pull: pass -4/-6 option to 'git fetch'
[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"
fd84986f 20#include "wt-status.h"
1e1ea69f 21
1678b81e
PT
22enum rebase_type {
23 REBASE_INVALID = -1,
24 REBASE_FALSE = 0,
25 REBASE_TRUE,
f5eb87b9
JS
26 REBASE_PRESERVE,
27 REBASE_INTERACTIVE
1678b81e
PT
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 */
36static 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;
f5eb87b9
JS
47 else if (!strcmp(value, "interactive"))
48 return REBASE_INTERACTIVE;
1678b81e
PT
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 */
61static 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
1e1ea69f 72static const char * const pull_usage[] = {
e7a7401f 73 N_("git pull [<options>] [<repository> [<refspec>...]]"),
1e1ea69f
PT
74 NULL
75};
76
2a747902
PT
77/* Shared options */
78static int opt_verbosity;
79static char *opt_progress;
80
1678b81e 81/* Options passed to git-merge or git-rebase */
81dbd768 82static enum rebase_type opt_rebase = -1;
11b6d178
PT
83static char *opt_diffstat;
84static char *opt_log;
85static char *opt_squash;
86static char *opt_commit;
87static char *opt_edit;
88static char *opt_ff;
89static char *opt_verify_signatures;
f66398eb 90static int opt_autostash = -1;
c48d73bd 91static int config_autostash;
11b6d178
PT
92static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
93static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
94static char *opt_gpg_sign;
09c2cb87 95static int opt_allow_unrelated_histories;
11b6d178 96
a32975f5
PT
97/* Options passed to git-fetch */
98static char *opt_all;
99static char *opt_append;
100static char *opt_upload_pack;
101static int opt_force;
102static char *opt_tags;
103static char *opt_prune;
104static char *opt_recurse_submodules;
62104ba1 105static char *max_children;
a32975f5
PT
106static int opt_dry_run;
107static char *opt_keep;
108static char *opt_depth;
109static char *opt_unshallow;
110static char *opt_update_shallow;
111static char *opt_refmap;
ffb4568a
WS
112static char *opt_ipv4;
113static char *opt_ipv6;
a32975f5 114
1e1ea69f 115static struct option pull_options[] = {
2a747902
PT
116 /* Shared options */
117 OPT__VERBOSITY(&opt_verbosity),
118 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
119 N_("force progress reporting"),
120 PARSE_OPT_NOARG),
121
1678b81e 122 /* Options passed to git-merge or git-rebase */
11b6d178 123 OPT_GROUP(N_("Options related to merging")),
1678b81e 124 { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
f5eb87b9 125 "false|true|preserve|interactive",
1678b81e
PT
126 N_("incorporate changes by rebasing rather than merging"),
127 PARSE_OPT_OPTARG, parse_opt_rebase },
11b6d178
PT
128 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
129 N_("do not show a diffstat at the end of the merge"),
130 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
131 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
132 N_("show a diffstat at the end of the merge"),
133 PARSE_OPT_NOARG),
134 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
135 N_("(synonym to --stat)"),
136 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
137 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
138 N_("add (at most <n>) entries from shortlog to merge commit message"),
139 PARSE_OPT_OPTARG),
140 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
141 N_("create a single commit instead of doing a merge"),
142 PARSE_OPT_NOARG),
143 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
144 N_("perform a commit if the merge succeeds (default)"),
145 PARSE_OPT_NOARG),
146 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
147 N_("edit message before committing"),
148 PARSE_OPT_NOARG),
149 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
150 N_("allow fast-forward"),
151 PARSE_OPT_NOARG),
152 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
153 N_("abort if fast-forward is not possible"),
154 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
155 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
156 N_("verify that the named commit has a valid GPG signature"),
157 PARSE_OPT_NOARG),
f66398eb
MJ
158 OPT_BOOL(0, "autostash", &opt_autostash,
159 N_("automatically stash/stash pop before and after rebase")),
11b6d178
PT
160 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
161 N_("merge strategy to use"),
162 0),
163 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
