Merge branch 'jc/maint-doc-checkout-b-always-takes-branch-name'
[git] / submodule.c
1 #include "cache.h"
2 #include "submodule.h"
3 #include "dir.h"
4 #include "diff.h"
5 #include "commit.h"
6 #include "revision.h"
7 #include "run-command.h"
8 #include "diffcore.h"
9 #include "refs.h"
10 #include "string-list.h"
11 #include "sha1-array.h"
12 #include "argv-array.h"
13
14 static struct string_list config_name_for_path;
15 static struct string_list config_fetch_recurse_submodules_for_name;
16 static struct string_list config_ignore_for_name;
17 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
18 static struct string_list changed_submodule_paths;
19 static int initialized_fetch_ref_tips;
20 static struct sha1_array ref_tips_before_fetch;
21 static struct sha1_array ref_tips_after_fetch;
22
23 /*
24  * The following flag is set if the .gitmodules file is unmerged. We then
25  * disable recursion for all submodules where .git/config doesn't have a
26  * matching config entry because we can't guess what might be configured in
27  * .gitmodules unless the user resolves the conflict. When a command line
28  * option is given (which always overrides configuration) this flag will be
29  * ignored.
30  */
31 static int gitmodules_is_unmerged;
32
33 static int add_submodule_odb(const char *path)
34 {
35         struct strbuf objects_directory = STRBUF_INIT;
36         struct alternate_object_database *alt_odb;
37         int ret = 0;
38         const char *git_dir;
39
40         strbuf_addf(&objects_directory, "%s/.git", path);
41         git_dir = read_gitfile(objects_directory.buf);
42         if (git_dir) {
43                 strbuf_reset(&objects_directory);
44                 strbuf_addstr(&objects_directory, git_dir);
45         }
46         strbuf_addstr(&objects_directory, "/objects/");
47         if (!is_directory(objects_directory.buf)) {
48                 ret = -1;
49                 goto done;
50         }
51         /* avoid adding it twice */
52         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
53                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
54                                 !strncmp(alt_odb->base, objects_directory.buf,
55                                         objects_directory.len))
56                         goto done;
57
58         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
59         alt_odb->next = alt_odb_list;
60         strcpy(alt_odb->base, objects_directory.buf);
61         alt_odb->name = alt_odb->base + objects_directory.len;
62         alt_odb->name[2] = '/';
63         alt_odb->name[40] = '\0';
64         alt_odb->name[41] = '\0';
65         alt_odb_list = alt_odb;
66
67         /* add possible alternates from the submodule */
68         read_info_alternates(objects_directory.buf, 0);
69         prepare_alt_odb();
70 done:
71         strbuf_release(&objects_directory);
72         return ret;
73 }
74
75 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
76                                              const char *path)
77 {
78         struct string_list_item *path_option, *ignore_option;
79         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
80         if (path_option) {
81                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
82                 if (ignore_option)
83                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
84                 else if (gitmodules_is_unmerged)
85                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
86         }
87 }
88
89 int submodule_config(const char *var, const char *value, void *cb)
90 {
91         if (!prefixcmp(var, "submodule."))
