freshlybakedca.ke
Git fork
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
9#define USE_THE_REPOSITORY_VARIABLE
10
11#include "builtin.h"
12#include "advice.h"
13#include "config.h"
14#include "environment.h"
15#include "gettext.h"
16#include "hex.h"
17#include "merge.h"
18#include "object-name.h"
19#include "parse-options.h"
20#include "run-command.h"
21#include "oid-array.h"
22#include "remote.h"
23#include "dir.h"
24#include "path.h"
25#include "read-cache-ll.h"
26#include "rebase.h"
27#include "refs.h"
28#include "refspec.h"
29#include "submodule.h"
30#include "submodule-config.h"
31#include "wt-status.h"
32#include "commit-reach.h"
33#include "sequencer.h"
34
35/**
36 * Parses the value of --rebase. If value is a false value, returns
37 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
38 * "merges", returns REBASE_MERGES. If value is a invalid value, dies with
39 * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
40 */
41static enum rebase_type parse_config_rebase(const char *key, const char *value,
42 int fatal)
43{
44 enum rebase_type v = rebase_parse_value(value);
45 if (v != REBASE_INVALID)
46 return v;
47
48 if (fatal)
49 die(_("invalid value for '%s': '%s'"), key, value);
50 else
51 error(_("invalid value for '%s': '%s'"), key, value);
52
53 return REBASE_INVALID;
54}
55
56/**
57 * Callback for --rebase, which parses arg with parse_config_rebase().
58 */
59static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
60{
61 enum rebase_type *value = opt->value;
62
63 if (arg)
64 *value = parse_config_rebase("--rebase", arg, 0);
65 else
66 *value = unset ? REBASE_FALSE : REBASE_TRUE;
67 return *value == REBASE_INVALID ? -1 : 0;
68}
69
70static const char * const pull_usage[] = {
71 N_("git pull [<options>] [<repository> [<refspec>...]]"),
72 NULL
73};
74
75/* Shared options */
76static int opt_verbosity;
77static const char *opt_progress;
78static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
79static int recurse_submodules_cli = RECURSE_SUBMODULES_DEFAULT;
80
81/* Options passed to git-merge or git-rebase */
82static enum rebase_type opt_rebase = -1;
83static const char *opt_diffstat;
84static const char *opt_log;
85static const char *opt_signoff;
86static const char *opt_squash;
87static const char *opt_commit;
88static const char *opt_edit;
89static const char *cleanup_arg;
90static char *opt_ff;
91static const char *opt_verify_signatures;
92static const char *opt_verify;
93static int opt_autostash = -1;
94static int config_rebase_autostash;
95static int config_pull_autostash = -1;
96static int check_trust_level = 1;
97static struct strvec opt_strategies = STRVEC_INIT;
98static struct strvec opt_strategy_opts = STRVEC_INIT;
99static const char *opt_gpg_sign;
100static int opt_allow_unrelated_histories;
101
102/* Options passed to git-fetch */
103static const char *opt_all;
104static const char *opt_append;
105static const char *opt_upload_pack;
106static int opt_force;
107static const char *opt_tags;
108static const char *opt_prune;
109static const char *max_children;
110static int opt_dry_run;
111static const char *opt_keep;
112static const char *opt_depth;
113static const char *opt_unshallow;
114static const char *opt_update_shallow;
115static const char *opt_refmap;
116static const char *opt_ipv4;
117static const char *opt_ipv6;
118static int opt_show_forced_updates = -1;
119static const char *set_upstream;
120static struct strvec opt_fetch = STRVEC_INIT;
121
122static struct option pull_options[] = {
123 /* Shared options */
124 OPT__VERBOSITY(&opt_verbosity),
125 OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
126 N_("force progress reporting"),
127 PARSE_OPT_NOARG),
128 OPT_CALLBACK_F(0, "recurse-submodules",
129 &recurse_submodules_cli, N_("on-demand"),
130 N_("control for recursive fetching of submodules"),
131 PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules),
132
133 /* Options passed to git-merge or git-rebase */
134 OPT_GROUP(N_("Options related to merging")),
135 OPT_CALLBACK_F('r', "rebase", &opt_rebase,
136 "(false|true|merges|interactive)",
137 N_("incorporate changes by rebasing rather than merging"),
138 PARSE_OPT_OPTARG, parse_opt_rebase),
139 OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
140 N_("do not show a diffstat at the end of the merge"),
141 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
142 OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
143 N_("show a diffstat at the end of the merge"),
144 PARSE_OPT_NOARG),
145 OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
146 N_("(synonym to --stat)"),
147 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
148 OPT_PASSTHRU(0, "compact-summary", &opt_diffstat, NULL,
149 N_("show a compact-summary at the end of the merge"),
150 PARSE_OPT_NOARG),
151 OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
152 N_("add (at most <n>) entries from shortlog to merge commit message"),
