORCE(&opt_force, N_("force overwrite of local branch"), 0),
202 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
203 N_("fetch all tags and associated objects"),
204 PARSE_OPT_NOARG),
205 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
206 N_("prune remote-tracking branches no longer on remote"),
207 PARSE_OPT_NOARG),
208 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
209 N_("number of submodules pulled in parallel"),
210 PARSE_OPT_OPTARG),
211 OPT_BOOL(0, "dry-run", &opt_dry_run,
212 N_("dry run")),
213 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
214 N_("keep downloaded pack"),
215 PARSE_OPT_NOARG),
216 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
217 N_("deepen history of shallow clone"),
218 0),
219 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
220 N_("convert to a complete repository"),
221 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
222 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
223 N_("accept refs that update .git/shallow"),
224 PARSE_OPT_NOARG),
225 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
226 N_("specify fetch refmap"),
227 PARSE_OPT_NONEG),
228 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
229 N_("use IPv4 addresses only"),
230 PARSE_OPT_NOARG),
231 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
232 N_("use IPv6 addresses only"),
233 PARSE_OPT_NOARG),
234
235 OPT_END()
236 };
237
238 /**
239 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
240 */
241 static void argv_push_verbosity(struct argv_array *arr)
242 {
243 int verbosity;
244
245 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
246 argv_array_push(arr, "-v");
247
248 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
249 argv_array_push(arr, "-q");
250 }
251
252 /**
253 * Pushes "-f" switches into arr to match the opt_force level.
254 */
255 static void argv_push_force(struct argv_array *arr)
256 {
257 int force = opt_force;
258 while (force-- > 0)
259 argv_array_push(arr, "-f");
260 }
261
262 /**
263 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
264 */
265 static void set_reflog_message(int argc, const char **argv)
266 {
267 int i;
268 struct strbuf msg = STRBUF_INIT;
269
270 for (i = 0; i < argc; i++) {
271 if (i)
272 strbuf_addch(&msg, ' ');
273 strbuf_addstr(&msg, argv[i]);
274 }
275
276 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
277
278 strbuf_release(&msg);
279 }
280
281 /**
282 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
283 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
284 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
285 * error.
286 */
287 static const char *config_get_ff(void)
288 {
289 const char *value;
290
291 if (git_config_get_value("pull.ff", &value))
292 return NULL;
293
294 switch (git_parse_maybe_bool(value)) {
295 case 0:
296 return "--no-ff";
297 case 1:
298 return "--ff";
299 }
300
301 if (!strcmp(value, "only"))
302 return "--ff-only";
303
304 die(_("Invalid value for pull.ff: %s"), value);
305 }
306
307 /**
308 * Returns the default configured value for --rebase. It first looks for the
309 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
310 * branch, and if HEAD is detached or the configuration key does not exist,
311 * looks for the value of "pull.rebase". If both configuration keys do not
312 * exist, returns REBASE_FALSE.
313 */
314 static enum rebase_type config_get_rebase(void)
315 {
316 struct branch *curr_branch = branch_get("HEAD");
317 const char *value;
318
319 if (curr_branch) {
320 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
321
322 if (!git_config_get_value(key, &value)) {
323 enum rebase_type ret = parse_config_rebase(key, value, 1);
324 free(key);
325 return ret;
326 }
327
328 free(key);
329 }
330
331 if (!git_config_get_value("pull.rebase", &value))
332 return parse_config_rebase("pull.rebase", value, 1);
333
334 return REBASE_FALSE;
335 }
336
337 /**
338 * Read config variables.
339 */
340 static int git_pull_config(const char *var, const char *value, void *cb)
341 {
342 if (!strcmp(var, "rebase.autostash")) {
343 config_autostash = git_config_bool(var, value);
344 return 0;
345 } else if (!strcmp(var, "submodule.recurse")) {
346 recurse_submodules = git_config_bool(var, value) ?
