submodule: make 'checkout' update_module mode more explicit
[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 #include "blob.h"
14
15 static struct string_list config_name_for_path;
16 static struct string_list config_fetch_recurse_submodules_for_name;
17 static struct string_list config_ignore_for_name;
18 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
19 static struct string_list changed_submodule_paths;
20 static int initialized_fetch_ref_tips;
21 static struct sha1_array ref_tips_before_fetch;
22 static struct sha1_array ref_tips_after_fetch;
23
24 /*
25  * The following flag is set if the .gitmodules file is unmerged. We then
26  * disable recursion for all submodules where .git/config doesn't have a
27  * matching config entry because we can't guess what might be configured in
28  * .gitmodules unless the user resolves the conflict. When a command line
29  * option is given (which always overrides configuration) this flag will be
30  * ignored.
31  */
32 static int gitmodules_is_unmerged;
33
34 /*
35  * This flag is set if the .gitmodules file had unstaged modifications on
36  * startup. This must be checked before allowing modifications to the
37  * .gitmodules file with the intention to stage them later, because when
38  * continuing we would stage the modifications the user didn't stage herself
39  * too. That might change in a future version when we learn to stage the
40  * changes we do ourselves without staging any previous modifications.
41  */
42 static int gitmodules_is_modified;
43
44
45 int is_staging_gitmodules_ok(void)
46 {
47         return !gitmodules_is_modified;
48 }
49
50 /*
51  * Try to update the "path" entry in the "submodule.<name>" section of the
52  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
53  * with the correct path=<oldpath> setting was found and we could update it.
54  */
55 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
56 {
57         struct strbuf entry = STRBUF_INIT;
58         struct string_list_item *path_option;
59
60         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
61                 return -1;
62
63         if (gitmodules_is_unmerged)
64                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
65
66         path_option = unsorted_string_list_lookup(&config_name_for_path, oldpath);
67         if (!path_option) {
68                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
69                 return -1;
70         }
71         strbuf_addstr(&entry, "submodule.");
72         strbuf_addstr(&entry, path_option->util);
73         strbuf_addstr(&entry, ".path");
74         if (git_config_set_in_file(".gitmodules", entry.buf, newpath) < 0) {
75                 /* Maybe the user already did that, don't error out here */
76                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
77                 strbuf_release(&entry);
78                 return -1;
79         }
80         strbuf_release(&entry);
81         return 0;
82 }
83
84 /*
85  * Try to remove the "submodule.<name>" section from .gitmodules where the given
86  * path is configured. Return 0 only if a .gitmodules file was found, a section
87  * with the correct path=<path> setting was found and we could remove it.
88  */
89 int remove_path_from_gitmodules(const char *path)
90 {
91         struct strbuf sect = STRBUF_INIT;
92         struct string_list_item *path_option;
93
94         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
95                 return -1;
96
97         if (gitmodules_is_unmerged)
98                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
99
100         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
101         if (!path_option) {
102                 warning(_("Could not find section in .gitmodules where path=%s"), path);
103                 return -1;
104         }
105         strbuf_addstr(&sect, "submodule.");
106         strbuf_addstr(&sect, path_option->util);
107         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
108                 /* Maybe the user already did that, don't error out here */
109                 warning(_("Could not remove .gitmodules entry for %s"), path);
110                 strbuf_release(&sect);
111                 return -1;
112         }
113         strbuf_release(&sect);
114         return 0;
115 }
116
117 void stage_updated_gitmodules(void)
118 {
119         struct strbuf buf = STRBUF_INIT;
120         struct stat st;
121         int pos;
122         struct cache_entry *ce;
123         int namelen = strlen(".gitmodules");
124
125         pos = cache_name_pos(".gitmodules", namelen);
126         if (pos < 0) {
127                 warning(_("could not find .gitmodules in index"));
128                 return;
129         }
130         ce = active_cache[pos];
131         ce->ce_flags = namelen;
132         if (strbuf_read_file(&buf, ".gitmodules", 0) < 0)
133                 die(_("reading updated .gitmodules failed"));
134         if (lstat(".gitmodules", &st) < 0)
135                 die_errno(_("unable to stat updated .gitmodules"));
136         fill_stat_cache_info(ce, &st);
137         ce->ce_mode = ce_mode_from_stat(ce, st.st_mode);
138         if (remove_cache_entry_at(pos) < 0)
139                 die(_("unable to remove .gitmodules from index"));
140         if (write_sha1_file(buf.buf, buf.len, blob_type, ce->sha1))
141                 die(_("adding updated .gitmodules failed"));
142         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
143                 die(_("staging updated .gitmodules failed"));
144 }
145
146 static int add_submodule_odb(const char *path)
