Merge branch 'sw/pull-ipv46-passthru' into maint
[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_squash;
90 static char *opt_commit;
91 static char *opt_edit;
92 static char *opt_ff;
93 static char *opt_verify_signatures;
94 static int opt_autostash = -1;
95 static int config_autostash;
96 static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
97 static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
98 static char *opt_gpg_sign;
99 static int opt_allow_unrelated_histories;
100
101 /* Options passed to git-fetch */
102 static char *opt_all;
103 static char *opt_append;
104 static char *opt_upload_pack;
105 static int opt_force;
106 static char *opt_tags;
107 static char *opt_prune;
108 static char *max_children;
109 static int opt_dry_run;
110 static char *opt_keep;
111 static char *opt_depth;
112 static char *opt_unshallow;
113 static char *opt_update_shallow;
114 static char *opt_refmap;
115 static char *opt_ipv4;
116 static char *opt_ipv6;
117
118 static struct option pull_options[] = {
119 /* Shared options */
120 OPT__VERBOSITY(&opt_verbosity),
121 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
122 N_("force progress reporting"),
123 PARSE_OPT_NOARG),
124 { OPTION_CALLBACK, 0, "recurse-submodules",
125 &recurse_submodules, N_("on-demand"),
126 N_("control for recursive fetching of submodules"),
127 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules },
128
129 /* Options passed to git-merge or git-rebase */
130 OPT_GROUP(N_("Options related to merging")),
131 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
132 "false|true|preserve|interactive",
133 N_("incorporate changes by rebasing rather than merging"),
134 PARSE_OPT_OPTARG, parse_opt_rebase },
135 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
136 N_("do not show a diffstat at the end of the merge"),
137 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
138 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
139 N_("show a diffstat at the end of the merge"),
140 PARSE_OPT_NOARG),
141 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
142 N_("(synonym to --stat)"),
143 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
144 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
145 N_("add (at most <n>) entries from shortlog to merge commit message"),
146 PARSE_OPT_OPTARG),
147 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
148 N_("create a single commit instead of doing a merge"),
149 PARSE_OPT_NOARG),
150 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
151 N_("perform a commit if the merge succeeds (default)"),
152 PARSE_OPT_NOARG),
153 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
154 N_("edit message before committing"),
155 PARSE_OPT_NOARG),
156 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
157 N_("allow fast-forward"),
158 PARSE_OPT_NOARG),
159 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
160 N_("abort if fast-forward is not possible"),
161 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
162 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
163 N_("verify that the named commit has a valid GPG signature"),
164 PARSE_OPT_NOARG),
165 OPT_BOOL(0, "autostash", &opt_autostash,
166 N_("automatically stash/stash pop before and after rebase")),
167 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
168 N_("merge strategy to use"),
169 0),
170 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
171 N_("option=value"),
172 N_("option for selected merge strategy"),
173 0),
174 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
175 N_("GPG sign commit"),
176 PARSE_OPT_OPTARG),
177 OPT_SET_INT(0, "allow-unrelated-histories",
178 &opt_allow_unrelated_histories,
179 N_("allow merging unrelated histories"), 1),
180
181 /* Options passed to git-fetch */
182 OPT_GROUP(N_("Options related to fetching")),
183 OPT_PASSTHRU(0, "all", &opt_all, NULL,
184 N_("fetch from all remotes"),
185 PARSE_OPT_NOARG),
186 OPT_PASSTHRU('a', "append", &opt_append, NULL,
187 N_("append to .git/FETCH_HEAD instead of overwriting"),
188 PARSE_OPT_NOARG),
189 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
190 N_("path to upload pack on remote end"),
191 0),
192 OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
193 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
194 N_("fetch all tags and associated objects"),
195 PARSE_OPT_NOARG),
196 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
197 N_("prune remote-tracking branches no longer on remote"),
198 PARSE_OPT_NOARG),
199 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
200 N_("number of submodules pulled in parallel"),
201 PARSE_OPT_OPTARG),
202 OPT_BOOL(0, "dry-run", &opt_dry_run,
203 N_("dry run")),
204 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
205 N_("keep downloaded pack"),
206 PARSE_OPT_NOARG),
207 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
208 N_("deepen history of shallow clone"),
209 0),
210 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
211 N_("convert to a complete repository"),
212 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
213 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
214 N_("accept refs that update .git/shallow"),
215 PARSE_OPT_NOARG),
216 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
217 N_("specify fetch refmap"),
218 PARSE_OPT_NONEG),
219 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
220 N_("use IPv4 addresses only"),
221 PARSE_OPT_NOARG),
222 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
223 N_("use IPv6 addresses only"),
224 PARSE_OPT_NOARG),
225
226 OPT_END()
227 };
228
229 /**
230 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
231 */
232 static void argv_push_verbosity(struct argv_array *arr)
233 {
234 int verbosity;
235
236 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
237 argv_array_push(arr, "-v");
238
239 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
240 argv_array_push(arr, "-q");
241 }
242
243 /**
244 * Pushes "-f" switches into arr to match the opt_force level.