92                 return parse_submodule_config_option(var, value);
93         else if (!strcmp(var, "fetch.recursesubmodules")) {
94                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
95                 return 0;
96         }
97         return 0;
98 }
99
100 void gitmodules_config(void)
101 {
102         const char *work_tree = get_git_work_tree();
103         if (work_tree) {
104                 struct strbuf gitmodules_path = STRBUF_INIT;
105                 int pos;
106                 strbuf_addstr(&gitmodules_path, work_tree);
107                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
108                 if (read_cache() < 0)
109                         die("index file corrupt");
110                 pos = cache_name_pos(".gitmodules", 11);
111                 if (pos < 0) { /* .gitmodules not found or isn't merged */
112                         pos = -1 - pos;
113                         if (active_nr > pos) {  /* there is a .gitmodules */
114                                 const struct cache_entry *ce = active_cache[pos];
115                                 if (ce_namelen(ce) == 11 &&
116                                     !memcmp(ce->name, ".gitmodules", 11))
117                                         gitmodules_is_unmerged = 1;
118                         }
119                 }
120
121                 if (!gitmodules_is_unmerged)
122                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
123                 strbuf_release(&gitmodules_path);
124         }
125 }
126
127 int parse_submodule_config_option(const char *var, const char *value)
128 {
129         int len;
130         struct string_list_item *config;
131         struct strbuf submodname = STRBUF_INIT;
132
133         var += 10;              /* Skip "submodule." */
134
135         len = strlen(var);
136         if ((len > 5) && !strcmp(var + len - 5, ".path")) {
137                 strbuf_add(&submodname, var, len - 5);
138                 config = unsorted_string_list_lookup(&config_name_for_path, value);
139                 if (config)
140                         free(config->util);
141                 else
142                         config = string_list_append(&config_name_for_path, xstrdup(value));
143                 config->util = strbuf_detach(&submodname, NULL);
144                 strbuf_release(&submodname);
145         } else if ((len > 23) && !strcmp(var + len - 23, ".fetchrecursesubmodules")) {
146                 strbuf_add(&submodname, var, len - 23);
147                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
148                 if (!config)
149                         config = string_list_append(&config_fetch_recurse_submodules_for_name,
150                                                     strbuf_detach(&submodname, NULL));
151                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
152                 strbuf_release(&submodname);
153         } else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
154                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
155                     strcmp(value, "all") && strcmp(value, "none")) {
156                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
157                         return 0;
158                 }
159
160                 strbuf_add(&submodname, var, len - 7);
161                 config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
162                 if (config)
163                         free(config->util);
164                 else
165                         config = string_list_append(&config_ignore_for_name,
166                                                     strbuf_detach(&submodname, NULL));
167                 strbuf_release(&submodname);
168                 config->util = xstrdup(value);
169                 return 0;
170         }
171         return 0;
172 }
173
174 void handle_ignore_submodules_arg(struct diff_options *diffopt,
175                                   const char *arg)
176 {
177         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
178         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
179         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
180
181         if (!strcmp(arg, "all"))
182                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
183         else if (!strcmp(arg, "untracked"))
184                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
185         else if (!strcmp(arg, "dirty"))
186                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
187         else if (strcmp(arg, "none"))
188                 die("bad --ignore-submodules argument: %s", arg);
189 }
190
191 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
192                 struct commit *left, struct commit *right,
193                 int *fast_forward, int *fast_backward)
194 {
195         struct commit_list *merge_bases, *list;
196
197         init_revisions(rev, NULL);
198         setup_revisions(0, NULL, rev, NULL);
199         rev->left_right = 1;
200         rev->first_parent_only = 1;
201         left->object.flags |= SYMMETRIC_LEFT;
202         add_pending_object(rev, &left->object, path);
203         add_pending_object(rev, &right->object, path);
204         merge_bases = get_merge_bases(left, right, 1);
205         if (merge_bases) {
206                 if (merge_bases->item == left)
207                         *fast_forward = 1;
208                 else if (merge_bases->item == right)
209                         *fast_backward = 1;
210         }
211         for (list = merge_bases; list; list = list->next) {
212                 list->item->object.flags |= UNINTERESTING;
213                 add_pending_object(rev, &list->item->object,
214                         sha1_to_hex(list->item->object.sha1));
215         }
216         return prepare_revision_walk(rev);