153 PARSE_OPT_OPTARG),
154 OPT_PASSTHRU(0, "signoff", &opt_signoff, NULL,
155 N_("add a Signed-off-by trailer"),
156 PARSE_OPT_OPTARG),
157 OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
158 N_("create a single commit instead of doing a merge"),
159 PARSE_OPT_NOARG),
160 OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
161 N_("perform a commit if the merge succeeds (default)"),
162 PARSE_OPT_NOARG),
163 OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
164 N_("edit message before committing"),
165 PARSE_OPT_NOARG),
166 OPT_CLEANUP(&cleanup_arg),
167 OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
168 N_("allow fast-forward"),
169 PARSE_OPT_NOARG),
170 OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
171 N_("abort if fast-forward is not possible"),
172 PARSE_OPT_NOARG | PARSE_OPT_NONEG),
173 OPT_PASSTHRU(0, "verify", &opt_verify, NULL,
174 N_("control use of pre-merge-commit and commit-msg hooks"),
175 PARSE_OPT_NOARG),
176 OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
177 N_("verify that the named commit has a valid GPG signature"),
178 PARSE_OPT_NOARG),
179 OPT_BOOL(0, "autostash", &opt_autostash,
180 N_("automatically stash/stash pop before and after")),
181 OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
182 N_("merge strategy to use"),
183 0),
184 OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
185 N_("option=value"),
186 N_("option for selected merge strategy"),
187 0),
188 OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
189 N_("GPG sign commit"),
190 PARSE_OPT_OPTARG),
191 OPT_SET_INT(0, "allow-unrelated-histories",
192 &opt_allow_unrelated_histories,
193 N_("allow merging unrelated histories"), 1),
194
195 /* Options passed to git-fetch */
196 OPT_GROUP(N_("Options related to fetching")),
197 OPT_PASSTHRU(0, "all", &opt_all, NULL,
198 N_("fetch from all remotes"),
199 PARSE_OPT_NOARG),
200 OPT_PASSTHRU('a', "append", &opt_append, NULL,
201 N_("append to .git/FETCH_HEAD instead of overwriting"),
202 PARSE_OPT_NOARG),
203 OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
204 N_("path to upload pack on remote end"),
205 0),
206 OPT__FORCE(&opt_force, N_("force overwrite of local branch"), 0),
207 OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
208 N_("fetch all tags and associated objects"),
209 PARSE_OPT_NOARG),
210 OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
211 N_("prune remote-tracking branches no longer on remote"),
212 PARSE_OPT_NOARG),
213 OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
214 N_("number of submodules pulled in parallel"),
215 PARSE_OPT_OPTARG),
216 OPT_BOOL(0, "dry-run", &opt_dry_run,
217 N_("dry run")),
218 OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
219 N_("keep downloaded pack"),
220 PARSE_OPT_NOARG),
221 OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
222 N_("deepen history of shallow clone"),
223 0),
224 OPT_PASSTHRU_ARGV(0, "shallow-since", &opt_fetch, N_("time"),
225 N_("deepen history of shallow repository based on time"),
226 0),
227 OPT_PASSTHRU_ARGV(0, "shallow-exclude", &opt_fetch, N_("ref"),
228 N_("deepen history of shallow clone, excluding ref"),
229 0),
230 OPT_PASSTHRU_ARGV(0, "deepen", &opt_fetch, N_("n"),
231 N_("deepen history of shallow clone"),
232 0),
233 OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
234 N_("convert to a complete repository"),
235 PARSE_OPT_NONEG | PARSE_OPT_NOARG),
236 OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
237 N_("accept refs that update .git/shallow"),
238 PARSE_OPT_NOARG),
239 OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
240 N_("specify fetch refmap"),
241 PARSE_OPT_NONEG),
242 OPT_PASSTHRU_ARGV('o', "server-option", &opt_fetch,
243 N_("server-specific"),
244 N_("option to transmit"),
245 0),
246 OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL,
247 N_("use IPv4 addresses only"),
248 PARSE_OPT_NOARG),
249 OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL,
250 N_("use IPv6 addresses only"),
251 PARSE_OPT_NOARG),
252 OPT_PASSTHRU_ARGV(0, "negotiation-tip", &opt_fetch, N_("revision"),
253 N_("report that we have only objects reachable from this object"),
254 0),
255 OPT_BOOL(0, "show-forced-updates", &opt_show_forced_updates,
256 N_("check for forced-updates on all updated branches")),
257 OPT_PASSTHRU(0, "set-upstream", &set_upstream, NULL,
258 N_("set upstream for git pull/fetch"),
259 PARSE_OPT_NOARG),
260
261 OPT_END()
262};
263
264/**
265 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
266 */
267static void argv_push_verbosity(struct strvec *arr)
268{
269 int verbosity;
270
271 for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
272 strvec_push(arr, "-v");
273
274 for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
275 strvec_push(arr, "-q");
276}
277
278/**
279 * Pushes "-f" switches into arr to match the opt_force level.