147 {
148         struct strbuf objects_directory = STRBUF_INIT;
149         struct alternate_object_database *alt_odb;
150         int ret = 0;
151         const char *git_dir;
152
153         strbuf_addf(&objects_directory, "%s/.git", path);
154         git_dir = read_gitfile(objects_directory.buf);
155         if (git_dir) {
156                 strbuf_reset(&objects_directory);
157                 strbuf_addstr(&objects_directory, git_dir);
158         }
159         strbuf_addstr(&objects_directory, "/objects/");
160         if (!is_directory(objects_directory.buf)) {
161                 ret = -1;
162                 goto done;
163         }
164         /* avoid adding it twice */
165         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
166                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
167                                 !strncmp(alt_odb->base, objects_directory.buf,
168                                         objects_directory.len))
169                         goto done;
170
171         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
172         alt_odb->next = alt_odb_list;
173         strcpy(alt_odb->base, objects_directory.buf);
174         alt_odb->name = alt_odb->base + objects_directory.len;
175         alt_odb->name[2] = '/';
176         alt_odb->name[40] = '\0';
177         alt_odb->name[41] = '\0';
178         alt_odb_list = alt_odb;
179
180         /* add possible alternates from the submodule */
181         read_info_alternates(objects_directory.buf, 0);
182         prepare_alt_odb();
183 done:
184         strbuf_release(&objects_directory);
185         return ret;
186 }
187
188 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
189                                              const char *path)
190 {
191         struct string_list_item *path_option, *ignore_option;
192         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
193         if (path_option) {
194                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
195                 if (ignore_option)
196                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
197                 else if (gitmodules_is_unmerged)
198                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
199         }
200 }
201
202 int submodule_config(const char *var, const char *value, void *cb)
203 {
204         if (!prefixcmp(var, "submodule."))
205                 return parse_submodule_config_option(var, value);
206         else if (!strcmp(var, "fetch.recursesubmodules")) {
207                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
208                 return 0;
209         }
210         return 0;
211 }
212
213 void gitmodules_config(void)
214 {
215         const char *work_tree = get_git_work_tree();
216         if (work_tree) {
217                 struct strbuf gitmodules_path = STRBUF_INIT;
218                 int pos;
219                 strbuf_addstr(&gitmodules_path, work_tree);
220                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
221                 if (read_cache() < 0)
222                         die("index file corrupt");
223                 pos = cache_name_pos(".gitmodules", 11);
224                 if (pos < 0) { /* .gitmodules not found or isn't merged */
225                         pos = -1 - pos;
226                         if (active_nr > pos) {  /* there is a .gitmodules */
227                                 const struct cache_entry *ce = active_cache[pos];
228                                 if (ce_namelen(ce) == 11 &&
229                                     !memcmp(ce->name, ".gitmodules", 11))
230                                         gitmodules_is_unmerged = 1;
231                         }
232                 } else if (pos < active_nr) {
233                         struct stat st;
234                         if (lstat(".gitmodules", &st) == 0 &&
235                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
236                                 gitmodules_is_modified = 1;
237                 }
238
239                 if (!gitmodules_is_unmerged)
240                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
241                 strbuf_release(&gitmodules_path);
242         }
243 }
244
245 int parse_submodule_config_option(const char *var, const char *value)
246 {
247         struct string_list_item *config;
248         const char *name, *key;
249         int namelen;
250
251         if (parse_config_key(var, "submodule", &name, &namelen, &key) < 0 || !name)
252                 return 0;
253
254         if (!strcmp(key, "path")) {
255                 if (!value)
256                         return config_error_nonbool(var);
257
258                 config = unsorted_string_list_lookup(&config_name_for_path, value);
259                 if (config)
260                         free(config->util);
261                 else
262                         config = string_list_append(&config_name_for_path, xstrdup(value));
263                 config->util = xmemdupz(name, namelen);
264         } else if (!strcmp(key, "fetchrecursesubmodules")) {
265                 char *name_cstr = xmemdupz(name, namelen);
266                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name_cstr);
267                 if (!config)
268                         config = string_list_append(&config_fetch_recurse_submodules_for_name, name_cstr);
269                 else
270                         free(name_cstr);
271                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
272         } else if (!strcmp(key, "ignore")) {