217 }
218
219 static void print_submodule_summary(struct rev_info *rev, FILE *f,
220                 const char *del, const char *add, const char *reset)
221 {
222         static const char format[] = "  %m %s";
223         struct strbuf sb = STRBUF_INIT;
224         struct commit *commit;
225
226         while ((commit = get_revision(rev))) {
227                 struct pretty_print_context ctx = {0};
228                 ctx.date_mode = rev->date_mode;
229                 strbuf_setlen(&sb, 0);
230                 if (commit->object.flags & SYMMETRIC_LEFT) {
231                         if (del)
232                                 strbuf_addstr(&sb, del);
233                 }
234                 else if (add)
235                         strbuf_addstr(&sb, add);
236                 format_commit_message(commit, format, &sb, &ctx);
237                 if (reset)
238                         strbuf_addstr(&sb, reset);
239                 strbuf_addch(&sb, '\n');
240                 fprintf(f, "%s", sb.buf);
241         }
242         strbuf_release(&sb);
243 }
244
245 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
246 {
247         switch (git_config_maybe_bool(opt, arg)) {
248         case 1:
249                 return RECURSE_SUBMODULES_ON;
250         case 0:
251                 return RECURSE_SUBMODULES_OFF;
252         default:
253                 if (!strcmp(arg, "on-demand"))
254                         return RECURSE_SUBMODULES_ON_DEMAND;
255                 die("bad %s argument: %s", opt, arg);
256         }
257 }
258
259 void show_submodule_summary(FILE *f, const char *path,
260                 unsigned char one[20], unsigned char two[20],
261                 unsigned dirty_submodule,
262                 const char *del, const char *add, const char *reset)
263 {
264         struct rev_info rev;
265         struct commit *left = left, *right = right;
266         const char *message = NULL;
267         struct strbuf sb = STRBUF_INIT;
268         int fast_forward = 0, fast_backward = 0;
269
270         if (is_null_sha1(two))
271                 message = "(submodule deleted)";
272         else if (add_submodule_odb(path))
273                 message = "(not checked out)";
274         else if (is_null_sha1(one))
275                 message = "(new submodule)";
276         else if (!(left = lookup_commit_reference(one)) ||
277                  !(right = lookup_commit_reference(two)))
278                 message = "(commits not present)";
279
280         if (!message &&
281             prepare_submodule_summary(&rev, path, left, right,
282                                         &fast_forward, &fast_backward))
283                 message = "(revision walker failed)";
284
285         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
286                 fprintf(f, "Submodule %s contains untracked content\n", path);
287         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
288                 fprintf(f, "Submodule %s contains modified content\n", path);
289
290         if (!hashcmp(one, two)) {
291                 strbuf_release(&sb);
292                 return;
293         }
294
295         strbuf_addf(&sb, "Submodule %s %s..", path,
296                         find_unique_abbrev(one, DEFAULT_ABBREV));
297         if (!fast_backward && !fast_forward)
298                 strbuf_addch(&sb, '.');
299         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
300         if (message)
301                 strbuf_addf(&sb, " %s\n", message);
302         else
303                 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
304         fwrite(sb.buf, sb.len, 1, f);
305
306         if (!message) {
307                 print_submodule_summary(&rev, f, del, add, reset);
308                 clear_commit_marks(left, ~0);
309                 clear_commit_marks(right, ~0);
310         }
311
312         strbuf_release(&sb);
313 }
314
315 void set_config_fetch_recurse_submodules(int value)
316 {
317         config_fetch_recurse_submodules = value;
318 }
319
320 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
321 {
322         return 1;
323 }
324
325 static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
326 {
327         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
328                 return 0;
329
330         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
331                 struct child_process cp;
332                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
333                 struct strbuf buf = STRBUF_INIT;
334                 int needs_pushing = 0;
335
336                 argv[1] = sha1_to_hex(sha1);
337                 memset(&cp, 0, sizeof(cp));
338                 cp.argv = argv;
339                 cp.env = local_repo_env;
340                 cp.git_cmd = 1;
341                 cp.no_stdin = 1;
342                 cp.out = -1;
343                 cp.dir = path;
344                 if (start_command(&cp))
345                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
346                                 sha1_to_hex(sha1), path);
347                 if (strbuf_read(&buf, cp.out, 41))
348                         needs_pushing = 1;
349                 finish_command(&cp);
350                 close(cp.out);
351                 strbuf_release(&buf);
352                 return needs_pushing;
353         }
354
355         return 0;
356 }
357
358 static void collect_submodules_from_diff(struct diff_queue_struct *q,
359                                          struct diff_options *options,
360                                          void *data)
361 {
362         int i;
363         struct string_list *needs_pushing = data;
364
365         for (i = 0; i < q->nr; i++) {
366                 struct diff_filepair *p = q->queue[i];
367                 if (!S_ISGITLINK(p->two->mode))
368                         continue;