280 */
281static void argv_push_force(struct strvec *arr)
282{
283 int force = opt_force;
284 while (force-- > 0)
285 strvec_push(arr, "-f");
286}
287
288/**
289 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
290 */
291static void set_reflog_message(int argc, const char **argv)
292{
293 int i;
294 struct strbuf msg = STRBUF_INIT;
295
296 for (i = 0; i < argc; i++) {
297 if (i)
298 strbuf_addch(&msg, ' ');
299 strbuf_addstr(&msg, argv[i]);
300 }
301
302 setenv("GIT_REFLOG_ACTION", msg.buf, 0);
303
304 strbuf_release(&msg);
305}
306
307/**
308 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
309 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
310 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
311 * error.
312 */
313static const char *config_get_ff(void)
314{
315 const char *value;
316
317 if (repo_config_get_value(the_repository, "pull.ff", &value))
318 return NULL;
319
320 switch (git_parse_maybe_bool(value)) {
321 case 0:
322 return "--no-ff";
323 case 1:
324 return "--ff";
325 }
326
327 if (!strcmp(value, "only"))
328 return "--ff-only";
329
330 die(_("invalid value for '%s': '%s'"), "pull.ff", value);
331}
332
333/**
334 * Returns the default configured value for --rebase. It first looks for the
335 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
336 * branch, and if HEAD is detached or the configuration key does not exist,
337 * looks for the value of "pull.rebase". If both configuration keys do not
338 * exist, returns REBASE_FALSE.
339 */
340static enum rebase_type config_get_rebase(int *rebase_unspecified)
341{
342 struct branch *curr_branch = branch_get("HEAD");
343 const char *value;
344
345 if (curr_branch) {
346 char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
347
348 if (!repo_config_get_value(the_repository, key, &value)) {
349 enum rebase_type ret = parse_config_rebase(key, value, 1);
350 free(key);
351 return ret;
352 }
353
354 free(key);
355 }
356
357 if (!repo_config_get_value(the_repository, "pull.rebase", &value))
358 return parse_config_rebase("pull.rebase", value, 1);
359
360 *rebase_unspecified = 1;
361
362 return REBASE_FALSE;
363}
364
365/**
366 * Read config variables.
367 */
368static int git_pull_config(const char *var, const char *value,
369 const struct config_context *ctx, void *cb)
370{
371 if (!strcmp(var, "rebase.autostash")) {
372 /*
373 * run_rebase() also reads this option. The reason we handle it here is
374 * that when pull.rebase is true, a fast-forward may occur without
375 * invoking run_rebase(). We need to ensure that autostash is set even
376 * in the fast-forward case.
377 *
378 * run_merge() handles merge.autostash, so we don't handle it here.
379 */
380 config_rebase_autostash = git_config_bool(var, value);
381 return 0;
382 } else if (!strcmp(var, "pull.autostash")) {
383 config_pull_autostash = git_config_bool(var, value);
384 return 0;
385 } else if (!strcmp(var, "submodule.recurse")) {
386 recurse_submodules = git_config_bool(var, value) ?
387 RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
388 return 0;
389 } else if (!strcmp(var, "gpg.mintrustlevel")) {
390 check_trust_level = 0;
391 }
392
393 return git_default_config(var, value, ctx, cb);
394}
395
396/**
397 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
398 * into merge_heads.
399 */
400static void get_merge_heads(struct oid_array *merge_heads)
401{
402 const char *filename = git_path_fetch_head(the_repository);
403 FILE *fp;
404 struct strbuf sb = STRBUF_INIT;
405 struct object_id oid;
406
407 fp = xfopen(filename, "r");
408 while (strbuf_getline_lf(&sb, fp) != EOF) {
409 const char *p;
410 if (parse_oid_hex(sb.buf, &oid, &p))
411 continue; /* invalid line: does not start with object ID */
412 if (starts_with(p, "\tnot-for-merge\t"))
413 continue; /* ref is not-for-merge */
414 oid_array_append(merge_heads, &oid);
415 }
416 fclose(fp);
417 strbuf_release(&sb);
418}
419
420/**
421 * Used by die_no_merge_candidates() as a for_each_remote() callback to
422 * retrieve the name of the remote if the repository only has one remote.
423 */
424static int get_only_remote(struct remote *remote, void *cb_data)
425{
426 const char **remote_name = cb_data;
427
428 if (*remote_name)
429 return -1;
430
431 *remote_name = remote->name;
432 return 0;
433}
434
435/**
436 * Dies with the appropriate reason for why there are no merge candidates:
437 *
438 * 1. We fetched from a specific remote, and a refspec was given, but it ended
439 * up not fetching anything. This is usually because the user provided a
440 * wildcard refspec which had no matches on the remote end.
441 *
442 * 2. We fetched from a non-default remote, but didn't specify a branch to
443 * merge. We can't use the configured one because it applies to the default
444 * remote, thus the user must specify the branches to merge.
445 *
446 * 3. We fetched from the branch's or repo's default remote, but:
447 *
448 * a. We are not on a branch, so there will never be a configured branch to
449 * merge with.
450 *
451 * b. We are on a branch, but there is no configured branch to merge with.
452 *
453 * 4. We fetched from the branch's or repo's default remote, but the configured
454 * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
455 * part of the configured fetch refspec.)