347 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
348 return 0;
349 }
350 return git_default_config(var, value, cb);
351 }
352
353 /**
354 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
355 * into merge_heads.
356 */
357 static void get_merge_heads(struct oid_array *merge_heads)
358 {
359 const char *filename = git_path_fetch_head(the_repository);
360 FILE *fp;
361 struct strbuf sb = STRBUF_INIT;
362 struct object_id oid;
363
364 fp = xfopen(filename, "r");
365 while (strbuf_getline_lf(&sb, fp) != EOF) {
366 if (get_oid_hex(sb.buf, &oid))
367 continue; /* invalid line: does not start with SHA1 */
368 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
369 continue; /* ref is not-for-merge */
370 oid_array_append(merge_heads, &oid);
371 }
372 fclose(fp);
373 strbuf_release(&sb);
374 }
375
376 /**
377 * Used by die_no_merge_candidates() as a for_each_remote() callback to
378 * retrieve the name of the remote if the repository only has one remote.
379 */
380 static int get_only_remote(struct remote *remote, void *cb_data)
381 {
382 const char **remote_name = cb_data;
383
384 if (*remote_name)
385 return -1;
386
387 *remote_name = remote->name;
388 return 0;
389 }
390
391 /**
392 * Dies with the appropriate reason for why there are no merge candidates:
393 *
394 * 1. We fetched from a specific remote, and a refspec was given, but it ended
395 * up not fetching anything. This is usually because the user provided a
396 * wildcard refspec which had no matches on the remote end.
397 *
398 * 2. We fetched from a non-default remote, but didn't specify a branch to
399 * merge. We can't use the configured one because it applies to the default
400 * remote, thus the user must specify the branches to merge.
401 *
402 * 3. We fetched from the branch's or repo's default remote, but:
403 *
404 * a. We are not on a branch, so there will never be a configured branch to
405 * merge with.
406 *
407 * b. We are on a branch, but there is no configured branch to merge with.
408 *
409 * 4. We fetched from the branch's or repo's default remote, but the configured
410 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
411 * part of the configured fetch refspec.)
412 */
413 static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
414 {
415 struct branch *curr_branch = branch_get("HEAD");
416 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
417
418 if (*refspecs) {
419 if (opt_rebase)
420 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
421 else
422 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
423 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
424 "matches on the remote end."));
425 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
426 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
427 "a branch. Because this is not the default configured remote\n"
428 "for your current branch, you must specify a branch on the command line."),
429 repo);
430 } else if (!curr_branch) {
431 fprintf_ln(stderr, _("You are not currently on a branch."));
432 if (opt_rebase)
433 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
434 else
435 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
436 fprintf_ln(stderr, _("See git-pull(1) for details."));
437 fprintf(stderr, "\n");
438 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
439 fprintf(stderr, "\n");
440 } else if (!curr_branch->merge_nr) {
441 const char *remote_name = NULL;
442
443 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
444 remote_name = _("<remote>");
445
446 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
447 if (opt_rebase)
448 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
449 else
450 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
451 fprintf_ln(stderr, _("See git-pull(1) for details."));
452 fprintf(stderr, "\n");
453 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
454 fprintf(stderr, "\n");
455 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
456 fprintf(stderr, "\n");
457 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
458 remote_name, _("<branch>"), curr_branch->name);
459 } else
460 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
461 "from the remote, but no such ref was fetched."),
462 *curr_branch->merge_name);
463 exit(1);
464 }
465
466 /**
467 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
468 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
469 * is not provided in argv, it is set to NULL.
470 */
471 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
472 const char ***refspecs)
473 {
474 if (argc > 0) {
475 *repo = *argv++;
476 argc--;
477 } else
478 *repo = NULL;
479 *refspecs = argv;
480 }
481
482 /**
483 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
484 * repository and refspecs to fetch, or NULL if they are not provided.