369                 if (submodule_needs_pushing(p->two->path, p->two->sha1))
370                         string_list_insert(needs_pushing, p->two->path);
371         }
372 }
373
374 static void find_unpushed_submodule_commits(struct commit *commit,
375                 struct string_list *needs_pushing)
376 {
377         struct rev_info rev;
378
379         init_revisions(&rev, NULL);
380         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
381         rev.diffopt.format_callback = collect_submodules_from_diff;
382         rev.diffopt.format_callback_data = needs_pushing;
383         diff_tree_combined_merge(commit, 1, &rev);
384 }
385
386 int find_unpushed_submodules(unsigned char new_sha1[20],
387                 const char *remotes_name, struct string_list *needs_pushing)
388 {
389         struct rev_info rev;
390         struct commit *commit;
391         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
392         int argc = ARRAY_SIZE(argv) - 1;
393         char *sha1_copy;
394
395         struct strbuf remotes_arg = STRBUF_INIT;
396
397         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
398         init_revisions(&rev, NULL);
399         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
400         argv[1] = sha1_copy;
401         argv[3] = remotes_arg.buf;
402         setup_revisions(argc, argv, &rev, NULL);
403         if (prepare_revision_walk(&rev))
404                 die("revision walk setup failed");
405
406         while ((commit = get_revision(&rev)) != NULL)
407                 find_unpushed_submodule_commits(commit, needs_pushing);
408
409         reset_revision_walk();
410         free(sha1_copy);
411         strbuf_release(&remotes_arg);
412
413         return needs_pushing->nr;
414 }
415
416 static int push_submodule(const char *path)
417 {
418         if (add_submodule_odb(path))
419                 return 1;
420
421         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
422                 struct child_process cp;
423                 const char *argv[] = {"push", NULL};
424
425                 memset(&cp, 0, sizeof(cp));
426                 cp.argv = argv;
427                 cp.env = local_repo_env;
428                 cp.git_cmd = 1;
429                 cp.no_stdin = 1;
430                 cp.dir = path;
431                 if (run_command(&cp))
432                         return 0;
433                 close(cp.out);
434         }
435
436         return 1;
437 }
438
439 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
440 {
441         int i, ret = 1;
442         struct string_list needs_pushing;
443
444         memset(&needs_pushing, 0, sizeof(struct string_list));
445         needs_pushing.strdup_strings = 1;
446
447         if (!find_unpushed_submodules(new_sha1, remotes_name, &needs_pushing))
448                 return 1;
449
450         for (i = 0; i < needs_pushing.nr; i++) {
451                 const char *path = needs_pushing.items[i].string;
452                 fprintf(stderr, "Pushing submodule '%s'\n", path);
453                 if (!push_submodule(path)) {
454                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
455                         ret = 0;
456                 }
457         }
458
459         string_list_clear(&needs_pushing, 0);
460
461         return ret;
462 }
463
464 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
465 {
466         int is_present = 0;
467         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
468                 /* Even if the submodule is checked out and the commit is
469                  * present, make sure it is reachable from a ref. */
470                 struct child_process cp;
471                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
472                 struct strbuf buf = STRBUF_INIT;
473
474                 argv[3] = sha1_to_hex(sha1);
475                 memset(&cp, 0, sizeof(cp));
476                 cp.argv = argv;
477                 cp.env = local_repo_env;
478                 cp.git_cmd = 1;
479                 cp.no_stdin = 1;
480                 cp.out = -1;
481                 cp.dir = path;
482                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
483                         is_present = 1;
484
485                 close(cp.out);
486                 strbuf_release(&buf);
487         }
488         return is_present;
489 }
490
491 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
492                                          struct diff_options *options,
493                                          void *data)
494 {
495         int i;
496         for (i = 0; i < q->nr; i++) {
497                 struct diff_filepair *p = q->queue[i];
498                 if (!S_ISGITLINK(p->two->mode))
499                         continue;
500
501                 if (S_ISGITLINK(p->one->mode)) {
502                         /* NEEDSWORK: We should honor the name configured in
503                          * the .gitmodules file of the commit we are examining
504                          * here to be able to correctly follow submodules
505                          * being moved around. */
506                         struct string_list_item *path;
507                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
508                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
509                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
510                 } else {
511                         /* Submodule is new or was moved here */
512                         /* NEEDSWORK: When the .git directories of submodules
513                          * live inside the superprojects .git directory some
514                          * day we should fetch new submodules directly into
515                          * that location too when config or options request
