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