273                 char *name_cstr;
274
275                 if (!value)
276                         return config_error_nonbool(var);
277
278                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
279                     strcmp(value, "all") && strcmp(value, "none")) {
280                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
281                         return 0;
282                 }
283
284                 name_cstr = xmemdupz(name, namelen);
285                 config = unsorted_string_list_lookup(&config_ignore_for_name, name_cstr);
286                 if (config) {
287                         free(config->util);
288                         free(name_cstr);
289                 } else
290                         config = string_list_append(&config_ignore_for_name, name_cstr);
291                 config->util = xstrdup(value);
292                 return 0;
293         }
294         return 0;
295 }
296
297 void handle_ignore_submodules_arg(struct diff_options *diffopt,
298                                   const char *arg)
299 {
300         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
301         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
302         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
303
304         if (!strcmp(arg, "all"))
305                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
306         else if (!strcmp(arg, "untracked"))
307                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
308         else if (!strcmp(arg, "dirty"))
309                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
310         else if (strcmp(arg, "none"))
311                 die("bad --ignore-submodules argument: %s", arg);
312 }
313
314 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
315                 struct commit *left, struct commit *right,
316                 int *fast_forward, int *fast_backward)
317 {
318         struct commit_list *merge_bases, *list;
319
320         init_revisions(rev, NULL);
321         setup_revisions(0, NULL, rev, NULL);
322         rev->left_right = 1;
323         rev->first_parent_only = 1;
324         left->object.flags |= SYMMETRIC_LEFT;
325         add_pending_object(rev, &left->object, path);
326         add_pending_object(rev, &right->object, path);
327         merge_bases = get_merge_bases(left, right, 1);
328         if (merge_bases) {
329                 if (merge_bases->item == left)
330                         *fast_forward = 1;
331                 else if (merge_bases->item == right)
332                         *fast_backward = 1;
333         }
334         for (list = merge_bases; list; list = list->next) {
335                 list->item->object.flags |= UNINTERESTING;
336                 add_pending_object(rev, &list->item->object,
337                         sha1_to_hex(list->item->object.sha1));
338         }
339         return prepare_revision_walk(rev);
340 }
341
342 static void print_submodule_summary(struct rev_info *rev, FILE *f,
343                 const char *line_prefix,
344                 const char *del, const char *add, const char *reset)
345 {
346         static const char format[] = "  %m %s";
347         struct strbuf sb = STRBUF_INIT;
348         struct commit *commit;
349
350         while ((commit = get_revision(rev))) {
351                 struct pretty_print_context ctx = {0};
352                 ctx.date_mode = rev->date_mode;
353                 ctx.output_encoding = get_log_output_encoding();
354                 strbuf_setlen(&sb, 0);
355                 strbuf_addstr(&sb, line_prefix);
356                 if (commit->object.flags & SYMMETRIC_LEFT) {
357                         if (del)
358                                 strbuf_addstr(&sb, del);
359                 }
360                 else if (add)
361                         strbuf_addstr(&sb, add);
362                 format_commit_message(commit, format, &sb, &ctx);
363                 if (reset)
364                         strbuf_addstr(&sb, reset);
365                 strbuf_addch(&sb, '\n');
366                 fprintf(f, "%s", sb.buf);
367         }
368         strbuf_release(&sb);
369 }
370
371 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
372 {
373         switch (git_config_maybe_bool(opt, arg)) {
374         case 1:
375                 return RECURSE_SUBMODULES_ON;
376         case 0:
377                 return RECURSE_SUBMODULES_OFF;
378         default:
379                 if (!strcmp(arg, "on-demand"))
380                         return RECURSE_SUBMODULES_ON_DEMAND;
381                 die("bad %s argument: %s", opt, arg);
382         }
383 }
384
385 void show_submodule_summary(FILE *f, const char *path,
386                 const char *line_prefix,
387                 unsigned char one[20], unsigned char two[20],
388                 unsigned dirty_submodule, const char *meta,
389                 const char *del, const char *add, const char *reset)
390 {
391         struct rev_info rev;
392         struct commit *left = NULL, *right = NULL;
393         const char *message = NULL;
394         struct strbuf sb = STRBUF_INIT;
395         int fast_forward = 0, fast_backward = 0;
396
397         if (is_null_sha1(two))
398                 message = "(submodule deleted)";
399         else if (add_submodule_odb(path))
400                 message = "(not checked out)";
401         else if (is_null_sha1(one))
402                 message = "(new submodule)";
403         else if (!(left = lookup_commit_reference(one)) ||
404                  !(right = lookup_commit_reference(two)))
