Convert struct object to object_id
[git/git.git] / builtin / pull.c
CommitLineData
1e1ea69f
PT
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 "builtin.h"
10#include "parse-options.h"
11#include "exec_cmd.h"
f2c5baa1 12#include "run-command.h"
44c175c7
PT
13#include "sha1-array.h"
14#include "remote.h"
4a4cf9e8 15#include "dir.h"
49ec402d 16#include "refs.h"
8944969c 17#include "revision.h"
db86e61c 18#include "tempfile.h"
8944969c 19#include "lockfile.h"
1e1ea69f 20
1678b81e
PT
21enum rebase_type {
22 REBASE_INVALID = -1,
23 REBASE_FALSE = 0,
24 REBASE_TRUE,
25 REBASE_PRESERVE
26};
27
28/**
29 * Parses the value of --rebase. If value is a false value, returns
30 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
31 * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
32 * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
33 */
34static enum rebase_type parse_config_rebase(const char *key, const char *value,
35 int fatal)
36{
37 int v = git_config_maybe_bool("pull.rebase", value);
38
39 if (!v)
40 return REBASE_FALSE;
41 else if (v > 0)
42 return REBASE_TRUE;
43 else if (!strcmp(value, "preserve"))
44 return REBASE_PRESERVE;
45
46 if (fatal)
47 die(_("Invalid value for %s: %s"), key, value);
48 else
49 error(_("Invalid value for %s: %s"), key, value);
50
51 return REBASE_INVALID;
52}
53
54/**
55 * Callback for --rebase, which parses arg with parse_config_rebase().
56 */
57static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
58{
59 enum rebase_type *value = opt->value;
60
61 if (arg)
62 *value = parse_config_rebase("--rebase", arg, 0);
63 else
64 *value = unset ? REBASE_FALSE : REBASE_TRUE;
65 return *value == REBASE_INVALID ? -1 : 0;
66}
67
1e1ea69f 68static const char * const pull_usage[] = {
e7a7401f 69 N_("git pull [<options>] [<repository> [<refspec>...]]"),
1e1ea69f
PT
70 NULL
71};
72
2a747902
PT
73/* Shared options */
74static int opt_verbosity;
75static char *opt_progress;
76
1678b81e 77/* Options passed to git-merge or git-rebase */
81dbd768 78static enum rebase_type opt_rebase = -1;
11b6d178
PT
79static char *opt_diffstat;
80static char *opt_log;
81static char *opt_squash;
82static char *opt_commit;
83static char *opt_edit;
84static char *opt_ff;
85static char *opt_verify_signatures;
86static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
87static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
88static char *opt_gpg_sign;
89
a32975f5
PT
90/* Options passed to git-fetch */
91static char *opt_all;
92static char *opt_append;
93static char *opt_upload_pack;
94static int opt_force;
95static char *opt_tags;
96static char *opt_prune;
97static char *opt_recurse_submodules;
98static int opt_dry_run;
99static char *opt_keep;
100static char *opt_depth;
101static char *opt_unshallow;
102static char *opt_update_shallow;
103static char *opt_refmap;
104
1e1ea69f 105static struct option pull_options[] = {
2a747902
PT
106 /* Shared options */
107 OPT__VERBOSITY(&opt_verbosity),
108 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
109 N_("force progress reporting"),
110 PARSE_OPT_NOARG),
111
1678b81e 112 /* Options passed to git-merge or git-rebase */
11b6d178 113 OPT_GROUP(N_("Options related to merging")),
1678b81e 114 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
7306b39f 115 "false|true|preserve",
1678b81e
PT
116 N_("incorporate changes by rebasing rather than merging"),
117 PARSE_OPT_OPTARG, parse_opt_rebase },
11b6d178
PT
118 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
119 N_("do not show a diffstat at the end of the merge"),
120 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
121 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
122 N_("show a diffstat at the end of the merge"),
123 PARSE_OPT_NOARG),
124 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
125 N_("(synonym to --stat)"),
126 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
127 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
128 N_("add (at most <n>) entries from shortlog to merge commit message"),
129 PARSE_OPT_OPTARG),
130 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
131 N_("create a single commit instead of doing a merge"),
132 PARSE_OPT_NOARG),
133 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
134 N_("perform a commit if the merge succeeds (default)"),
135 PARSE_OPT_NOARG),
136 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
137 N_("edit message before committing"),