164 N_("option=value"),
165 N_("option for selected merge strategy"),
166 0),
167 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
168 N_("GPG sign commit"),
169 PARSE_OPT_OPTARG),
09c2cb87
JH
170 OPT_SET_INT(0, "allow-unrelated-histories",
171 &opt_allow_unrelated_histories,
172 N_("allow merging unrelated histories"), 1),
11b6d178 173
a32975f5
PT
174 /* Options passed to git-fetch */
175 OPT_GROUP(N_("Options related to fetching")),
176 OPT_PASSTHRU(0, "all", &opt_all, NULL,
177 N_("fetch from all remotes"),
178 PARSE_OPT_NOARG),
179 OPT_PASSTHRU('a', "append", &opt_append, NULL,
180 N_("append to .git/FETCH_HEAD instead of overwriting"),
181 PARSE_OPT_NOARG),
182 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
183 N_("path to upload pack on remote end"),
184 0),
185 OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
186 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
187 N_("fetch all tags and associated objects"),
188 PARSE_OPT_NOARG),
189 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
190 N_("prune remote-tracking branches no longer on remote"),
191 PARSE_OPT_NOARG),
192 OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules,
193 N_("on-demand"),
194 N_("control recursive fetching of submodules"),
195 PARSE_OPT_OPTARG),
62104ba1
SB
196 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
197 N_("number of submodules pulled in parallel"),
198 PARSE_OPT_OPTARG),
a32975f5
PT
199 OPT_BOOL(0, "dry-run", &opt_dry_run,
200 N_("dry run")),
201 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
202 N_("keep downloaded pack"),
203 PARSE_OPT_NOARG),
204 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
205 N_("deepen history of shallow clone"),
206 0),
207 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
208 N_("convert to a complete repository"),
209 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
210 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
211 N_("accept refs that update .git/shallow"),
212 PARSE_OPT_NOARG),
213 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
214 N_("specify fetch refmap"),
215 PARSE_OPT_NONEG),
ffb4568a
WS
216 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
217 N_("use IPv4 addresses only"),
218 PARSE_OPT_NOARG),
219 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
220 N_("use IPv6 addresses only"),
221 PARSE_OPT_NOARG),
a32975f5 222
1e1ea69f
PT
223 OPT_END()
224};
225
2a747902
PT
226/**
227 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
228 */
229static void argv_push_verbosity(struct argv_array *arr)
230{
231 int verbosity;
232
233 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
234 argv_array_push(arr, "-v");
235
236 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
237 argv_array_push(arr, "-q");
238}
239
a32975f5
PT
240/**
241 * Pushes "-f" switches into arr to match the opt_force level.
242 */
243static void argv_push_force(struct argv_array *arr)
244{
245 int force = opt_force;
246 while (force-- > 0)
247 argv_array_push(arr, "-f");
248}
249
41fca098
PT
250/**
251 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
252 */
253static void set_reflog_message(int argc, const char **argv)
254{
255 int i;
256 struct strbuf msg = STRBUF_INIT;
257
258 for (i = 0; i < argc; i++) {
259 if (i)
260 strbuf_addch(&msg, ' ');
261 strbuf_addstr(&msg, argv[i]);
262 }
263
264 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
265
266 strbuf_release(&msg);
267}
268
a9de9897
PT
269/**
270 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
271 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
272 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
273 * error.
274 */
275static const char *config_get_ff(void)
276{
277 const char *value;
278
279 if (git_config_get_value("pull.ff", &value))
280 return NULL;
281
282 switch (git_config_maybe_bool("pull.ff", value)) {
283 case 0:
284 return "--no-ff";
285 case 1:
286 return "--ff";
287 }
288
289 if (!strcmp(value, "only"))
290 return "--ff-only";
291
292 die(_("Invalid value for pull.ff: %s"), value);
293}
294
81dbd768
PT
295/**
296 * Returns the default configured value for --rebase. It first looks for the
297 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
298 * branch, and if HEAD is detached or the configuration key does not exist,
299 * looks for the value of "pull.rebase". If both configuration keys do not
300 * exist, returns REBASE_FALSE.