245 */
246 static void argv_push_force(struct argv_array *arr)
247 {
248 int force = opt_force;
249 while (force-- > 0)
250 argv_array_push(arr, "-f");
251 }
252
253 /**
254 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
255 */
256 static void set_reflog_message(int argc, const char **argv)
257 {
258 int i;
259 struct strbuf msg = STRBUF_INIT;
260
261 for (i = 0; i < argc; i++) {
262 if (i)
263 strbuf_addch(&msg, ' ');
264 strbuf_addstr(&msg, argv[i]);
265 }
266
267 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
268
269 strbuf_release(&msg);
270 }
271
272 /**
273 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
274 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
275 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
276 * error.
277 */
278 static const char *config_get_ff(void)
279 {
280 const char *value;
281
282 if (git_config_get_value("pull.ff", &value))
283 return NULL;
284
285 switch (git_parse_maybe_bool(value)) {
286 case 0:
287 return "--no-ff";
288 case 1:
289 return "--ff";
290 }
291
292 if (!strcmp(value, "only"))
293 return "--ff-only";
294
295 die(_("Invalid value for pull.ff: %s"), value);
296 }
297
298 /**
299 * Returns the default configured value for --rebase. It first looks for the
300 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
301 * branch, and if HEAD is detached or the configuration key does not exist,
302 * looks for the value of "pull.rebase". If both configuration keys do not
303 * exist, returns REBASE_FALSE.
304 */
305 static enum rebase_type config_get_rebase(void)
306 {
307 struct branch *curr_branch = branch_get("HEAD");
308 const char *value;
309
310 if (curr_branch) {
311 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
312
313 if (!git_config_get_value(key, &value)) {
314 enum rebase_type ret = parse_config_rebase(key, value, 1);
315 free(key);
316 return ret;
317 }
318
319 free(key);
320 }
321
322 if (!git_config_get_value("pull.rebase", &value))
323 return parse_config_rebase("pull.rebase", value, 1);
324
325 return REBASE_FALSE;
326 }
327
328 /**
329 * Read config variables.
330 */
331 static int git_pull_config(const char *var, const char *value, void *cb)
332 {
333 if (!strcmp(var, "rebase.autostash")) {
334 config_autostash = git_config_bool(var, value);
335 return 0;
336 } else if (!strcmp(var, "submodule.recurse")) {
337 recurse_submodules = git_config_bool(var, value) ?
338 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
339 return 0;
340 }
341 return git_default_config(var, value, cb);
342 }
343
344 /**
345 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
346 * into merge_heads.
347 */
348 static void get_merge_heads(struct oid_array *merge_heads)
349 {
350 const char *filename = git_path_fetch_head();
351 FILE *fp;
352 struct strbuf sb = STRBUF_INIT;
353 struct object_id oid;
354
355 fp = xfopen(filename, "r");
356 while (strbuf_getline_lf(&sb, fp) != EOF) {
357 if (get_oid_hex(sb.buf, &oid))
358 continue; /* invalid line: does not start with SHA1 */
359 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
360 continue; /* ref is not-for-merge */
361 oid_array_append(merge_heads, &oid);
362 }
363 fclose(fp);
364 strbuf_release(&sb);
365 }
366
367 /**
368 * Used by die_no_merge_candidates() as a for_each_remote() callback to
369 * retrieve the name of the remote if the repository only has one remote.
370 */
371 static int get_only_remote(struct remote *remote, void *cb_data)
372 {
373 const char **remote_name = cb_data;
374
375 if (*remote_name)
376 return -1;
377
378 *remote_name = remote->name;
379 return 0;
380 }
381
382 /**
383 * Dies with the appropriate reason for why there are no merge candidates:
384 *
385 * 1. We fetched from a specific remote, and a refspec was given, but it ended
386 * up not fetching anything. This is usually because the user provided a
387 * wildcard refspec which had no matches on the remote end.