138 PARSE_OPT_NOARG),
139 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
140 N_("allow fast-forward"),
141 PARSE_OPT_NOARG),
142 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
143 N_("abort if fast-forward is not possible"),
144 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
145 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
146 N_("verify that the named commit has a valid GPG signature"),
147 PARSE_OPT_NOARG),
148 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
149 N_("merge strategy to use"),
150 0),
151 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
152 N_("option=value"),
153 N_("option for selected merge strategy"),
154 0),
155 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
156 N_("GPG sign commit"),
157 PARSE_OPT_OPTARG),
158
a32975f5
PT
159 /* Options passed to git-fetch */
160 OPT_GROUP(N_("Options related to fetching")),
161 OPT_PASSTHRU(0, "all", &opt_all, NULL,
162 N_("fetch from all remotes"),
163 PARSE_OPT_NOARG),
164 OPT_PASSTHRU('a', "append", &opt_append, NULL,
165 N_("append to .git/FETCH_HEAD instead of overwriting"),
166 PARSE_OPT_NOARG),
167 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
168 N_("path to upload pack on remote end"),
169 0),
170 OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
171 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
172 N_("fetch all tags and associated objects"),
173 PARSE_OPT_NOARG),
174 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
175 N_("prune remote-tracking branches no longer on remote"),
176 PARSE_OPT_NOARG),
177 OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules,
178 N_("on-demand"),
179 N_("control recursive fetching of submodules"),
180 PARSE_OPT_OPTARG),
181 OPT_BOOL(0, "dry-run", &opt_dry_run,
182 N_("dry run")),
183 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
184 N_("keep downloaded pack"),
185 PARSE_OPT_NOARG),
186 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
187 N_("deepen history of shallow clone"),
188 0),
189 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
190 N_("convert to a complete repository"),
191 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
192 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
193 N_("accept refs that update .git/shallow"),
194 PARSE_OPT_NOARG),
195 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
196 N_("specify fetch refmap"),
197 PARSE_OPT_NONEG),
198
1e1ea69f
PT
199 OPT_END()
200};
201
2a747902
PT
202/**
203 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
204 */
205static void argv_push_verbosity(struct argv_array *arr)
206{
207 int verbosity;
208
209 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
210 argv_array_push(arr, "-v");
211
212 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
213 argv_array_push(arr, "-q");
214}
215
a32975f5
PT
216/**
217 * Pushes "-f" switches into arr to match the opt_force level.
218 */
219static void argv_push_force(struct argv_array *arr)
220{
221 int force = opt_force;
222 while (force-- > 0)
223 argv_array_push(arr, "-f");
224}
225
41fca098
PT
226/**
227 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
228 */
229static void set_reflog_message(int argc, const char **argv)
230{
231 int i;
232 struct strbuf msg = STRBUF_INIT;
233
234 for (i = 0; i < argc; i++) {
235 if (i)
236 strbuf_addch(&msg, ' ');
237 strbuf_addstr(&msg, argv[i]);
238 }
239
240 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
241
242 strbuf_release(&msg);
243}
244
a9de9897
PT
245/**
246 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
247 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
248 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
249 * error.
250 */
251static const char *config_get_ff(void)
252{
253 const char *value;
254
255 if (git_config_get_value("pull.ff", &value))
256 return NULL;
257
258 switch (git_config_maybe_bool("pull.ff", value)) {
259 case 0:
260 return "--no-ff";
261 case 1:
262 return "--ff";
263 }
264
265 if (!strcmp(value, "only"))
266 return "--ff-only";
267
268 die(_("Invalid value for pull.ff: %s"), value);
269}
270
81dbd768
PT
271/**
272 * Returns the default configured value for --rebase. It first looks for the
273 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
274 * branch, and if HEAD is detached or the configuration key does not exist,
275 * looks for the value of "pull.rebase". If both configuration keys do not
276 * exist, returns REBASE_FALSE.
