Merge branch 'ls/no-double-utf8-author-name' of ../git-gui into ls/git-gui-no-double...
[git] / submodule.c
1 #include "cache.h"
2 #include "repository.h"
3 #include "config.h"
4 #include "submodule-config.h"
5 #include "submodule.h"
6 #include "dir.h"
7 #include "diff.h"
8 #include "commit.h"
9 #include "revision.h"
10 #include "run-command.h"
11 #include "diffcore.h"
12 #include "refs.h"
13 #include "string-list.h"
14 #include "sha1-array.h"
15 #include "argv-array.h"
16 #include "blob.h"
17 #include "thread-utils.h"
18 #include "quote.h"
19 #include "remote.h"
20 #include "worktree.h"
21 #include "parse-options.h"
22
23 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
24 static struct string_list changed_submodule_names = STRING_LIST_INIT_DUP;
25 static int initialized_fetch_ref_tips;
26 static struct oid_array ref_tips_before_fetch;
27 static struct oid_array ref_tips_after_fetch;
28
29 /*
30  * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
31  * will be disabled because we can't guess what might be configured in
32  * .gitmodules unless the user resolves the conflict.
33  */
34 int is_gitmodules_unmerged(const struct index_state *istate)
35 {
36         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
37         if (pos < 0) { /* .gitmodules not found or isn't merged */
38                 pos = -1 - pos;
39                 if (istate->cache_nr > pos) {  /* there is a .gitmodules */
40                         const struct cache_entry *ce = istate->cache[pos];
41                         if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
42                             !strcmp(ce->name, GITMODULES_FILE))
43                                 return 1;
44                 }
45         }
46
47         return 0;
48 }
49
50 /*
51  * Check if the .gitmodules file has unstaged modifications.  This must be
52  * checked before allowing modifications to the .gitmodules file with the
53  * intention to stage them later, because when continuing we would stage the
54  * modifications the user didn't stage herself too. That might change in a
55  * future version when we learn to stage the changes we do ourselves without
56  * staging any previous modifications.
57  */
58 int is_staging_gitmodules_ok(const struct index_state *istate)
59 {
60         int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
61
62         if ((pos >= 0) && (pos < istate->cache_nr)) {
63                 struct stat st;
64                 if (lstat(GITMODULES_FILE, &st) == 0 &&
65                     ce_match_stat(istate->cache[pos], &st, CE_MATCH_IGNORE_FSMONITOR) & DATA_CHANGED)
66                         return 0;
67         }
68
69         return 1;
70 }
71
72 static int for_each_remote_ref_submodule(const char *submodule,
73                                          each_ref_fn fn, void *cb_data)
74 {
75         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
76                                         fn, cb_data);
77 }
78
79 /*
80  * Try to update the "path" entry in the "submodule.<name>" section of the
81  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
82  * with the correct path=<oldpath> setting was found and we could update it.
83  */
84 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
85 {
86         struct strbuf entry = STRBUF_INIT;
87         const struct submodule *submodule;
88
89         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
90                 return -1;
91
92         if (is_gitmodules_unmerged(&the_index))
93                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
94
95         submodule = submodule_from_path(&null_oid, oldpath);
96         if (!submodule || !submodule->name) {
97                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
98                 return -1;
99         }
100         strbuf_addstr(&entry, "submodule.");
101         strbuf_addstr(&entry, submodule->name);
102         strbuf_addstr(&entry, ".path");
103         if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
104                 /* Maybe the user already did that, don't error out here */
105                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
106                 strbuf_release(&entry);
107                 return -1;
108         }
109         strbuf_release(&entry);
110         return 0;
111 }
112
113 /*
114  * Try to remove the "submodule.<name>" section from .gitmodules where the given
115  * path is configured. Return 0 only if a .gitmodules file was found, a section
116  * with the correct path=<path> setting was found and we could remove it.
117  */
118 int remove_path_from_gitmodules(const char *path)
119 {
120         struct strbuf sect = STRBUF_INIT;
121         const struct submodule *submodule;
122
123         if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
124                 return -1;
125
126         if (is_gitmodules_unmerged(&the_index))
127                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
128
129         submodule = submodule_from_path(&null_oid, path);
130         if (!submodule || !submodule->name) {
131                 warning(_("Could not find section in .gitmodules where path=%s"), path);
132                 return -1;
133         }
134         strbuf_addstr(&sect, "submodule.");
135         strbuf_addstr(&sect, submodule->name);
136         if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
137                 /* Maybe the user already did that, don't error out here */
138                 warning(_("Could not remove .gitmodules entry for %s"), path);
139                 strbuf_release(&sect);
140                 return -1;
141         }
142         strbuf_release(&sect);
143         return 0;
144 }
145
146 void stage_updated_gitmodules(void)
147 {
148         if (add_file_to_cache(GITMODULES_FILE, 0))
149                 die(_("staging updated .gitmodules failed"));
150 }
151
152 static int add_submodule_odb(const char *path)
153 {
154         struct strbuf objects_directory = STRBUF_INIT;
155         int ret = 0;
156
157         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
158         if (ret)
159                 goto done;
160         if (!is_directory(objects_directory.buf)) {
161                 ret = -1;
162                 goto done;
163         }
164         add_to_alternates_memory(objects_directory.buf);
165 done:
166         strbuf_release(&objects_directory);
167         return ret;
168 }
169
170 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
171                                              const char *path)
172 {
173         const struct submodule *submodule = submodule_from_path(&null_oid, path);
174         if (submodule) {
175                 const char *ignore;
176                 char *key;
177
178                 key = xstrfmt("submodule.%s.ignore", submodule->name);
179                 if (repo_config_get_string_const(the_repository, key, &ignore))
180                         ignore = submodule->ignore;
181                 free(key);
182
183                 if (ignore)
184                         handle_ignore_submodules_arg(diffopt, ignore);
185                 else if (is_gitmodules_unmerged(&the_index))
186                         diffopt->flags.ignore_submodules = 1;
187         }
188 }
189
190 /* Cheap function that only determines if we're interested in submodules at all */
191 int git_default_submodule_config(const char *var, const char *value, void *cb)
192 {
193         if (!strcmp(var, "submodule.recurse")) {
194                 int v = git_config_bool(var, value) ?