388 *
389 * 2. We fetched from a non-default remote, but didn't specify a branch to
390 * merge. We can't use the configured one because it applies to the default
391 * remote, thus the user must specify the branches to merge.
392 *
393 * 3. We fetched from the branch's or repo's default remote, but:
394 *
395 * a. We are not on a branch, so there will never be a configured branch to
396 * merge with.
397 *
398 * b. We are on a branch, but there is no configured branch to merge with.
399 *
400 * 4. We fetched from the branch's or repo's default remote, but the configured
401 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
402 * part of the configured fetch refspec.)
403 */
404 static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
405 {
406 struct branch *curr_branch = branch_get("HEAD");
407 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
408
409 if (*refspecs) {
410 if (opt_rebase)
411 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
412 else
413 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
414 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
415 "matches on the remote end."));
416 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
417 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
418 "a branch. Because this is not the default configured remote\n"
419 "for your current branch, you must specify a branch on the command line."),
420 repo);
421 } else if (!curr_branch) {
422 fprintf_ln(stderr, _("You are not currently on a branch."));
423 if (opt_rebase)
424 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
425 else
426 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
427 fprintf_ln(stderr, _("See git-pull(1) for details."));
428 fprintf(stderr, "\n");
429 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
430 fprintf(stderr, "\n");
431 } else if (!curr_branch->merge_nr) {
432 const char *remote_name = NULL;
433
434 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
435 remote_name = _("<remote>");
436
437 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
438 if (opt_rebase)
439 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
440 else
441 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
442 fprintf_ln(stderr, _("See git-pull(1) for details."));
443 fprintf(stderr, "\n");
444 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
445 fprintf(stderr, "\n");
446 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
447 fprintf(stderr, "\n");
448 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
449 remote_name, _("<branch>"), curr_branch->name);
450 } else
451 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
452 "from the remote, but no such ref was fetched."),
453 *curr_branch->merge_name);
454 exit(1);
455 }
456
457 /**
458 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
459 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
460 * is not provided in argv, it is set to NULL.
461 */
462 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
463 const char ***refspecs)
464 {
465 if (argc > 0) {
466 *repo = *argv++;
467 argc--;
468 } else
469 *repo = NULL;
470 *refspecs = argv;
471 }
472
473 /**
474 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
475 * repository and refspecs to fetch, or NULL if they are not provided.
476 */
477 static int run_fetch(const char *repo, const char **refspecs)
478 {
479 struct argv_array args = ARGV_ARRAY_INIT;
480 int ret;
481
482 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
483
484 /* Shared options */
485 argv_push_verbosity(&args);
486 if (opt_progress)
487 argv_array_push(&args, opt_progress);
488
489 /* Options passed to git-fetch */
490 if (opt_all)
491 argv_array_push(&args, opt_all);
492 if (opt_append)
493 argv_array_push(&args, opt_append);
494 if (opt_upload_pack)
495 argv_array_push(&args, opt_upload_pack);
496 argv_push_force(&args);
497 if (opt_tags)
498 argv_array_push(&args, opt_tags);
499 if (opt_prune)
500 argv_array_push(&args, opt_prune);
501 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
502 switch (recurse_submodules) {
503 case RECURSE_SUBMODULES_ON:
504 argv_array_push(&args, "--recurse-submodules=on");
505 break;
506 case RECURSE_SUBMODULES_OFF:
507 argv_array_push(&args, "--recurse-submodules=no");
508 break;
509 case RECURSE_SUBMODULES_ON_DEMAND:
510 argv_array_push(&args, "--recurse-submodules=on-demand");
511 break;
512 default:
513 BUG("submodule recursion option not understood");
514 }
515 if (max_children)
516 argv_array_push(&args, max_children);
517 if (opt_dry_run)
518 argv_array_push(&args, "--dry-run");
519 if (opt_keep)
520 argv_array_push(&args, opt_keep);
521 if (opt_depth)
522 argv_array_push(&args, opt_depth);
523 if (opt_unshallow)
524 argv_array_push(&args, opt_unshallow);
525 if (opt_update_shallow)
526 argv_array_push(&args, opt_update_shallow);
527 if (opt_refmap)
528 argv_array_push(&args, opt_refmap);
529 if (opt_ipv4)
530 argv_array_push(&args, opt_ipv4);
531 if (opt_ipv6)
532 argv_array_push(&args, opt_ipv6);
533
534 if (repo) {
535 argv_array_push(&args, repo);
536 argv_array_pushv(&args, refspecs);
537 } else if (*refspecs)
538 die("BUG: refspecs without repo?");
539 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
540 argv_array_clear(&args);
541 return ret;
542 }
543
544 /**
545 * "Pulls into void" by branching off merge_head.