301 */
302static enum rebase_type config_get_rebase(void)
303{
304 struct branch *curr_branch = branch_get("HEAD");
305 const char *value;
306
307 if (curr_branch) {
308 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
309
310 if (!git_config_get_value(key, &value)) {
311 enum rebase_type ret = parse_config_rebase(key, value, 1);
312 free(key);
313 return ret;
314 }
315
316 free(key);
317 }
318
319 if (!git_config_get_value("pull.rebase", &value))
320 return parse_config_rebase("pull.rebase", value, 1);
321
322 return REBASE_FALSE;
323}
324
c48d73bd
MJ
325/**
326 * Read config variables.
327 */
328static int git_pull_config(const char *var, const char *value, void *cb)
329{
330 if (!strcmp(var, "rebase.autostash")) {
331 config_autostash = git_config_bool(var, value);
332 return 0;
333 }
334 return git_default_config(var, value, cb);
335}
336
44c175c7
PT
337/**
338 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
339 * into merge_heads.
340 */
910650d2 341static void get_merge_heads(struct oid_array *merge_heads)
44c175c7 342{
ca03e067 343 const char *filename = git_path_fetch_head();
44c175c7
PT
344 FILE *fp;
345 struct strbuf sb = STRBUF_INIT;
14bb40b3 346 struct object_id oid;
44c175c7
PT
347
348 if (!(fp = fopen(filename, "r")))
349 die_errno(_("could not open '%s' for reading"), filename);
8f309aeb 350 while (strbuf_getline_lf(&sb, fp) != EOF) {
14bb40b3 351 if (get_oid_hex(sb.buf, &oid))
44c175c7
PT
352 continue; /* invalid line: does not start with SHA1 */
353 if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
354 continue; /* ref is not-for-merge */
910650d2 355 oid_array_append(merge_heads, &oid);
44c175c7
PT
356 }
357 fclose(fp);
358 strbuf_release(&sb);
359}
360
361/**
362 * Used by die_no_merge_candidates() as a for_each_remote() callback to
363 * retrieve the name of the remote if the repository only has one remote.
364 */
365static int get_only_remote(struct remote *remote, void *cb_data)
366{
367 const char **remote_name = cb_data;
368
369 if (*remote_name)
370 return -1;
371
372 *remote_name = remote->name;
373 return 0;
374}
375
376/**
377 * Dies with the appropriate reason for why there are no merge candidates:
378 *
379 * 1. We fetched from a specific remote, and a refspec was given, but it ended
380 * up not fetching anything. This is usually because the user provided a
381 * wildcard refspec which had no matches on the remote end.
382 *
383 * 2. We fetched from a non-default remote, but didn't specify a branch to
384 * merge. We can't use the configured one because it applies to the default
385 * remote, thus the user must specify the branches to merge.
386 *
387 * 3. We fetched from the branch's or repo's default remote, but:
388 *
389 * a. We are not on a branch, so there will never be a configured branch to
390 * merge with.
391 *
392 * b. We are on a branch, but there is no configured branch to merge with.
393 *
394 * 4. We fetched from the branch's or repo's default remote, but the configured
395 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
396 * part of the configured fetch refspec.)
397 */
398static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
399{
400 struct branch *curr_branch = branch_get("HEAD");
401 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
402
403 if (*refspecs) {
b7b31471
PT
404 if (opt_rebase)
405 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
406 else
407 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
44c175c7
PT
408 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
409 "matches on the remote end."));
410 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
411 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
412 "a branch. Because this is not the default configured remote\n"
413 "for your current branch, you must specify a branch on the command line."),
414 repo);
415 } else if (!curr_branch) {
416 fprintf_ln(stderr, _("You are not currently on a branch."));
b7b31471
PT
417 if (opt_rebase)
418 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
419 else
420 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
44c175c7
PT
421 fprintf_ln(stderr, _("See git-pull(1) for details."));
422 fprintf(stderr, "\n");
8a0de58a 423 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
44c175c7
PT
424 fprintf(stderr, "\n");
425 } else if (!curr_branch->merge_nr) {
426 const char *remote_name = NULL;
427
428 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
8a0de58a 429 remote_name = _("<remote>");
44c175c7
PT
430
431 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
b7b31471
PT
432 if (opt_rebase)
433 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
434 else
435 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
44c175c7
PT
436 fprintf_ln(stderr, _("See git-pull(1) for details."));
437 fprintf(stderr, "\n");
8a0de58a 438 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
44c175c7 439 fprintf(stderr, "\n");
daf9f649
VA
440 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
441 fprintf(stderr, "\n");
442 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
443 remote_name, _("<branch>"), curr_branch->name);
44c175c7
PT
444 } else
445 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
446 "from the remote, but no such ref was fetched."),
447 *curr_branch->merge_name);
448 exit(1);
449}
450
f2c5baa1
PT
451/**
452 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
453 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
454 * is not provided in argv, it is set to NULL.
