apply: demonstrate a problem applying svn diffs
[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_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
24 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
25 static int parallel_jobs = 1;
26 static struct string_list changed_submodule_paths = STRING_LIST_INIT_DUP;
27 static int initialized_fetch_ref_tips;
28 static struct oid_array ref_tips_before_fetch;
29 static struct oid_array ref_tips_after_fetch;
30
31 /*
32  * The following flag is set if the .gitmodules file is unmerged. We then
33  * disable recursion for all submodules where .git/config doesn't have a
34  * matching config entry because we can't guess what might be configured in
35  * .gitmodules unless the user resolves the conflict. When a command line
36  * option is given (which always overrides configuration) this flag will be
37  * ignored.
38  */
39 static int gitmodules_is_unmerged;
40
41 /*
42  * This flag is set if the .gitmodules file had unstaged modifications on
43  * startup. This must be checked before allowing modifications to the
44  * .gitmodules file with the intention to stage them later, because when
45  * continuing we would stage the modifications the user didn't stage herself
46  * too. That might change in a future version when we learn to stage the
47  * changes we do ourselves without staging any previous modifications.
48  */
49 static int gitmodules_is_modified;
50
51 int is_staging_gitmodules_ok(void)
52 {
53         return !gitmodules_is_modified;
54 }
55
56 /*
57  * Try to update the "path" entry in the "submodule.<name>" section of the
58  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
59  * with the correct path=<oldpath> setting was found and we could update it.
60  */
61 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
62 {
63         struct strbuf entry = STRBUF_INIT;
64         const struct submodule *submodule;
65
66         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
67                 return -1;
68
69         if (gitmodules_is_unmerged)
70                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
71
72         submodule = submodule_from_path(null_sha1, oldpath);
73         if (!submodule || !submodule->name) {
74                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
75                 return -1;
76         }
77         strbuf_addstr(&entry, "submodule.");
78         strbuf_addstr(&entry, submodule->name);
79         strbuf_addstr(&entry, ".path");
80         if (git_config_set_in_file_gently(".gitmodules", entry.buf, newpath) < 0) {
81                 /* Maybe the user already did that, don't error out here */
82                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
83                 strbuf_release(&entry);
84                 return -1;
85         }
86         strbuf_release(&entry);
87         return 0;
88 }
89
90 /*
91  * Try to remove the "submodule.<name>" section from .gitmodules where the given
92  * path is configured. Return 0 only if a .gitmodules file was found, a section
93  * with the correct path=<path> setting was found and we could remove it.
94  */
95 int remove_path_from_gitmodules(const char *path)
96 {
97         struct strbuf sect = STRBUF_INIT;
98         const struct submodule *submodule;
99
100         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
101                 return -1;
102
103         if (gitmodules_is_unmerged)
104                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
105
106         submodule = submodule_from_path(null_sha1, path);
107         if (!submodule || !submodule->name) {
108                 warning(_("Could not find section in .gitmodules where path=%s"), path);
109                 return -1;
110         }
111         strbuf_addstr(&sect, "submodule.");
112         strbuf_addstr(&sect, submodule->name);
113         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
114                 /* Maybe the user already did that, don't error out here */
115                 warning(_("Could not remove .gitmodules entry for %s"), path);
116                 strbuf_release(&sect);
117                 return -1;
118         }
119         strbuf_release(&sect);
120         return 0;
121 }
122
123 void stage_updated_gitmodules(void)
124 {
125         if (add_file_to_cache(".gitmodules", 0))
126                 die(_("staging updated .gitmodules failed"));
127 }
128
129 static int add_submodule_odb(const char *path)
130 {
131         struct strbuf objects_directory = STRBUF_INIT;
132         int ret = 0;
133
134         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
135         if (ret)
136                 goto done;
137         if (!is_directory(objects_directory.buf)) {
138                 ret = -1;
139                 goto done;
140         }
141         add_to_alternates_memory(objects_directory.buf);
142 done:
143         strbuf_release(&objects_directory);
144         return ret;
145 }
146
147 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
148                                              const char *path)
149 {
150         const struct submodule *submodule = submodule_from_path(null_sha1, path);
151         if (submodule) {
152                 if (submodule->ignore)
153                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
154                 else if (gitmodules_is_unmerged)
155                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
156         }
157 }
158
159 /* For loading from the .gitmodules file. */
160 static int git_modules_config(const char *var, const char *value, void *cb)
161 {
162         if (!strcmp(var, "submodule.fetchjobs")) {
163                 parallel_jobs = git_config_int(var, value);
164                 if (parallel_jobs < 0)
165                         die(_("negative values not allowed for submodule.fetchJobs"));
166                 return 0;
167         } else if (starts_with(var, "submodule."))
168                 return parse_submodule_config_option(var, value);
169         else if (!strcmp(var, "fetch.recursesubmodules")) {
170                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
171                 return 0;
172         }
173         return 0;
174 }
175
176 /* Loads all submodule settings from the config. */
177 int submodule_config(const char *var, const char *value, void *cb)
178 {
179         if (!strcmp(var, "submodule.recurse")) {
180                 int v = git_config_bool(var, value) ?
181                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
182                 config_update_recurse_submodules = v;
183                 return 0;
184         } else {
185                 return git_modules_config(var, value, cb);
186         }
187 }
188
189 /* Cheap function that only determines if we're interested in submodules at all */
190 int git_default_submodule_config(const char *var, const char *value, void *cb)
191 {
192         if (!strcmp(var, "submodule.recurse")) {
193                 int v = git_config_bool(var, value) ?
194                         RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
195                 config_update_recurse_submodules = v;
196         }
197         return 0;
198 }
199
200 int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
201                                                      const char *arg, int unset)
202 {
203         if (unset) {
204                 config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
205                 return 0;
206         }
207         if (arg)
208                 config_update_recurse_submodules =
209                         parse_update_recurse_submodules_arg(opt->long_name,
210                                                             arg);
211         else
212                 config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
213
214         return 0;
215 }
216
217 void load_submodule_cache(void)
218 {
219         if (config_update_recurse_submodules == RECURSE_SUBMODULES_OFF)
220                 return;
221
222         gitmodules_config();
223         git_config(submodule_config, NULL);
224 }
225
226 void gitmodules_config(void)
227 {
228         const char *work_tree = get_git_work_tree();
229         if (work_tree) {
230                 struct strbuf gitmodules_path = STRBUF_INIT;
231                 int pos;
232                 strbuf_addstr(&gitmodules_path, work_tree);
233                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
234                 if (read_cache() < 0)
235                         die("index file corrupt");
236                 pos = cache_name_pos(".gitmodules", 11);
237                 if (pos < 0) { /* .gitmodules not found or isn't merged */
238                         pos = -1 - pos;
239                         if (active_nr > pos) {  /* there is a .gitmodules */
240                                 const struct cache_entry *ce = active_cache[pos];
241                                 if (ce_namelen(ce) == 11 &&
242                                     !memcmp(ce->name, ".gitmodules", 11))
243                                         gitmodules_is_unmerged = 1;
244                         }
245                 } else if (pos < active_nr) {
246                         struct stat st;
247                         if (lstat(".gitmodules", &st) == 0 &&
248                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
249                                 gitmodules_is_modified = 1;
250                 }
251
252                 if (!gitmodules_is_unmerged)
253                         git_config_from_file(git_modules_config,
254                                 gitmodules_path.buf, NULL);
255                 strbuf_release(&gitmodules_path);
256         }
257 }
258
259 static int gitmodules_cb(const char *var, const char *value, void *data)
260 {
261         struct repository *repo = data;
262         return submodule_config_option(repo, var, value);
263 }
264
265 void repo_read_gitmodules(struct repository *repo)
266 {
267         char *gitmodules_path = repo_worktree_path(repo, ".gitmodules");
268
269         git_config_from_file(gitmodules_cb, gitmodules_path, repo);