546 */
547 static int pull_into_void(const struct object_id *merge_head,
548 const struct object_id *curr_head)
549 {
550 /*
551 * Two-way merge: we treat the index as based on an empty tree,
552 * and try to fast-forward to HEAD. This ensures we will not lose
553 * index/worktree changes that the user already made on the unborn
554 * branch.
555 */
556 if (checkout_fast_forward(&empty_tree_oid, merge_head, 0))
557 return 1;
558
559 if (update_ref("initial pull", "HEAD", merge_head->hash, curr_head->hash, 0, UPDATE_REFS_DIE_ON_ERR))
560 return 1;
561
562 return 0;
563 }
564
565 static int rebase_submodules(void)
566 {
567 struct child_process cp = CHILD_PROCESS_INIT;
568
569 cp.git_cmd = 1;
570 cp.no_stdin = 1;
571 argv_array_pushl(&cp.args, "submodule", "update",
572 "--recursive", "--rebase", NULL);
573
574 return run_command(&cp);
575 }
576
577 static int update_submodules(void)
578 {
579 struct child_process cp = CHILD_PROCESS_INIT;
580
581 cp.git_cmd = 1;
582 cp.no_stdin = 1;
583 argv_array_pushl(&cp.args, "submodule", "update",
584 "--recursive", "--checkout", NULL);
585
586 return run_command(&cp);
587 }
588
589 /**
590 * Runs git-merge, returning its exit status.
591 */
592 static int run_merge(void)
593 {
594 int ret;
595 struct argv_array args = ARGV_ARRAY_INIT;
596
597 argv_array_pushl(&args, "merge", NULL);
598
599 /* Shared options */
600 argv_push_verbosity(&args);
601 if (opt_progress)
602 argv_array_push(&args, opt_progress);
603
604 /* Options passed to git-merge */
605 if (opt_diffstat)
606 argv_array_push(&args, opt_diffstat);
607 if (opt_log)
608 argv_array_push(&args, opt_log);
609 if (opt_squash)
610 argv_array_push(&args, opt_squash);
611 if (opt_commit)
612 argv_array_push(&args, opt_commit);
613 if (opt_edit)
614 argv_array_push(&args, opt_edit);
615 if (opt_ff)
616 argv_array_push(&args, opt_ff);
617 if (opt_verify_signatures)
618 argv_array_push(&args, opt_verify_signatures);
619 argv_array_pushv(&args, opt_strategies.argv);
620 argv_array_pushv(&args, opt_strategy_opts.argv);
621 if (opt_gpg_sign)
622 argv_array_push(&args, opt_gpg_sign);
623 if (opt_allow_unrelated_histories > 0)
624 argv_array_push(&args, "--allow-unrelated-histories");
625
626 argv_array_push(&args, "FETCH_HEAD");
627 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
628 argv_array_clear(&args);
629 return ret;
630 }
631
632 /**
633 * Returns remote's upstream branch for the current branch. If remote is NULL,
634 * the current branch's configured default remote is used. Returns NULL if
635 * `remote` does not name a valid remote, HEAD does not point to a branch,
636 * remote is not the branch's configured remote or the branch does not have any
637 * configured upstream branch.
638 */
639 static const char *get_upstream_branch(const char *remote)
640 {
641 struct remote *rm;
642 struct branch *curr_branch;
643 const char *curr_branch_remote;
644
645 rm = remote_get(remote);
646 if (!rm)
647 return NULL;
648
649 curr_branch = branch_get("HEAD");
650 if (!curr_branch)
651 return NULL;
652
653 curr_branch_remote = remote_for_branch(curr_branch, NULL);
654 assert(curr_branch_remote);
655
656 if (strcmp(curr_branch_remote, rm->name))
657 return NULL;
658
659 return branch_get_upstream(curr_branch, NULL);
660 }
661
662 /**
663 * Derives the remote tracking branch from the remote and refspec.