455 */
456static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
457 const char ***refspecs)
458{
459 if (argc > 0) {
460 *repo = *argv++;
461 argc--;
462 } else
463 *repo = NULL;
464 *refspecs = argv;
465}
466
467/**
468 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
469 * repository and refspecs to fetch, or NULL if they are not provided.
470 */
471static int run_fetch(const char *repo, const char **refspecs)
472{
473 struct argv_array args = ARGV_ARRAY_INIT;
474 int ret;
475
476 argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
2a747902
PT
477
478 /* Shared options */
479 argv_push_verbosity(&args);
480 if (opt_progress)
481 argv_array_push(&args, opt_progress);
482
a32975f5
PT
483 /* Options passed to git-fetch */
484 if (opt_all)
485 argv_array_push(&args, opt_all);
486 if (opt_append)
487 argv_array_push(&args, opt_append);
488 if (opt_upload_pack)
489 argv_array_push(&args, opt_upload_pack);
490 argv_push_force(&args);
491 if (opt_tags)
492 argv_array_push(&args, opt_tags);
493 if (opt_prune)
494 argv_array_push(&args, opt_prune);
495 if (opt_recurse_submodules)
496 argv_array_push(&args, opt_recurse_submodules);
62104ba1
SB
497 if (max_children)
498 argv_array_push(&args, max_children);
a32975f5
PT
499 if (opt_dry_run)
500 argv_array_push(&args, "--dry-run");
501 if (opt_keep)
502 argv_array_push(&args, opt_keep);
503 if (opt_depth)
504 argv_array_push(&args, opt_depth);
505 if (opt_unshallow)
506 argv_array_push(&args, opt_unshallow);
507 if (opt_update_shallow)
508 argv_array_push(&args, opt_update_shallow);
509 if (opt_refmap)
510 argv_array_push(&args, opt_refmap);
ffb4568a
WS
511 if (opt_ipv4)
512 argv_array_push(&args, opt_ipv4);
513 if (opt_ipv6)
514 argv_array_push(&args, opt_ipv6);
a32975f5 515
f2c5baa1
PT
516 if (repo) {
517 argv_array_push(&args, repo);
518 argv_array_pushv(&args, refspecs);
519 } else if (*refspecs)
520 die("BUG: refspecs without repo?");
521 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
522 argv_array_clear(&args);
523 return ret;
524}
525
49ec402d
PT
526/**
527 * "Pulls into void" by branching off merge_head.
528 */
ee3051bd 529static int pull_into_void(const struct object_id *merge_head,
f9b11147 530 const struct object_id *curr_head)
49ec402d
PT
531{
532 /*
533 * Two-way merge: we treat the index as based on an empty tree,
534 * and try to fast-forward to HEAD. This ensures we will not lose
535 * index/worktree changes that the user already made on the unborn
536 * branch.
537 */
ee3051bd 538 if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head->hash, 0))
49ec402d
PT
539 return 1;
540
ee3051bd 541 if (update_ref("initial pull", "HEAD", merge_head->hash, curr_head->hash, 0, UPDATE_REFS_DIE_ON_ERR))
49ec402d
PT
542 return 1;
543
544 return 0;
545}
546
f2c5baa1
PT
547/**
548 * Runs git-merge, returning its exit status.
