submodule.c: submodule_move_head works with broken submodules
[git] / submodule.c
1 #include "cache.h"
2 #include "submodule-config.h"
3 #include "submodule.h"
4 #include "dir.h"
5 #include "diff.h"
6 #include "commit.h"
7 #include "revision.h"
8 #include "run-command.h"
9 #include "diffcore.h"
10 #include "refs.h"
11 #include "string-list.h"
12 #include "sha1-array.h"
13 #include "argv-array.h"
14 #include "blob.h"
15 #include "thread-utils.h"
16 #include "quote.h"
17 #include "worktree.h"
18
19 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
20 static int config_update_recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
21 static int parallel_jobs = 1;
22 static struct string_list changed_submodule_paths = STRING_LIST_INIT_NODUP;
23 static int initialized_fetch_ref_tips;
24 static struct sha1_array ref_tips_before_fetch;
25 static struct sha1_array ref_tips_after_fetch;
26
27 /*
28  * The following flag is set if the .gitmodules file is unmerged. We then
29  * disable recursion for all submodules where .git/config doesn't have a
30  * matching config entry because we can't guess what might be configured in
31  * .gitmodules unless the user resolves the conflict. When a command line
32  * option is given (which always overrides configuration) this flag will be
33  * ignored.
34  */
35 static int gitmodules_is_unmerged;
36
37 /*
38  * This flag is set if the .gitmodules file had unstaged modifications on
39  * startup. This must be checked before allowing modifications to the
40  * .gitmodules file with the intention to stage them later, because when
41  * continuing we would stage the modifications the user didn't stage herself
42  * too. That might change in a future version when we learn to stage the
43  * changes we do ourselves without staging any previous modifications.
44  */
45 static int gitmodules_is_modified;
46
47 int is_staging_gitmodules_ok(void)
48 {
49         return !gitmodules_is_modified;
50 }
51
52 /*
53  * Try to update the "path" entry in the "submodule.<name>" section of the
54  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
55  * with the correct path=<oldpath> setting was found and we could update it.
56  */
57 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
58 {
59         struct strbuf entry = STRBUF_INIT;
60         const struct submodule *submodule;
61
62         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
63                 return -1;
64
65         if (gitmodules_is_unmerged)
66                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
67
68         submodule = submodule_from_path(null_sha1, oldpath);
69         if (!submodule || !submodule->name) {
70                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
71                 return -1;
72         }
73         strbuf_addstr(&entry, "submodule.");
74         strbuf_addstr(&entry, submodule->name);
75         strbuf_addstr(&entry, ".path");
76         if (git_config_set_in_file_gently(".gitmodules", entry.buf, newpath) < 0) {
77                 /* Maybe the user already did that, don't error out here */
78                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
79                 strbuf_release(&entry);
80                 return -1;
81         }
82         strbuf_release(&entry);
83         return 0;
84 }
85
86 /*
87  * Try to remove the "submodule.<name>" section from .gitmodules where the given
88  * path is configured. Return 0 only if a .gitmodules file was found, a section
89  * with the correct path=<path> setting was found and we could remove it.
90  */
91 int remove_path_from_gitmodules(const char *path)
92 {
93         struct strbuf sect = STRBUF_INIT;
94         const struct submodule *submodule;
95
96         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
97                 return -1;
98
99         if (gitmodules_is_unmerged)
100                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
101
102         submodule = submodule_from_path(null_sha1, path);
103         if (!submodule || !submodule->name) {
104                 warning(_("Could not find section in .gitmodules where path=%s"), path);
105                 return -1;
106         }
107         strbuf_addstr(&sect, "submodule.");
108         strbuf_addstr(&sect, submodule->name);
109         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
110                 /* Maybe the user already did that, don't error out here */
111                 warning(_("Could not remove .gitmodules entry for %s"), path);
112                 strbuf_release(&sect);
113                 return -1;
114         }
115         strbuf_release(&sect);
116         return 0;
117 }
118
119 void stage_updated_gitmodules(void)
120 {
121         if (add_file_to_cache(".gitmodules", 0))
122                 die(_("staging updated .gitmodules failed"));
123 }
124
125 static int add_submodule_odb(const char *path)
126 {
127         struct strbuf objects_directory = STRBUF_INIT;
128         int ret = 0;
129
130         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
131         if (ret)
132                 goto done;
133         if (!is_directory(objects_directory.buf)) {
134                 ret = -1;
135                 goto done;
136         }
137         add_to_alternates_memory(objects_directory.buf);
138 done:
139         strbuf_release(&objects_directory);
140         return ret;
141 }
142
143 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
144                                              const char *path)
145 {
146         const struct submodule *submodule = submodule_from_path(null_sha1, path);
147         if (submodule) {
148                 if (submodule->ignore)
149                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
150                 else if (gitmodules_is_unmerged)
151                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
152         }
153 }
154
155 int submodule_config(const char *var, const char *value, void *cb)
156 {
157         if (!strcmp(var, "submodule.fetchjobs")) {
158                 parallel_jobs = git_config_int(var, value);
159                 if (parallel_jobs < 0)
160                         die(_("negative values not allowed for submodule.fetchJobs"));
161                 return 0;
162         } else if (starts_with(var, "submodule."))