664 *
665 * FIXME: The current implementation assumes the default mapping of
666 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
667 */
668 static const char *get_tracking_branch(const char *remote, const char *refspec)
669 {
670 struct refspec *spec;
671 const char *spec_src;
672 const char *merge_branch;
673
674 spec = parse_fetch_refspec(1, &refspec);
675 spec_src = spec->src;
676 if (!*spec_src || !strcmp(spec_src, "HEAD"))
677 spec_src = "HEAD";
678 else if (skip_prefix(spec_src, "heads/", &spec_src))
679 ;
680 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
681 ;
682 else if (starts_with(spec_src, "refs/") ||
683 starts_with(spec_src, "tags/") ||
684 starts_with(spec_src, "remotes/"))
685 spec_src = "";
686
687 if (*spec_src) {
688 if (!strcmp(remote, "."))
689 merge_branch = mkpath("refs/heads/%s", spec_src);
690 else
691 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
692 } else
693 merge_branch = NULL;
694
695 free_refspec(1, spec);
696 return merge_branch;
697 }
698
699 /**
700 * Given the repo and refspecs, sets fork_point to the point at which the
701 * current branch forked from its remote tracking branch. Returns 0 on success,
702 * -1 on failure.
703 */
704 static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
705 const char *refspec)
706 {
707 int ret;
708 struct branch *curr_branch;
709 const char *remote_branch;
710 struct child_process cp = CHILD_PROCESS_INIT;
711 struct strbuf sb = STRBUF_INIT;
712
713 curr_branch = branch_get("HEAD");
714 if (!curr_branch)
715 return -1;
716
717 if (refspec)
718 remote_branch = get_tracking_branch(repo, refspec);
719 else
720 remote_branch = get_upstream_branch(repo);
721
722 if (!remote_branch)
723 return -1;
724
725 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
726 remote_branch, curr_branch->name, NULL);
727 cp.no_stdin = 1;
728 cp.no_stderr = 1;
729 cp.git_cmd = 1;
730
731 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
732 if (ret)
733 goto cleanup;
734
735 ret = get_oid_hex(sb.buf, fork_point);
736 if (ret)
737 goto cleanup;
738
739 cleanup:
740 strbuf_release(&sb);
741 return ret ? -1 : 0;
742 }
743
744 /**
745 * Sets merge_base to the octopus merge base of curr_head, merge_head and
746 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
747 */
748 static int get_octopus_merge_base(struct object_id *merge_base,
749 const struct object_id *curr_head,
750 const struct object_id *merge_head,
751 const struct object_id *fork_point)
752 {
753 struct commit_list *revs = NULL, *result;
754
755 commit_list_insert(lookup_commit_reference(curr_head), &revs);
756 commit_list_insert(lookup_commit_reference(merge_head), &revs);
757 if (!is_null_oid(fork_point))
758 commit_list_insert(lookup_commit_reference(fork_point), &revs);
759
760 result = get_octopus_merge_bases(revs);
761 free_commit_list(revs);
762 reduce_heads_replace(&result);
763
764 if (!result)
765 return 1;
766
767 oidcpy(merge_base, &result->item->object.oid);
768 free_commit_list(result);
769 return 0;
770 }
771
772 /**
773 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
774 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
775 * appropriate arguments and returns its exit status.
776 */
777 static int run_rebase(const struct object_id *curr_head,
778 const struct object_id *merge_head,
779 const struct object_id *fork_point)
780 {
781 int ret;
782 struct object_id oct_merge_base;
783 struct argv_array args = ARGV_ARRAY_INIT;
784
785 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
786 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
787 fork_point = NULL;
788
789 argv_array_push(&args, "rebase");
790
791 /* Shared options */
792 argv_push_verbosity(&args);
793
794 /* Options passed to git-rebase */
795 if (opt_rebase == REBASE_PRESERVE)
796 argv_array_push(&args, "--preserve-merges");
797 else if (opt_rebase == REBASE_INTERACTIVE)
798 argv_array_push(&args, "--interactive");
799 if (opt_diffstat)
800 argv_array_push(&args, opt_diffstat);
801 argv_array_pushv(&args, opt_strategies.argv);
802 argv_array_pushv(&args, opt_strategy_opts.argv);
803 if (opt_gpg_sign)
804 argv_array_push(&args, opt_gpg_sign);
805 if (opt_autostash == 0)
806 argv_array_push(&args, "--no-autostash");
807 else if (opt_autostash == 1)
808 argv_array_push(&args, "--autostash");
809 if (opt_verify_signatures &&
810 !strcmp(opt_verify_signatures, "--verify-signatures"))