485 */
486 static int run_fetch(const char *repo, const char **refspecs)
487 {
488 struct argv_array args = ARGV_ARRAY_INIT;
489 int ret;
490
491 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
492
493 /* Shared options */
494 argv_push_verbosity(&args);
495 if (opt_progress)
496 argv_array_push(&args, opt_progress);
497
498 /* Options passed to git-fetch */
499 if (opt_all)
500 argv_array_push(&args, opt_all);
501 if (opt_append)
502 argv_array_push(&args, opt_append);
503 if (opt_upload_pack)
504 argv_array_push(&args, opt_upload_pack);
505 argv_push_force(&args);
506 if (opt_tags)
507 argv_array_push(&args, opt_tags);
508 if (opt_prune)
509 argv_array_push(&args, opt_prune);
510 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
511 switch (recurse_submodules) {
512 case RECURSE_SUBMODULES_ON:
513 argv_array_push(&args, "--recurse-submodules=on");
514 break;
515 case RECURSE_SUBMODULES_OFF:
516 argv_array_push(&args, "--recurse-submodules=no");
517 break;
518 case RECURSE_SUBMODULES_ON_DEMAND:
519 argv_array_push(&args, "--recurse-submodules=on-demand");
520 break;
521 default:
522 BUG("submodule recursion option not understood");
523 }
524 if (max_children)
525 argv_array_push(&args, max_children);
526 if (opt_dry_run)
527 argv_array_push(&args, "--dry-run");
528 if (opt_keep)
529 argv_array_push(&args, opt_keep);
530 if (opt_depth)
531 argv_array_push(&args, opt_depth);
532 if (opt_unshallow)
533 argv_array_push(&args, opt_unshallow);
534 if (opt_update_shallow)
535 argv_array_push(&args, opt_update_shallow);
536 if (opt_refmap)
537 argv_array_push(&args, opt_refmap);
538 if (opt_ipv4)
539 argv_array_push(&args, opt_ipv4);
540 if (opt_ipv6)
541 argv_array_push(&args, opt_ipv6);
542
543 if (repo) {
544 argv_array_push(&args, repo);
545 argv_array_pushv(&args, refspecs);
546 } else if (*refspecs)
547 BUG("refspecs without repo?");
548 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
549 argv_array_clear(&args);
550 return ret;
551 }
552
553 /**
554 * "Pulls into void" by branching off merge_head.
555 */
556 static int pull_into_void(const struct object_id *merge_head,
557 const struct object_id *curr_head)
558 {
559 /*
560 * Two-way merge: we treat the index as based on an empty tree,
561 * and try to fast-forward to HEAD. This ensures we will not lose
562 * index/worktree changes that the user already made on the unborn
563 * branch.
564 */
565 if (checkout_fast_forward(the_repository,
566 the_hash_algo->empty_tree,
567 merge_head, 0))
568 return 1;
569
570 if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
571 return 1;
572
573 return 0;
574 }
575
576 static int rebase_submodules(void)
577 {
578 struct child_process cp = CHILD_PROCESS_INIT;
579
580 cp.git_cmd = 1;
581 cp.no_stdin = 1;
582 argv_array_pushl(&cp.args, "submodule", "update",
583 "--recursive", "--rebase", NULL);
584 argv_push_verbosity(&cp.args);
585
586 return run_command(&cp);
587 }
588
589 static int update_submodules(void)
590 {
591 struct child_process cp = CHILD_PROCESS_INIT;
592
593 cp.git_cmd = 1;
594 cp.no_stdin = 1;
595 argv_array_pushl(&cp.args, "submodule", "update",
596 "--recursive", "--checkout", NULL);
597 argv_push_verbosity(&cp.args);
598
599 return run_command(&cp);
600 }
601
602 /**
603 * Runs git-merge, returning its exit status.