405                 message = "(commits not present)";
406         else if (prepare_submodule_summary(&rev, path, left, right,
407                                            &fast_forward, &fast_backward))
408                 message = "(revision walker failed)";
409
410         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
411                 fprintf(f, "%sSubmodule %s contains untracked content\n",
412                         line_prefix, path);
413         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
414                 fprintf(f, "%sSubmodule %s contains modified content\n",
415                         line_prefix, path);
416
417         if (!hashcmp(one, two)) {
418                 strbuf_release(&sb);
419                 return;
420         }
421
422         strbuf_addf(&sb, "%s%sSubmodule %s %s..", line_prefix, meta, path,
423                         find_unique_abbrev(one, DEFAULT_ABBREV));
424         if (!fast_backward && !fast_forward)
425                 strbuf_addch(&sb, '.');
426         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
427         if (message)
428                 strbuf_addf(&sb, " %s%s\n", message, reset);
429         else
430                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
431         fwrite(sb.buf, sb.len, 1, f);
432
433         if (!message) /* only NULL if we succeeded in setting up the walk */
434                 print_submodule_summary(&rev, f, line_prefix, del, add, reset);
435         if (left)
436                 clear_commit_marks(left, ~0);
437         if (right)
438                 clear_commit_marks(right, ~0);
439
440         strbuf_release(&sb);
441 }
442
443 void set_config_fetch_recurse_submodules(int value)
444 {
445         config_fetch_recurse_submodules = value;
446 }
447
448 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
449 {
450         return 1;
451 }
452
453 static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
454 {
455         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
456                 return 0;
457
458         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
459                 struct child_process cp;
460                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
461                 struct strbuf buf = STRBUF_INIT;
462                 int needs_pushing = 0;
463
464                 argv[1] = sha1_to_hex(sha1);
465                 memset(&cp, 0, sizeof(cp));
466                 cp.argv = argv;
467                 cp.env = local_repo_env;
468                 cp.git_cmd = 1;
469                 cp.no_stdin = 1;
470                 cp.out = -1;
471                 cp.dir = path;
472                 if (start_command(&cp))
473                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
474                                 sha1_to_hex(sha1), path);
475                 if (strbuf_read(&buf, cp.out, 41))
476                         needs_pushing = 1;
477                 finish_command(&cp);
478                 close(cp.out);
479                 strbuf_release(&buf);
480                 return needs_pushing;
481         }
482
483         return 0;
484 }
485
486 static void collect_submodules_from_diff(struct diff_queue_struct *q,
487                                          struct diff_options *options,
488                                          void *data)
489 {
490         int i;
491         struct string_list *needs_pushing = data;
492
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                 if (submodule_needs_pushing(p->two->path, p->two->sha1))
498                         string_list_insert(needs_pushing, p->two->path);
499         }
500 }
501
502 static void find_unpushed_submodule_commits(struct commit *commit,
503                 struct string_list *needs_pushing)
504 {
505         struct rev_info rev;
506
507         init_revisions(&rev, NULL);
508         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
509         rev.diffopt.format_callback = collect_submodules_from_diff;
510         rev.diffopt.format_callback_data = needs_pushing;
511         diff_tree_combined_merge(commit, 1, &rev);
512 }
513
514 int find_unpushed_submodules(unsigned char new_sha1[20],
515                 const char *remotes_name, struct string_list *needs_pushing)
516 {
517         struct rev_info rev;
518         struct commit *commit;
519         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
520         int argc = ARRAY_SIZE(argv) - 1;
521         char *sha1_copy;
522
523         struct strbuf remotes_arg = STRBUF_INIT;
524
525         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
526         init_revisions(&rev, NULL);
527         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
528         argv[1] = sha1_copy;
529         argv[3] = remotes_arg.buf;
530         setup_revisions(argc, argv, &rev, NULL);
531         if (prepare_revision_walk(&rev))
532                 die("revision walk setup failed");
533
534         while ((commit = get_revision(&rev)) != NULL)
535                 find_unpushed_submodule_commits(commit, needs_pushing);
536
537         reset_revision_walk();
538         free(sha1_copy);
539         strbuf_release(&remotes_arg);
540
541         return needs_pushing->nr;
542 }
543
544 static int push_submodule(const char *path)
545 {
546         if (add_submodule_odb(path))
547                 return 1;
548
549         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
550                 struct child_process cp;
551                 const char *argv[] = {"push", NULL};
552
553                 memset(&cp, 0, sizeof(cp));
554                 cp.argv = argv;