456 */
457static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
458{
459 struct branch *curr_branch = branch_get("HEAD");
460 const char *remote = curr_branch ? curr_branch->remote_name : NULL;
461
462 if (*refspecs) {
463 if (opt_rebase)
464 fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
465 else
466 fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
467 fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
468 "matches on the remote end."));
469 } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
470 fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
471 "a branch. Because this is not the default configured remote\n"
472 "for your current branch, you must specify a branch on the command line."),
473 repo);
474 } else if (!curr_branch) {
475 fprintf_ln(stderr, _("You are not currently on a branch."));
476 if (opt_rebase)
477 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
478 else
479 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
480 fprintf_ln(stderr, _("See git-pull(1) for details."));
481 fprintf(stderr, "\n");
482 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
483 fprintf(stderr, "\n");
484 } else if (!curr_branch->merge_nr) {
485 const char *remote_name = NULL;
486
487 if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
488 remote_name = _("<remote>");
489
490 fprintf_ln(stderr, _("There is no tracking information for the current branch."));
491 if (opt_rebase)
492 fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
493 else
494 fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
495 fprintf_ln(stderr, _("See git-pull(1) for details."));
496 fprintf(stderr, "\n");
497 fprintf_ln(stderr, " git pull %s %s", _("<remote>"), _("<branch>"));
498 fprintf(stderr, "\n");
499 fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
500 fprintf(stderr, "\n");
501 fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n",
502 remote_name, _("<branch>"), curr_branch->name);
503 } else
504 fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
505 "from the remote, but no such ref was fetched."),
506 curr_branch->merge[0]->src);
507 exit(1);
508}
509
510/**
511 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
512 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
513 * is not provided in argv, it is set to NULL.
514 */
515static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
516 const char ***refspecs)
517{
518 if (argc > 0) {
519 *repo = *argv++;
520 argc--;
521 } else
522 *repo = NULL;
523 *refspecs = argv;
524}
525
526/**
527 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
528 * repository and refspecs to fetch, or NULL if they are not provided.
529 */
530static int run_fetch(const char *repo, const char **refspecs)
531{
532 struct child_process cmd = CHILD_PROCESS_INIT;
533
534 strvec_pushl(&cmd.args, "fetch", "--update-head-ok", NULL);
535
536 /* Shared options */
537 argv_push_verbosity(&cmd.args);
538 if (opt_progress)
539 strvec_push(&cmd.args, opt_progress);
540
541 /* Options passed to git-fetch */
542 if (opt_all)
543 strvec_push(&cmd.args, opt_all);
544 if (opt_append)
545 strvec_push(&cmd.args, opt_append);
546 if (opt_upload_pack)
547 strvec_push(&cmd.args, opt_upload_pack);
548 argv_push_force(&cmd.args);
549 if (opt_tags)
550 strvec_push(&cmd.args, opt_tags);
551 if (opt_prune)
552 strvec_push(&cmd.args, opt_prune);
553 if (recurse_submodules_cli != RECURSE_SUBMODULES_DEFAULT)
554 switch (recurse_submodules_cli) {
555 case RECURSE_SUBMODULES_ON:
556 strvec_push(&cmd.args, "--recurse-submodules=on");
557 break;
558 case RECURSE_SUBMODULES_OFF:
559 strvec_push(&cmd.args, "--recurse-submodules=no");
560 break;
561 case RECURSE_SUBMODULES_ON_DEMAND:
562 strvec_push(&cmd.args, "--recurse-submodules=on-demand");
563 break;
564 default:
565 BUG("submodule recursion option not understood");
566 }
567 if (max_children)
568 strvec_push(&cmd.args, max_children);
569 if (opt_dry_run)
570 strvec_push(&cmd.args, "--dry-run");
571 if (opt_keep)
572 strvec_push(&cmd.args, opt_keep);
573 if (opt_depth)
574 strvec_push(&cmd.args, opt_depth);
575 if (opt_unshallow)
576 strvec_push(&cmd.args, opt_unshallow);
577 if (opt_update_shallow)
578 strvec_push(&cmd.args, opt_update_shallow);
579 if (opt_refmap)
580 strvec_push(&cmd.args, opt_refmap);
581 if (opt_ipv4)
582 strvec_push(&cmd.args, opt_ipv4);
583 if (opt_ipv6)
584 strvec_push(&cmd.args, opt_ipv6);
585 if (opt_show_forced_updates > 0)
586 strvec_push(&cmd.args, "--show-forced-updates");
587 else if (opt_show_forced_updates == 0)
588 strvec_push(&cmd.args, "--no-show-forced-updates");
589 if (set_upstream)
590 strvec_push(&cmd.args, set_upstream);
591 strvec_pushv(&cmd.args, opt_fetch.v);
592
593 if (repo) {
594 strvec_push(&cmd.args, repo);
595 strvec_pushv(&cmd.args, refspecs);
596 } else if (*refspecs)
597 BUG("refspecs without repo?");
598 cmd.git_cmd = 1;
599 cmd.close_object_store = 1;
600 return run_command(&cmd);
601}
602
603/**
604 * "Pulls into void" by branching off merge_head.