270         free(gitmodules_path);
271 }
272
273 void gitmodules_config_sha1(const unsigned char *commit_sha1)
274 {
275         struct strbuf rev = STRBUF_INIT;
276         unsigned char sha1[20];
277
278         if (gitmodule_sha1_from_commit(commit_sha1, sha1, &rev)) {
279                 git_config_from_blob_sha1(git_modules_config, rev.buf,
280                                           sha1, NULL);
281         }
282         strbuf_release(&rev);
283 }
284
285 /*
286  * Determine if a submodule has been initialized at a given 'path'
287  */
288 int is_submodule_active(struct repository *repo, const char *path)
289 {
290         int ret = 0;
291         char *key = NULL;
292         char *value = NULL;
293         const struct string_list *sl;
294         const struct submodule *module;
295
296         module = submodule_from_cache(repo, null_sha1, path);
297
298         /* early return if there isn't a path->module mapping */
299         if (!module)
300                 return 0;
301
302         /* submodule.<name>.active is set */
303         key = xstrfmt("submodule.%s.active", module->name);
304         if (!repo_config_get_bool(repo, key, &ret)) {
305                 free(key);
306                 return ret;
307         }
308         free(key);
309
310         /* submodule.active is set */
311         sl = repo_config_get_value_multi(repo, "submodule.active");
312         if (sl) {
313                 struct pathspec ps;
314                 struct argv_array args = ARGV_ARRAY_INIT;
315                 const struct string_list_item *item;
316
317                 for_each_string_list_item(item, sl) {
318                         argv_array_push(&args, item->string);
319                 }
320
321                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
322                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
323
324                 argv_array_clear(&args);
325                 clear_pathspec(&ps);
326                 return ret;
327         }
328
329         /* fallback to checking if the URL is set */
330         key = xstrfmt("submodule.%s.url", module->name);
331         ret = !repo_config_get_string(repo, key, &value);
332
333         free(value);
334         free(key);
335         return ret;
336 }
337
338 int is_submodule_populated_gently(const char *path, int *return_error_code)
339 {
340         int ret = 0;
341         char *gitdir = xstrfmt("%s/.git", path);
342
343         if (resolve_gitdir_gently(gitdir, return_error_code))
344                 ret = 1;
345
346         free(gitdir);
347         return ret;
348 }
349
350 /*
351  * Dies if the provided 'prefix' corresponds to an unpopulated submodule
352  */
353 void die_in_unpopulated_submodule(const struct index_state *istate,
354                                   const char *prefix)
355 {
356         int i, prefixlen;
357
358         if (!prefix)
359                 return;
360
361         prefixlen = strlen(prefix);
362
363         for (i = 0; i < istate->cache_nr; i++) {
364                 struct cache_entry *ce = istate->cache[i];
365                 int ce_len = ce_namelen(ce);
366
367                 if (!S_ISGITLINK(ce->ce_mode))
368                         continue;
369                 if (prefixlen <= ce_len)
370                         continue;
371                 if (strncmp(ce->name, prefix, ce_len))
372                         continue;
373                 if (prefix[ce_len] != '/')
374                         continue;
375
376                 die(_("in unpopulated submodule '%s'"), ce->name);
377         }
378 }
379
380 /*
381  * Dies if any paths in the provided pathspec descends into a submodule
382  */
383 void die_path_inside_submodule(const struct index_state *istate,
384                                const struct pathspec *ps)
385 {
386         int i, j;
387
388         for (i = 0; i < istate->cache_nr; i++) {
389                 struct cache_entry *ce = istate->cache[i];
390                 int ce_len = ce_namelen(ce);
391
392                 if (!S_ISGITLINK(ce->ce_mode))
393                         continue;
394
395                 for (j = 0; j < ps->nr ; j++) {
396                         const struct pathspec_item *item = &ps->items[j];
397
398                         if (item->len <= ce_len)
399                                 continue;
400                         if (item->match[ce_len] != '/')
401                                 continue;
402                         if (strncmp(ce->name, item->match, ce_len))
403                                 continue;
404                         if (item->len == ce_len + 1)
405                                 continue;
406
407                         die(_("Pathspec '%s' is in submodule '%.*s'"),
408                             item->original, ce_len, ce->name);
409                 }
410         }
411 }
412
413 int parse_submodule_update_strategy(const char *value,
414                 struct submodule_update_strategy *dst)
415 {
416         free((void*)dst->command);
417         dst->command = NULL;
418         if (!strcmp(value, "none"))
419                 dst->type = SM_UPDATE_NONE;
420         else if (!strcmp(value, "checkout"))
421                 dst->type = SM_UPDATE_CHECKOUT;
422         else if (!strcmp(value, "rebase"))
423                 dst->type = SM_UPDATE_REBASE;
424         else if (!strcmp(value, "merge"))
425                 dst->type = SM_UPDATE_MERGE;
426         else if (skip_prefix(value, "!", &value)) {
427                 dst->type = SM_UPDATE_COMMAND;
428                 dst->command = xstrdup(value);
429         } else
430                 return -1;
431         return 0;
432 }
433
434 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
435 {
436         struct strbuf sb = STRBUF_INIT;
437         switch (s->type) {
438         case SM_UPDATE_CHECKOUT:
439                 return "checkout";
440         case SM_UPDATE_MERGE:
441                 return "merge";
442         case SM_UPDATE_REBASE:
443                 return "rebase";
444         case SM_UPDATE_NONE:
445                 return "none";
446         case SM_UPDATE_UNSPECIFIED:
447                 return NULL;
448         case SM_UPDATE_COMMAND:
449                 strbuf_addf(&sb, "!%s", s->command);
450                 return strbuf_detach(&sb, NULL);
451         }
452         return NULL;
453 }
454
455 void handle_ignore_submodules_arg(struct diff_options *diffopt,
456                                   const char *arg)
457 {
458         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
459         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
460         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
461
462         if (!strcmp(arg, "all"))
463                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
464         else if (!strcmp(arg, "untracked"))
465                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
466         else if (!strcmp(arg, "dirty"))
467                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
468         else if (strcmp(arg, "none"))
469                 die("bad --ignore-submodules argument: %s", arg);
470 }
471
472 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
473                 struct commit *left, struct commit *right,
474                 struct commit_list *merge_bases)
475 {
476         struct commit_list *list;
477
478         init_revisions(rev, NULL);
479         setup_revisions(0, NULL, rev, NULL);
480         rev->left_right = 1;
481         rev->first_parent_only = 1;
482         left->object.flags |= SYMMETRIC_LEFT;
483         add_pending_object(rev, &left->object, path);
484         add_pending_object(rev, &right->object, path);
485         for (list = merge_bases; list; list = list->next) {
486                 list->item->object.flags |= UNINTERESTING;
487                 add_pending_object(rev, &list->item->object,
488                         oid_to_hex(&list->item->object.oid));
489         }
490         return prepare_revision_walk(rev);
491 }
492
493 static void print_submodule_summary(struct rev_info *rev, FILE *f,
494                 const char *line_prefix,
495                 const char *del, const char *add, const char *reset)
496 {
497         static const char format[] = "  %m %s";
498         struct strbuf sb = STRBUF_INIT;
499         struct commit *commit;
500
501         while ((commit = get_revision(rev))) {
502                 struct pretty_print_context ctx = {0};
503                 ctx.date_mode = rev->date_mode;
504                 ctx.output_encoding = get_log_output_encoding();
505                 strbuf_setlen(&sb, 0);
506                 strbuf_addstr(&sb, line_prefix);
507                 if (commit->object.flags & SYMMETRIC_LEFT) {
508                         if (del)
509                                 strbuf_addstr(&sb, del);
510                 }
511                 else if (add)
512                         strbuf_addstr(&sb, add);
513                 format_commit_message(commit, format, &sb, &ctx);
514                 if (reset)
515                         strbuf_addstr(&sb, reset);
516                 strbuf_addch(&sb, '\n');
517                 fprintf(f, "%s", sb.buf);
518         }
519         strbuf_release(&sb);
520 }
521
522 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
523 {
524         const char * const *var;
525
526         for (var = local_repo_env; *var; var++) {
527                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
528                         argv_array_push(out, *var);
529         }
530 }
531
532 void prepare_submodule_repo_env(struct argv_array *out)
533 {
534         prepare_submodule_repo_env_no_git_dir(out);
535         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
536                          DEFAULT_GIT_DIR_ENVIRONMENT);
537 }
538
539 /* Helper function to display the submodule header line prior to the full
540  * summary output. If it can locate the submodule objects directory it will
541  * attempt to lookup both the left and right commits and put them into the
542  * left and right pointers.