555                 cp.env = local_repo_env;
556                 cp.git_cmd = 1;
557                 cp.no_stdin = 1;
558                 cp.dir = path;
559                 if (run_command(&cp))
560                         return 0;
561                 close(cp.out);
562         }
563
564         return 1;
565 }
566
567 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
568 {
569         int i, ret = 1;
570         struct string_list needs_pushing;
571
572         memset(&needs_pushing, 0, sizeof(struct string_list));
573         needs_pushing.strdup_strings = 1;
574
575         if (!find_unpushed_submodules(new_sha1, remotes_name, &needs_pushing))
576                 return 1;
577
578         for (i = 0; i < needs_pushing.nr; i++) {
579                 const char *path = needs_pushing.items[i].string;
580                 fprintf(stderr, "Pushing submodule '%s'\n", path);
581                 if (!push_submodule(path)) {
582                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
583                         ret = 0;
584                 }
585         }
586
587         string_list_clear(&needs_pushing, 0);
588
589         return ret;
590 }
591
592 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
593 {
594         int is_present = 0;
595         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
596                 /* Even if the submodule is checked out and the commit is
597                  * present, make sure it is reachable from a ref. */
598                 struct child_process cp;
599                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
600                 struct strbuf buf = STRBUF_INIT;
601
602                 argv[3] = sha1_to_hex(sha1);
603                 memset(&cp, 0, sizeof(cp));
604                 cp.argv = argv;
605                 cp.env = local_repo_env;
606                 cp.git_cmd = 1;
607                 cp.no_stdin = 1;
608                 cp.out = -1;
609                 cp.dir = path;
610                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
611                         is_present = 1;
612
613                 close(cp.out);
614                 strbuf_release(&buf);
615         }
616         return is_present;
617 }
618
619 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
620                                          struct diff_options *options,
621                                          void *data)
622 {
623         int i;
624         for (i = 0; i < q->nr; i++) {
625                 struct diff_filepair *p = q->queue[i];
626                 if (!S_ISGITLINK(p->two->mode))
627                         continue;
628
629                 if (S_ISGITLINK(p->one->mode)) {
630                         /* NEEDSWORK: We should honor the name configured in
631                          * the .gitmodules file of the commit we are examining
632                          * here to be able to correctly follow submodules
633                          * being moved around. */
634                         struct string_list_item *path;
635                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
636                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
637                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
638                 } else {
639                         /* Submodule is new or was moved here */
640                         /* NEEDSWORK: When the .git directories of submodules
641                          * live inside the superprojects .git directory some
642                          * day we should fetch new submodules directly into
643                          * that location too when config or options request
644                          * that so they can be checked out from there. */
645                         continue;
646                 }
647         }
648 }
649
650 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
651                              int flags, void *data)
652 {
653         sha1_array_append(data, sha1);
654         return 0;
655 }
656
657 void check_for_new_submodule_commits(unsigned char new_sha1[20])
658 {
659         if (!initialized_fetch_ref_tips) {
660                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
661                 initialized_fetch_ref_tips = 1;
662         }
663
664         sha1_array_append(&ref_tips_after_fetch, new_sha1);
665 }
666
667 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
668 {
669         argv_array_push(data, sha1_to_hex(sha1));
670 }
671
672 static void calculate_changed_submodule_paths(void)
673 {
674         struct rev_info rev;
675         struct commit *commit;
676         struct argv_array argv = ARGV_ARRAY_INIT;
677
678         /* No need to check if there are no submodules configured */
679         if (!config_name_for_path.nr)
680                 return;
681
682         init_revisions(&rev, NULL);
683         argv_array_push(&argv, "--"); /* argv[0] program name */
684         sha1_array_for_each_unique(&ref_tips_after_fetch,
685                                    add_sha1_to_argv, &argv);
686         argv_array_push(&argv, "--not");
687         sha1_array_for_each_unique(&ref_tips_before_fetch,
688                                    add_sha1_to_argv, &argv);
689         setup_revisions(argv.argc, argv.argv, &rev, NULL);
690         if (prepare_revision_walk(&rev))
691                 die("revision walk setup failed");
692
693         /*
694          * Collect all submodules (whether checked out or not) for which new
695          * commits have been recorded upstream in "changed_submodule_paths".