277 */
278static enum rebase_type config_get_rebase(void)
279{
280 struct branch *curr_branch = branch_get("HEAD");
281 const char *value;
282
283 if (curr_branch) {
284 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
285
286 if (!git_config_get_value(key, &value)) {
287 enum rebase_type ret = parse_config_rebase(key, value, 1);
288 free(key);
289 return ret;
290 }
291
292 free(key);
293 }
294
295 if (!git_config_get_value("pull.rebase", &value))
296 return parse_config_rebase("pull.rebase", value, 1);
297
298 return REBASE_FALSE;
299}
300
8944969c
PT
301/**
302 * Returns 1 if there are unstaged changes, 0 otherwise.
303 */
304static int has_unstaged_changes(const char *prefix)
305{
306 struct rev_info rev_info;
307 int result;
308
309 init_revisions(&rev_info, prefix);
310 DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
311 DIFF_OPT_SET(&rev_info.diffopt, QUICK);
312 diff_setup_done(&rev_info.diffopt);
313 result = run_diff_files(&rev_info, 0);
314 return diff_result_code(&rev_info.diffopt, result);
315}
316
317/**
318 * Returns 1 if there are uncommitted changes, 0 otherwise.
319 */
320static int has_uncommitted_changes(const char *prefix)
321{
322 struct rev_info rev_info;
323 int result;
324
325 if (is_cache_unborn())
326 return 0;
327
328 init_revisions(&rev_info, prefix);
329 DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
330 DIFF_OPT_SET(&rev_info.diffopt, QUICK);
331 add_head_to_pending(&rev_info);
332 diff_setup_done(&rev_info.diffopt);
333 result = run_diff_index(&rev_info, 1);
334 return diff_result_code(&rev_info.diffopt, result);
335}
336
337/**
338 * If the work tree has unstaged or uncommitted changes, dies with the
339 * appropriate message.
340 */
341static void die_on_unclean_work_tree(const char *prefix)
342{
343 struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file));
344 int do_die = 0;
345
346 hold_locked_index(lock_file, 0);
347 refresh_cache(REFRESH_QUIET);
348 update_index_if_able(&the_index, lock_file);
349 rollback_lock_file(lock_file);
350
351 if (has_unstaged_changes(prefix)) {
352 error(_("Cannot pull with rebase: You have unstaged changes."));
353 do_die = 1;
354 }
355
356 if (has_uncommitted_changes(prefix)) {
357 if (do_die)
358 error(_("Additionally, your index contains uncommitted changes."));
359 else
360 error(_("Cannot pull with rebase: Your index contains uncommitted changes."));
361 do_die = 1;
362 }
363
364 if (do_die)
365 exit(1);
366}
367
44c175c7
PT
368/**
369 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
370 * into merge_heads.
371 */
372static void get_merge_heads(struct sha1_array *merge_heads)
373{
374 const char *filename = git_path("FETCH_HEAD");
375 FILE *fp;
376 struct strbuf sb = STRBUF_INIT;
377 unsigned char sha1[GIT_SHA1_RAWSZ];
378
379 if (!(fp = fopen(filename, "r")))
380 die_errno(_("could not open '%s' for reading"), filename);
381 while (strbuf_getline(&sb, fp, '\n') != EOF) {
382 if (get_sha1_hex(sb.buf, sha1))
383 continue; /* invalid line: does not start with SHA1 */
384 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
385 continue; /* ref is not-for-merge */
386 sha1_array_append(merge_heads, sha1);
387 }
388 fclose(fp);
389 strbuf_release(&sb);
390}
391
392/**
393 * Used by die_no_merge_candidates() as a for_each_remote() callback to
394 * retrieve the name of the remote if the repository only has one remote.