195                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
196                 config_update_recurse_submodules = v;
197         }
198         return 0;
199 }
200
201 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
202                                                      const char *arg, int unset)
203 {
204         if (unset) {
205                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
206                 return 0;
207         }
208         if (arg)
209                 config_update_recurse_submodules =
210                         parse_update_recurse_submodules_arg(opt->long_name,
211                                                             arg);
212         else
213                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
214
215         return 0;
216 }
217
218 /*
219  * Determine if a submodule has been initialized at a given 'path'
220  */
221 int is_submodule_active(struct repository *repo, const char *path)
222 {
223         int ret = 0;
224         char *key = NULL;
225         char *value = NULL;
226         const struct string_list *sl;
227         const struct submodule *module;
228
229         module = submodule_from_cache(repo, &null_oid, path);
230
231         /* early return if there isn't a path->module mapping */
232         if (!module)
233                 return 0;
234
235         /* submodule.<name>.active is set */
236         key = xstrfmt("submodule.%s.active", module->name);
237         if (!repo_config_get_bool(repo, key, &ret)) {
238                 free(key);
239                 return ret;
240         }
241         free(key);
242
243         /* submodule.active is set */
244         sl = repo_config_get_value_multi(repo, "submodule.active");
245         if (sl) {
246                 struct pathspec ps;
247                 struct argv_array args = ARGV_ARRAY_INIT;
248                 const struct string_list_item *item;
249
250                 for_each_string_list_item(item, sl) {
251                         argv_array_push(&args, item->string);
252                 }
253
254                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
255                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
256
257                 argv_array_clear(&args);
258                 clear_pathspec(&ps);
259                 return ret;
260         }
261
262         /* fallback to checking if the URL is set */
263         key = xstrfmt("submodule.%s.url", module->name);
264         ret = !repo_config_get_string(repo, key, &value);
265
266         free(value);
267         free(key);
268         return ret;
269 }
270
271 int is_submodule_populated_gently(const char *path, int *return_error_code)
272 {
273         int ret = 0;
274         char *gitdir = xstrfmt("%s/.git", path);
275
276         if (resolve_gitdir_gently(gitdir, return_error_code))
277                 ret = 1;
278
279         free(gitdir);
280         return ret;
281 }
282
283 /*
284  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
285  */
286 void die_in_unpopulated_submodule(const struct index_state *istate,
287                                   const char *prefix)
288 {
289         int i, prefixlen;
290
291         if (!prefix)
292                 return;
293
294         prefixlen = strlen(prefix);
295
296         for (i = 0; i < istate->cache_nr; i++) {
297                 struct cache_entry *ce = istate->cache[i];
298                 int ce_len = ce_namelen(ce);
299
300                 if (!S_ISGITLINK(ce->ce_mode))
301                         continue;
302                 if (prefixlen <= ce_len)
303                         continue;
304                 if (strncmp(ce->name, prefix, ce_len))
305                         continue;
306                 if (prefix[ce_len] != '/')
307                         continue;
308
309                 die(_("in unpopulated submodule '%s'"), ce->name);
310         }
311 }
312
313 /*
314  * Dies if any paths in the provided pathspec descends into a submodule
315  */
316 void die_path_inside_submodule(const struct index_state *istate,
317                                const struct pathspec *ps)
318 {
319         int i, j;
320
321         for (i = 0; i < istate->cache_nr; i++) {
322                 struct cache_entry *ce = istate->cache[i];
323                 int ce_len = ce_namelen(ce);
324
325                 if (!S_ISGITLINK(ce->ce_mode))
326                         continue;
327
328                 for (j = 0; j < ps->nr ; j++) {
329                         const struct pathspec_item *item = &ps->items[j];
330
331                         if (item->len <= ce_len)
332                                 continue;
333                         if (item->match[ce_len] != '/')
334                                 continue;
335                         if (strncmp(ce->name, item->match, ce_len))
336                                 continue;
337                         if (item->len == ce_len + 1)
338                                 continue;
339
340                         die(_("Pathspec '%s' is in submodule '%.*s'"),
341                             item->original, ce_len, ce->name);
342                 }
343         }
344 }
345
346 enum submodule_update_type parse_submodule_update_type(const char *value)
347 {
348         if (!strcmp(value, "none"))
349                 return SM_UPDATE_NONE;
350         else if (!strcmp(value, "checkout"))
351                 return SM_UPDATE_CHECKOUT;
352         else if (!strcmp(value, "rebase"))
353                 return SM_UPDATE_REBASE;
354         else if (!strcmp(value, "merge"))
355                 return SM_UPDATE_MERGE;
356         else if (*value == '!')
357                 return SM_UPDATE_COMMAND;
358         else
359                 return SM_UPDATE_UNSPECIFIED;
360 }
361
362 int parse_submodule_update_strategy(const char *value,
363                 struct submodule_update_strategy *dst)
364 {
365         enum submodule_update_type type;
366
367         free((void*)dst->command);
368         dst->command = NULL;
369
370         type = parse_submodule_update_type(value);
371         if (type == SM_UPDATE_UNSPECIFIED)
372                 return -1;
373
374         dst->type = type;
375         if (type == SM_UPDATE_COMMAND)
376                 dst->command = xstrdup(value + 1);
377
378         return 0;
379 }
380
381 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
382 {
383         struct strbuf sb = STRBUF_INIT;
384         switch (s->type) {
385         case SM_UPDATE_CHECKOUT:
386                 return "checkout";
387         case SM_UPDATE_MERGE:
388                 return "merge";
389         case SM_UPDATE_REBASE:
390                 return "rebase";
391         case SM_UPDATE_NONE:
392                 return "none";
393         case SM_UPDATE_UNSPECIFIED:
394                 return NULL;
395         case SM_UPDATE_COMMAND:
396                 strbuf_addf(&sb, "!%s", s->command);
397                 return strbuf_detach(&sb, NULL);
398         }
399         return NULL;
400 }
401
402 void handle_ignore_submodules_arg(struct diff_options *diffopt,
403                                   const char *arg)
404 {
405         diffopt->flags.ignore_submodules = 0;
406         diffopt->flags.ignore_untracked_in_submodules = 0;
407         diffopt->flags.ignore_dirty_submodules = 0;
408
409         if (!strcmp(arg, "all"))
410                 diffopt->flags.ignore_submodules = 1;
411         else if (!strcmp(arg, "untracked"))
412                 diffopt->flags.ignore_untracked_in_submodules = 1;
413         else if (!strcmp(arg, "dirty"))
414                 diffopt->flags.ignore_dirty_submodules = 1;
415         else if (strcmp(arg, "none"))
416                 die("bad --ignore-submodules argument: %s", arg);
417 }
418
419 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
420                 struct commit *left, struct commit *right,
421                 struct commit_list *merge_bases)
422 {
423         struct commit_list *list;
424
425         init_revisions(rev, NULL);
426         setup_revisions(0, NULL, rev, NULL);
427         rev->left_right = 1;
428         rev->first_parent_only = 1;
429         left->object.flags |= SYMMETRIC_LEFT;
430         add_pending_object(rev, &left->object, path);
431         add_pending_object(rev, &right->object, path);
432         for (list = merge_bases; list; list = list->next) {
433                 list->item->object.flags |= UNINTERESTING;
434                 add_pending_object(rev, &list->item->object,
435                         oid_to_hex(&list->item->object.oid));
436         }
437         return prepare_revision_walk(rev);
438 }
439
440 static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
441 {
442         static const char format[] = "  %m %s";
443         struct strbuf sb = STRBUF_INIT;
444         struct commit *commit;
445
446         while ((commit = get_revision(rev))) {
447                 struct pretty_print_context ctx = {0};
448                 ctx.date_mode = rev->date_mode;
449                 ctx.output_encoding = get_log_output_encoding();
450                 strbuf_setlen(&sb, 0);
451                 format_commit_message(commit, format, &sb, &ctx);
452                 strbuf_addch(&sb, '\n');
453                 if (commit->object.flags & SYMMETRIC_LEFT)
454                         diff_emit_submodule_del(o, sb.buf);
455                 else
456                         diff_emit_submodule_add(o, sb.buf);
457         }
458         strbuf_release(&sb);
459 }
460
461 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
462 {
463         const char * const *var;
464
465         for (var = local_repo_env; *var; var++) {
466                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
467                         argv_array_push(out, *var);
468         }
469 }
470
471 void prepare_submodule_repo_env(struct argv_array *out)
472 {
473         prepare_submodule_repo_env_no_git_dir(out);
474         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
475                          DEFAULT_GIT_DIR_ENVIRONMENT);
476 }
477
478 /* Helper function to display the submodule header line prior to the full
479  * summary output. If it can locate the submodule objects directory it will
480  * attempt to lookup both the left and right commits and put them into the
481  * left and right pointers.
482  */
483 static void show_submodule_header(struct diff_options *o, const char *path,
484                 struct object_id *one, struct object_id *two,
485                 unsigned dirty_submodule,
486                 struct commit **left, struct commit **right,
487                 struct commit_list **merge_bases)
488 {
489         const char *message = NULL;
490         struct strbuf sb = STRBUF_INIT;
491         int fast_forward = 0, fast_backward = 0;
492
493         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
494                 diff_emit_submodule_untracked(o, path);
495
496         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
497                 diff_emit_submodule_modified(o, path);
498
499         if (is_null_oid(one))
500                 message = "(new submodule)";
501         else if (is_null_oid(two))
502                 message = "(submodule deleted)";
503
504         if (add_submodule_odb(path)) {
505                 if (!message)
506                         message = "(commits not present)";
507                 goto output_header;
508         }
509
510         /*
511          * Attempt to lookup the commit references, and determine if this is
512          * a fast forward or fast backwards update.
513          */
514         *left = lookup_commit_reference(one);
515         *right = lookup_commit_reference(two);
516
517         /*
518          * Warn about missing commits in the submodule project, but only if
519          * they aren't null.