604 */
605 static int run_merge(void)
606 {
607 int ret;
608 struct argv_array args = ARGV_ARRAY_INIT;
609
610 argv_array_pushl(&args, "merge", NULL);
611
612 /* Shared options */
613 argv_push_verbosity(&args);
614 if (opt_progress)
615 argv_array_push(&args, opt_progress);
616
617 /* Options passed to git-merge */
618 if (opt_diffstat)
619 argv_array_push(&args, opt_diffstat);
620 if (opt_log)
621 argv_array_push(&args, opt_log);
622 if (opt_signoff)
623 argv_array_push(&args, opt_signoff);
624 if (opt_squash)
625 argv_array_push(&args, opt_squash);
626 if (opt_commit)
627 argv_array_push(&args, opt_commit);
628 if (opt_edit)
629 argv_array_push(&args, opt_edit);
630 if (opt_ff)
631 argv_array_push(&args, opt_ff);
632 if (opt_verify_signatures)
633 argv_array_push(&args, opt_verify_signatures);
634 argv_array_pushv(&args, opt_strategies.argv);
635 argv_array_pushv(&args, opt_strategy_opts.argv);
636 if (opt_gpg_sign)
637 argv_array_push(&args, opt_gpg_sign);
638 if (opt_allow_unrelated_histories > 0)
639 argv_array_push(&args, "--allow-unrelated-histories");
640
641 argv_array_push(&args, "FETCH_HEAD");
642 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
643 argv_array_clear(&args);
644 return ret;
645 }
646
647 /**
648 * Returns remote's upstream branch for the current branch. If remote is NULL,
649 * the current branch's configured default remote is used. Returns NULL if
650 * `remote` does not name a valid remote, HEAD does not point to a branch,
651 * remote is not the branch's configured remote or the branch does not have any
652 * configured upstream branch.
653 */
654 static const char *get_upstream_branch(const char *remote)
655 {
656 struct remote *rm;
657 struct branch *curr_branch;
658 const char *curr_branch_remote;
659
660 rm = remote_get(remote);
661 if (!rm)
662 return NULL;
663
664 curr_branch = branch_get("HEAD");
665 if (!curr_branch)
666 return NULL;
667
668 curr_branch_remote = remote_for_branch(curr_branch, NULL);
669 assert(curr_branch_remote);
670
671 if (strcmp(curr_branch_remote, rm->name))
672 return NULL;
673
674 return branch_get_upstream(curr_branch, NULL);
675 }
676
677 /**
678 * Derives the remote-tracking branch from the remote and refspec.
679 *
680 * FIXME: The current implementation assumes the default mapping of
681 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
682 */
683 static const char *get_tracking_branch(const char *remote, const char *refspec)
684 {
685 struct refspec_item spec;
686 const char *spec_src;
687 const char *merge_branch;
688
689 refspec_item_init_or_die(&spec, refspec, REFSPEC_FETCH);
690 spec_src = spec.src;
691 if (!*spec_src || !strcmp(spec_src, "HEAD"))
692 spec_src = "HEAD";
693 else if (skip_prefix(spec_src, "heads/", &spec_src))
694 ;
695 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
696 ;
697 else if (starts_with(spec_src, "refs/") ||
698 starts_with(spec_src, "tags/") ||
699 starts_with(spec_src, "remotes/"))
700 spec_src = "";
701
702 if (*spec_src) {
703 if (!strcmp(remote, "."))
704 merge_branch = mkpath("refs/heads/%s", spec_src);
705 else
706 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
707 } else
708 merge_branch = NULL;
709
710 refspec_item_clear(&spec);
711 return merge_branch;
712 }
713
714 /**
715 * Given the repo and refspecs, sets fork_point to the point at which the
716 * current branch forked from its remote-tracking branch. Returns 0 on success,
717 * -1 on failure.