543  */
544 static void show_submodule_header(FILE *f, const char *path,
545                 const char *line_prefix,
546                 struct object_id *one, struct object_id *two,
547                 unsigned dirty_submodule, const char *meta,
548                 const char *reset,
549                 struct commit **left, struct commit **right,
550                 struct commit_list **merge_bases)
551 {
552         const char *message = NULL;
553         struct strbuf sb = STRBUF_INIT;
554         int fast_forward = 0, fast_backward = 0;
555
556         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
557                 fprintf(f, "%sSubmodule %s contains untracked content\n",
558                         line_prefix, path);
559         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
560                 fprintf(f, "%sSubmodule %s contains modified content\n",
561                         line_prefix, path);
562
563         if (is_null_oid(one))
564                 message = "(new submodule)";
565         else if (is_null_oid(two))
566                 message = "(submodule deleted)";
567
568         if (add_submodule_odb(path)) {
569                 if (!message)
570                         message = "(not initialized)";
571                 goto output_header;
572         }
573
574         /*
575          * Attempt to lookup the commit references, and determine if this is
576          * a fast forward or fast backwards update.
577          */
578         *left = lookup_commit_reference(one);
579         *right = lookup_commit_reference(two);
580
581         /*
582          * Warn about missing commits in the submodule project, but only if
583          * they aren't null.
584          */
585         if ((!is_null_oid(one) && !*left) ||
586              (!is_null_oid(two) && !*right))
587                 message = "(commits not present)";
588
589         *merge_bases = get_merge_bases(*left, *right);
590         if (*merge_bases) {
591                 if ((*merge_bases)->item == *left)
592                         fast_forward = 1;
593                 else if ((*merge_bases)->item == *right)
594                         fast_backward = 1;
595         }
596
597         if (!oidcmp(one, two)) {
598                 strbuf_release(&sb);
599                 return;
600         }
601
602 output_header:
603         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
604         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
605         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
606         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
607         if (message)
608                 strbuf_addf(&sb, " %s%s\n", message, reset);
609         else
610                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
611         fwrite(sb.buf, sb.len, 1, f);
612
613         strbuf_release(&sb);
614 }
615
616 void show_submodule_summary(FILE *f, const char *path,
617                 const char *line_prefix,
618                 struct object_id *one, struct object_id *two,
619                 unsigned dirty_submodule, const char *meta,
620                 const char *del, const char *add, const char *reset)
621 {
622         struct rev_info rev;
623         struct commit *left = NULL, *right = NULL;
624         struct commit_list *merge_bases = NULL;
625
626         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
627                               meta, reset, &left, &right, &merge_bases);
628
629         /*
630          * If we don't have both a left and a right pointer, there is no
631          * reason to try and display a summary. The header line should contain
632          * all the information the user needs.
633          */
634         if (!left || !right)
635                 goto out;
636
637         /* Treat revision walker failure the same as missing commits */
638         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
639                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
640                 goto out;
641         }
642
643         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
644
645 out:
646         if (merge_bases)
647                 free_commit_list(merge_bases);
648         clear_commit_marks(left, ~0);
649         clear_commit_marks(right, ~0);
650 }
651
652 void show_submodule_inline_diff(FILE *f, const char *path,
653                 const char *line_prefix,
654                 struct object_id *one, struct object_id *two,
655                 unsigned dirty_submodule, const char *meta,
656                 const char *del, const char *add, const char *reset,
657                 const struct diff_options *o)
658 {
659         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
660         struct commit *left = NULL, *right = NULL;
661         struct commit_list *merge_bases = NULL;
662         struct strbuf submodule_dir = STRBUF_INIT;
663         struct child_process cp = CHILD_PROCESS_INIT;
664
665         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
666                               meta, reset, &left, &right, &merge_bases);
667
668         /* We need a valid left and right commit to display a difference */
669         if (!(left || is_null_oid(one)) ||
670             !(right || is_null_oid(two)))
671                 goto done;
672
673         if (left)
674                 old = one;
675         if (right)
676                 new = two;
677
678         fflush(f);
679         cp.git_cmd = 1;
680         cp.dir = path;
681         cp.out = dup(fileno(f));
682         cp.no_stdin = 1;
683
684         /* TODO: other options may need to be passed here. */
685         argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
686
687         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
688         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
689                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
690                                  o->b_prefix, path);
691                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
692                                  o->a_prefix, path);
693         } else {
694                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
695                                  o->a_prefix, path);
696                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
697                                  o->b_prefix, path);
698         }
699         argv_array_push(&cp.args, oid_to_hex(old));
700         /*
701          * If the submodule has modified content, we will diff against the
702          * work tree, under the assumption that the user has asked for the
703          * diff format and wishes to actually see all differences even if they
704          * haven't yet been committed to the submodule yet.
705          */
706         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
707                 argv_array_push(&cp.args, oid_to_hex(new));
708
709         prepare_submodule_repo_env(&cp.env_array);
710         if (run_command(&cp))
711                 fprintf(f, "(diff failed)\n");
712
713 done:
714         strbuf_release(&submodule_dir);
715         if (merge_bases)
716                 free_commit_list(merge_bases);
717         if (left)
718                 clear_commit_marks(left, ~0);
719         if (right)
720                 clear_commit_marks(right, ~0);
721 }
722
723 void set_config_fetch_recurse_submodules(int value)
724 {
725         config_fetch_recurse_submodules = value;
726 }
727
728 int should_update_submodules(void)
729 {
730         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
731 }
732
733 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
734 {
735         if (!S_ISGITLINK(ce->ce_mode))
736                 return NULL;
737
738         if (!should_update_submodules())
739                 return NULL;
740
741         return submodule_from_path(null_sha1, ce->name);
742 }
743
744 static struct oid_array *submodule_commits(struct string_list *submodules,
745                                            const char *path)
746 {
747         struct string_list_item *item;
748
749         item = string_list_insert(submodules, path);
750         if (item->util)
751                 return (struct oid_array *) item->util;
752
753         /* NEEDSWORK: should we have oid_array_init()? */
754         item->util = xcalloc(1, sizeof(struct oid_array));
755         return (struct oid_array *) item->util;
756 }
757
758 static void collect_changed_submodules_cb(struct diff_queue_struct *q,
759                                           struct diff_options *options,
760                                           void *data)
761 {
762         int i;
763         struct string_list *changed = data;
764
765         for (i = 0; i < q->nr; i++) {
766                 struct diff_filepair *p = q->queue[i];
767                 struct oid_array *commits;
768                 if (!S_ISGITLINK(p->two->mode))
769                         continue;
770
771                 if (S_ISGITLINK(p->one->mode)) {
772                         /*
773                          * NEEDSWORK: We should honor the name configured in
774                          * the .gitmodules file of the commit we are examining
775                          * here to be able to correctly follow submodules
776                          * being moved around.
777                          */
778                         commits = submodule_commits(changed, p->two->path);
779                         oid_array_append(commits, &p->two->oid);
780                 } else {
781                         /* Submodule is new or was moved here */
782                         /*
783                          * NEEDSWORK: When the .git directories of submodules
784                          * live inside the superprojects .git directory some
785                          * day we should fetch new submodules directly into
786                          * that location too when config or options request
787                          * that so they can be checked out from there.
788                          */
789                         continue;
790                 }
791         }
792 }
793
794 /*
795  * Collect the paths of submodules in 'changed' which have changed based on
796  * the revisions as specified in 'argv'.  Each entry in 'changed' will also
797  * have a corresponding 'struct oid_array' (in the 'util' field) which lists
798  * what the submodule pointers were updated to during the change.