696          */
697         while ((commit = get_revision(&rev))) {
698                 struct commit_list *parent = commit->parents;
699                 while (parent) {
700                         struct diff_options diff_opts;
701                         diff_setup(&diff_opts);
702                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
703                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
704                         diff_opts.format_callback = submodule_collect_changed_cb;
705                         diff_setup_done(&diff_opts);
706                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
707                         diffcore_std(&diff_opts);
708                         diff_flush(&diff_opts);
709                         parent = parent->next;
710                 }
711         }
712
713         argv_array_clear(&argv);
714         sha1_array_clear(&ref_tips_before_fetch);
715         sha1_array_clear(&ref_tips_after_fetch);
716         initialized_fetch_ref_tips = 0;
717 }
718
719 int fetch_populated_submodules(const struct argv_array *options,
720                                const char *prefix, int command_line_option,
721                                int quiet)
722 {
723         int i, result = 0;
724         struct child_process cp;
725         struct argv_array argv = ARGV_ARRAY_INIT;
726         struct string_list_item *name_for_path;
727         const char *work_tree = get_git_work_tree();
728         if (!work_tree)
729                 goto out;
730
731         if (read_cache() < 0)
732                 die("index file corrupt");
733
734         argv_array_push(&argv, "fetch");
735         for (i = 0; i < options->argc; i++)
736                 argv_array_push(&argv, options->argv[i]);
737         argv_array_push(&argv, "--recurse-submodules-default");
738         /* default value, "--submodule-prefix" and its value are added later */
739
740         memset(&cp, 0, sizeof(cp));
741         cp.env = local_repo_env;
742         cp.git_cmd = 1;
743         cp.no_stdin = 1;
744
745         calculate_changed_submodule_paths();
746
747         for (i = 0; i < active_nr; i++) {
748                 struct strbuf submodule_path = STRBUF_INIT;
749                 struct strbuf submodule_git_dir = STRBUF_INIT;
750                 struct strbuf submodule_prefix = STRBUF_INIT;
751                 const struct cache_entry *ce = active_cache[i];
752                 const char *git_dir, *name, *default_argv;
753
754                 if (!S_ISGITLINK(ce->ce_mode))
755                         continue;
756
757                 name = ce->name;
758                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
759                 if (name_for_path)
760                         name = name_for_path->util;
761
762                 default_argv = "yes";
763                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
764                         struct string_list_item *fetch_recurse_submodules_option;
765                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
766                         if (fetch_recurse_submodules_option) {
767                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
768                                         continue;
769                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
770                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
771                                                 continue;
772                                         default_argv = "on-demand";
773                                 }
774                         } else {
775                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
776                                     gitmodules_is_unmerged)
777                                         continue;
778                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
779                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
780                                                 continue;
781                                         default_argv = "on-demand";
782                                 }
783                         }
784                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
785                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
786                                 continue;
787                         default_argv = "on-demand";
788                 }
789
790                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
791                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
792                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
793                 git_dir = read_gitfile(submodule_git_dir.buf);
794                 if (!git_dir)
795                         git_dir = submodule_git_dir.buf;
796                 if (is_directory(git_dir)) {
797                         if (!quiet)
798                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
799                         cp.dir = submodule_path.buf;
800                         argv_array_push(&argv, default_argv);
801                         argv_array_push(&argv, "--submodule-prefix");
802                         argv_array_push(&argv, submodule_prefix.buf);
803                         cp.argv = argv.argv;
804                         if (run_command(&cp))
805                                 result = 1;
806                         argv_array_pop(&argv);
807                         argv_array_pop(&argv);
808                         argv_array_pop(&argv);
809                 }
810                 strbuf_release(&submodule_path);
811                 strbuf_release(&submodule_git_dir);
812                 strbuf_release(&submodule_prefix);
813         }
814         argv_array_clear(&argv);
815 out:
816         string_list_clear(&changed_submodule_paths, 1);
817         return result;
818 }
819
820 unsigned is_submodule_modified(const char *path, int ignore_untracked)
821 {
822         ssize_t len;
823         struct child_process cp;
824         const char *argv[] = {
825                 "status",
826                 "--porcelain",
827                 NULL,
828                 NULL,
829         };