718 */
719 static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
720 const char *refspec)
721 {
722 int ret;
723 struct branch *curr_branch;
724 const char *remote_branch;
725 struct child_process cp = CHILD_PROCESS_INIT;
726 struct strbuf sb = STRBUF_INIT;
727
728 curr_branch = branch_get("HEAD");
729 if (!curr_branch)
730 return -1;
731
732 if (refspec)
733 remote_branch = get_tracking_branch(repo, refspec);
734 else
735 remote_branch = get_upstream_branch(repo);
736
737 if (!remote_branch)
738 return -1;
739
740 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
741 remote_branch, curr_branch->name, NULL);
742 cp.no_stdin = 1;
743 cp.no_stderr = 1;
744 cp.git_cmd = 1;
745
746 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
747 if (ret)
748 goto cleanup;
749
750 ret = get_oid_hex(sb.buf, fork_point);
751 if (ret)
752 goto cleanup;
753
754 cleanup:
755 strbuf_release(&sb);
756 return ret ? -1 : 0;
757 }
758
759 /**
760 * Sets merge_base to the octopus merge base of curr_head, merge_head and
761 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
762 */
763 static int get_octopus_merge_base(struct object_id *merge_base,
764 const struct object_id *curr_head,
765 const struct object_id *merge_head,
766 const struct object_id *fork_point)
767 {
768 struct commit_list *revs = NULL, *result;
769
770 commit_list_insert(lookup_commit_reference(the_repository, curr_head),
771 &revs);
772 commit_list_insert(lookup_commit_reference(the_repository, merge_head),
773 &revs);
774 if (!is_null_oid(fork_point))
775 commit_list_insert(lookup_commit_reference(the_repository, fork_point),
776 &revs);
777
778 result = get_octopus_merge_bases(revs);
779 free_commit_list(revs);
780 reduce_heads_replace(&result);
781
782 if (!result)
783 return 1;
784
785 oidcpy(merge_base, &result->item->object.oid);
786 free_commit_list(result);
787 return 0;
788 }
789
790 /**
791 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
792 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
793 * appropriate arguments and returns its exit status.
794 */
795 static int run_rebase(const struct object_id *curr_head,
796 const struct object_id *merge_head,
797 const struct object_id *fork_point)
798 {
799 int ret;
800 struct object_id oct_merge_base;
801 struct argv_array args = ARGV_ARRAY_INIT;
802
803 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
804 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
805 fork_point = NULL;
806
807 argv_array_push(&args, "rebase");
808
809 /* Shared options */
810 argv_push_verbosity(&args);
811
812 /* Options passed to git-rebase */
813 if (opt_rebase == REBASE_MERGES)
814 argv_array_push(&args, "--rebase-merges");
815 else if (opt_rebase == REBASE_PRESERVE)
816 argv_array_push(&args, "--preserve-merges");
817 else if (opt_rebase == REBASE_INTERACTIVE)
818 argv_array_push(&args, "--interactive");
819 if (opt_diffstat)
820 argv_array_push(&args, opt_diffstat);
821 argv_array_pushv(&args, opt_strategies.argv);
822 argv_array_pushv(&args, opt_strategy_opts.argv);
823 if (opt_gpg_sign)
824 argv_array_push(&args, opt_gpg_sign);
825 if (opt_autostash == 0)
826 argv_array_push(&args, "--no-autostash");
827 else if (opt_autostash == 1)
828 argv_array_push(&args, "--autostash");
829 if (opt_verify_signatures &&
830 !strcmp(opt_verify_signatures, "--verify-signatures"))
831 warning(_("ignoring --verify-signatures for rebase"));
832
833 argv_array_push(&args, "--onto");
834 argv_array_push(&args, oid_to_hex(merge_head));
835
836 if (fork_point && !is_null_oid(fork_point))
837 argv_array_push(&args, oid_to_hex(fork_point));
838 else
839 argv_array_push(&args, oid_to_hex(merge_head));
840
841 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
842 argv_array_clear(&args);
843 return ret;
844 }
845
846 int cmd_pull(int argc, const char **argv, const char *prefix)
847 {
848 const char *repo, **refspecs;