516                          * that so they can be checked out from there. */
517                         continue;
518                 }
519         }
520 }
521
522 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
523                              int flags, void *data)
524 {
525         sha1_array_append(data, sha1);
526         return 0;
527 }
528
529 void check_for_new_submodule_commits(unsigned char new_sha1[20])
530 {
531         if (!initialized_fetch_ref_tips) {
532                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
533                 initialized_fetch_ref_tips = 1;
534         }
535
536         sha1_array_append(&ref_tips_after_fetch, new_sha1);
537 }
538
539 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
540 {
541         argv_array_push(data, sha1_to_hex(sha1));
542 }
543
544 static void calculate_changed_submodule_paths(void)
545 {
546         struct rev_info rev;
547         struct commit *commit;
548         struct argv_array argv = ARGV_ARRAY_INIT;
549
550         /* No need to check if there are no submodules configured */
551         if (!config_name_for_path.nr)
552                 return;
553
554         init_revisions(&rev, NULL);
555         argv_array_push(&argv, "--"); /* argv[0] program name */
556         sha1_array_for_each_unique(&ref_tips_after_fetch,
557                                    add_sha1_to_argv, &argv);
558         argv_array_push(&argv, "--not");
559         sha1_array_for_each_unique(&ref_tips_before_fetch,
560                                    add_sha1_to_argv, &argv);
561         setup_revisions(argv.argc, argv.argv, &rev, NULL);
562         if (prepare_revision_walk(&rev))
563                 die("revision walk setup failed");
564
565         /*
566          * Collect all submodules (whether checked out or not) for which new
567          * commits have been recorded upstream in "changed_submodule_paths".
568          */
569         while ((commit = get_revision(&rev))) {
570                 struct commit_list *parent = commit->parents;
571                 while (parent) {
572                         struct diff_options diff_opts;
573                         diff_setup(&diff_opts);
574                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
575                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
576                         diff_opts.format_callback = submodule_collect_changed_cb;
577                         diff_setup_done(&diff_opts);
578                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
579                         diffcore_std(&diff_opts);
580                         diff_flush(&diff_opts);
581                         parent = parent->next;
582                 }
583         }
584
585         argv_array_clear(&argv);
586         sha1_array_clear(&ref_tips_before_fetch);
587         sha1_array_clear(&ref_tips_after_fetch);
588         initialized_fetch_ref_tips = 0;
589 }
590
591 int fetch_populated_submodules(int num_options, const char **options,
592                                const char *prefix, int command_line_option,
593                                int quiet)
594 {
595         int i, result = 0, argc = 0, default_argc;
596         struct child_process cp;
597         const char **argv;
598         struct string_list_item *name_for_path;
599         const char *work_tree = get_git_work_tree();
600         if (!work_tree)
601                 goto out;
602
603         if (!the_index.initialized)
604                 if (read_cache() < 0)
605                         die("index file corrupt");
606
607         /* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
608         argv = xcalloc(num_options + 6, sizeof(const char *));
609         argv[argc++] = "fetch";
610         for (i = 0; i < num_options; i++)
611                 argv[argc++] = options[i];
612         argv[argc++] = "--recurse-submodules-default";
613         default_argc = argc++;
614         argv[argc++] = "--submodule-prefix";
615
616         memset(&cp, 0, sizeof(cp));
617         cp.argv = argv;
618         cp.env = local_repo_env;
619         cp.git_cmd = 1;
620         cp.no_stdin = 1;
621
622         calculate_changed_submodule_paths();
623
624         for (i = 0; i < active_nr; i++) {
625                 struct strbuf submodule_path = STRBUF_INIT;
626                 struct strbuf submodule_git_dir = STRBUF_INIT;
627                 struct strbuf submodule_prefix = STRBUF_INIT;
628                 struct cache_entry *ce = active_cache[i];
629                 const char *git_dir, *name, *default_argv;
630
631                 if (!S_ISGITLINK(ce->ce_mode))
632                         continue;
633
634                 name = ce->name;
635                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
636                 if (name_for_path)
637                         name = name_for_path->util;
638
639                 default_argv = "yes";
640                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
641                         struct string_list_item *fetch_recurse_submodules_option;
642                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
643                         if (fetch_recurse_submodules_option) {
644                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
645                                         continue;
646                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
647                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
648                                                 continue;
649                                         default_argv = "on-demand";
650                                 }
651                         } else {
652                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
653                                     gitmodules_is_unmerged)
654                                         continue;