395 */
396static int get_only_remote(struct remote *remote, void *cb_data)
397{
398 const char **remote_name = cb_data;
399
400 if (*remote_name)
401 return -1;
402
403 *remote_name = remote->name;
404 return 0;
405}
406
407/**
408 * Dies with the appropriate reason for why there are no merge candidates:
409 *
410 * 1. We fetched from a specific remote, and a refspec was given, but it ended
411 * up not fetching anything. This is usually because the user provided a
412 * wildcard refspec which had no matches on the remote end.
413 *
414 * 2. We fetched from a non-default remote, but didn't specify a branch to
415 * merge. We can't use the configured one because it applies to the default
416 * remote, thus the user must specify the branches to merge.
417 *
418 * 3. We fetched from the branch's or repo's default remote, but:
419 *
420 * a. We are not on a branch, so there will never be a configured branch to
421 * merge with.
422 *
423 * b. We are on a branch, but there is no configured branch to merge with.
424 *
425 * 4. We fetched from the branch's or repo's default remote, but the configured
426 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
427 * part of the configured fetch refspec.)
428 */
429static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
430{
431 struct branch *curr_branch = branch_get("HEAD");
432 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
433
434 if (*refspecs) {
b7b31471
PT
435 if (opt_rebase)
436 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
437 else
438 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
44c175c7
PT
439 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
440 "matches on the remote end."));
441 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
442 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
443 "a branch. Because this is not the default configured remote\n"
444 "for your current branch, you must specify a branch on the command line."),
445 repo);
446 } else if (!curr_branch) {
447 fprintf_ln(stderr, _("You are not currently on a branch."));
b7b31471
PT
448 if (opt_rebase)
449 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
450 else
451 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
44c175c7
PT
452 fprintf_ln(stderr, _("See git-pull(1) for details."));
453 fprintf(stderr, "\n");
454 fprintf_ln(stderr, " git pull <remote> <branch>");
455 fprintf(stderr, "\n");
456 } else if (!curr_branch->merge_nr) {
457 const char *remote_name = NULL;
458
459 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
460 remote_name = "<remote>";
461
462 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
b7b31471
PT
463 if (opt_rebase)
464 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
465 else
466 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
44c175c7
PT
467 fprintf_ln(stderr, _("See git-pull(1) for details."));
468 fprintf(stderr, "\n");
469 fprintf_ln(stderr, " git pull <remote> <branch>");
470 fprintf(stderr, "\n");
471 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:\n"
472 "\n"
473 " git branch --set-upstream-to=%s/<branch> %s\n"),
474 remote_name, curr_branch->name);
475 } else
476 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
477 "from the remote, but no such ref was fetched."),
478 *curr_branch->merge_name);
479 exit(1);
480}
481
f2c5baa1
PT
482/**
483 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
484 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
485 * is not provided in argv, it is set to NULL.
486 */
487static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
488 const char ***refspecs)
489{
490 if (argc > 0) {
491 *repo = *argv++;
492 argc--;
493 } else
494 *repo = NULL;
495 *refspecs = argv;
496}
497
498/**
499 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
500 * repository and refspecs to fetch, or NULL if they are not provided.
501 */
502static int run_fetch(const char *repo, const char **refspecs)
503{
504 struct argv_array args = ARGV_ARRAY_INIT;
505 int ret;
506
507 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
2a747902
PT
508
509 /* Shared options */
510 argv_push_verbosity(&args);
511 if (opt_progress)
512 argv_array_push(&args, opt_progress);
513
a32975f5
PT
514 /* Options passed to git-fetch */
515 if (opt_all)
516 argv_array_push(&args, opt_all);
517 if (opt_append)
518 argv_array_push(&args, opt_append);
519 if (opt_upload_pack)
520 argv_array_push(&args, opt_upload_pack);
521 argv_push_force(&args);
522 if (opt_tags)
523 argv_array_push(&args, opt_tags);
524 if (opt_prune)
525 argv_array_push(&args, opt_prune);
526 if (opt_recurse_submodules)
527 argv_array_push(&args, opt_recurse_submodules);
528 if (opt_dry_run)
529 argv_array_push(&args, "--dry-run");
530 if (opt_keep)
531 argv_array_push(&args, opt_keep);
532 if (opt_depth)
533 argv_array_push(&args, opt_depth);
534 if (opt_unshallow)
535 argv_array_push(&args, opt_unshallow);
536 if (opt_update_shallow)
537 argv_array_push(&args, opt_update_shallow);
538 if (opt_refmap)
539 argv_array_push(&args, opt_refmap);
540
f2c5baa1
PT
541 if (repo) {
542 argv_array_push(&args, repo);
543 argv_array_pushv(&args, refspecs);
544 } else if (*refspecs)
545 die("BUG: refspecs without repo?");
546 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
547 argv_array_clear(&args);
548 return ret;
549}
550
49ec402d
PT
551/**
552 * "Pulls into void" by branching off merge_head.