549 */
550static int run_merge(void)
551{
552 int ret;
553 struct argv_array args = ARGV_ARRAY_INIT;
554
555 argv_array_pushl(&args, "merge", NULL);
2a747902
PT
556
557 /* Shared options */
558 argv_push_verbosity(&args);
559 if (opt_progress)
560 argv_array_push(&args, opt_progress);
561
11b6d178
PT
562 /* Options passed to git-merge */
563 if (opt_diffstat)
564 argv_array_push(&args, opt_diffstat);
565 if (opt_log)
566 argv_array_push(&args, opt_log);
567 if (opt_squash)
568 argv_array_push(&args, opt_squash);
569 if (opt_commit)
570 argv_array_push(&args, opt_commit);
571 if (opt_edit)
572 argv_array_push(&args, opt_edit);
573 if (opt_ff)
574 argv_array_push(&args, opt_ff);
575 if (opt_verify_signatures)
576 argv_array_push(&args, opt_verify_signatures);
577 argv_array_pushv(&args, opt_strategies.argv);
578 argv_array_pushv(&args, opt_strategy_opts.argv);
579 if (opt_gpg_sign)
580 argv_array_push(&args, opt_gpg_sign);
09c2cb87
JH
581 if (opt_allow_unrelated_histories > 0)
582 argv_array_push(&args, "--allow-unrelated-histories");
11b6d178 583
f2c5baa1
PT
584 argv_array_push(&args, "FETCH_HEAD");
585 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
586 argv_array_clear(&args);
587 return ret;
588}
589
1678b81e
PT
590/**
591 * Returns remote's upstream branch for the current branch. If remote is NULL,
592 * the current branch's configured default remote is used. Returns NULL if
593 * `remote` does not name a valid remote, HEAD does not point to a branch,
594 * remote is not the branch's configured remote or the branch does not have any
595 * configured upstream branch.
596 */
597static const char *get_upstream_branch(const char *remote)
598{
599 struct remote *rm;
600 struct branch *curr_branch;
601 const char *curr_branch_remote;
602
603 rm = remote_get(remote);
604 if (!rm)
605 return NULL;
606
607 curr_branch = branch_get("HEAD");
608 if (!curr_branch)
609 return NULL;
610
611 curr_branch_remote = remote_for_branch(curr_branch, NULL);
612 assert(curr_branch_remote);
613
614 if (strcmp(curr_branch_remote, rm->name))
615 return NULL;
616
617 return branch_get_upstream(curr_branch, NULL);
618}
619
620/**
621 * Derives the remote tracking branch from the remote and refspec.
622 *
623 * FIXME: The current implementation assumes the default mapping of
624 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
625 */
626static const char *get_tracking_branch(const char *remote, const char *refspec)
627{
628 struct refspec *spec;
629 const char *spec_src;
630 const char *merge_branch;
631
632 spec = parse_fetch_refspec(1, &refspec);
633 spec_src = spec->src;
634 if (!*spec_src || !strcmp(spec_src, "HEAD"))
635 spec_src = "HEAD";
636 else if (skip_prefix(spec_src, "heads/", &spec_src))
637 ;
638 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
639 ;
640 else if (starts_with(spec_src, "refs/") ||
641 starts_with(spec_src, "tags/") ||
642 starts_with(spec_src, "remotes/"))
643 spec_src = "";
644
645 if (*spec_src) {
646 if (!strcmp(remote, "."))
647 merge_branch = mkpath("refs/heads/%s", spec_src);
648 else
649 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
650 } else
651 merge_branch = NULL;
652
653 free_refspec(1, spec);
654 return merge_branch;
655}
656
657/**
658 * Given the repo and refspecs, sets fork_point to the point at which the
659 * current branch forked from its remote tracking branch. Returns 0 on success,
660 * -1 on failure.