799  */
800 static void collect_changed_submodules(struct string_list *changed,
801                                        struct argv_array *argv)
802 {
803         struct rev_info rev;
804         const struct commit *commit;
805
806         init_revisions(&rev, NULL);
807         setup_revisions(argv->argc, argv->argv, &rev, NULL);
808         if (prepare_revision_walk(&rev))
809                 die("revision walk setup failed");
810
811         while ((commit = get_revision(&rev))) {
812                 struct rev_info diff_rev;
813
814                 init_revisions(&diff_rev, NULL);
815                 diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
816                 diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
817                 diff_rev.diffopt.format_callback_data = changed;
818                 diff_tree_combined_merge(commit, 1, &diff_rev);
819         }
820
821         reset_revision_walk();
822 }
823
824 static void free_submodules_oids(struct string_list *submodules)
825 {
826         struct string_list_item *item;
827         for_each_string_list_item(item, submodules)
828                 oid_array_clear((struct oid_array *) item->util);
829         string_list_clear(submodules, 1);
830 }
831
832 static int has_remote(const char *refname, const struct object_id *oid,
833                       int flags, void *cb_data)
834 {
835         return 1;
836 }
837
838 static int append_oid_to_argv(const struct object_id *oid, void *data)
839 {
840         struct argv_array *argv = data;
841         argv_array_push(argv, oid_to_hex(oid));
842         return 0;
843 }
844
845 static int check_has_commit(const struct object_id *oid, void *data)
846 {
847         int *has_commit = data;
848
849         if (!lookup_commit_reference(oid))
850                 *has_commit = 0;
851
852         return 0;
853 }
854
855 static int submodule_has_commits(const char *path, struct oid_array *commits)
856 {
857         int has_commit = 1;
858
859         /*
860          * Perform a cheap, but incorrect check for the existence of 'commits'.
861          * This is done by adding the submodule's object store to the in-core
862          * object store, and then querying for each commit's existence.  If we
863          * do not have the commit object anywhere, there is no chance we have
864          * it in the object store of the correct submodule and have it
865          * reachable from a ref, so we can fail early without spawning rev-list
866          * which is expensive.
867          */
868         if (add_submodule_odb(path))
869                 return 0;
870
871         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
872
873         if (has_commit) {
874                 /*
875                  * Even if the submodule is checked out and the commit is
876                  * present, make sure it exists in the submodule's object store
877                  * and that it is reachable from a ref.
878                  */
879                 struct child_process cp = CHILD_PROCESS_INIT;
880                 struct strbuf out = STRBUF_INIT;
881
882                 argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
883                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
884                 argv_array_pushl(&cp.args, "--not", "--all", NULL);
885
886                 prepare_submodule_repo_env(&cp.env_array);
887                 cp.git_cmd = 1;
888                 cp.no_stdin = 1;
889                 cp.dir = path;
890
891                 if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
892                         has_commit = 0;
893
894                 strbuf_release(&out);
895         }
896
897         return has_commit;
898 }
899
900 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
901 {
902         if (!submodule_has_commits(path, commits))
903                 /*
904                  * NOTE: We do consider it safe to return "no" here. The
905                  * correct answer would be "We do not know" instead of
906                  * "No push needed", but it is quite hard to change
907                  * the submodule pointer without having the submodule
908                  * around. If a user did however change the submodules
909                  * without having the submodule around, this indicates
910                  * an expert who knows what they are doing or a
911                  * maintainer integrating work from other people. In
912                  * both cases it should be safe to skip this check.
913                  */
914                 return 0;
915
916         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
917                 struct child_process cp = CHILD_PROCESS_INIT;
918                 struct strbuf buf = STRBUF_INIT;
919                 int needs_pushing = 0;
920
921                 argv_array_push(&cp.args, "rev-list");
922                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
923                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
924
925                 prepare_submodule_repo_env(&cp.env_array);
926                 cp.git_cmd = 1;
927                 cp.no_stdin = 1;
928                 cp.out = -1;
929                 cp.dir = path;
930                 if (start_command(&cp))
931                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
932                                         path);
933                 if (strbuf_read(&buf, cp.out, 41))
934                         needs_pushing = 1;
935                 finish_command(&cp);
936                 close(cp.out);
937                 strbuf_release(&buf);
938                 return needs_pushing;
939         }
940
941         return 0;
942 }
943
944 int find_unpushed_submodules(struct oid_array *commits,
945                 const char *remotes_name, struct string_list *needs_pushing)
946 {
947         struct string_list submodules = STRING_LIST_INIT_DUP;
948         struct string_list_item *submodule;
949         struct argv_array argv = ARGV_ARRAY_INIT;
950
951         /* argv.argv[0] will be ignored by setup_revisions */
952         argv_array_push(&argv, "find_unpushed_submodules");
953         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
954         argv_array_push(&argv, "--not");
955         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
956
957         collect_changed_submodules(&submodules, &argv);
958
959         for_each_string_list_item(submodule, &submodules) {
960                 struct oid_array *commits = submodule->util;
961                 const char *path = submodule->string;
962
963                 if (submodule_needs_pushing(path, commits))
964                         string_list_insert(needs_pushing, path);
965         }
966
967         free_submodules_oids(&submodules);
968         argv_array_clear(&argv);
969
970         return needs_pushing->nr;
971 }
972
973 static int push_submodule(const char *path,
974                           const struct remote *remote,
975                           const char **refspec, int refspec_nr,
976                           const struct string_list *push_options,
977                           int dry_run)
978 {
979         if (add_submodule_odb(path))
980                 return 1;
981
982         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
983                 struct child_process cp = CHILD_PROCESS_INIT;
984                 argv_array_push(&cp.args, "push");
985                 if (dry_run)
986                         argv_array_push(&cp.args, "--dry-run");
987
988                 if (push_options && push_options->nr) {
989                         const struct string_list_item *item;
990                         for_each_string_list_item(item, push_options)
991                                 argv_array_pushf(&cp.args, "--push-option=%s",
992                                                  item->string);
993                 }
994
995                 if (remote->origin != REMOTE_UNCONFIGURED) {
996                         int i;
997                         argv_array_push(&cp.args, remote->name);
998                         for (i = 0; i < refspec_nr; i++)
999                                 argv_array_push(&cp.args, refspec[i]);
1000                 }
1001
1002                 prepare_submodule_repo_env(&cp.env_array);
1003                 cp.git_cmd = 1;
1004                 cp.no_stdin = 1;
1005                 cp.dir = path;
1006                 if (run_command(&cp))
1007                         return 0;
1008                 close(cp.out);
1009         }
1010
1011         return 1;
1012 }
1013
1014 /*
1015  * Perform a check in the submodule to see if the remote and refspec work.
1016  * Die if the submodule can't be pushed.
1017  */
1018 static void submodule_push_check(const char *path, const char *head,
1019                                  const struct remote *remote,
1020                                  const char **refspec, int refspec_nr)
1021 {
1022         struct child_process cp = CHILD_PROCESS_INIT;
1023         int i;
1024
1025         argv_array_push(&cp.args, "submodule--helper");
1026         argv_array_push(&cp.args, "push-check");
1027         argv_array_push(&cp.args, head);
1028         argv_array_push(&cp.args, remote->name);
1029
1030         for (i = 0; i < refspec_nr; i++)
1031                 argv_array_push(&cp.args, refspec[i]);
1032
1033         prepare_submodule_repo_env(&cp.env_array);
1034         cp.git_cmd = 1;
1035         cp.no_stdin = 1;
1036         cp.no_stdout = 1;
1037         cp.dir = path;
1038
1039         /*
1040          * Simply indicate if 'submodule--helper push-check' failed.
1041          * More detailed error information will be provided by the
1042          * child process.
1043          */
1044         if (run_command(&cp))
1045                 die("process for submodule '%s' failed", path);
1046 }
1047
1048 int push_unpushed_submodules(struct oid_array *commits,
1049                              const struct remote *remote,
1050                              const char **refspec, int refspec_nr,
1051                              const struct string_list *push_options,
1052                              int dry_run)
1053 {
1054         int i, ret = 1;
1055         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1056
1057         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1058                 return 1;
1059
1060         /*
1061          * Verify that the remote and refspec can be propagated to all
1062          * submodules.  This check can be skipped if the remote and refspec
1063          * won't be propagated due to the remote being unconfigured (e.g. a URL
1064          * instead of a remote name).