163                 return parse_submodule_config_option(var, value);
164         else if (!strcmp(var, "fetch.recursesubmodules")) {
165                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
166                 return 0;
167         }
168         return 0;
169 }
170
171 void gitmodules_config(void)
172 {
173         const char *work_tree = get_git_work_tree();
174         if (work_tree) {
175                 struct strbuf gitmodules_path = STRBUF_INIT;
176                 int pos;
177                 strbuf_addstr(&gitmodules_path, work_tree);
178                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
179                 if (read_cache() < 0)
180                         die("index file corrupt");
181                 pos = cache_name_pos(".gitmodules", 11);
182                 if (pos < 0) { /* .gitmodules not found or isn't merged */
183                         pos = -1 - pos;
184                         if (active_nr > pos) {  /* there is a .gitmodules */
185                                 const struct cache_entry *ce = active_cache[pos];
186                                 if (ce_namelen(ce) == 11 &&
187                                     !memcmp(ce->name, ".gitmodules", 11))
188                                         gitmodules_is_unmerged = 1;
189                         }
190                 } else if (pos < active_nr) {
191                         struct stat st;
192                         if (lstat(".gitmodules", &st) == 0 &&
193                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
194                                 gitmodules_is_modified = 1;
195                 }
196
197                 if (!gitmodules_is_unmerged)
198                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
199                 strbuf_release(&gitmodules_path);
200         }
201 }
202
203 void gitmodules_config_sha1(const unsigned char *commit_sha1)
204 {
205         struct strbuf rev = STRBUF_INIT;
206         unsigned char sha1[20];
207
208         if (gitmodule_sha1_from_commit(commit_sha1, sha1, &rev)) {
209                 git_config_from_blob_sha1(submodule_config, rev.buf,
210                                           sha1, NULL);
211         }
212         strbuf_release(&rev);
213 }
214
215 /*
216  * NEEDSWORK: With the addition of different configuration options to determine
217  * if a submodule is of interests, the validity of this function's name comes
218  * into question.  Once the dust has settled and more concrete terminology is
219  * decided upon, come up with a more proper name for this function.  One
220  * potential candidate could be 'is_submodule_active()'.
221  *
222  * Determine if a submodule has been initialized at a given 'path'
223  */
224 int is_submodule_initialized(const char *path)
225 {
226         int ret = 0;
227         char *key = NULL;
228         char *value = NULL;
229         const struct string_list *sl;
230         const struct submodule *module = submodule_from_path(null_sha1, path);
231
232         /* early return if there isn't a path->module mapping */
233         if (!module)
234                 return 0;
235
236         /* submodule.<name>.active is set */
237         key = xstrfmt("submodule.%s.active", module->name);
238         if (!git_config_get_bool(key, &ret)) {
239                 free(key);
240                 return ret;
241         }
242         free(key);
243
244         /* submodule.active is set */
245         sl = git_config_get_value_multi("submodule.active");
246         if (sl) {
247                 struct pathspec ps;
248                 struct argv_array args = ARGV_ARRAY_INIT;
249                 const struct string_list_item *item;
250
251                 for_each_string_list_item(item, sl) {
252                         argv_array_push(&args, item->string);
253                 }
254
255                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
256                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
257
258                 argv_array_clear(&args);
259                 clear_pathspec(&ps);
260                 return ret;
261         }
262
263         /* fallback to checking if the URL is set */
264         key = xstrfmt("submodule.%s.url", module->name);
265         ret = !git_config_get_string(key, &value);
266
267         free(value);
268         free(key);
269         return ret;
270 }
271
272 int is_submodule_populated_gently(const char *path, int *return_error_code)
273 {
274         int ret = 0;
275         char *gitdir = xstrfmt("%s/.git", path);
276
277         if (resolve_gitdir_gently(gitdir, return_error_code))
278                 ret = 1;
279
280         free(gitdir);
281         return ret;
282 }
283
284 int parse_submodule_update_strategy(const char *value,
285                 struct submodule_update_strategy *dst)
286 {
287         free((void*)dst->command);
288         dst->command = NULL;
289         if (!strcmp(value, "none"))
290                 dst->type = SM_UPDATE_NONE;
291         else if (!strcmp(value, "checkout"))
292                 dst->type = SM_UPDATE_CHECKOUT;
293         else if (!strcmp(value, "rebase"))
294                 dst->type = SM_UPDATE_REBASE;
295         else if (!strcmp(value, "merge"))
296                 dst->type = SM_UPDATE_MERGE;
297         else if (skip_prefix(value, "!", &value)) {
298                 dst->type = SM_UPDATE_COMMAND;
299                 dst->command = xstrdup(value);
300         } else
301                 return -1;
302         return 0;
303 }
304
305 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
306 {
307         struct strbuf sb = STRBUF_INIT;