553 */
554static int pull_into_void(const unsigned char *merge_head,
555 const unsigned char *curr_head)
556{
557 /*
558 * Two-way merge: we treat the index as based on an empty tree,
559 * and try to fast-forward to HEAD. This ensures we will not lose
560 * index/worktree changes that the user already made on the unborn
561 * branch.
562 */
563 if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0))
564 return 1;
565
566 if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
567 return 1;
568
569 return 0;
570}
571
f2c5baa1
PT
572/**
573 * Runs git-merge, returning its exit status.
574 */
575static int run_merge(void)
576{
577 int ret;
578 struct argv_array args = ARGV_ARRAY_INIT;
579
580 argv_array_pushl(&args, "merge", NULL);
2a747902
PT
581
582 /* Shared options */
583 argv_push_verbosity(&args);
584 if (opt_progress)
585 argv_array_push(&args, opt_progress);
586
11b6d178
PT
587 /* Options passed to git-merge */
588 if (opt_diffstat)
589 argv_array_push(&args, opt_diffstat);
590 if (opt_log)
591 argv_array_push(&args, opt_log);
592 if (opt_squash)
593 argv_array_push(&args, opt_squash);
594 if (opt_commit)
595 argv_array_push(&args, opt_commit);
596 if (opt_edit)
597 argv_array_push(&args, opt_edit);
598 if (opt_ff)
599 argv_array_push(&args, opt_ff);
600 if (opt_verify_signatures)
601 argv_array_push(&args, opt_verify_signatures);
602 argv_array_pushv(&args, opt_strategies.argv);
603 argv_array_pushv(&args, opt_strategy_opts.argv);
604 if (opt_gpg_sign)
605 argv_array_push(&args, opt_gpg_sign);
606
f2c5baa1
PT
607 argv_array_push(&args, "FETCH_HEAD");
608 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
609 argv_array_clear(&args);
610 return ret;
611}
612
1678b81e
PT
613/**
614 * Returns remote's upstream branch for the current branch. If remote is NULL,
615 * the current branch's configured default remote is used. Returns NULL if
616 * `remote` does not name a valid remote, HEAD does not point to a branch,
617 * remote is not the branch's configured remote or the branch does not have any
618 * configured upstream branch.
619 */
620static const char *get_upstream_branch(const char *remote)
621{
622 struct remote *rm;
623 struct branch *curr_branch;
624 const char *curr_branch_remote;
625
626 rm = remote_get(remote);
627 if (!rm)
628 return NULL;
629
630 curr_branch = branch_get("HEAD");
631 if (!curr_branch)
632 return NULL;
633
634 curr_branch_remote = remote_for_branch(curr_branch, NULL);
635 assert(curr_branch_remote);
636
637 if (strcmp(curr_branch_remote, rm->name))
638 return NULL;
639
640 return branch_get_upstream(curr_branch, NULL);
641}
642
643/**
644 * Derives the remote tracking branch from the remote and refspec.