1065          */
1066         if (remote->origin != REMOTE_UNCONFIGURED) {
1067                 char *head;
1068                 struct object_id head_oid;
1069
1070                 head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
1071                 if (!head)
1072                         die(_("Failed to resolve HEAD as a valid ref."));
1073
1074                 for (i = 0; i < needs_pushing.nr; i++)
1075                         submodule_push_check(needs_pushing.items[i].string,
1076                                              head, remote,
1077                                              refspec, refspec_nr);
1078                 free(head);
1079         }
1080
1081         /* Actually push the submodules */
1082         for (i = 0; i < needs_pushing.nr; i++) {
1083                 const char *path = needs_pushing.items[i].string;
1084                 fprintf(stderr, "Pushing submodule '%s'\n", path);
1085                 if (!push_submodule(path, remote, refspec, refspec_nr,
1086                                     push_options, dry_run)) {
1087                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
1088                         ret = 0;
1089                 }
1090         }
1091
1092         string_list_clear(&needs_pushing, 0);
1093
1094         return ret;
1095 }
1096
1097 static int append_oid_to_array(const char *ref, const struct object_id *oid,
1098                                int flags, void *data)
1099 {
1100         struct oid_array *array = data;
1101         oid_array_append(array, oid);
1102         return 0;
1103 }
1104
1105 void check_for_new_submodule_commits(struct object_id *oid)
1106 {
1107         if (!initialized_fetch_ref_tips) {
1108                 for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1109                 initialized_fetch_ref_tips = 1;
1110         }
1111
1112         oid_array_append(&ref_tips_after_fetch, oid);
1113 }
1114
1115 static void calculate_changed_submodule_paths(void)
1116 {
1117         struct argv_array argv = ARGV_ARRAY_INIT;
1118         struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1119         const struct string_list_item *item;
1120
1121         /* No need to check if there are no submodules configured */
1122         if (!submodule_from_path(NULL, NULL))
1123                 return;
1124
1125         argv_array_push(&argv, "--"); /* argv[0] program name */
1126         oid_array_for_each_unique(&ref_tips_after_fetch,
1127                                    append_oid_to_argv, &argv);
1128         argv_array_push(&argv, "--not");
1129         oid_array_for_each_unique(&ref_tips_before_fetch,
1130                                    append_oid_to_argv, &argv);
1131
1132         /*
1133          * Collect all submodules (whether checked out or not) for which new
1134          * commits have been recorded upstream in "changed_submodule_paths".
1135          */
1136         collect_changed_submodules(&changed_submodules, &argv);
1137
1138         for_each_string_list_item(item, &changed_submodules) {
1139                 struct oid_array *commits = item->util;
1140                 const char *path = item->string;
1141
1142                 if (!submodule_has_commits(path, commits))
1143                         string_list_append(&changed_submodule_paths, path);
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         gitmodules_config();
1161         /* No need to check if there are no submodules configured */
1162         if (!submodule_from_path(NULL, NULL))
1163                 return 0;
1164
1165         argv_array_push(&args, "--"); /* args[0] program name */
1166         argv_array_push(&args, oid_to_hex(incl_oid));
1167         argv_array_push(&args, "--not");
1168         argv_array_push(&args, oid_to_hex(excl_oid));
1169
1170         collect_changed_submodules(&subs, &args);
1171         ret = subs.nr;
1172
1173         argv_array_clear(&args);
1174
1175         free_submodules_oids(&subs);
1176         return ret;
1177 }
1178
1179 struct submodule_parallel_fetch {
1180         int count;
1181         struct argv_array args;
1182         const char *work_tree;
1183         const char *prefix;
1184         int command_line_option;
1185         int quiet;
1186         int result;
1187 };
1188 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0}
1189
1190 static int get_next_submodule(struct child_process *cp,
1191                               struct strbuf *err, void *data, void **task_cb)
1192 {
1193         int ret = 0;
1194         struct submodule_parallel_fetch *spf = data;
1195
1196         for (; spf->count < active_nr; spf->count++) {
1197                 struct strbuf submodule_path = STRBUF_INIT;
1198                 struct strbuf submodule_git_dir = STRBUF_INIT;
1199                 struct strbuf submodule_prefix = STRBUF_INIT;
1200                 const struct cache_entry *ce = active_cache[spf->count];
1201                 const char *git_dir, *default_argv;
1202                 const struct submodule *submodule;
1203
1204                 if (!S_ISGITLINK(ce->ce_mode))
1205                         continue;
1206
1207                 submodule = submodule_from_path(null_sha1, ce->name);
1208                 if (!submodule)
1209                         submodule = submodule_from_name(null_sha1, ce->name);
1210
1211                 default_argv = "yes";
1212                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1213                         if (submodule &&
1214                             submodule->fetch_recurse !=
1215                                                 RECURSE_SUBMODULES_NONE) {
1216                                 if (submodule->fetch_recurse ==
1217                                                 RECURSE_SUBMODULES_OFF)
1218                                         continue;
1219                                 if (submodule->fetch_recurse ==
1220                                                 RECURSE_SUBMODULES_ON_DEMAND) {
1221                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1222                                                 continue;
1223                                         default_argv = "on-demand";
1224                                 }
1225                         } else {
1226                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
1227                                     gitmodules_is_unmerged)
1228                                         continue;
1229                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
1230                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1231                                                 continue;
1232                                         default_argv = "on-demand";
1233                                 }
1234                         }
1235                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1236                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1237                                 continue;
1238                         default_argv = "on-demand";
1239                 }
1240
1241                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1242                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1243                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1244                 git_dir = read_gitfile(submodule_git_dir.buf);
1245                 if (!git_dir)
1246                         git_dir = submodule_git_dir.buf;
1247                 if (is_directory(git_dir)) {
1248                         child_process_init(cp);
1249                         cp->dir = strbuf_detach(&submodule_path, NULL);
1250                         prepare_submodule_repo_env(&cp->env_array);
1251                         cp->git_cmd = 1;
1252                         if (!spf->quiet)
1253                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1254                                             spf->prefix, ce->name);
1255                         argv_array_init(&cp->args);
1256                         argv_array_pushv(&cp->args, spf->args.argv);
1257                         argv_array_push(&cp->args, default_argv);
1258                         argv_array_push(&cp->args, "--submodule-prefix");
1259                         argv_array_push(&cp->args, submodule_prefix.buf);
1260                         ret = 1;
1261                 }
1262                 strbuf_release(&submodule_path);
1263                 strbuf_release(&submodule_git_dir);
1264                 strbuf_release(&submodule_prefix);
1265                 if (ret) {
1266                         spf->count++;
1267                         return 1;
1268                 }
1269         }
1270         return 0;
1271 }
1272
1273 static int fetch_start_failure(struct strbuf *err,
1274                                void *cb, void *task_cb)
1275 {
1276         struct submodule_parallel_fetch *spf = cb;
1277
1278         spf->result = 1;
1279
1280         return 0;
1281 }
1282
1283 static int fetch_finish(int retvalue, struct strbuf *err,
1284                         void *cb, void *task_cb)
1285 {
1286         struct submodule_parallel_fetch *spf = cb;
1287
1288         if (retvalue)
1289                 spf->result = 1;
1290
1291         return 0;
1292 }
1293
1294 int fetch_populated_submodules(const struct argv_array *options,
1295                                const char *prefix, int command_line_option,
1296                                int quiet, int max_parallel_jobs)
1297 {
1298         int i;
1299         struct submodule_parallel_fetch spf = SPF_INIT;
1300
1301         spf.work_tree = get_git_work_tree();
1302         spf.command_line_option = command_line_option;
1303         spf.quiet = quiet;
1304         spf.prefix = prefix;
1305
1306         if (!spf.work_tree)
1307                 goto out;
1308
1309         if (read_cache() < 0)
1310                 die("index file corrupt");
1311
1312         argv_array_push(&spf.args, "fetch");
1313         for (i = 0; i < options->argc; i++)
1314                 argv_array_push(&spf.args, options->argv[i]);
1315         argv_array_push(&spf.args, "--recurse-submodules-default");
1316         /* default value, "--submodule-prefix" and its value are added later */
1317
1318         if (max_parallel_jobs < 0)
1319                 max_parallel_jobs = parallel_jobs;
1320
1321         calculate_changed_submodule_paths();
1322         run_processes_parallel(max_parallel_jobs,
1323                                get_next_submodule,
1324                                fetch_start_failure,
1325                                fetch_finish,
1326                                &spf);
1327
1328         argv_array_clear(&spf.args);
1329 out:
1330         string_list_clear(&changed_submodule_paths, 1);
1331         return spf.result;
1332 }
1333
1334 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1335 {
1336         struct child_process cp = CHILD_PROCESS_INIT;
1337         struct strbuf buf = STRBUF_INIT;
1338         FILE *fp;
1339         unsigned dirty_submodule = 0;
1340         const char *git_dir;
1341         int ignore_cp_exit_code = 0;
1342
1343         strbuf_addf(&buf, "%s/.git", path);
1344         git_dir = read_gitfile(buf.buf);
1345         if (!git_dir)
1346                 git_dir = buf.buf;
1347         if (!is_git_directory(git_dir)) {
1348                 if (is_directory(git_dir))
1349                         die(_("'%s' not recognized as a git repository"), git_dir);
1350                 strbuf_release(&buf);
1351                 /* The submodule is not checked out, so it is not modified */
1352                 return 0;
1353         }
1354         strbuf_reset(&buf);
1355
1356         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1357         if (ignore_untracked)
1358                 argv_array_push(&cp.args, "-uno");
1359
1360         prepare_submodule_repo_env(&cp.env_array);
1361         cp.git_cmd = 1;
1362         cp.no_stdin = 1;
1363         cp.out = -1;
1364         cp.dir = path;
1365         if (start_command(&cp))
1366                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1367
1368         fp = xfdopen(cp.out, "r");
1369         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1370                 /* regular untracked files */
1371                 if (buf.buf[0] == '?')