520          */
521         if ((!is_null_oid(one) && !*left) ||
522              (!is_null_oid(two) && !*right))
523                 message = "(commits not present)";
524
525         *merge_bases = get_merge_bases(*left, *right);
526         if (*merge_bases) {
527                 if ((*merge_bases)->item == *left)
528                         fast_forward = 1;
529                 else if ((*merge_bases)->item == *right)
530                         fast_backward = 1;
531         }
532
533         if (!oidcmp(one, two)) {
534                 strbuf_release(&sb);
535                 return;
536         }
537
538 output_header:
539         strbuf_addf(&sb, "Submodule %s ", path);
540         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
541         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
542         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
543         if (message)
544                 strbuf_addf(&sb, " %s\n", message);
545         else
546                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
547         diff_emit_submodule_header(o, sb.buf);
548
549         strbuf_release(&sb);
550 }
551
552 void show_submodule_summary(struct diff_options *o, const char *path,
553                 struct object_id *one, struct object_id *two,
554                 unsigned dirty_submodule)
555 {
556         struct rev_info rev;
557         struct commit *left = NULL, *right = NULL;
558         struct commit_list *merge_bases = NULL;
559
560         show_submodule_header(o, path, one, two, dirty_submodule,
561                               &left, &right, &merge_bases);
562
563         /*
564          * If we don't have both a left and a right pointer, there is no
565          * reason to try and display a summary. The header line should contain
566          * all the information the user needs.
567          */
568         if (!left || !right)
569                 goto out;
570
571         /* Treat revision walker failure the same as missing commits */
572         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
573                 diff_emit_submodule_error(o, "(revision walker failed)\n");
574                 goto out;
575         }
576
577         print_submodule_summary(&rev, o);
578
579 out:
580         if (merge_bases)
581                 free_commit_list(merge_bases);
582         clear_commit_marks(left, ~0);
583         clear_commit_marks(right, ~0);
584 }
585
586 void show_submodule_inline_diff(struct diff_options *o, const char *path,
587                 struct object_id *one, struct object_id *two,
588                 unsigned dirty_submodule)
589 {
590         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
591         struct commit *left = NULL, *right = NULL;
592         struct commit_list *merge_bases = NULL;
593         struct child_process cp = CHILD_PROCESS_INIT;
594         struct strbuf sb = STRBUF_INIT;
595
596         show_submodule_header(o, path, one, two, dirty_submodule,
597                               &left, &right, &merge_bases);
598
599         /* We need a valid left and right commit to display a difference */
600         if (!(left || is_null_oid(one)) ||
601             !(right || is_null_oid(two)))
602                 goto done;
603
604         if (left)
605                 old = one;
606         if (right)
607                 new = two;
608
609         cp.git_cmd = 1;
610         cp.dir = path;
611         cp.out = -1;
612         cp.no_stdin = 1;
613
614         /* TODO: other options may need to be passed here. */
615         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
616         argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
617                          "always" : "never");
618
619         if (o->flags.reverse_diff) {
620                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
621                                  o->b_prefix, path);
622                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
623                                  o->a_prefix, path);
624         } else {
625                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
626                                  o->a_prefix, path);
627                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
628                                  o->b_prefix, path);
629         }
630         argv_array_push(&cp.args, oid_to_hex(old));
631         /*
632          * If the submodule has modified content, we will diff against the
633          * work tree, under the assumption that the user has asked for the
634          * diff format and wishes to actually see all differences even if they
635          * haven't yet been committed to the submodule yet.
636          */
637         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
638                 argv_array_push(&cp.args, oid_to_hex(new));
639
640         prepare_submodule_repo_env(&cp.env_array);
641         if (start_command(&cp))
642                 diff_emit_submodule_error(o, "(diff failed)\n");
643
644         while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
645                 diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
646
647         if (finish_command(&cp))
648                 diff_emit_submodule_error(o, "(diff failed)\n");
649
650 done:
651         strbuf_release(&sb);
652         if (merge_bases)
653                 free_commit_list(merge_bases);
654         if (left)
655                 clear_commit_marks(left, ~0);
656         if (right)
657                 clear_commit_marks(right, ~0);
658 }
659
660 int should_update_submodules(void)
661 {
662         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
663 }
664
665 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
666 {
667         if (!S_ISGITLINK(ce->ce_mode))
668                 return NULL;
669
670         if (!should_update_submodules())
671                 return NULL;
672
673         return submodule_from_path(&null_oid, ce->name);
674 }
675
676 static struct oid_array *submodule_commits(struct string_list *submodules,
677                                            const char *name)
678 {
679         struct string_list_item *item;
680
681         item = string_list_insert(submodules, name);
682         if (item->util)
683                 return (struct oid_array *) item->util;
684
685         /* NEEDSWORK: should we have oid_array_init()? */
686         item->util = xcalloc(1, sizeof(struct oid_array));
687         return (struct oid_array *) item->util;
688 }
689
690 struct collect_changed_submodules_cb_data {
691         struct string_list *changed;
692         const struct object_id *commit_oid;
693 };
694
695 /*
696  * this would normally be two functions: default_name_from_path() and
697  * path_from_default_name(). Since the default name is the same as
698  * the submodule path we can get away with just one function which only
699  * checks whether there is a submodule in the working directory at that
700  * location.
701  */
702 static const char *default_name_or_path(const char *path_or_name)
703 {
704         int error_code;
705
706         if (!is_submodule_populated_gently(path_or_name, &error_code))
707                 return NULL;
708
709         return path_or_name;
710 }
711
712 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
713                                           struct diff_options *options,
714                                           void *data)
715 {
716         struct collect_changed_submodules_cb_data *me = data;
717         struct string_list *changed = me->changed;
718         const struct object_id *commit_oid = me->commit_oid;
719         int i;
720
721         for (i = 0; i < q->nr; i++) {
722                 struct diff_filepair *p = q->queue[i];
723                 struct oid_array *commits;
724                 const struct submodule *submodule;
725                 const char *name;
726
727                 if (!S_ISGITLINK(p->two->mode))
728                         continue;
729
730                 submodule = submodule_from_path(commit_oid, p->two->path);
731                 if (submodule)
732                         name = submodule->name;
733                 else {
734                         name = default_name_or_path(p->two->path);
735                         /* make sure name does not collide with existing one */
736                         submodule = submodule_from_name(commit_oid, name);
737                         if (submodule) {
738                                 warning("Submodule in commit %s at path: "
739                                         "'%s' collides with a submodule named "
740                                         "the same. Skipping it.",
741                                         oid_to_hex(commit_oid), name);
742                                 name = NULL;
743                         }
744                 }
745
746                 if (!name)
747                         continue;
748
749                 commits = submodule_commits(changed, name);
750                 oid_array_append(commits, &p->two->oid);
751         }
752 }
753
754 /*
755  * Collect the paths of submodules in 'changed' which have changed based on
756  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
757  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
758  * what the submodule pointers were updated to during the change.
759  */
760 static void collect_changed_submodules(struct string_list *changed,
761                                        struct argv_array *argv)
762 {
763         struct rev_info rev;
764         const struct commit *commit;
765
766         init_revisions(&rev, NULL);
767         setup_revisions(argv->argc, argv->argv, &rev, NULL);
768         if (prepare_revision_walk(&rev))
769                 die("revision walk setup failed");
770
771         while ((commit = get_revision(&rev))) {
772                 struct rev_info diff_rev;
773                 struct collect_changed_submodules_cb_data data;
774                 data.changed = changed;
775                 data.commit_oid = &commit->object.oid;
776
777                 init_revisions(&diff_rev, NULL);
778                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
779                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
780                 diff_rev.diffopt.format_callback_data = &data;
781                 diff_tree_combined_merge(commit, 1, &diff_rev);
782         }
783
784         reset_revision_walk();
785 }
786
787 static void free_submodules_oids(struct string_list *submodules)
788 {
789         struct string_list_item *item;
790         for_each_string_list_item(item, submodules)
791                 oid_array_clear((struct oid_array *) item->util);
792         string_list_clear(submodules, 1);
793 }
794
795 static int has_remote(const char *refname, const struct object_id *oid,
796                       int flags, void *cb_data)
797 {
798         return 1;
799 }
800
801 static int append_oid_to_argv(const struct object_id *oid, void *data)
802 {
803         struct argv_array *argv = data;
804         argv_array_push(argv, oid_to_hex(oid));
805         return 0;
806 }
807
808 struct has_commit_data {
809         int result;
810         const char *path;
811 };
812
813 static int check_has_commit(const struct object_id *oid, void *data)
814 {
815         struct has_commit_data *cb = data;
816
817         enum object_type type = sha1_object_info(oid->hash, NULL);
818
819         switch (type) {
820         case OBJ_COMMIT:
821                 return 0;
822         case OBJ_BAD:
823                 /*
824                  * Object is missing or invalid. If invalid, an error message
825                  * has already been printed.