830         struct strbuf buf = STRBUF_INIT;
831         unsigned dirty_submodule = 0;
832         const char *line, *next_line;
833         const char *git_dir;
834
835         strbuf_addf(&buf, "%s/.git", path);
836         git_dir = read_gitfile(buf.buf);
837         if (!git_dir)
838                 git_dir = buf.buf;
839         if (!is_directory(git_dir)) {
840                 strbuf_release(&buf);
841                 /* The submodule is not checked out, so it is not modified */
842                 return 0;
843
844         }
845         strbuf_reset(&buf);
846
847         if (ignore_untracked)
848                 argv[2] = "-uno";
849
850         memset(&cp, 0, sizeof(cp));
851         cp.argv = argv;
852         cp.env = local_repo_env;
853         cp.git_cmd = 1;
854         cp.no_stdin = 1;
855         cp.out = -1;
856         cp.dir = path;
857         if (start_command(&cp))
858                 die("Could not run 'git status --porcelain' in submodule %s", path);
859
860         len = strbuf_read(&buf, cp.out, 1024);
861         line = buf.buf;
862         while (len > 2) {
863                 if ((line[0] == '?') && (line[1] == '?')) {
864                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
865                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
866                                 break;
867                 } else {
868                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
869                         if (ignore_untracked ||
870                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
871                                 break;
872                 }
873                 next_line = strchr(line, '\n');
874                 if (!next_line)
875                         break;
876                 next_line++;
877                 len -= (next_line - line);
878                 line = next_line;
879         }
880         close(cp.out);
881
882         if (finish_command(&cp))
883                 die("'git status --porcelain' failed in submodule %s", path);
884
885         strbuf_release(&buf);
886         return dirty_submodule;
887 }
888
889 int submodule_uses_gitfile(const char *path)
890 {
891         struct child_process cp;
892         const char *argv[] = {
893                 "submodule",
894                 "foreach",
895                 "--quiet",
896                 "--recursive",
897                 "test -f .git",
898                 NULL,
899         };
900         struct strbuf buf = STRBUF_INIT;
901         const char *git_dir;
902
903         strbuf_addf(&buf, "%s/.git", path);
904         git_dir = read_gitfile(buf.buf);
905         if (!git_dir) {
906                 strbuf_release(&buf);
907                 return 0;
908         }
909         strbuf_release(&buf);
910
911         /* Now test that all nested submodules use a gitfile too */
912         memset(&cp, 0, sizeof(cp));
913         cp.argv = argv;
914         cp.env = local_repo_env;
915         cp.git_cmd = 1;
916         cp.no_stdin = 1;
917         cp.no_stderr = 1;
918         cp.no_stdout = 1;
919         cp.dir = path;
920         if (run_command(&cp))
921                 return 0;
922
923         return 1;
924 }
925
926 int ok_to_remove_submodule(const char *path)
927 {
928         struct stat st;
929         ssize_t len;
930         struct child_process cp;
931         const char *argv[] = {
932                 "status",
933                 "--porcelain",
934                 "-u",
935                 "--ignore-submodules=none",
936                 NULL,
937         };
938         struct strbuf buf = STRBUF_INIT;
939         int ok_to_remove = 1;
940
941         if ((lstat(path, &st) < 0) || is_empty_dir(path))
942                 return 1;
943
944         if (!submodule_uses_gitfile(path))
945                 return 0;
946
947         memset(&cp, 0, sizeof(cp));
948         cp.argv = argv;
949         cp.env = local_repo_env;
950         cp.git_cmd = 1;
951         cp.no_stdin = 1;
952         cp.out = -1;
953         cp.dir = path;
954         if (start_command(&cp))
955                 die("Could not run 'git status --porcelain -uall --ignore-submodules=none' in submodule %s", path);
956
957         len = strbuf_read(&buf, cp.out, 1024);
958         if (len > 2)
959                 ok_to_remove = 0;
960         close(cp.out);
961
962         if (finish_command(&cp))
963                 die("'git status --porcelain -uall --ignore-submodules=none' failed in submodule %s", path);
964
965         strbuf_release(&buf);
966         return ok_to_remove;
967 }
968
969 static int find_first_merges(struct object_array *result, const char *path,
970                 struct commit *a, struct commit *b)
971 {
972         int i, j;
973         struct object_array merges = OBJECT_ARRAY_INIT;
974         struct commit *commit;
975         int contains_another;
976
977         char merged_revision[42];
978         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
979                                    "--all", merged_revision, NULL };
980         struct rev_info revs;
981         struct setup_revision_opt rev_opts;
982
983         memset(result, 0, sizeof(struct object_array));
984         memset(&rev_opts, 0, sizeof(rev_opts));
985
986         /* get all revisions that merge commit a */
987         snprintf(merged_revision, sizeof(merged_revision), "^%s",
988                         sha1_to_hex(a->object.sha1));
989         init_revisions(&revs, NULL);
990         rev_opts.submodule = path;
991         setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
992
993         /* save all revisions from the above list that contain b */
994         if (prepare_revision_walk(&revs))
995                 die("revision walk setup failed");
996         while ((commit = get_revision(&revs)) != NULL) {
997                 struct object *o = &(commit->object);
998                 if (in_merge_bases(b, commit))
999                         add_object_array(o, NULL, &merges);
1000         }
1001         reset_revision_walk();
1002
1003         /* Now we've got all merges that contain a and b. Prune all
1004          * merges that contain another found merge and save them in
1005          * result.