1372                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1373
1374                 if (buf.buf[0] == 'u' ||
1375                     buf.buf[0] == '1' ||
1376                     buf.buf[0] == '2') {
1377                         /* T = line type, XY = status, SSSS = submodule state */
1378                         if (buf.len < strlen("T XY SSSS"))
1379                                 die("BUG: invalid status --porcelain=2 line %s",
1380                                     buf.buf);
1381
1382                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1383                                 /* nested untracked file */
1384                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1385
1386                         if (buf.buf[0] == 'u' ||
1387                             buf.buf[0] == '2' ||
1388                             memcmp(buf.buf + 5, "S..U", 4))
1389                                 /* other change */
1390                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1391                 }
1392
1393                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1394                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1395                      ignore_untracked)) {
1396                         /*
1397                          * We're not interested in any further information from
1398                          * the child any more, neither output nor its exit code.
1399                          */
1400                         ignore_cp_exit_code = 1;
1401                         break;
1402                 }
1403         }
1404         fclose(fp);
1405
1406         if (finish_command(&cp) && !ignore_cp_exit_code)
1407                 die("'git status --porcelain=2' failed in submodule %s", path);
1408
1409         strbuf_release(&buf);
1410         return dirty_submodule;
1411 }
1412
1413 int submodule_uses_gitfile(const char *path)
1414 {
1415         struct child_process cp = CHILD_PROCESS_INIT;
1416         const char *argv[] = {
1417                 "submodule",
1418                 "foreach",
1419                 "--quiet",
1420                 "--recursive",
1421                 "test -f .git",
1422                 NULL,
1423         };
1424         struct strbuf buf = STRBUF_INIT;
1425         const char *git_dir;
1426
1427         strbuf_addf(&buf, "%s/.git", path);
1428         git_dir = read_gitfile(buf.buf);
1429         if (!git_dir) {
1430                 strbuf_release(&buf);
1431                 return 0;
1432         }
1433         strbuf_release(&buf);
1434
1435         /* Now test that all nested submodules use a gitfile too */
1436         cp.argv = argv;
1437         prepare_submodule_repo_env(&cp.env_array);
1438         cp.git_cmd = 1;
1439         cp.no_stdin = 1;
1440         cp.no_stderr = 1;
1441         cp.no_stdout = 1;
1442         cp.dir = path;
1443         if (run_command(&cp))
1444                 return 0;
1445
1446         return 1;
1447 }
1448
1449 /*
1450  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1451  * when doing so.
1452  *
1453  * Return 1 if we'd lose data, return 0 if the removal is fine,
1454  * and negative values for errors.
1455  */
1456 int bad_to_remove_submodule(const char *path, unsigned flags)
1457 {
1458         ssize_t len;
1459         struct child_process cp = CHILD_PROCESS_INIT;
1460         struct strbuf buf = STRBUF_INIT;
1461         int ret = 0;
1462
1463         if (!file_exists(path) || is_empty_dir(path))
1464                 return 0;
1465
1466         if (!submodule_uses_gitfile(path))
1467                 return 1;
1468
1469         argv_array_pushl(&cp.args, "status", "--porcelain",
1470                                    "--ignore-submodules=none", NULL);
1471
1472         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1473                 argv_array_push(&cp.args, "-uno");
1474         else
1475                 argv_array_push(&cp.args, "-uall");
1476
1477         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1478                 argv_array_push(&cp.args, "--ignored");
1479
1480         prepare_submodule_repo_env(&cp.env_array);
1481         cp.git_cmd = 1;
1482         cp.no_stdin = 1;
1483         cp.out = -1;
1484         cp.dir = path;
1485         if (start_command(&cp)) {
1486                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1487                         die(_("could not start 'git status' in submodule '%s'"),
1488                                 path);
1489                 ret = -1;
1490                 goto out;
1491         }
1492
1493         len = strbuf_read(&buf, cp.out, 1024);
1494         if (len > 2)
1495                 ret = 1;
1496         close(cp.out);
1497
1498         if (finish_command(&cp)) {
1499                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1500                         die(_("could not run 'git status' in submodule '%s'"),
1501                                 path);
1502                 ret = -1;
1503         }
1504 out:
1505         strbuf_release(&buf);
1506         return ret;
1507 }
1508
1509 static const char *get_super_prefix_or_empty(void)
1510 {
1511         const char *s = get_super_prefix();
1512         if (!s)
1513                 s = "";
1514         return s;
1515 }
1516
1517 static int submodule_has_dirty_index(const struct submodule *sub)
1518 {
1519         struct child_process cp = CHILD_PROCESS_INIT;
1520
1521         prepare_submodule_repo_env(&cp.env_array);
1522
1523         cp.git_cmd = 1;
1524         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1525                                    "--cached", "HEAD", NULL);
1526         cp.no_stdin = 1;
1527         cp.no_stdout = 1;
1528         cp.dir = sub->path;
1529         if (start_command(&cp))
1530                 die("could not recurse into submodule '%s'", sub->path);
1531
1532         return finish_command(&cp);
1533 }
1534
1535 static void submodule_reset_index(const char *path)
1536 {
1537         struct child_process cp = CHILD_PROCESS_INIT;
1538         prepare_submodule_repo_env(&cp.env_array);
1539
1540         cp.git_cmd = 1;
1541         cp.no_stdin = 1;
1542         cp.dir = path;
1543
1544         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1545                                    get_super_prefix_or_empty(), path);
1546         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1547
1548         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1549
1550         if (run_command(&cp))
1551                 die("could not reset submodule index");
1552 }
1553
1554 /**
1555  * Moves a submodule at a given path from a given head to another new head.
1556  * For edge cases (a submodule coming into existence or removing a submodule)
1557  * pass NULL for old or new respectively.
1558  */
1559 int submodule_move_head(const char *path,
1560                          const char *old,
1561                          const char *new,
1562                          unsigned flags)
1563 {
1564         int ret = 0;
1565         struct child_process cp = CHILD_PROCESS_INIT;
1566         const struct submodule *sub;
1567         int *error_code_ptr, error_code;
1568
1569         if (!is_submodule_active(the_repository, path))
1570                 return 0;
1571
1572         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1573                 /*
1574                  * Pass non NULL pointer to is_submodule_populated_gently
1575                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1576                  * to fixup the submodule in the force case later.