826                  */
827                 cb->result = 0;
828                 return 0;
829         default:
830                 die(_("submodule entry '%s' (%s) is a %s, not a commit"),
831                     cb->path, oid_to_hex(oid), typename(type));
832         }
833 }
834
835 static int submodule_has_commits(const char *path, struct oid_array *commits)
836 {
837         struct has_commit_data has_commit = { 1, path };
838
839         /*
840          * Perform a cheap, but incorrect check for the existence of 'commits'.
841          * This is done by adding the submodule's object store to the in-core
842          * object store, and then querying for each commit's existence.  If we
843          * do not have the commit object anywhere, there is no chance we have
844          * it in the object store of the correct submodule and have it
845          * reachable from a ref, so we can fail early without spawning rev-list
846          * which is expensive.
847          */
848         if (add_submodule_odb(path))
849                 return 0;
850
851         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
852
853         if (has_commit.result) {
854                 /*
855                  * Even if the submodule is checked out and the commit is
856                  * present, make sure it exists in the submodule's object store
857                  * and that it is reachable from a ref.
858                  */
859                 struct child_process cp = CHILD_PROCESS_INIT;
860                 struct strbuf out = STRBUF_INIT;
861
862                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
863                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
864                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
865
866                 prepare_submodule_repo_env(&cp.env_array);
867                 cp.git_cmd = 1;
868                 cp.no_stdin = 1;
869                 cp.dir = path;
870
871                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
872                         has_commit.result = 0;
873
874                 strbuf_release(&out);
875         }
876
877         return has_commit.result;
878 }
879
880 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
881 {
882         if (!submodule_has_commits(path, commits))
883                 /*
884                  * NOTE: We do consider it safe to return "no" here. The
885                  * correct answer would be "We do not know" instead of
886                  * "No push needed", but it is quite hard to change
887                  * the submodule pointer without having the submodule
888                  * around. If a user did however change the submodules
889                  * without having the submodule around, this indicates
890                  * an expert who knows what they are doing or a
891                  * maintainer integrating work from other people. In
892                  * both cases it should be safe to skip this check.
893                  */
894                 return 0;
895
896         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
897                 struct child_process cp = CHILD_PROCESS_INIT;
898                 struct strbuf buf = STRBUF_INIT;
899                 int needs_pushing = 0;
900
901                 argv_array_push(&cp.args, "rev-list");
902                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
903                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
904
905                 prepare_submodule_repo_env(&cp.env_array);
906                 cp.git_cmd = 1;
907                 cp.no_stdin = 1;
908                 cp.out = -1;
909                 cp.dir = path;
910                 if (start_command(&cp))
911                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
912                                         path);
913                 if (strbuf_read(&buf, cp.out, 41))
914                         needs_pushing = 1;
915                 finish_command(&cp);
916                 close(cp.out);
917                 strbuf_release(&buf);
918                 return needs_pushing;
919         }
920
921         return 0;
922 }
923
924 int find_unpushed_submodules(struct oid_array *commits,
925                 const char *remotes_name, struct string_list *needs_pushing)
926 {
927         struct string_list submodules = STRING_LIST_INIT_DUP;
928         struct string_list_item *name;
929         struct argv_array argv = ARGV_ARRAY_INIT;
930
931         /* argv.argv[0] will be ignored by setup_revisions */
932         argv_array_push(&argv, "find_unpushed_submodules");
933         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
934         argv_array_push(&argv, "--not");
935         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
936
937         collect_changed_submodules(&submodules, &argv);
938
939         for_each_string_list_item(name, &submodules) {
940                 struct oid_array *commits = name->util;
941                 const struct submodule *submodule;
942                 const char *path = NULL;
943
944                 submodule = submodule_from_name(&null_oid, name->string);
945                 if (submodule)
946                         path = submodule->path;
947                 else
948                         path = default_name_or_path(name->string);
949
950                 if (!path)
951                         continue;
952
953                 if (submodule_needs_pushing(path, commits))
954                         string_list_insert(needs_pushing, path);
955         }
956
957         free_submodules_oids(&submodules);
958         argv_array_clear(&argv);
959
960         return needs_pushing->nr;
961 }
962
963 static int push_submodule(const char *path,
964                           const struct remote *remote,
965                           const char **refspec, int refspec_nr,
966                           const struct string_list *push_options,
967                           int dry_run)
968 {
969         if (add_submodule_odb(path))
970                 return 1;
971
972         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
973                 struct child_process cp = CHILD_PROCESS_INIT;
974                 argv_array_push(&cp.args, "push");
975                 if (dry_run)
976                         argv_array_push(&cp.args, "--dry-run");
977
978                 if (push_options && push_options->nr) {
979                         const struct string_list_item *item;
980                         for_each_string_list_item(item, push_options)
981                                 argv_array_pushf(&cp.args, "--push-option=%s",
982                                                  item->string);
983                 }
984
985                 if (remote->origin != REMOTE_UNCONFIGURED) {
986                         int i;
987                         argv_array_push(&cp.args, remote->name);
988                         for (i = 0; i < refspec_nr; i++)
989                                 argv_array_push(&cp.args, refspec[i]);
990                 }
991
992                 prepare_submodule_repo_env(&cp.env_array);
993                 cp.git_cmd = 1;
994                 cp.no_stdin = 1;
995                 cp.dir = path;
996                 if (run_command(&cp))
997                         return 0;
998                 close(cp.out);
999         }
1000
1001         return 1;
1002 }
1003
1004 /*
1005  * Perform a check in the submodule to see if the remote and refspec work.
1006  * Die if the submodule can't be pushed.
1007  */
1008 static void submodule_push_check(const char *path, const char *head,
1009                                  const struct remote *remote,
1010                                  const char **refspec, int refspec_nr)
1011 {
1012         struct child_process cp = CHILD_PROCESS_INIT;
1013         int i;
1014
1015         argv_array_push(&cp.args, "submodule--helper");
1016         argv_array_push(&cp.args, "push-check");
1017         argv_array_push(&cp.args, head);
1018         argv_array_push(&cp.args, remote->name);
1019
1020         for (i = 0; i < refspec_nr; i++)
1021                 argv_array_push(&cp.args, refspec[i]);
1022
1023         prepare_submodule_repo_env(&cp.env_array);
1024         cp.git_cmd = 1;
1025         cp.no_stdin = 1;
1026         cp.no_stdout = 1;
1027         cp.dir = path;
1028
1029         /*
1030          * Simply indicate if 'submodule--helper push-check' failed.
1031          * More detailed error information will be provided by the
1032          * child process.
1033          */
1034         if (run_command(&cp))
1035                 die("process for submodule '%s' failed", path);
1036 }
1037
1038 int push_unpushed_submodules(struct oid_array *commits,
1039                              const struct remote *remote,
1040                              const char **refspec, int refspec_nr,
1041                              const struct string_list *push_options,
1042                              int dry_run)
1043 {
1044         int i, ret = 1;
1045         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1046
1047         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1048                 return 1;
1049
1050         /*
1051          * Verify that the remote and refspec can be propagated to all
1052          * submodules.  This check can be skipped if the remote and refspec
1053          * won't be propagated due to the remote being unconfigured (e.g. a URL
1054          * instead of a remote name).