605 */
606static int pull_into_void(const struct object_id *merge_head,
607 const struct object_id *curr_head)
608{
609 if (opt_verify_signatures) {
610 struct commit *commit;
611
612 commit = lookup_commit(the_repository, merge_head);
613 if (!commit)
614 die(_("unable to access commit %s"),
615 oid_to_hex(merge_head));
616
617 verify_merge_signature(commit, opt_verbosity,
618 check_trust_level);
619 }
620
621 /*
622 * Two-way merge: we treat the index as based on an empty tree,
623 * and try to fast-forward to HEAD. This ensures we will not lose
624 * index/worktree changes that the user already made on the unborn
625 * branch.
626 */
627 if (checkout_fast_forward(the_repository,
628 the_hash_algo->empty_tree,
629 merge_head, 0))
630 return 1;
631
632 if (refs_update_ref(get_main_ref_store(the_repository), "initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
633 return 1;
634
635 return 0;
636}
637
638static int rebase_submodules(void)
639{
640 struct child_process cp = CHILD_PROCESS_INIT;
641
642 cp.git_cmd = 1;
643 cp.no_stdin = 1;
644 strvec_pushl(&cp.args, "submodule", "update",
645 "--recursive", "--rebase", NULL);
646 argv_push_verbosity(&cp.args);
647
648 return run_command(&cp);
649}
650
651static int update_submodules(void)
652{
653 struct child_process cp = CHILD_PROCESS_INIT;
654
655 cp.git_cmd = 1;
656 cp.no_stdin = 1;
657 strvec_pushl(&cp.args, "submodule", "update",
658 "--recursive", "--checkout", NULL);
659 argv_push_verbosity(&cp.args);
660
661 return run_command(&cp);
662}
663
664/**
665 * Runs git-merge, returning its exit status.
666 */
667static int run_merge(void)
668{
669 struct child_process cmd = CHILD_PROCESS_INIT;
670
671 strvec_pushl(&cmd.args, "merge", NULL);
672
673 /* Shared options */
674 argv_push_verbosity(&cmd.args);
675 if (opt_progress)
676 strvec_push(&cmd.args, opt_progress);
677
678 /* Options passed to git-merge */
679 if (opt_diffstat)
680 strvec_push(&cmd.args, opt_diffstat);
681 if (opt_log)
682 strvec_push(&cmd.args, opt_log);
683 if (opt_signoff)
684 strvec_push(&cmd.args, opt_signoff);
685 if (opt_squash)
686 strvec_push(&cmd.args, opt_squash);
687 if (opt_commit)
688 strvec_push(&cmd.args, opt_commit);
689 if (opt_edit)
690 strvec_push(&cmd.args, opt_edit);
691 if (cleanup_arg)
692 strvec_pushf(&cmd.args, "--cleanup=%s", cleanup_arg);
693 if (opt_ff)
694 strvec_push(&cmd.args, opt_ff);
695 if (opt_verify)
696 strvec_push(&cmd.args, opt_verify);
697 if (opt_verify_signatures)
698 strvec_push(&cmd.args, opt_verify_signatures);
699 strvec_pushv(&cmd.args, opt_strategies.v);
700 strvec_pushv(&cmd.args, opt_strategy_opts.v);
701 if (opt_gpg_sign)
702 strvec_push(&cmd.args, opt_gpg_sign);
703 if (opt_autostash == 0)
704 strvec_push(&cmd.args, "--no-autostash");
705 else if (opt_autostash == 1)
706 strvec_push(&cmd.args, "--autostash");
707 if (opt_allow_unrelated_histories > 0)
708 strvec_push(&cmd.args, "--allow-unrelated-histories");
709
710 strvec_push(&cmd.args, "FETCH_HEAD");
711 cmd.git_cmd = 1;
712 return run_command(&cmd);
713}
714
715/**
716 * Returns remote's upstream branch for the current branch. If remote is NULL,
717 * the current branch's configured default remote is used. Returns NULL if
718 * `remote` does not name a valid remote, HEAD does not point to a branch,
719 * remote is not the branch's configured remote or the branch does not have any
720 * configured upstream branch.
721 */
722static const char *get_upstream_branch(const char *remote)
723{
724 struct remote *rm;
725 struct branch *curr_branch;
726 const char *curr_branch_remote;
727
728 rm = remote_get(remote);
729 if (!rm)
730 return NULL;
731
732 curr_branch = branch_get("HEAD");
733 if (!curr_branch)
734 return NULL;
735
736 curr_branch_remote = remote_for_branch(curr_branch, NULL);
737 assert(curr_branch_remote);
738
739 if (strcmp(curr_branch_remote, rm->name))
740 return NULL;
741
742 return branch_get_upstream(curr_branch, NULL);
743}
744
745/**
746 * Derives the remote-tracking branch from the remote and refspec.