1577                  */
1578                 error_code_ptr = &error_code;
1579         else
1580                 error_code_ptr = NULL;
1581
1582         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1583                 return 0;
1584
1585         sub = submodule_from_path(null_sha1, path);
1586
1587         if (!sub)
1588                 die("BUG: could not get submodule information for '%s'", path);
1589
1590         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1591                 /* Check if the submodule has a dirty index. */
1592                 if (submodule_has_dirty_index(sub))
1593                         return error(_("submodule '%s' has dirty index"), path);
1594         }
1595
1596         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1597                 if (old) {
1598                         if (!submodule_uses_gitfile(path))
1599                                 absorb_git_dir_into_superproject("", path,
1600                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1601                 } else {
1602                         char *gitdir = xstrfmt("%s/modules/%s",
1603                                     get_git_common_dir(), sub->name);
1604                         connect_work_tree_and_git_dir(path, gitdir);
1605                         free(gitdir);
1606
1607                         /* make sure the index is clean as well */
1608                         submodule_reset_index(path);
1609                 }
1610
1611                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1612                         char *gitdir = xstrfmt("%s/modules/%s",
1613                                     get_git_common_dir(), sub->name);
1614                         connect_work_tree_and_git_dir(path, gitdir);
1615                         free(gitdir);
1616                 }
1617         }
1618
1619         prepare_submodule_repo_env(&cp.env_array);
1620
1621         cp.git_cmd = 1;
1622         cp.no_stdin = 1;
1623         cp.dir = path;
1624
1625         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1626                         get_super_prefix_or_empty(), path);
1627         argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1628
1629         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1630                 argv_array_push(&cp.args, "-n");
1631         else
1632                 argv_array_push(&cp.args, "-u");
1633
1634         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1635                 argv_array_push(&cp.args, "--reset");
1636         else
1637                 argv_array_push(&cp.args, "-m");
1638
1639         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1640         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1641
1642         if (run_command(&cp)) {
1643                 ret = -1;
1644                 goto out;
1645         }
1646
1647         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1648                 if (new) {
1649                         child_process_init(&cp);
1650                         /* also set the HEAD accordingly */
1651                         cp.git_cmd = 1;
1652                         cp.no_stdin = 1;
1653                         cp.dir = path;
1654
1655                         prepare_submodule_repo_env(&cp.env_array);
1656                         argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1657
1658                         if (run_command(&cp)) {
1659                                 ret = -1;
1660                                 goto out;
1661                         }
1662                 } else {
1663                         struct strbuf sb = STRBUF_INIT;
1664
1665                         strbuf_addf(&sb, "%s/.git", path);
1666                         unlink_or_warn(sb.buf);
1667                         strbuf_release(&sb);
1668
1669                         if (is_empty_dir(path))
1670                                 rmdir_or_warn(path);
1671                 }
1672         }
1673 out:
1674         return ret;
1675 }
1676
1677 static int find_first_merges(struct object_array *result, const char *path,
1678                 struct commit *a, struct commit *b)
1679 {
1680         int i, j;
1681         struct object_array merges = OBJECT_ARRAY_INIT;
1682         struct commit *commit;
1683         int contains_another;
1684
1685         char merged_revision[42];
1686         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1687                                    "--all", merged_revision, NULL };
1688         struct rev_info revs;
1689         struct setup_revision_opt rev_opts;
1690
1691         memset(result, 0, sizeof(struct object_array));
1692         memset(&rev_opts, 0, sizeof(rev_opts));
1693
1694         /* get all revisions that merge commit a */
1695         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1696                         oid_to_hex(&a->object.oid));
1697         init_revisions(&revs, NULL);
1698         rev_opts.submodule = path;
1699         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1700
1701         /* save all revisions from the above list that contain b */
1702         if (prepare_revision_walk(&revs))
1703                 die("revision walk setup failed");
1704         while ((commit = get_revision(&revs)) != NULL) {
1705                 struct object *o = &(commit->object);
1706                 if (in_merge_bases(b, commit))
1707                         add_object_array(o, NULL, &merges);
1708         }
1709         reset_revision_walk();
1710
1711         /* Now we've got all merges that contain a and b. Prune all
1712          * merges that contain another found merge and save them in
1713          * result.
1714          */
1715         for (i = 0; i < merges.nr; i++) {
1716                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1717
1718                 contains_another = 0;
1719                 for (j = 0; j < merges.nr; j++) {
1720                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1721                         if (i != j && in_merge_bases(m2, m1)) {
1722                                 contains_another = 1;
1723                                 break;
1724                         }
1725                 }
1726
1727                 if (!contains_another)
1728                         add_object_array(merges.objects[i].item, NULL, result);
1729         }
1730
1731         free(merges.objects);
1732         return result->nr;
1733 }
1734
1735 static void print_commit(struct commit *commit)
1736 {
1737         struct strbuf sb = STRBUF_INIT;
1738         struct pretty_print_context ctx = {0};
1739         ctx.date_mode.type = DATE_NORMAL;
1740         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1741         fprintf(stderr, "%s\n", sb.buf);
1742         strbuf_release(&sb);
1743 }
1744
1745 #define MERGE_WARNING(path, msg) \
1746         warning("Failed to merge submodule %s (%s)", path, msg);
1747
1748 int merge_submodule(struct object_id *result, const char *path,
1749                     const struct object_id *base, const struct object_id *a,
1750                     const struct object_id *b, int search)
1751 {
1752         struct commit *commit_base, *commit_a, *commit_b;
1753         int parent_count;
1754         struct object_array merges;
1755
1756         int i;
1757
1758         /* store a in result in case we fail */
1759         oidcpy(result, a);
1760
1761         /* we can not handle deletion conflicts */
1762         if (is_null_oid(base))
1763                 return 0;
1764         if (is_null_oid(a))
1765                 return 0;
1766         if (is_null_oid(b))
1767                 return 0;
1768
1769         if (add_submodule_odb(path)) {
1770                 MERGE_WARNING(path, "not checked out");
1771                 return 0;
1772         }
1773
1774         if (!(commit_base = lookup_commit_reference(base)) ||
1775             !(commit_a = lookup_commit_reference(a)) ||
1776             !(commit_b = lookup_commit_reference(b))) {
1777                 MERGE_WARNING(path, "commits not present");
1778                 return 0;
1779         }
1780
1781         /* check whether both changes are forward */
1782         if (!in_merge_bases(commit_base, commit_a) ||
1783             !in_merge_bases(commit_base, commit_b)) {
1784                 MERGE_WARNING(path, "commits don't follow merge-base");
1785                 return 0;
1786         }
1787
1788         /* Case #1: a is contained in b or vice versa */
1789         if (in_merge_bases(commit_a, commit_b)) {
1790                 oidcpy(result, b);
1791                 return 1;
1792         }
1793         if (in_merge_bases(commit_b, commit_a)) {
1794                 oidcpy(result, a);
1795                 return 1;
1796         }
1797
1798         /*
1799          * Case #2: There are one or more merges that contain a and b in
1800          * the submodule. If there is only one, then present it as a
1801          * suggestion to the user, but leave it marked unmerged so the
1802          * user needs to confirm the resolution.
1803          */
1804
1805         /* Skip the search if makes no sense to the calling context.  */
1806         if (!search)
1807                 return 0;
1808
1809         /* find commit which merges them */
1810         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1811         switch (parent_count) {
1812         case 0:
1813                 MERGE_WARNING(path, "merge following commits not found");
1814                 break;
1815
1816         case 1:
1817                 MERGE_WARNING(path, "not fast-forward");
1818                 fprintf(stderr, "Found a possible merge resolution "
1819                                 "for the submodule:\n");
1820                 print_commit((struct commit *) merges.objects[0].item);
1821                 fprintf(stderr,
1822                         "If this is correct simply add it to the index "
1823                         "for example\n"
1824                         "by using:\n\n"
1825                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1826                         "which will accept this suggestion.\n",
1827                         oid_to_hex(&merges.objects[0].item->oid), path);
1828                 break;
1829
1830         default:
1831                 MERGE_WARNING(path, "multiple merges found");
1832                 for (i = 0; i < merges.nr; i++)
1833                         print_commit((struct commit *) merges.objects[i].item);
1834         }
1835
1836         free(merges.objects);
1837         return 0;
1838 }
1839
1840 int parallel_submodules(void)
1841 {
1842         return parallel_jobs;
1843 }
1844
1845 /*
1846  * Embeds a single submodules git directory into the superprojects git dir,
1847  * non recursively.