645 *
646 * FIXME: The current implementation assumes the default mapping of
647 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
648 */
649static const char *get_tracking_branch(const char *remote, const char *refspec)
650{
651 struct refspec *spec;
652 const char *spec_src;
653 const char *merge_branch;
654
655 spec = parse_fetch_refspec(1, &refspec);
656 spec_src = spec->src;
657 if (!*spec_src || !strcmp(spec_src, "HEAD"))
658 spec_src = "HEAD";
659 else if (skip_prefix(spec_src, "heads/", &spec_src))
660 ;
661 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
662 ;
663 else if (starts_with(spec_src, "refs/") ||
664 starts_with(spec_src, "tags/") ||
665 starts_with(spec_src, "remotes/"))
666 spec_src = "";
667
668 if (*spec_src) {
669 if (!strcmp(remote, "."))
670 merge_branch = mkpath("refs/heads/%s", spec_src);
671 else
672 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
673 } else
674 merge_branch = NULL;
675
676 free_refspec(1, spec);
677 return merge_branch;
678}
679
680/**
681 * Given the repo and refspecs, sets fork_point to the point at which the
682 * current branch forked from its remote tracking branch. Returns 0 on success,
683 * -1 on failure.
684 */
685static int get_rebase_fork_point(unsigned char *fork_point, const char *repo,
686 const char *refspec)
687{
688 int ret;
689 struct branch *curr_branch;
690 const char *remote_branch;
691 struct child_process cp = CHILD_PROCESS_INIT;
692 struct strbuf sb = STRBUF_INIT;
693
694 curr_branch = branch_get("HEAD");
695 if (!curr_branch)
696 return -1;
697
698 if (refspec)
699 remote_branch = get_tracking_branch(repo, refspec);
700 else
701 remote_branch = get_upstream_branch(repo);
702
703 if (!remote_branch)
704 return -1;
705
706 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
707 remote_branch, curr_branch->name, NULL);
708 cp.no_stdin = 1;
709 cp.no_stderr = 1;
710 cp.git_cmd = 1;
711
712 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
713 if (ret)
714 goto cleanup;
715
716 ret = get_sha1_hex(sb.buf, fork_point);
717 if (ret)
718 goto cleanup;
719
720cleanup:
721 strbuf_release(&sb);
722 return ret ? -1 : 0;
723}
724
725/**
726 * Sets merge_base to the octopus merge base of curr_head, merge_head and
727 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
728 */
729static int get_octopus_merge_base(unsigned char *merge_base,
730 const unsigned char *curr_head,
731 const unsigned char *merge_head,
732 const unsigned char *fork_point)
733{
734 struct commit_list *revs = NULL, *result;
735
736 commit_list_insert(lookup_commit_reference(curr_head), &revs);
737 commit_list_insert(lookup_commit_reference(merge_head), &revs);
738 if (!is_null_sha1(fork_point))
739 commit_list_insert(lookup_commit_reference(fork_point), &revs);
740
741 result = reduce_heads(get_octopus_merge_bases(revs));
742 free_commit_list(revs);
743 if (!result)
744 return 1;
745
f2fd0760 746 hashcpy(merge_base, get_object_hash(result->item->object));
1678b81e
PT
747 return 0;
748}
749
750/**
751 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
752 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
753 * appropriate arguments and returns its exit status.