747 *
748 * FIXME: The current implementation assumes the default mapping of
749 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
750 */
751static const char *get_tracking_branch(const char *remote, const char *refspec)
752{
753 struct refspec_item spec;
754 const char *spec_src;
755 const char *merge_branch;
756
757 if (!refspec_item_init_fetch(&spec, refspec))
758 die(_("invalid refspec '%s'"), refspec);
759 spec_src = spec.src;
760 if (!*spec_src || !strcmp(spec_src, "HEAD"))
761 spec_src = "HEAD";
762 else if (skip_prefix(spec_src, "heads/", &spec_src))
763 ;
764 else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
765 ;
766 else if (starts_with(spec_src, "refs/") ||
767 starts_with(spec_src, "tags/") ||
768 starts_with(spec_src, "remotes/"))
769 spec_src = "";
770
771 if (*spec_src) {
772 if (!strcmp(remote, "."))
773 merge_branch = mkpath("refs/heads/%s", spec_src);
774 else
775 merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
776 } else
777 merge_branch = NULL;
778
779 refspec_item_clear(&spec);
780 return merge_branch;
781}
782
783/**
784 * Given the repo and refspecs, sets fork_point to the point at which the
785 * current branch forked from its remote-tracking branch. Returns 0 on success,
786 * -1 on failure.
787 */
788static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
789 const char *refspec)
790{
791 int ret;
792 struct branch *curr_branch;
793 const char *remote_branch;
794 struct child_process cp = CHILD_PROCESS_INIT;
795 struct strbuf sb = STRBUF_INIT;
796
797 curr_branch = branch_get("HEAD");
798 if (!curr_branch)
799 return -1;
800
801 if (refspec)
802 remote_branch = get_tracking_branch(repo, refspec);
803 else
804 remote_branch = get_upstream_branch(repo);
805
806 if (!remote_branch)
807 return -1;
808
809 strvec_pushl(&cp.args, "merge-base", "--fork-point",
810 remote_branch, curr_branch->name, NULL);
811 cp.no_stdin = 1;
812 cp.no_stderr = 1;
813 cp.git_cmd = 1;
814
815 ret = capture_command(&cp, &sb, GIT_MAX_HEXSZ);
816 if (ret)
817 goto cleanup;
818
819 ret = get_oid_hex(sb.buf, fork_point);
820 if (ret)
821 goto cleanup;
822
823cleanup:
824 strbuf_release(&sb);
825 return ret ? -1 : 0;
826}
827
828/**
829 * Sets merge_base to the octopus merge base of curr_head, merge_head and
830 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
831 */
832static int get_octopus_merge_base(struct object_id *merge_base,
833 const struct object_id *curr_head,
834 const struct object_id *merge_head,
835 const struct object_id *fork_point)
836{
837 struct commit_list *revs = NULL, *result = NULL;
838
839 commit_list_insert(lookup_commit_reference(the_repository, curr_head),
840 &revs);
841 commit_list_insert(lookup_commit_reference(the_repository, merge_head),
842 &revs);
843 if (!is_null_oid(fork_point))
844 commit_list_insert(lookup_commit_reference(the_repository, fork_point),
845 &revs);
846
847 if (get_octopus_merge_bases(revs, &result) < 0)
848 exit(128);
849 free_commit_list(revs);
850 reduce_heads_replace(&result);
851
852 if (!result)
853 return 1;
854
855 oidcpy(merge_base, &result->item->object.oid);
856 free_commit_list(result);
857 return 0;
858}
859
860/**
861 * Given the current HEAD oid, the merge head returned from git-fetch and the
862 * fork point calculated by get_rebase_fork_point(), compute the <newbase> and
863 * <upstream> arguments to use for the upcoming git-rebase invocation.
864 */
865static int get_rebase_newbase_and_upstream(struct object_id *newbase,
866 struct object_id *upstream,
867 const struct object_id *curr_head,
868 const struct object_id *merge_head,
869 const struct object_id *fork_point)
870{
871 struct object_id oct_merge_base;
872
873 if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
874 if (!is_null_oid(fork_point) && oideq(&oct_merge_base, fork_point))
875 fork_point = NULL;
876
877 if (fork_point && !is_null_oid(fork_point))
878 oidcpy(upstream, fork_point);
879 else
880 oidcpy(upstream, merge_head);
881
882 oidcpy(newbase, merge_head);
883
884 return 0;
885}
886
887/**
888 * Given the <newbase> and <upstream> calculated by
889 * get_rebase_newbase_and_upstream(), runs git-rebase with the
890 * appropriate arguments and returns its exit status.