1848  */
1849 static void relocate_single_git_dir_into_superproject(const char *prefix,
1850                                                       const char *path)
1851 {
1852         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1853         const char *new_git_dir;
1854         const struct submodule *sub;
1855
1856         if (submodule_uses_worktrees(path))
1857                 die(_("relocate_gitdir for submodule '%s' with "
1858                       "more than one worktree not supported"), path);
1859
1860         old_git_dir = xstrfmt("%s/.git", path);
1861         if (read_gitfile(old_git_dir))
1862                 /* If it is an actual gitfile, it doesn't need migration. */
1863                 return;
1864
1865         real_old_git_dir = real_pathdup(old_git_dir, 1);
1866
1867         sub = submodule_from_path(null_sha1, path);
1868         if (!sub)
1869                 die(_("could not lookup name for submodule '%s'"), path);
1870
1871         new_git_dir = git_path("modules/%s", sub->name);
1872         if (safe_create_leading_directories_const(new_git_dir) < 0)
1873                 die(_("could not create directory '%s'"), new_git_dir);
1874         real_new_git_dir = real_pathdup(new_git_dir, 1);
1875
1876         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1877                 get_super_prefix_or_empty(), path,
1878                 real_old_git_dir, real_new_git_dir);
1879
1880         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1881
1882         free(old_git_dir);
1883         free(real_old_git_dir);
1884         free(real_new_git_dir);
1885 }
1886
1887 /*
1888  * Migrate the git directory of the submodule given by path from
1889  * having its git directory within the working tree to the git dir nested
1890  * in its superprojects git dir under modules/.
1891  */
1892 void absorb_git_dir_into_superproject(const char *prefix,
1893                                       const char *path,
1894                                       unsigned flags)
1895 {
1896         int err_code;
1897         const char *sub_git_dir;
1898         struct strbuf gitdir = STRBUF_INIT;
1899         strbuf_addf(&gitdir, "%s/.git", path);
1900         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1901
1902         /* Not populated? */
1903         if (!sub_git_dir) {
1904                 const struct submodule *sub;
1905
1906                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1907                         /* unpopulated as expected */
1908                         strbuf_release(&gitdir);
1909                         return;
1910                 }
1911
1912                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1913                         /* We don't know what broke here. */
1914                         read_gitfile_error_die(err_code, path, NULL);
1915
1916                 /*
1917                 * Maybe populated, but no git directory was found?
1918                 * This can happen if the superproject is a submodule
1919                 * itself and was just absorbed. The absorption of the
1920                 * superproject did not rewrite the git file links yet,
1921                 * fix it now.
1922                 */
1923                 sub = submodule_from_path(null_sha1, path);
1924                 if (!sub)
1925                         die(_("could not lookup name for submodule '%s'"), path);
1926                 connect_work_tree_and_git_dir(path,
1927                         git_path("modules/%s", sub->name));
1928         } else {
1929                 /* Is it already absorbed into the superprojects git dir? */
1930                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1931                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1932
1933                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1934                         relocate_single_git_dir_into_superproject(prefix, path);
1935
1936                 free(real_sub_git_dir);
1937                 free(real_common_git_dir);
1938         }
1939         strbuf_release(&gitdir);
1940
1941         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1942                 struct child_process cp = CHILD_PROCESS_INIT;
1943                 struct strbuf sb = STRBUF_INIT;
1944
1945                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1946                         die("BUG: we don't know how to pass the flags down?");
1947
1948                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1949                 strbuf_addstr(&sb, path);
1950                 strbuf_addch(&sb, '/');
1951
1952                 cp.dir = path;
1953                 cp.git_cmd = 1;
1954                 cp.no_stdin = 1;
1955                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1956                                            "submodule--helper",
1957                                            "absorb-git-dirs", NULL);
1958                 prepare_submodule_repo_env(&cp.env_array);
1959                 if (run_command(&cp))
1960                         die(_("could not recurse into submodule '%s'"), path);
1961
1962                 strbuf_release(&sb);
1963         }
1964 }
1965
1966 const char *get_superproject_working_tree(void)
1967 {
1968         struct child_process cp = CHILD_PROCESS_INIT;
1969         struct strbuf sb = STRBUF_INIT;
1970         const char *one_up = real_path_if_valid("../");
1971         const char *cwd = xgetcwd();
1972         const char *ret = NULL;
1973         const char *subpath;
1974         int code;
1975         ssize_t len;
1976
1977         if (!is_inside_work_tree())
1978                 /*
1979                  * FIXME:
1980                  * We might have a superproject, but it is harder
1981                  * to determine.
1982                  */
1983                 return NULL;
1984
1985         if (!one_up)
1986                 return NULL;
1987
1988         subpath = relative_path(cwd, one_up, &sb);
1989
1990         prepare_submodule_repo_env(&cp.env_array);
1991         argv_array_pop(&cp.env_array);
1992
1993         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1994                         "ls-files", "-z", "--stage", "--full-name", "--",
1995                         subpath, NULL);
1996         strbuf_reset(&sb);
1997
1998         cp.no_stdin = 1;
1999         cp.no_stderr = 1;
2000         cp.out = -1;
2001         cp.git_cmd = 1;
2002
2003         if (start_command(&cp))
2004                 die(_("could not start ls-files in .."));
2005
2006         len = strbuf_read(&sb, cp.out, PATH_MAX);
2007         close(cp.out);
2008
2009         if (starts_with(sb.buf, "160000")) {
2010                 int super_sub_len;
2011                 int cwd_len = strlen(cwd);
2012                 char *super_sub, *super_wt;
2013
2014                 /*
2015                  * There is a superproject having this repo as a submodule.
2016                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2017                  * We're only interested in the name after the tab.
2018                  */
2019                 super_sub = strchr(sb.buf, '\t') + 1;
2020                 super_sub_len = sb.buf + sb.len - super_sub - 1;
2021
2022                 if (super_sub_len > cwd_len ||
2023                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2024                         die (_("BUG: returned path string doesn't match cwd?"));
2025
2026                 super_wt = xstrdup(cwd);
2027                 super_wt[cwd_len - super_sub_len] = '\0';
2028
2029                 ret = real_path(super_wt);
2030                 free(super_wt);
2031         }
2032         strbuf_release(&sb);
2033
2034         code = finish_command(&cp);
2035
2036         if (code == 128)
2037                 /* '../' is not a git repository */
2038                 return NULL;
2039         if (code == 0 && len == 0)
2040                 /* There is an unrelated git repository at '../' */
2041                 return NULL;
2042         if (code)
2043                 die(_("ls-tree returned unexpected return code %d"), code);
2044
2045         return ret;
2046 }
2047
2048 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2049 {
2050         const struct submodule *sub;
2051         const char *git_dir;
2052         int ret = 0;
2053
2054         strbuf_reset(buf);
2055         strbuf_addstr(buf, submodule);
2056         strbuf_complete(buf, '/');
2057         strbuf_addstr(buf, ".git");
2058
2059         git_dir = read_gitfile(buf->buf);
2060         if (git_dir) {
2061                 strbuf_reset(buf);
2062                 strbuf_addstr(buf, git_dir);
2063         }
2064         if (!is_git_directory(buf->buf)) {
2065                 gitmodules_config();
2066                 sub = submodule_from_path(null_sha1, submodule);
2067                 if (!sub) {
2068                         ret = -1;
2069                         goto cleanup;
2070                 }
2071                 strbuf_reset(buf);
2072                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2073         }
2074
2075 cleanup:
2076         return ret;
2077 }