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