655                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
656                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
657                                                 continue;
658                                         default_argv = "on-demand";
659                                 }
660                         }
661                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
662                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
663                                 continue;
664                         default_argv = "on-demand";
665                 }
666
667                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
668                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
669                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
670                 git_dir = read_gitfile(submodule_git_dir.buf);
671                 if (!git_dir)
672                         git_dir = submodule_git_dir.buf;
673                 if (is_directory(git_dir)) {
674                         if (!quiet)
675                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
676                         cp.dir = submodule_path.buf;
677                         argv[default_argc] = default_argv;
678                         argv[argc] = submodule_prefix.buf;
679                         if (run_command(&cp))
680                                 result = 1;
681                 }
682                 strbuf_release(&submodule_path);
683                 strbuf_release(&submodule_git_dir);
684                 strbuf_release(&submodule_prefix);
685         }
686         free(argv);
687 out:
688         string_list_clear(&changed_submodule_paths, 1);
689         return result;
690 }
691
692 unsigned is_submodule_modified(const char *path, int ignore_untracked)
693 {
694         ssize_t len;
695         struct child_process cp;
696         const char *argv[] = {
697                 "status",
698                 "--porcelain",
699                 NULL,
700                 NULL,
701         };
702         struct strbuf buf = STRBUF_INIT;
703         unsigned dirty_submodule = 0;
704         const char *line, *next_line;
705         const char *git_dir;
706
707         strbuf_addf(&buf, "%s/.git", path);
708         git_dir = read_gitfile(buf.buf);
709         if (!git_dir)
710                 git_dir = buf.buf;
711         if (!is_directory(git_dir)) {
712                 strbuf_release(&buf);
713                 /* The submodule is not checked out, so it is not modified */
714                 return 0;
715
716         }
717         strbuf_reset(&buf);
718
719         if (ignore_untracked)
720                 argv[2] = "-uno";
721
722         memset(&cp, 0, sizeof(cp));
723         cp.argv = argv;
724         cp.env = local_repo_env;
725         cp.git_cmd = 1;
726         cp.no_stdin = 1;
727         cp.out = -1;
728         cp.dir = path;
729         if (start_command(&cp))
730                 die("Could not run 'git status --porcelain' in submodule %s", path);
731
732         len = strbuf_read(&buf, cp.out, 1024);
733         line = buf.buf;
734         while (len > 2) {
735                 if ((line[0] == '?') && (line[1] == '?')) {
736                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
737                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
738                                 break;
739                 } else {
740                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
741                         if (ignore_untracked ||
742                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
743                                 break;
744                 }
745                 next_line = strchr(line, '\n');
746                 if (!next_line)
747                         break;
748                 next_line++;
749                 len -= (next_line - line);
750                 line = next_line;
751         }
752         close(cp.out);
753
754         if (finish_command(&cp))
755                 die("'git status --porcelain' failed in submodule %s", path);
756
757         strbuf_release(&buf);
758         return dirty_submodule;
759 }
760
761 static int find_first_merges(struct object_array *result, const char *path,
762                 struct commit *a, struct commit *b)
763 {
764         int i, j;
765         struct object_array merges;
766         struct commit *commit;
767         int contains_another;
768
769         char merged_revision[42];
770         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
771                                    "--all", merged_revision, NULL };
772         struct rev_info revs;
773         struct setup_revision_opt rev_opts;
774
775         memset(&merges, 0, sizeof(merges));
776         memset(result, 0, sizeof(struct object_array));
777         memset(&rev_opts, 0, sizeof(rev_opts));
778
779         /* get all revisions that merge commit a */
780         snprintf(merged_revision, sizeof(merged_revision), "^%s",
781                         sha1_to_hex(a->object.sha1));
782         init_revisions(&revs, NULL);
783         rev_opts.submodule = path;
784         setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
785
786         /* save all revisions from the above list that contain b */
787         if (prepare_revision_walk(&revs))
788                 die("revision walk setup failed");
789         while ((commit = get_revision(&revs)) != NULL) {
790                 struct object *o = &(commit->object);
791                 if (in_merge_bases(b, &commit, 1))
792                         add_object_array(o, NULL, &merges);
793         }
794         reset_revision_walk();
795
796         /* Now we've got all merges that contain a and b. Prune all
797          * merges that contain another found merge and save them in
798          * result.