1055          */
1056         if (remote->origin != REMOTE_UNCONFIGURED) {
1057                 char *head;
1058                 struct object_id head_oid;
1059
1060                 head = resolve_refdup("HEAD", 0, &head_oid, NULL);
1061                 if (!head)
1062                         die(_("Failed to resolve HEAD as a valid ref."));
1063
1064                 for (i = 0; i < needs_pushing.nr; i++)
1065                         submodule_push_check(needs_pushing.items[i].string,
1066                                              head, remote,
1067                                              refspec, refspec_nr);
1068                 free(head);
1069         }
1070
1071         /* Actually push the submodules */
1072         for (i = 0; i < needs_pushing.nr; i++) {
1073                 const char *path = needs_pushing.items[i].string;
1074                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1075                 if (!push_submodule(path, remote, refspec, refspec_nr,
1076                                     push_options, dry_run)) {
1077                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1078                         ret = 0;
1079                 }
1080         }
1081
1082         string_list_clear(&needs_pushing, 0);
1083
1084         return ret;
1085 }
1086
1087 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1088                                int flags, void *data)
1089 {
1090         struct oid_array *array = data;
1091         oid_array_append(array, oid);
1092         return 0;
1093 }
1094
1095 void check_for_new_submodule_commits(struct object_id *oid)
1096 {
1097         if (!initialized_fetch_ref_tips) {
1098                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1099                 initialized_fetch_ref_tips = 1;
1100         }
1101
1102         oid_array_append(&ref_tips_after_fetch, oid);
1103 }
1104
1105 static void calculate_changed_submodule_paths(void)
1106 {
1107         struct argv_array argv = ARGV_ARRAY_INIT;
1108         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1109         const struct string_list_item *name;
1110
1111         /* No need to check if there are no submodules configured */
1112         if (!submodule_from_path(NULL, NULL))
1113                 return;
1114
1115         argv_array_push(&argv, "--"); /* argv[0] program name */
1116         oid_array_for_each_unique(&ref_tips_after_fetch,
1117                                    append_oid_to_argv, &argv);
1118         argv_array_push(&argv, "--not");
1119         oid_array_for_each_unique(&ref_tips_before_fetch,
1120                                    append_oid_to_argv, &argv);
1121
1122         /*
1123          * Collect all submodules (whether checked out or not) for which new
1124          * commits have been recorded upstream in "changed_submodule_names".
1125          */
1126         collect_changed_submodules(&changed_submodules, &argv);
1127
1128         for_each_string_list_item(name, &changed_submodules) {
1129                 struct oid_array *commits = name->util;
1130                 const struct submodule *submodule;
1131                 const char *path = NULL;
1132
1133                 submodule = submodule_from_name(&null_oid, name->string);
1134                 if (submodule)
1135                         path = submodule->path;
1136                 else
1137                         path = default_name_or_path(name->string);
1138
1139                 if (!path)
1140                         continue;
1141
1142                 if (!submodule_has_commits(path, commits))
1143                         string_list_append(&changed_submodule_names, name->string);
1144         }
1145
1146         free_submodules_oids(&changed_submodules);
1147         argv_array_clear(&argv);
1148         oid_array_clear(&ref_tips_before_fetch);
1149         oid_array_clear(&ref_tips_after_fetch);
1150         initialized_fetch_ref_tips = 0;
1151 }
1152
1153 int submodule_touches_in_range(struct object_id *excl_oid,
1154                                struct object_id *incl_oid)
1155 {
1156         struct string_list subs = STRING_LIST_INIT_DUP;
1157         struct argv_array args = ARGV_ARRAY_INIT;
1158         int ret;
1159
1160         /* No need to check if there are no submodules configured */
1161         if (!submodule_from_path(NULL, NULL))
1162                 return 0;
1163
1164         argv_array_push(&args, "--"); /* args[0] program name */
1165         argv_array_push(&args, oid_to_hex(incl_oid));
1166         argv_array_push(&args, "--not");
1167         argv_array_push(&args, oid_to_hex(excl_oid));
1168
1169         collect_changed_submodules(&subs, &args);
1170         ret = subs.nr;
1171
1172         argv_array_clear(&args);
1173
1174         free_submodules_oids(&subs);
1175         return ret;
1176 }
1177
1178 struct submodule_parallel_fetch {
1179         int count;
1180         struct argv_array args;
1181         const char *work_tree;
1182         const char *prefix;
1183         int command_line_option;
1184         int default_option;
1185         int quiet;
1186         int result;
1187 };
1188 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1189
1190 static int get_fetch_recurse_config(const struct submodule *submodule,
1191                                     struct submodule_parallel_fetch *spf)
1192 {
1193         if (spf->command_line_option != RECURSE_SUBMODULES_DEFAULT)
1194                 return spf->command_line_option;
1195
1196         if (submodule) {
1197                 char *key;
1198                 const char *value;
1199
1200                 int fetch_recurse = submodule->fetch_recurse;
1201                 key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1202                 if (!repo_config_get_string_const(the_repository, key, &value)) {
1203                         fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1204                 }
1205                 free(key);
1206
1207                 if (fetch_recurse != RECURSE_SUBMODULES_NONE)
1208                         /* local config overrules everything except commandline */
1209                         return fetch_recurse;
1210         }
1211
1212         return spf->default_option;
1213 }
1214
1215 static int get_next_submodule(struct child_process *cp,
1216                               struct strbuf *err, void *data, void **task_cb)
1217 {
1218         int ret = 0;
1219         struct submodule_parallel_fetch *spf = data;
1220
1221         for (; spf->count < active_nr; spf->count++) {
1222                 struct strbuf submodule_path = STRBUF_INIT;
1223                 struct strbuf submodule_git_dir = STRBUF_INIT;
1224                 struct strbuf submodule_prefix = STRBUF_INIT;
1225                 const struct cache_entry *ce = active_cache[spf->count];
1226                 const char *git_dir, *default_argv;
1227                 const struct submodule *submodule;
1228                 struct submodule default_submodule = SUBMODULE_INIT;
1229
1230                 if (!S_ISGITLINK(ce->ce_mode))
1231                         continue;
1232
1233                 submodule = submodule_from_path(&null_oid, ce->name);
1234                 if (!submodule) {
1235                         const char *name = default_name_or_path(ce->name);
1236                         if (name) {
1237                                 default_submodule.path = default_submodule.name = name;
1238                                 submodule = &default_submodule;
1239                         }
1240                 }
1241
1242                 switch (get_fetch_recurse_config(submodule, spf))
1243                 {
1244                 default:
1245                 case RECURSE_SUBMODULES_DEFAULT:
1246                 case RECURSE_SUBMODULES_ON_DEMAND:
1247                         if (!submodule || !unsorted_string_list_lookup(&changed_submodule_names,
1248                                                          submodule->name))
1249                                 continue;
1250                         default_argv = "on-demand";
1251                         break;
1252                 case RECURSE_SUBMODULES_ON:
1253                         default_argv = "yes";
1254                         break;
1255                 case RECURSE_SUBMODULES_OFF:
1256                         continue;
1257                 }
1258
1259                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1260                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1261                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1262                 git_dir = read_gitfile(submodule_git_dir.buf);
1263                 if (!git_dir)
1264                         git_dir = submodule_git_dir.buf;
1265                 if (is_directory(git_dir)) {
1266                         child_process_init(cp);
1267                         cp->dir = strbuf_detach(&submodule_path, NULL);
1268                         prepare_submodule_repo_env(&cp->env_array);
1269                         cp->git_cmd = 1;
1270                         if (!spf->quiet)
1271                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1272                                             spf->prefix, ce->name);
1273                         argv_array_init(&cp->args);
1274                         argv_array_pushv(&cp->args, spf->args.argv);
1275                         argv_array_push(&cp->args, default_argv);
1276                         argv_array_push(&cp->args, "--submodule-prefix");
1277                         argv_array_push(&cp->args, submodule_prefix.buf);
1278                         ret = 1;
1279                 }
1280                 strbuf_release(&submodule_path);
1281                 strbuf_release(&submodule_git_dir);
1282                 strbuf_release(&submodule_prefix);
1283                 if (ret) {
1284                         spf->count++;
1285                         return 1;
1286                 }
1287         }
1288         return 0;
1289 }
1290
1291 static int fetch_start_failure(struct strbuf *err,
1292                                void *cb, void *task_cb)
1293 {
1294         struct submodule_parallel_fetch *spf = cb;
1295
1296         spf->result = 1;
1297
1298         return 0;
1299 }
1300
1301 static int fetch_finish(int retvalue, struct strbuf *err,
1302                         void *cb, void *task_cb)
1303 {
1304         struct submodule_parallel_fetch *spf = cb;
1305
1306         if (retvalue)
1307                 spf->result = 1;
1308
1309         return 0;
1310 }
1311
1312 int fetch_populated_submodules(const struct argv_array *options,
1313                                const char *prefix, int command_line_option,
1314                                int default_option,
1315                                int quiet, int max_parallel_jobs)
1316 {
1317         int i;
1318         struct submodule_parallel_fetch spf = SPF_INIT;
1319
1320         spf.work_tree = get_git_work_tree();
1321         spf.command_line_option = command_line_option;
1322         spf.default_option = default_option;
1323         spf.quiet = quiet;
1324         spf.prefix = prefix;
1325
1326         if (!spf.work_tree)
1327                 goto out;
1328
1329         if (read_cache() < 0)
1330                 die("index file corrupt");
1331
1332         argv_array_push(&spf.args, "fetch");
1333         for (i = 0; i < options->argc; i++)
1334                 argv_array_push(&spf.args, options->argv[i]);
1335         argv_array_push(&spf.args, "--recurse-submodules-default");
1336         /* default value, "--submodule-prefix" and its value are added later */
1337
1338         calculate_changed_submodule_paths();
1339         run_processes_parallel(max_parallel_jobs,
1340                                get_next_submodule,
1341                                fetch_start_failure,
1342                                fetch_finish,
1343                                &spf);
1344
1345         argv_array_clear(&spf.args);
1346 out:
1347         string_list_clear(&changed_submodule_names, 1);
1348         return spf.result;
1349 }
1350
1351 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1352 {
1353         struct child_process cp = CHILD_PROCESS_INIT;
1354         struct strbuf buf = STRBUF_INIT;
1355         FILE *fp;
1356         unsigned dirty_submodule = 0;
1357         const char *git_dir;
1358         int ignore_cp_exit_code = 0;
1359
1360         strbuf_addf(&buf, "%s/.git", path);
1361         git_dir = read_gitfile(buf.buf);
1362         if (!git_dir)
1363                 git_dir = buf.buf;
1364         if (!is_git_directory(git_dir)) {
1365                 if (is_directory(git_dir))
1366                         die(_("'%s' not recognized as a git repository"), git_dir);
1367                 strbuf_release(&buf);
1368                 /* The submodule is not checked out, so it is not modified */
1369                 return 0;
1370         }
1371         strbuf_reset(&buf);
1372
1373         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1374         if (ignore_untracked)
1375                 argv_array_push(&cp.args, "-uno");
1376
1377         prepare_submodule_repo_env(&cp.env_array);
1378         cp.git_cmd = 1;
1379         cp.no_stdin = 1;
1380         cp.out = -1;
1381         cp.dir = path;
1382         if (start_command(&cp))
1383                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1384
1385         fp = xfdopen(cp.out, "r");
1386         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1387                 /* regular untracked files */
1388                 if (buf.buf[0] == '?')