811 warning(_("ignoring --verify-signatures for rebase"));
812
813 argv_array_push(&args, "--onto");
814 argv_array_push(&args, oid_to_hex(merge_head));
815
816 if (fork_point && !is_null_oid(fork_point))
817 argv_array_push(&args, oid_to_hex(fork_point));
818 else
819 argv_array_push(&args, oid_to_hex(merge_head));
820
821 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
822 argv_array_clear(&args);
823 return ret;
824 }
825
826 int cmd_pull(int argc, const char **argv, const char *prefix)
827 {
828 const char *repo, **refspecs;
829 struct oid_array merge_heads = OID_ARRAY_INIT;
830 struct object_id orig_head, curr_head;
831 struct object_id rebase_fork_point;
832 int autostash;
833
834 if (!getenv("GIT_REFLOG_ACTION"))
835 set_reflog_message(argc, argv);
836
837 git_config(git_pull_config, NULL);
838
839 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
840
841 parse_repo_refspecs(argc, argv, &repo, &refspecs);
842
843 if (!opt_ff)
844 opt_ff = xstrdup_or_null(config_get_ff());
845
846 if (opt_rebase < 0)
847 opt_rebase = config_get_rebase();
848
849 if (read_cache_unmerged())
850 die_resolve_conflict("pull");
851
852 if (file_exists(git_path_merge_head()))
853 die_conclude_merge();
854
855 if (get_oid("HEAD", &orig_head))
856 oidclr(&orig_head);
857
858 if (!opt_rebase && opt_autostash != -1)
859 die(_("--[no-]autostash option is only valid with --rebase."));
860
861 autostash = config_autostash;
862 if (opt_rebase) {
863 if (opt_autostash != -1)
864 autostash = opt_autostash;
865
866 if (is_null_oid(&orig_head) && !is_cache_unborn())
867 die(_("Updating an unborn branch with changes added to the index."));
868
869 if (!autostash)
870 require_clean_work_tree(N_("pull with rebase"),
871 _("please commit or stash them."), 1, 0);
872
873 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
874 oidclr(&rebase_fork_point);
875 }
876
877 if (run_fetch(repo, refspecs))
878 return 1;
879
880 if (opt_dry_run)
881 return 0;
882
883 if (get_oid("HEAD", &curr_head))
884 oidclr(&curr_head);
885
886 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
887 oidcmp(&orig_head, &curr_head)) {
888 /*
889 * The fetch involved updating the current branch.
890 *
891 * The working tree and the index file are still based on
892 * orig_head commit, but we are merging into curr_head.
893 * Update the working tree to match curr_head.
894 */
895
896 warning(_("fetch updated the current branch head.\n"
897 "fast-forwarding your working tree from\n"
898 "commit %s."), oid_to_hex(&orig_head));
899
900 if (checkout_fast_forward(&orig_head, &curr_head, 0))
901 die(_("Cannot fast-forward your working tree.\n"
902 "After making sure that you saved anything precious from\n"
903 "$ git diff %s\n"
904 "output, run\n"
905 "$ git reset --hard\n"
906 "to recover."), oid_to_hex(&orig_head));
907 }
908
909 get_merge_heads(&merge_heads);
910
911 if (!merge_heads.nr)
912 die_no_merge_candidates(repo, refspecs);
913
914 if (is_null_oid(&orig_head)) {
915 if (merge_heads.nr > 1)
916 die(_("Cannot merge multiple branches into empty head."));
917 return pull_into_void(merge_heads.oid, &curr_head);
918 }
919 if (opt_rebase && merge_heads.nr > 1)
920 die(_("Cannot rebase onto multiple branches."));
921
922 if (opt_rebase) {
923 int ret = 0;
924 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
925 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
926 submodule_touches_in_range(&rebase_fork_point, &curr_head))
927 die(_("cannot rebase with locally recorded submodule modifications"));
928 if (!autostash) {
929 struct commit_list *list = NULL;
930 struct commit *merge_head, *head;
931
932 head = lookup_commit_reference(&orig_head);
933 commit_list_insert(head, &list);
934 merge_head = lookup_commit_reference(&merge_heads.oid[0]);
935 if (is_descendant_of(merge_head, list)) {
936 /* we can fast-forward this without invoking rebase */
937 opt_ff = "--ff-only";
938 ret = run_merge();
939 }
940 }
941 ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
942
943 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
944 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
945 ret = rebase_submodules();
946
947 return ret;
948 } else {
949 int ret = run_merge();
950 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
951 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
952 ret = update_submodules();
953 return ret;
954 }
955 }