661 */
f9b11147 662static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
1678b81e
PT
663 const char *refspec)
664{
665 int ret;
666 struct branch *curr_branch;
667 const char *remote_branch;
668 struct child_process cp = CHILD_PROCESS_INIT;
669 struct strbuf sb = STRBUF_INIT;
670
671 curr_branch = branch_get("HEAD");
672 if (!curr_branch)
673 return -1;
674
675 if (refspec)
676 remote_branch = get_tracking_branch(repo, refspec);
677 else
678 remote_branch = get_upstream_branch(repo);
679
680 if (!remote_branch)
681 return -1;
682
683 argv_array_pushl(&cp.args, "merge-base", "--fork-point",
684 remote_branch, curr_branch->name, NULL);
685 cp.no_stdin = 1;
686 cp.no_stderr = 1;
687 cp.git_cmd = 1;
688
689 ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
690 if (ret)
691 goto cleanup;
692
f9b11147 693 ret = get_oid_hex(sb.buf, fork_point);
1678b81e
PT
694 if (ret)
695 goto cleanup;
696
697cleanup:
698 strbuf_release(&sb);
699 return ret ? -1 : 0;
700}
701
702/**
703 * Sets merge_base to the octopus merge base of curr_head, merge_head and
704 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
705 */
f9b11147 706static int get_octopus_merge_base(struct object_id *merge_base,
707 const struct object_id *curr_head,
ee3051bd 708 const struct object_id *merge_head,
f9b11147 709 const struct object_id *fork_point)
1678b81e
PT
710{
711 struct commit_list *revs = NULL, *result;
712
f9b11147 713 commit_list_insert(lookup_commit_reference(curr_head->hash), &revs);
ee3051bd 714 commit_list_insert(lookup_commit_reference(merge_head->hash), &revs);
f9b11147 715 if (!is_null_oid(fork_point))
716 commit_list_insert(lookup_commit_reference(fork_point->hash), &revs);
1678b81e
PT
717
718 result = reduce_heads(get_octopus_merge_bases(revs));
719 free_commit_list(revs);
720 if (!result)
721 return 1;
722
f9b11147 723 oidcpy(merge_base, &result->item->object.oid);
1678b81e
PT
724 return 0;
725}
726
727/**
728 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
729 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
730 * appropriate arguments and returns its exit status.
731 */
f9b11147 732static int run_rebase(const struct object_id *curr_head,
ee3051bd 733 const struct object_id *merge_head,
f9b11147 734 const struct object_id *fork_point)
1678b81e
PT
735{
736 int ret;
f9b11147 737 struct object_id oct_merge_base;
1678b81e
PT
738 struct argv_array args = ARGV_ARRAY_INIT;
739
f9b11147 740 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
741 if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
1678b81e
PT
742 fork_point = NULL;
743
744 argv_array_push(&args, "rebase");
745
746 /* Shared options */
747 argv_push_verbosity(&args);
748
749 /* Options passed to git-rebase */
750 if (opt_rebase == REBASE_PRESERVE)
751 argv_array_push(&args, "--preserve-merges");
f5eb87b9
JS
752 else if (opt_rebase == REBASE_INTERACTIVE)
753 argv_array_push(&args, "--interactive");
1678b81e
PT
754 if (opt_diffstat)
755 argv_array_push(&args, opt_diffstat);
756 argv_array_pushv(&args, opt_strategies.argv);
757 argv_array_pushv(&args, opt_strategy_opts.argv);
758 if (opt_gpg_sign)
759 argv_array_push(&args, opt_gpg_sign);
f66398eb
MJ
760 if (opt_autostash == 0)
761 argv_array_push(&args, "--no-autostash");
762 else if (opt_autostash == 1)
763 argv_array_push(&args, "--autostash");
c57e501c
AH
764 if (opt_verify_signatures &&
765 !strcmp(opt_verify_signatures, "--verify-signatures"))
766 warning(_("ignoring --verify-signatures for rebase"));
1678b81e
PT
767
768 argv_array_push(&args, "--onto");
ee3051bd 769 argv_array_push(&args, oid_to_hex(merge_head));
1678b81e 770
f9b11147 771 if (fork_point && !is_null_oid(fork_point))
772 argv_array_push(&args, oid_to_hex(fork_point));
1678b81e 773 else
ee3051bd 774 argv_array_push(&args, oid_to_hex(merge_head));
1678b81e
PT
775
776 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
777 argv_array_clear(&args);
778 return ret;
779}
780