1389                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1390
1391                 if (buf.buf[0] == 'u' ||
1392                     buf.buf[0] == '1' ||
1393                     buf.buf[0] == '2') {
1394                         /* T = line type, XY = status, SSSS = submodule state */
1395                         if (buf.len < strlen("T XY SSSS"))
1396                                 die("BUG: invalid status --porcelain=2 line %s",
1397                                     buf.buf);
1398
1399                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1400                                 /* nested untracked file */
1401                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1402
1403                         if (buf.buf[0] == 'u' ||
1404                             buf.buf[0] == '2' ||
1405                             memcmp(buf.buf + 5, "S..U", 4))
1406                                 /* other change */
1407                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1408                 }
1409
1410                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1411                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1412                      ignore_untracked)) {
1413                         /*
1414                          * We're not interested in any further information from
1415                          * the child any more, neither output nor its exit code.
1416                          */
1417                         ignore_cp_exit_code = 1;
1418                         break;
1419                 }
1420         }
1421         fclose(fp);
1422
1423         if (finish_command(&cp) && !ignore_cp_exit_code)
1424                 die("'git status --porcelain=2' failed in submodule %s", path);
1425
1426         strbuf_release(&buf);
1427         return dirty_submodule;
1428 }
1429
1430 int submodule_uses_gitfile(const char *path)
1431 {
1432         struct child_process cp = CHILD_PROCESS_INIT;
1433         const char *argv[] = {
1434                 "submodule",
1435                 "foreach",
1436                 "--quiet",
1437                 "--recursive",
1438                 "test -f .git",
1439                 NULL,
1440         };
1441         struct strbuf buf = STRBUF_INIT;
1442         const char *git_dir;
1443
1444         strbuf_addf(&buf, "%s/.git", path);
1445         git_dir = read_gitfile(buf.buf);
1446         if (!git_dir) {
1447                 strbuf_release(&buf);
1448                 return 0;
1449         }
1450         strbuf_release(&buf);
1451
1452         /* Now test that all nested submodules use a gitfile too */
1453         cp.argv = argv;
1454         prepare_submodule_repo_env(&cp.env_array);
1455         cp.git_cmd = 1;
1456         cp.no_stdin = 1;
1457         cp.no_stderr = 1;
1458         cp.no_stdout = 1;
1459         cp.dir = path;
1460         if (run_command(&cp))
1461                 return 0;
1462
1463         return 1;
1464 }
1465
1466 /*
1467  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1468  * when doing so.
1469  *
1470  * Return 1 if we'd lose data, return 0 if the removal is fine,
1471  * and negative values for errors.
1472  */
1473 int bad_to_remove_submodule(const char *path, unsigned flags)
1474 {
1475         ssize_t len;
1476         struct child_process cp = CHILD_PROCESS_INIT;
1477         struct strbuf buf = STRBUF_INIT;
1478         int ret = 0;
1479
1480         if (!file_exists(path) || is_empty_dir(path))
1481                 return 0;
1482
1483         if (!submodule_uses_gitfile(path))
1484                 return 1;
1485
1486         argv_array_pushl(&cp.args, "status", "--porcelain",
1487                                    "--ignore-submodules=none", NULL);
1488
1489         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1490                 argv_array_push(&cp.args, "-uno");
1491         else
1492                 argv_array_push(&cp.args, "-uall");
1493
1494         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1495                 argv_array_push(&cp.args, "--ignored");
1496
1497         prepare_submodule_repo_env(&cp.env_array);
1498         cp.git_cmd = 1;
1499         cp.no_stdin = 1;
1500         cp.out = -1;
1501         cp.dir = path;
1502         if (start_command(&cp)) {
1503                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1504                         die(_("could not start 'git status' in submodule '%s'"),
1505                                 path);
1506                 ret = -1;
1507                 goto out;
1508         }
1509
1510         len = strbuf_read(&buf, cp.out, 1024);
1511         if (len > 2)
1512                 ret = 1;
1513         close(cp.out);
1514
1515         if (finish_command(&cp)) {
1516                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1517                         die(_("could not run 'git status' in submodule '%s'"),
1518                                 path);
1519                 ret = -1;
1520         }
1521 out:
1522         strbuf_release(&buf);
1523         return ret;
1524 }
1525
1526 static const char *get_super_prefix_or_empty(void)
1527 {
1528         const char *s = get_super_prefix();
1529         if (!s)
1530                 s = "";
1531         return s;
1532 }
1533
1534 static int submodule_has_dirty_index(const struct submodule *sub)
1535 {
1536         struct child_process cp = CHILD_PROCESS_INIT;
1537
1538         prepare_submodule_repo_env(&cp.env_array);
1539
1540         cp.git_cmd = 1;
1541         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1542                                    "--cached", "HEAD", NULL);
1543         cp.no_stdin = 1;
1544         cp.no_stdout = 1;
1545         cp.dir = sub->path;
1546         if (start_command(&cp))
1547                 die("could not recurse into submodule '%s'", sub->path);
1548
1549         return finish_command(&cp);
1550 }
1551
1552 static void submodule_reset_index(const char *path)
1553 {
1554         struct child_process cp = CHILD_PROCESS_INIT;
1555         prepare_submodule_repo_env(&cp.env_array);
1556
1557         cp.git_cmd = 1;
1558         cp.no_stdin = 1;
1559         cp.dir = path;
1560
1561         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1562                                    get_super_prefix_or_empty(), path);
1563         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1564
1565         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1566
1567         if (run_command(&cp))
1568                 die("could not reset submodule index");
1569 }
1570
1571 /**
1572  * Moves a submodule at a given path from a given head to another new head.
1573  * For edge cases (a submodule coming into existence or removing a submodule)
1574  * pass NULL for old or new respectively.