891 */
892static int run_rebase(const struct object_id *newbase,
893 const struct object_id *upstream)
894{
895 struct child_process cmd = CHILD_PROCESS_INIT;
896
897 strvec_push(&cmd.args, "rebase");
898
899 /* Shared options */
900 argv_push_verbosity(&cmd.args);
901
902 /* Options passed to git-rebase */
903 if (opt_rebase == REBASE_MERGES)
904 strvec_push(&cmd.args, "--rebase-merges");
905 else if (opt_rebase == REBASE_INTERACTIVE)
906 strvec_push(&cmd.args, "--interactive");
907 if (opt_diffstat)
908 strvec_push(&cmd.args, opt_diffstat);
909 strvec_pushv(&cmd.args, opt_strategies.v);
910 strvec_pushv(&cmd.args, opt_strategy_opts.v);
911 if (opt_gpg_sign)
912 strvec_push(&cmd.args, opt_gpg_sign);
913 if (opt_signoff)
914 strvec_push(&cmd.args, opt_signoff);
915 if (opt_autostash == 0)
916 strvec_push(&cmd.args, "--no-autostash");
917 else if (opt_autostash == 1)
918 strvec_push(&cmd.args, "--autostash");
919 if (opt_verify_signatures &&
920 !strcmp(opt_verify_signatures, "--verify-signatures"))
921 warning(_("ignoring --verify-signatures for rebase"));
922
923 strvec_push(&cmd.args, "--onto");
924 strvec_push(&cmd.args, oid_to_hex(newbase));
925
926 strvec_push(&cmd.args, oid_to_hex(upstream));
927
928 cmd.git_cmd = 1;
929 return run_command(&cmd);
930}
931
932static int get_can_ff(struct object_id *orig_head,
933 struct oid_array *merge_heads)
934{
935 int ret;
936 struct commit_list *list = NULL;
937 struct commit *merge_head, *head;
938 struct object_id *orig_merge_head;
939
940 if (merge_heads->nr > 1)
941 return 0;
942
943 orig_merge_head = &merge_heads->oid[0];
944 head = lookup_commit_reference(the_repository, orig_head);
945 commit_list_insert(head, &list);
946 merge_head = lookup_commit_reference(the_repository, orig_merge_head);
947 ret = repo_is_descendant_of(the_repository, merge_head, list);
948 free_commit_list(list);
949 if (ret < 0)
950 exit(128);
951 return ret;
952}
953
954/*
955 * Is orig_head a descendant of _all_ merge_heads?
956 * Unfortunately is_descendant_of() cannot be used as it asks
957 * if orig_head is a descendant of at least one of them.
958 */
959static int already_up_to_date(struct object_id *orig_head,
960 struct oid_array *merge_heads)
961{
962 struct commit *ours;
963
964 ours = lookup_commit_reference(the_repository, orig_head);
965 for (size_t i = 0; i < merge_heads->nr; i++) {
966 struct commit_list *list = NULL;
967 struct commit *theirs;
968 int ok;
969
970 theirs = lookup_commit_reference(the_repository, &merge_heads->oid[i]);
971 commit_list_insert(theirs, &list);
972 ok = repo_is_descendant_of(the_repository, ours, list);
973 free_commit_list(list);
974 if (ok < 0)
975 exit(128);
976 if (!ok)
977 return 0;
978 }
979 return 1;
980}
981
982static void show_advice_pull_non_ff(void)
983{
984 advise(_("You have divergent branches and need to specify how to reconcile them.\n"
985 "You can do so by running one of the following commands sometime before\n"
986 "your next pull:\n"
987 "\n"
988 " git config pull.rebase false # merge\n"
989 " git config pull.rebase true # rebase\n"
990 " git config pull.ff only # fast-forward only\n"
991 "\n"
992 "You can replace \"git config\" with \"git config --global\" to set a default\n"
993 "preference for all repositories. You can also pass --rebase, --no-rebase,\n"
994 "or --ff-only on the command line to override the configured default per\n"
995 "invocation.\n"));
996}
997
998int cmd_pull(int argc,
999 const char **argv,
1000 const char *prefix,
1001 struct repository *repository UNUSED)
1002{
1003 const char *repo, **refspecs;
1004 struct oid_array merge_heads = OID_ARRAY_INIT;
1005 struct object_id orig_head, curr_head;
1006 struct object_id rebase_fork_point;
1007 int rebase_unspecified = 0;
1008 int can_ff;
1009 int divergent;
1010 int ret;
1011
1012 if (!getenv("GIT_REFLOG_ACTION"))
1013 set_reflog_message(argc, argv);
1014
1015 repo_config(the_repository, git_pull_config, NULL);
1016 if (the_repository->gitdir) {
1017 prepare_repo_settings(the_repository);
1018 the_repository->settings.command_requires_full_index = 0;
1019 }
1020
1021 argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
1022 if (opt_autostash == -1)
1023 opt_autostash = config_pull_autostash;
1024
1025 if (recurse_submodules_cli != RECURSE_SUBMODULES_DEFAULT)
1026 recurse_submodules = recurse_submodules_cli;
1027
1028 if (cleanup_arg)
1029 /*
1030 * this only checks the validity of cleanup_arg; we don't need
1031 * a valid value for use_editor
1032 */
1033 get_cleanup_mode(cleanup_arg, 0);
1034
1035 parse_repo_refspecs(argc, argv, &repo, &refspecs);
1036
1037 if (!opt_ff) {
1038 opt_ff = xstrdup_or_null(config_get_ff());
1039 /*
1040 * A subtle point: opt_ff was set on the line above via
1041 * reading from config. opt_rebase, in contrast, is set
1042 * before this point via command line options. The setting
1043 * of opt_rebase via reading from config (using
1044 * config_get_rebase()) does not happen until later. We
1045 * are relying on the next if-condition happening before
1046 * the config_get_rebase() call so that an explicit
1047 * "--rebase" can override a config setting of
1048 * pull.ff=only.