849 struct oid_array merge_heads = OID_ARRAY_INIT;
850 struct object_id orig_head, curr_head;
851 struct object_id rebase_fork_point;
852 int autostash;
853
854 if (!getenv("GIT_REFLOG_ACTION"))
855 set_reflog_message(argc, argv);
856
857 git_config(git_pull_config, NULL);
858
859 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
860
861 parse_repo_refspecs(argc, argv, &repo, &refspecs);
862
863 if (!opt_ff)
864 opt_ff = xstrdup_or_null(config_get_ff());
865
866 if (opt_rebase < 0)
867 opt_rebase = config_get_rebase();
868
869 if (read_cache_unmerged())
870 die_resolve_conflict("pull");
871
872 if (file_exists(git_path_merge_head(the_repository)))
873 die_conclude_merge();
874
875 if (get_oid("HEAD", &orig_head))
876 oidclr(&orig_head);
877
878 if (!opt_rebase && opt_autostash != -1)
879 die(_("--[no-]autostash option is only valid with --rebase."));
880
881 autostash = config_autostash;
882 if (opt_rebase) {
883 if (opt_autostash != -1)
884 autostash = opt_autostash;
885
886 if (is_null_oid(&orig_head) && !is_cache_unborn())
887 die(_("Updating an unborn branch with changes added to the index."));
888
889 if (!autostash)
890 require_clean_work_tree(N_("pull with rebase"),
891 _("please commit or stash them."), 1, 0);
892
893 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
894 oidclr(&rebase_fork_point);
895 }
896
897 if (run_fetch(repo, refspecs))
898 return 1;
899
900 if (opt_dry_run)
901 return 0;
902
903 if (get_oid("HEAD", &curr_head))
904 oidclr(&curr_head);
905
906 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
907 oidcmp(&orig_head, &curr_head)) {
908 /*
909 * The fetch involved updating the current branch.
910 *
911 * The working tree and the index file are still based on
912 * orig_head commit, but we are merging into curr_head.
913 * Update the working tree to match curr_head.
914 */
915
916 warning(_("fetch updated the current branch head.\n"
917 "fast-forwarding your working tree from\n"
918 "commit %s."), oid_to_hex(&orig_head));
919
920 if (checkout_fast_forward(the_repository, &orig_head,
921 &curr_head, 0))
922 die(_("Cannot fast-forward your working tree.\n"
923 "After making sure that you saved anything precious from\n"
924 "$ git diff %s\n"
925 "output, run\n"
926 "$ git reset --hard\n"
927 "to recover."), oid_to_hex(&orig_head));
928 }
929
930 get_merge_heads(&merge_heads);
931
932 if (!merge_heads.nr)
933 die_no_merge_candidates(repo, refspecs);
934
935 if (is_null_oid(&orig_head)) {
936 if (merge_heads.nr > 1)
937 die(_("Cannot merge multiple branches into empty head."));
938 return pull_into_void(merge_heads.oid, &curr_head);
939 }
940 if (opt_rebase && merge_heads.nr > 1)
941 die(_("Cannot rebase onto multiple branches."));
942
943 if (opt_rebase) {
944 int ret = 0;
945 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
946 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
947 submodule_touches_in_range(&rebase_fork_point, &curr_head))
948 die(_("cannot rebase with locally recorded submodule modifications"));
949 if (!autostash) {
950 struct commit_list *list = NULL;
951 struct commit *merge_head, *head;
952
953 head = lookup_commit_reference(the_repository,
954 &orig_head);
955 commit_list_insert(head, &list);
956 merge_head = lookup_commit_reference(the_repository,
957 &merge_heads.oid[0]);
958 if (is_descendant_of(merge_head, list)) {
959 /* we can fast-forward this without invoking rebase */
960 opt_ff = "--ff-only";
961 ret = run_merge();
962 }
963 }
964 ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
965
966 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
967 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
968 ret = rebase_submodules();
969
970 return ret;
971 } else {
972 int ret = run_merge();
973 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
974 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
975 ret = update_submodules();
976 return ret;
977 }
978 }