1006          */
1007         for (i = 0; i < merges.nr; i++) {
1008                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1009
1010                 contains_another = 0;
1011                 for (j = 0; j < merges.nr; j++) {
1012                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1013                         if (i != j && in_merge_bases(m2, m1)) {
1014                                 contains_another = 1;
1015                                 break;
1016                         }
1017                 }
1018
1019                 if (!contains_another)
1020                         add_object_array(merges.objects[i].item, NULL, result);
1021         }
1022
1023         free(merges.objects);
1024         return result->nr;
1025 }
1026
1027 static void print_commit(struct commit *commit)
1028 {
1029         struct strbuf sb = STRBUF_INIT;
1030         struct pretty_print_context ctx = {0};
1031         ctx.date_mode = DATE_NORMAL;
1032         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1033         fprintf(stderr, "%s\n", sb.buf);
1034         strbuf_release(&sb);
1035 }
1036
1037 #define MERGE_WARNING(path, msg) \
1038         warning("Failed to merge submodule %s (%s)", path, msg);
1039
1040 int merge_submodule(unsigned char result[20], const char *path,
1041                     const unsigned char base[20], const unsigned char a[20],
1042                     const unsigned char b[20], int search)
1043 {
1044         struct commit *commit_base, *commit_a, *commit_b;
1045         int parent_count;
1046         struct object_array merges;
1047
1048         int i;
1049
1050         /* store a in result in case we fail */
1051         hashcpy(result, a);
1052
1053         /* we can not handle deletion conflicts */
1054         if (is_null_sha1(base))
1055                 return 0;
1056         if (is_null_sha1(a))
1057                 return 0;
1058         if (is_null_sha1(b))
1059                 return 0;
1060
1061         if (add_submodule_odb(path)) {
1062                 MERGE_WARNING(path, "not checked out");
1063                 return 0;
1064         }
1065
1066         if (!(commit_base = lookup_commit_reference(base)) ||
1067             !(commit_a = lookup_commit_reference(a)) ||
1068             !(commit_b = lookup_commit_reference(b))) {
1069                 MERGE_WARNING(path, "commits not present");
1070                 return 0;
1071         }
1072
1073         /* check whether both changes are forward */
1074         if (!in_merge_bases(commit_base, commit_a) ||
1075             !in_merge_bases(commit_base, commit_b)) {
1076                 MERGE_WARNING(path, "commits don't follow merge-base");
1077                 return 0;
1078         }
1079
1080         /* Case #1: a is contained in b or vice versa */
1081         if (in_merge_bases(commit_a, commit_b)) {
1082                 hashcpy(result, b);
1083                 return 1;
1084         }
1085         if (in_merge_bases(commit_b, commit_a)) {
1086                 hashcpy(result, a);
1087                 return 1;
1088         }
1089
1090         /*
1091          * Case #2: There are one or more merges that contain a and b in
1092          * the submodule. If there is only one, then present it as a
1093          * suggestion to the user, but leave it marked unmerged so the
1094          * user needs to confirm the resolution.
1095          */
1096
1097         /* Skip the search if makes no sense to the calling context.  */
1098         if (!search)
1099                 return 0;
1100
1101         /* find commit which merges them */
1102         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1103         switch (parent_count) {
1104         case 0:
1105                 MERGE_WARNING(path, "merge following commits not found");
1106                 break;
1107
1108         case 1:
1109                 MERGE_WARNING(path, "not fast-forward");
1110                 fprintf(stderr, "Found a possible merge resolution "
1111                                 "for the submodule:\n");
1112                 print_commit((struct commit *) merges.objects[0].item);
1113                 fprintf(stderr,
1114                         "If this is correct simply add it to the index "
1115                         "for example\n"
1116                         "by using:\n\n"
1117                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1118                         "which will accept this suggestion.\n",
1119                         sha1_to_hex(merges.objects[0].item->sha1), path);
1120                 break;
1121
1122         default:
1123                 MERGE_WARNING(path, "multiple merges found");
1124                 for (i = 0; i < merges.nr; i++)
1125                         print_commit((struct commit *) merges.objects[i].item);
1126         }
1127
1128         free(merges.objects);
1129         return 0;
1130 }
1131
1132 /* Update gitfile and core.worktree setting to connect work tree and git dir */
1133 void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
1134 {
1135         struct strbuf file_name = STRBUF_INIT;
1136         struct strbuf rel_path = STRBUF_INIT;
1137         const char *real_work_tree = xstrdup(real_path(work_tree));
1138         FILE *fp;
1139
1140         /* Update gitfile */
1141         strbuf_addf(&file_name, "%s/.git", work_tree);
1142         fp = fopen(file_name.buf, "w");
1143         if (!fp)
1144                 die(_("Could not create git link %s"), file_name.buf);
1145         fprintf(fp, "gitdir: %s\n", relative_path(git_dir, real_work_tree,
1146                                                   &rel_path));
1147         fclose(fp);
1148
1149         /* Update core.worktree setting */
1150         strbuf_reset(&file_name);
1151         strbuf_addf(&file_name, "%s/config", git_dir);
1152         if (git_config_set_in_file(file_name.buf, "core.worktree",
1153                                    relative_path(real_work_tree, git_dir,
1154                                                  &rel_path)))
1155                 die(_("Could not set core.worktree in %s"),
1156                     file_name.buf);
1157
1158         strbuf_release(&file_name);
1159         strbuf_release(&rel_path);
1160         free((void *)real_work_tree);
1161 }