1575  */
1576 int submodule_move_head(const char *path,
1577                          const char *old,
1578                          const char *new,
1579                          unsigned flags)
1580 {
1581         int ret = 0;
1582         struct child_process cp = CHILD_PROCESS_INIT;
1583         const struct submodule *sub;
1584         int *error_code_ptr, error_code;
1585
1586         if (!is_submodule_active(the_repository, path))
1587                 return 0;
1588
1589         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1590                 /*
1591                  * Pass non NULL pointer to is_submodule_populated_gently
1592                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1593                  * to fixup the submodule in the force case later.
1594                  */
1595                 error_code_ptr = &error_code;
1596         else
1597                 error_code_ptr = NULL;
1598
1599         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1600                 return 0;
1601
1602         sub = submodule_from_path(&null_oid, path);
1603
1604         if (!sub)
1605                 die("BUG: could not get submodule information for '%s'", path);
1606
1607         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1608                 /* Check if the submodule has a dirty index. */
1609                 if (submodule_has_dirty_index(sub))
1610                         return error(_("submodule '%s' has dirty index"), path);
1611         }
1612
1613         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1614                 if (old) {
1615                         if (!submodule_uses_gitfile(path))
1616                                 absorb_git_dir_into_superproject("", path,
1617                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1618                 } else {
1619                         char *gitdir = xstrfmt("%s/modules/%s",
1620                                     get_git_common_dir(), sub->name);
1621                         connect_work_tree_and_git_dir(path, gitdir);
1622                         free(gitdir);
1623
1624                         /* make sure the index is clean as well */
1625                         submodule_reset_index(path);
1626                 }
1627
1628                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1629                         char *gitdir = xstrfmt("%s/modules/%s",
1630                                     get_git_common_dir(), sub->name);
1631                         connect_work_tree_and_git_dir(path, gitdir);
1632                         free(gitdir);
1633                 }
1634         }
1635
1636         prepare_submodule_repo_env(&cp.env_array);
1637
1638         cp.git_cmd = 1;
1639         cp.no_stdin = 1;
1640         cp.dir = path;
1641
1642         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1643                         get_super_prefix_or_empty(), path);
1644         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1645
1646         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1647                 argv_array_push(&cp.args, "-n");
1648         else
1649                 argv_array_push(&cp.args, "-u");
1650
1651         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1652                 argv_array_push(&cp.args, "--reset");
1653         else
1654                 argv_array_push(&cp.args, "-m");
1655
1656         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1657         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1658
1659         if (run_command(&cp)) {
1660                 ret = -1;
1661                 goto out;
1662         }
1663
1664         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1665                 if (new) {
1666                         child_process_init(&cp);
1667                         /* also set the HEAD accordingly */
1668                         cp.git_cmd = 1;
1669                         cp.no_stdin = 1;
1670                         cp.dir = path;
1671
1672                         prepare_submodule_repo_env(&cp.env_array);
1673                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1674
1675                         if (run_command(&cp)) {
1676                                 ret = -1;
1677                                 goto out;
1678                         }
1679                 } else {
1680                         struct strbuf sb = STRBUF_INIT;
1681
1682                         strbuf_addf(&sb, "%s/.git", path);
1683                         unlink_or_warn(sb.buf);
1684                         strbuf_release(&sb);
1685
1686                         if (is_empty_dir(path))
1687                                 rmdir_or_warn(path);
1688                 }
1689         }
1690 out:
1691         return ret;
1692 }
1693
1694 static int find_first_merges(struct object_array *result, const char *path,
1695                 struct commit *a, struct commit *b)
1696 {
1697         int i, j;
1698         struct object_array merges = OBJECT_ARRAY_INIT;
1699         struct commit *commit;
1700         int contains_another;
1701
1702         char merged_revision[42];
1703         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1704                                    "--all", merged_revision, NULL };
1705         struct rev_info revs;
1706         struct setup_revision_opt rev_opts;
1707
1708         memset(result, 0, sizeof(struct object_array));
1709         memset(&rev_opts, 0, sizeof(rev_opts));
1710
1711         /* get all revisions that merge commit a */
1712         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1713                         oid_to_hex(&a->object.oid));
1714         init_revisions(&revs, NULL);
1715         rev_opts.submodule = path;
1716         /* FIXME: can't handle linked worktrees in submodules yet */
1717         revs.single_worktree = path != NULL;
1718         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1719
1720         /* save all revisions from the above list that contain b */
1721         if (prepare_revision_walk(&revs))
1722                 die("revision walk setup failed");
1723         while ((commit = get_revision(&revs)) != NULL) {
1724                 struct object *o = &(commit->object);
1725                 if (in_merge_bases(b, commit))
1726                         add_object_array(o, NULL, &merges);
1727         }
1728         reset_revision_walk();
1729
1730         /* Now we've got all merges that contain a and b. Prune all
1731          * merges that contain another found merge and save them in
1732          * result.
1733          */
1734         for (i = 0; i < merges.nr; i++) {
1735                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1736
1737                 contains_another = 0;
1738                 for (j = 0; j < merges.nr; j++) {
1739                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1740                         if (i != j && in_merge_bases(m2, m1)) {
1741                                 contains_another = 1;
1742                                 break;
1743                         }
1744                 }
1745
1746                 if (!contains_another)
1747                         add_object_array(merges.objects[i].item, NULL, result);
1748         }
1749
1750         object_array_clear(&merges);
1751         return result->nr;
1752 }
1753
1754 static void print_commit(struct commit *commit)
1755 {
1756         struct strbuf sb = STRBUF_INIT;
1757         struct pretty_print_context ctx = {0};
1758         ctx.date_mode.type = DATE_NORMAL;
1759         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1760         fprintf(stderr, "%s\n", sb.buf);
1761         strbuf_release(&sb);
1762 }
1763
1764 #define MERGE_WARNING(path, msg) \
1765         warning("Failed to merge submodule %s (%s)", path, msg);
1766
1767 int merge_submodule(struct object_id *result, const char *path,
1768                     const struct object_id *base, const struct object_id *a,
1769                     const struct object_id *b, int search)
1770 {
1771         struct commit *commit_base, *commit_a, *commit_b;
1772         int parent_count;
1773         struct object_array merges;
1774
1775         int i;
1776
1777         /* store a in result in case we fail */
1778         oidcpy(result, a);
1779
1780         /* we can not handle deletion conflicts */
1781         if (is_null_oid(base))
1782                 return 0;
1783         if (is_null_oid(a))
1784                 return 0;
1785         if (is_null_oid(b))
1786                 return 0;
1787
1788         if (add_submodule_odb(path)) {
1789                 MERGE_WARNING(path, "not checked out");
1790                 return 0;
1791         }
1792
1793         if (!(commit_base = lookup_commit_reference(base)) ||
1794             !(commit_a = lookup_commit_reference(a)) ||
1795             !(commit_b = lookup_commit_reference(b))) {
1796                 MERGE_WARNING(path, "commits not present");
1797                 return 0;
1798         }
1799
1800         /* check whether both changes are forward */
1801         if (!in_merge_bases(commit_base, commit_a) ||
1802             !in_merge_bases(commit_base, commit_b)) {
1803                 MERGE_WARNING(path, "commits don't follow merge-base");
1804                 return 0;
1805         }
1806
1807         /* Case #1: a is contained in b or vice versa */
1808         if (in_merge_bases(commit_a, commit_b)) {
1809                 oidcpy(result, b);
1810                 return 1;
1811         }
1812         if (in_merge_bases(commit_b, commit_a)) {
1813                 oidcpy(result, a);
1814                 return 1;
1815         }
1816
1817         /*
1818          * Case #2: There are one or more merges that contain a and b in
1819          * the submodule. If there is only one, then present it as a
1820          * suggestion to the user, but leave it marked unmerged so the
1821          * user needs to confirm the resolution.