754 */
755static int run_rebase(const unsigned char *curr_head,
756 const unsigned char *merge_head,
757 const unsigned char *fork_point)
758{
759 int ret;
760 unsigned char oct_merge_base[GIT_SHA1_RAWSZ];
761 struct argv_array args = ARGV_ARRAY_INIT;
762
763 if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point))
764 if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point))
765 fork_point = NULL;
766
767 argv_array_push(&args, "rebase");
768
769 /* Shared options */
770 argv_push_verbosity(&args);
771
772 /* Options passed to git-rebase */
773 if (opt_rebase == REBASE_PRESERVE)
774 argv_array_push(&args, "--preserve-merges");
775 if (opt_diffstat)
776 argv_array_push(&args, opt_diffstat);
777 argv_array_pushv(&args, opt_strategies.argv);
778 argv_array_pushv(&args, opt_strategy_opts.argv);
779 if (opt_gpg_sign)
780 argv_array_push(&args, opt_gpg_sign);
781
782 argv_array_push(&args, "--onto");
783 argv_array_push(&args, sha1_to_hex(merge_head));
784
785 if (fork_point && !is_null_sha1(fork_point))
786 argv_array_push(&args, sha1_to_hex(fork_point));
787 else
788 argv_array_push(&args, sha1_to_hex(merge_head));
789
790 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
791 argv_array_clear(&args);
792 return ret;
793}
794
1e1ea69f
PT
795int cmd_pull(int argc, const char **argv, const char *prefix)
796{
f2c5baa1 797 const char *repo, **refspecs;
44c175c7 798 struct sha1_array merge_heads = SHA1_ARRAY_INIT;
fe911b8c 799 unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
1678b81e 800 unsigned char rebase_fork_point[GIT_SHA1_RAWSZ];
f2c5baa1 801
41fca098
PT
802 if (!getenv("GIT_REFLOG_ACTION"))
803 set_reflog_message(argc, argv);
804
1e1ea69f
PT
805 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
806
f2c5baa1
PT
807 parse_repo_refspecs(argc, argv, &repo, &refspecs);
808
a9de9897
PT
809 if (!opt_ff)
810 opt_ff = xstrdup_or_null(config_get_ff());
811
81dbd768
PT
812 if (opt_rebase < 0)
813 opt_rebase = config_get_rebase();
814
4a4cf9e8
PT
815 git_config(git_default_config, NULL);
816
817 if (read_cache_unmerged())
818 die_resolve_conflict("Pull");
819
820 if (file_exists(git_path("MERGE_HEAD")))
821 die_conclude_merge();
822
fe911b8c
PT
823 if (get_sha1("HEAD", orig_head))
824 hashclr(orig_head);
825
8944969c 826 if (opt_rebase) {
53c76dc0
KD
827 int autostash = 0;
828
8944969c
PT
829 if (is_null_sha1(orig_head) && !is_cache_unborn())
830 die(_("Updating an unborn branch with changes added to the index."));
831
53c76dc0
KD
832 git_config_get_bool("rebase.autostash", &autostash);
833 if (!autostash)
834 die_on_unclean_work_tree(prefix);
8944969c 835
1678b81e
PT
836 if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
837 hashclr(rebase_fork_point);
8944969c 838 }
1678b81e 839
f2c5baa1
PT
840 if (run_fetch(repo, refspecs))
841 return 1;
842
a32975f5
PT
843 if (opt_dry_run)
844 return 0;
845
fe911b8c
PT
846 if (get_sha1("HEAD", curr_head))
847 hashclr(curr_head);
848
849 if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
850 hashcmp(orig_head, curr_head)) {
851 /*
852 * The fetch involved updating the current branch.
853 *
854 * The working tree and the index file are still based on
855 * orig_head commit, but we are merging into curr_head.
856 * Update the working tree to match curr_head.
857 */
858
859 warning(_("fetch updated the current branch head.\n"
860 "fast-forwarding your working tree from\n"
861 "commit %s."), sha1_to_hex(orig_head));
862
863 if (checkout_fast_forward(orig_head, curr_head, 0))
864 die(_("Cannot fast-forward your working tree.\n"
865 "After making sure that you saved anything precious from\n"
866 "$ git diff %s\n"
867 "output, run\n"
868 "$ git reset --hard\n"
869 "to recover."), sha1_to_hex(orig_head));
870 }
871
44c175c7
PT
872 get_merge_heads(&merge_heads);
873
874 if (!merge_heads.nr)
875 die_no_merge_candidates(repo, refspecs);
876
49ec402d
PT
877 if (is_null_sha1(orig_head)) {
878 if (merge_heads.nr > 1)
879 die(_("Cannot merge multiple branches into empty head."));
880 return pull_into_void(*merge_heads.sha1, curr_head);
1678b81e
PT
881 } else if (opt_rebase) {
882 if (merge_heads.nr > 1)
883 die(_("Cannot rebase onto multiple branches."));
884 return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
49ec402d
PT
885 } else
886 return run_merge();
1e1ea69f 887}