1e1ea69f
PT
781int cmd_pull(int argc, const char **argv, const char *prefix)
782{
f2c5baa1 783 const char *repo, **refspecs;
910650d2 784 struct oid_array merge_heads = OID_ARRAY_INIT;
f9b11147 785 struct object_id orig_head, curr_head;
786 struct object_id rebase_fork_point;
f15e7cf5 787 int autostash;
f2c5baa1 788
41fca098
PT
789 if (!getenv("GIT_REFLOG_ACTION"))
790 set_reflog_message(argc, argv);
791
1e1ea69f
PT
792 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
793
f2c5baa1
PT
794 parse_repo_refspecs(argc, argv, &repo, &refspecs);
795
a9de9897
PT
796 if (!opt_ff)
797 opt_ff = xstrdup_or_null(config_get_ff());
798
81dbd768
PT
799 if (opt_rebase < 0)
800 opt_rebase = config_get_rebase();
801
c48d73bd 802 git_config(git_pull_config, NULL);
4a4cf9e8
PT
803
804 if (read_cache_unmerged())
8785c425 805 die_resolve_conflict("pull");
4a4cf9e8 806
ca03e067 807 if (file_exists(git_path_merge_head()))
4a4cf9e8
PT
808 die_conclude_merge();
809
f9b11147 810 if (get_oid("HEAD", &orig_head))
811 oidclr(&orig_head);
fe911b8c 812
f66398eb
MJ
813 if (!opt_rebase && opt_autostash != -1)
814 die(_("--[no-]autostash option is only valid with --rebase."));
815
f15e7cf5 816 autostash = config_autostash;
8944969c 817 if (opt_rebase) {
f66398eb
MJ
818 if (opt_autostash != -1)
819 autostash = opt_autostash;
53c76dc0 820
f9b11147 821 if (is_null_oid(&orig_head) && !is_cache_unborn())
8944969c
PT
822 die(_("Updating an unborn branch with changes added to the index."));
823
53c76dc0 824 if (!autostash)
ea63b393 825 require_clean_work_tree(N_("pull with rebase"),
d8cc92ab 826 _("please commit or stash them."), 1, 0);
8944969c 827
f9b11147 828 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
829 oidclr(&rebase_fork_point);
8944969c 830 }
1678b81e 831
f2c5baa1
PT
832 if (run_fetch(repo, refspecs))
833 return 1;
834
a32975f5
PT
835 if (opt_dry_run)
836 return 0;
837
f9b11147 838 if (get_oid("HEAD", &curr_head))
839 oidclr(&curr_head);
fe911b8c 840
f9b11147 841 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
842 oidcmp(&orig_head, &curr_head)) {
fe911b8c
PT
843 /*
844 * The fetch involved updating the current branch.
845 *
846 * The working tree and the index file are still based on
847 * orig_head commit, but we are merging into curr_head.
848 * Update the working tree to match curr_head.
849 */
850
851 warning(_("fetch updated the current branch head.\n"
852 "fast-forwarding your working tree from\n"
f9b11147 853 "commit %s."), oid_to_hex(&orig_head));
fe911b8c 854
f9b11147 855 if (checkout_fast_forward(orig_head.hash, curr_head.hash, 0))
fe911b8c
PT
856 die(_("Cannot fast-forward your working tree.\n"
857 "After making sure that you saved anything precious from\n"
858 "$ git diff %s\n"
859 "output, run\n"
860 "$ git reset --hard\n"
f9b11147 861 "to recover."), oid_to_hex(&orig_head));
fe911b8c
PT
862 }
863
44c175c7
PT
864 get_merge_heads(&merge_heads);
865
866 if (!merge_heads.nr)
867 die_no_merge_candidates(repo, refspecs);
868
f9b11147 869 if (is_null_oid(&orig_head)) {
49ec402d
PT
870 if (merge_heads.nr > 1)
871 die(_("Cannot merge multiple branches into empty head."));
ee3051bd 872 return pull_into_void(merge_heads.oid, &curr_head);
33b842a1
JH
873 }
874 if (opt_rebase && merge_heads.nr > 1)
875 die(_("Cannot rebase onto multiple branches."));
876
877 if (opt_rebase) {
f15e7cf5
TB
878 if (!autostash) {
879 struct commit_list *list = NULL;
880 struct commit *merge_head, *head;
881
882 head = lookup_commit_reference(orig_head.hash);
883 commit_list_insert(head, &list);
884 merge_head = lookup_commit_reference(merge_heads.oid[0].hash);
885 if (is_descendant_of(merge_head, list)) {
886 /* we can fast-forward this without invoking rebase */
887 opt_ff = "--ff-only";
888 return run_merge();
889 }
33b842a1 890 }
ee3051bd 891 return run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
33b842a1 892 } else {
49ec402d 893 return run_merge();
33b842a1 894 }
1e1ea69f 895}