1049 */
1050 if (opt_rebase >= 0 && opt_ff && !strcmp(opt_ff, "--ff-only")) {
1051 free(opt_ff);
1052 opt_ff = xstrdup("--ff");
1053 }
1054 }
1055
1056 if (opt_rebase < 0)
1057 opt_rebase = config_get_rebase(&rebase_unspecified);
1058
1059 if (repo_read_index_unmerged(the_repository))
1060 die_resolve_conflict("pull");
1061
1062 if (file_exists(git_path_merge_head(the_repository)))
1063 die_conclude_merge();
1064
1065 if (repo_get_oid(the_repository, "HEAD", &orig_head))
1066 oidclr(&orig_head, the_repository->hash_algo);
1067
1068 if (opt_rebase) {
1069 if (opt_autostash == -1)
1070 opt_autostash = config_rebase_autostash;
1071
1072 if (is_null_oid(&orig_head) && !is_index_unborn(the_repository->index))
1073 die(_("Updating an unborn branch with changes added to the index."));
1074
1075 if (!opt_autostash)
1076 require_clean_work_tree(the_repository,
1077 N_("pull with rebase"),
1078 _("Please commit or stash them."), 1, 0);
1079
1080 if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
1081 oidclr(&rebase_fork_point, the_repository->hash_algo);
1082 }
1083
1084 if (run_fetch(repo, refspecs))
1085 return 1;
1086
1087 if (opt_dry_run)
1088 return 0;
1089
1090 if (repo_get_oid(the_repository, "HEAD", &curr_head))
1091 oidclr(&curr_head, the_repository->hash_algo);
1092
1093 if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
1094 !oideq(&orig_head, &curr_head)) {
1095 /*
1096 * The fetch involved updating the current branch.
1097 *
1098 * The working tree and the index file are still based on
1099 * orig_head commit, but we are merging into curr_head.
1100 * Update the working tree to match curr_head.
1101 */
1102
1103 warning(_("fetch updated the current branch head.\n"
1104 "fast-forwarding your working tree from\n"
1105 "commit %s."), oid_to_hex(&orig_head));
1106
1107 if (checkout_fast_forward(the_repository, &orig_head,
1108 &curr_head, 0))
1109 die(_("Cannot fast-forward your working tree.\n"
1110 "After making sure that you saved anything precious from\n"
1111 "$ git diff %s\n"
1112 "output, run\n"
1113 "$ git reset --hard\n"
1114 "to recover."), oid_to_hex(&orig_head));
1115 }
1116
1117 get_merge_heads(&merge_heads);
1118
1119 if (!merge_heads.nr)
1120 die_no_merge_candidates(repo, refspecs);
1121
1122 if (is_null_oid(&orig_head)) {
1123 if (merge_heads.nr > 1)
1124 die(_("Cannot merge multiple branches into empty head."));
1125 ret = pull_into_void(merge_heads.oid, &curr_head);
1126 goto cleanup;
1127 }
1128 if (merge_heads.nr > 1) {
1129 if (opt_rebase)
1130 die(_("Cannot rebase onto multiple branches."));
1131 if (opt_ff && !strcmp(opt_ff, "--ff-only"))
1132 die(_("Cannot fast-forward to multiple branches."));
1133 }
1134
1135 can_ff = get_can_ff(&orig_head, &merge_heads);
1136 divergent = !can_ff && !already_up_to_date(&orig_head, &merge_heads);
1137
1138 /* ff-only takes precedence over rebase */
1139 if (opt_ff && !strcmp(opt_ff, "--ff-only")) {
1140 if (divergent)
1141 die_ff_impossible();
1142 opt_rebase = REBASE_FALSE;
1143 }
1144 /* If no action specified and we can't fast forward, then warn. */
1145 if (!opt_ff && rebase_unspecified && divergent) {
1146 show_advice_pull_non_ff();
1147 die(_("Need to specify how to reconcile divergent branches."));
1148 }
1149
1150 if (opt_rebase) {
1151 struct object_id newbase;
1152 struct object_id upstream;
1153 get_rebase_newbase_and_upstream(&newbase, &upstream, &curr_head,
1154 merge_heads.oid, &rebase_fork_point);
1155
1156 if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
1157 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
1158 submodule_touches_in_range(the_repository, &upstream, &curr_head))
1159 die(_("cannot rebase with locally recorded submodule modifications"));
1160
1161 if (can_ff) {
1162 /* we can fast-forward this without invoking rebase */
1163 free(opt_ff);
1164 opt_ff = xstrdup("--ff-only");
1165 ret = run_merge();
1166 } else {
1167 ret = run_rebase(&newbase, &upstream);
1168 }
1169
1170 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
1171 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
1172 ret = rebase_submodules();
1173
1174 goto cleanup;
1175 } else {
1176 ret = run_merge();
1177 if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
1178 recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
1179 ret = update_submodules();
1180 goto cleanup;
1181 }
1182
1183cleanup:
1184 oid_array_clear(&merge_heads);
1185 return ret;
1186}