1822          */
1823
1824         /* Skip the search if makes no sense to the calling context.  */
1825         if (!search)
1826                 return 0;
1827
1828         /* find commit which merges them */
1829         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1830         switch (parent_count) {
1831         case 0:
1832                 MERGE_WARNING(path, "merge following commits not found");
1833                 break;
1834
1835         case 1:
1836                 MERGE_WARNING(path, "not fast-forward");
1837                 fprintf(stderr, "Found a possible merge resolution "
1838                                 "for the submodule:\n");
1839                 print_commit((struct commit *) merges.objects[0].item);
1840                 fprintf(stderr,
1841                         "If this is correct simply add it to the index "
1842                         "for example\n"
1843                         "by using:\n\n"
1844                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1845                         "which will accept this suggestion.\n",
1846                         oid_to_hex(&merges.objects[0].item->oid), path);
1847                 break;
1848
1849         default:
1850                 MERGE_WARNING(path, "multiple merges found");
1851                 for (i = 0; i < merges.nr; i++)
1852                         print_commit((struct commit *) merges.objects[i].item);
1853         }
1854
1855         object_array_clear(&merges);
1856         return 0;
1857 }
1858
1859 /*
1860  * Embeds a single submodules git directory into the superprojects git dir,
1861  * non recursively.
1862  */
1863 static void relocate_single_git_dir_into_superproject(const char *prefix,
1864                                                       const char *path)
1865 {
1866         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1867         const char *new_git_dir;
1868         const struct submodule *sub;
1869
1870         if (submodule_uses_worktrees(path))
1871                 die(_("relocate_gitdir for submodule '%s' with "
1872                       "more than one worktree not supported"), path);
1873
1874         old_git_dir = xstrfmt("%s/.git", path);
1875         if (read_gitfile(old_git_dir))
1876                 /* If it is an actual gitfile, it doesn't need migration. */
1877                 return;
1878
1879         real_old_git_dir = real_pathdup(old_git_dir, 1);
1880
1881         sub = submodule_from_path(&null_oid, path);
1882         if (!sub)
1883                 die(_("could not lookup name for submodule '%s'"), path);
1884
1885         new_git_dir = git_path("modules/%s", sub->name);
1886         if (safe_create_leading_directories_const(new_git_dir) < 0)
1887                 die(_("could not create directory '%s'"), new_git_dir);
1888         real_new_git_dir = real_pathdup(new_git_dir, 1);
1889
1890         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1891                 get_super_prefix_or_empty(), path,
1892                 real_old_git_dir, real_new_git_dir);
1893
1894         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1895
1896         free(old_git_dir);
1897         free(real_old_git_dir);
1898         free(real_new_git_dir);
1899 }
1900
1901 /*
1902  * Migrate the git directory of the submodule given by path from
1903  * having its git directory within the working tree to the git dir nested
1904  * in its superprojects git dir under modules/.
1905  */
1906 void absorb_git_dir_into_superproject(const char *prefix,
1907                                       const char *path,
1908                                       unsigned flags)
1909 {
1910         int err_code;
1911         const char *sub_git_dir;
1912         struct strbuf gitdir = STRBUF_INIT;
1913         strbuf_addf(&gitdir, "%s/.git", path);
1914         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1915
1916         /* Not populated? */
1917         if (!sub_git_dir) {
1918                 const struct submodule *sub;
1919
1920                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1921                         /* unpopulated as expected */
1922                         strbuf_release(&gitdir);
1923                         return;
1924                 }
1925
1926                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1927                         /* We don't know what broke here. */
1928                         read_gitfile_error_die(err_code, path, NULL);
1929
1930                 /*
1931                 * Maybe populated, but no git directory was found?
1932                 * This can happen if the superproject is a submodule
1933                 * itself and was just absorbed. The absorption of the
1934                 * superproject did not rewrite the git file links yet,
1935                 * fix it now.
1936                 */
1937                 sub = submodule_from_path(&null_oid, path);
1938                 if (!sub)
1939                         die(_("could not lookup name for submodule '%s'"), path);
1940                 connect_work_tree_and_git_dir(path,
1941                         git_path("modules/%s", sub->name));
1942         } else {
1943                 /* Is it already absorbed into the superprojects git dir? */
1944                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1945                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1946
1947                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1948                         relocate_single_git_dir_into_superproject(prefix, path);
1949
1950                 free(real_sub_git_dir);
1951                 free(real_common_git_dir);
1952         }
1953         strbuf_release(&gitdir);
1954
1955         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1956                 struct child_process cp = CHILD_PROCESS_INIT;
1957                 struct strbuf sb = STRBUF_INIT;
1958
1959                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1960                         die("BUG: we don't know how to pass the flags down?");
1961
1962                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1963                 strbuf_addstr(&sb, path);
1964                 strbuf_addch(&sb, '/');
1965
1966                 cp.dir = path;
1967                 cp.git_cmd = 1;
1968                 cp.no_stdin = 1;
1969                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1970                                            "submodule--helper",
1971                                            "absorb-git-dirs", NULL);
1972                 prepare_submodule_repo_env(&cp.env_array);
1973                 if (run_command(&cp))
1974                         die(_("could not recurse into submodule '%s'"), path);
1975
1976                 strbuf_release(&sb);
1977         }
1978 }
1979
1980 const char *get_superproject_working_tree(void)
1981 {
1982         struct child_process cp = CHILD_PROCESS_INIT;
1983         struct strbuf sb = STRBUF_INIT;
1984         const char *one_up = real_path_if_valid("../");
1985         const char *cwd = xgetcwd();
1986         const char *ret = NULL;
1987         const char *subpath;
1988         int code;
1989         ssize_t len;
1990
1991         if (!is_inside_work_tree())
1992                 /*
1993                  * FIXME:
1994                  * We might have a superproject, but it is harder
1995                  * to determine.
1996                  */
1997                 return NULL;
1998
1999         if (!one_up)
2000                 return NULL;
2001
2002         subpath = relative_path(cwd, one_up, &sb);
2003
2004         prepare_submodule_repo_env(&cp.env_array);
2005         argv_array_pop(&cp.env_array);
2006
2007         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2008                         "ls-files", "-z", "--stage", "--full-name", "--",
2009                         subpath, NULL);
2010         strbuf_reset(&sb);
2011
2012         cp.no_stdin = 1;
2013         cp.no_stderr = 1;
2014         cp.out = -1;
2015         cp.git_cmd = 1;
2016
2017         if (start_command(&cp))
2018                 die(_("could not start ls-files in .."));
2019
2020         len = strbuf_read(&sb, cp.out, PATH_MAX);
2021         close(cp.out);
2022
2023         if (starts_with(sb.buf, "160000")) {
2024                 int super_sub_len;
2025                 int cwd_len = strlen(cwd);
2026                 char *super_sub, *super_wt;
2027
2028                 /*
2029                  * There is a superproject having this repo as a submodule.
2030                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2031                  * We're only interested in the name after the tab.
2032                  */
2033                 super_sub = strchr(sb.buf, '\t') + 1;
2034                 super_sub_len = sb.buf + sb.len - super_sub - 1;
2035
2036                 if (super_sub_len > cwd_len ||
2037                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2038                         die (_("BUG: returned path string doesn't match cwd?"));
2039
2040                 super_wt = xstrdup(cwd);
2041                 super_wt[cwd_len - super_sub_len] = '\0';
2042
2043                 ret = real_path(super_wt);
2044                 free(super_wt);
2045         }
2046         strbuf_release(&sb);
2047
2048         code = finish_command(&cp);
2049
2050         if (code == 128)
2051                 /* '../' is not a git repository */
2052                 return NULL;
2053         if (code == 0 && len == 0)
2054                 /* There is an unrelated git repository at '../' */
2055                 return NULL;
2056         if (code)
2057                 die(_("ls-tree returned unexpected return code %d"), code);
2058
2059         return ret;
2060 }
2061
2062 /*
2063  * Put the gitdir for a submodule (given relative to the main
2064  * repository worktree) into `buf`, or return -1 on error.
2065  */
2066 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2067 {
2068         const struct submodule *sub;
2069         const char *git_dir;
2070         int ret = 0;
2071
2072         strbuf_reset(buf);
2073         strbuf_addstr(buf, submodule);
2074         strbuf_complete(buf, '/');
2075         strbuf_addstr(buf, ".git");
2076
2077         git_dir = read_gitfile(buf->buf);
2078         if (git_dir) {
2079                 strbuf_reset(buf);
2080                 strbuf_addstr(buf, git_dir);
2081         }
2082         if (!is_git_directory(buf->buf)) {
2083                 sub = submodule_from_path(&null_oid, submodule);
2084                 if (!sub) {
2085                         ret = -1;
2086                         goto cleanup;
2087                 }
2088                 strbuf_reset(buf);
2089                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2090         }
2091
2092 cleanup:
2093         return ret;
2094 }