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