799          */
800         for (i = 0; i < merges.nr; i++) {
801                 struct commit *m1 = (struct commit *) merges.objects[i].item;
802
803                 contains_another = 0;
804                 for (j = 0; j < merges.nr; j++) {
805                         struct commit *m2 = (struct commit *) merges.objects[j].item;
806                         if (i != j && in_merge_bases(m2, &m1, 1)) {
807                                 contains_another = 1;
808                                 break;
809                         }
810                 }
811
812                 if (!contains_another)
813                         add_object_array(merges.objects[i].item,
814                                          merges.objects[i].name, result);
815         }
816
817         free(merges.objects);
818         return result->nr;
819 }
820
821 static void print_commit(struct commit *commit)
822 {
823         struct strbuf sb = STRBUF_INIT;
824         struct pretty_print_context ctx = {0};
825         ctx.date_mode = DATE_NORMAL;
826         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
827         fprintf(stderr, "%s\n", sb.buf);
828         strbuf_release(&sb);
829 }
830
831 #define MERGE_WARNING(path, msg) \
832         warning("Failed to merge submodule %s (%s)", path, msg);
833
834 int merge_submodule(unsigned char result[20], const char *path,
835                     const unsigned char base[20], const unsigned char a[20],
836                     const unsigned char b[20], int search)
837 {
838         struct commit *commit_base, *commit_a, *commit_b;
839         int parent_count;
840         struct object_array merges;
841
842         int i;
843
844         /* store a in result in case we fail */
845         hashcpy(result, a);
846
847         /* we can not handle deletion conflicts */
848         if (is_null_sha1(base))
849                 return 0;
850         if (is_null_sha1(a))
851                 return 0;
852         if (is_null_sha1(b))
853                 return 0;
854
855         if (add_submodule_odb(path)) {
856                 MERGE_WARNING(path, "not checked out");
857                 return 0;
858         }
859
860         if (!(commit_base = lookup_commit_reference(base)) ||
861             !(commit_a = lookup_commit_reference(a)) ||
862             !(commit_b = lookup_commit_reference(b))) {
863                 MERGE_WARNING(path, "commits not present");
864                 return 0;
865         }
866
867         /* check whether both changes are forward */
868         if (!in_merge_bases(commit_base, &commit_a, 1) ||
869             !in_merge_bases(commit_base, &commit_b, 1)) {
870                 MERGE_WARNING(path, "commits don't follow merge-base");
871                 return 0;
872         }
873
874         /* Case #1: a is contained in b or vice versa */
875         if (in_merge_bases(commit_a, &commit_b, 1)) {
876                 hashcpy(result, b);
877                 return 1;
878         }
879         if (in_merge_bases(commit_b, &commit_a, 1)) {
880                 hashcpy(result, a);
881                 return 1;
882         }
883
884         /*
885          * Case #2: There are one or more merges that contain a and b in
886          * the submodule. If there is only one, then present it as a
887          * suggestion to the user, but leave it marked unmerged so the
888          * user needs to confirm the resolution.
889          */
890
891         /* Skip the search if makes no sense to the calling context.  */
892         if (!search)
893                 return 0;
894
895         /* find commit which merges them */
896         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
897         switch (parent_count) {
898         case 0:
899                 MERGE_WARNING(path, "merge following commits not found");
900                 break;
901
902         case 1:
903                 MERGE_WARNING(path, "not fast-forward");
904                 fprintf(stderr, "Found a possible merge resolution "
905                                 "for the submodule:\n");
906                 print_commit((struct commit *) merges.objects[0].item);
907                 fprintf(stderr,
908                         "If this is correct simply add it to the index "
909                         "for example\n"
910                         "by using:\n\n"
911                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
912                         "which will accept this suggestion.\n",
913                         sha1_to_hex(merges.objects[0].item->sha1), path);
914                 break;
915
916         default:
917                 MERGE_WARNING(path, "multiple merges found");
918                 for (i = 0; i < merges.nr; i++)
919                         print_commit((struct commit *) merges.objects[i].item);
920         }
921
922         free(merges.objects);
923         return 0;
924 }