308         switch (s->type) {
309         case SM_UPDATE_CHECKOUT:
310                 return "checkout";
311         case SM_UPDATE_MERGE:
312                 return "merge";
313         case SM_UPDATE_REBASE:
314                 return "rebase";
315         case SM_UPDATE_NONE:
316                 return "none";
317         case SM_UPDATE_UNSPECIFIED:
318                 return NULL;
319         case SM_UPDATE_COMMAND:
320                 strbuf_addf(&sb, "!%s", s->command);
321                 return strbuf_detach(&sb, NULL);
322         }
323         return NULL;
324 }
325
326 void handle_ignore_submodules_arg(struct diff_options *diffopt,
327                                   const char *arg)
328 {
329         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
330         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
331         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
332
333         if (!strcmp(arg, "all"))
334                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
335         else if (!strcmp(arg, "untracked"))
336                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
337         else if (!strcmp(arg, "dirty"))
338                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
339         else if (strcmp(arg, "none"))
340                 die("bad --ignore-submodules argument: %s", arg);
341 }
342
343 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
344                 struct commit *left, struct commit *right,
345                 struct commit_list *merge_bases)
346 {
347         struct commit_list *list;
348
349         init_revisions(rev, NULL);
350         setup_revisions(0, NULL, rev, NULL);
351         rev->left_right = 1;
352         rev->first_parent_only = 1;
353         left->object.flags |= SYMMETRIC_LEFT;
354         add_pending_object(rev, &left->object, path);
355         add_pending_object(rev, &right->object, path);
356         for (list = merge_bases; list; list = list->next) {
357                 list->item->object.flags |= UNINTERESTING;
358                 add_pending_object(rev, &list->item->object,
359                         oid_to_hex(&list->item->object.oid));
360         }
361         return prepare_revision_walk(rev);
362 }
363
364 static void print_submodule_summary(struct rev_info *rev, FILE *f,
365                 const char *line_prefix,
366                 const char *del, const char *add, const char *reset)
367 {
368         static const char format[] = "  %m %s";
369         struct strbuf sb = STRBUF_INIT;
370         struct commit *commit;
371
372         while ((commit = get_revision(rev))) {
373                 struct pretty_print_context ctx = {0};
374                 ctx.date_mode = rev->date_mode;
375                 ctx.output_encoding = get_log_output_encoding();
376                 strbuf_setlen(&sb, 0);
377                 strbuf_addstr(&sb, line_prefix);
378                 if (commit->object.flags & SYMMETRIC_LEFT) {
379                         if (del)
380                                 strbuf_addstr(&sb, del);
381                 }
382                 else if (add)
383                         strbuf_addstr(&sb, add);
384                 format_commit_message(commit, format, &sb, &ctx);
385                 if (reset)
386                         strbuf_addstr(&sb, reset);
387                 strbuf_addch(&sb, '\n');
388                 fprintf(f, "%s", sb.buf);
389         }
390         strbuf_release(&sb);
391 }
392
393 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
394 {
395         const char * const *var;
396
397         for (var = local_repo_env; *var; var++) {
398                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
399                         argv_array_push(out, *var);
400         }
401 }
402
403 void prepare_submodule_repo_env(struct argv_array *out)
404 {
405         prepare_submodule_repo_env_no_git_dir(out);
406         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
407                          DEFAULT_GIT_DIR_ENVIRONMENT);
408 }
409
410 /* Helper function to display the submodule header line prior to the full
411  * summary output. If it can locate the submodule objects directory it will
412  * attempt to lookup both the left and right commits and put them into the
413  * left and right pointers.
414  */
415 static void show_submodule_header(FILE *f, const char *path,
416                 const char *line_prefix,
417                 struct object_id *one, struct object_id *two,
418                 unsigned dirty_submodule, const char *meta,
419                 const char *reset,
420                 struct commit **left, struct commit **right,
421                 struct commit_list **merge_bases)
422 {
423         const char *message = NULL;
424         struct strbuf sb = STRBUF_INIT;
425         int fast_forward = 0, fast_backward = 0;
426
427         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
428                 fprintf(f, "%sSubmodule %s contains untracked content\n",
429                         line_prefix, path);
430         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
431                 fprintf(f, "%sSubmodule %s contains modified content\n",
432                         line_prefix, path);
433
434         if (is_null_oid(one))
435                 message = "(new submodule)";
436         else if (is_null_oid(two))
437                 message = "(submodule deleted)";
438
439         if (add_submodule_odb(path)) {
440                 if (!message)
441                         message = "(not initialized)";
442                 goto output_header;
443         }
444
445         /*
446          * Attempt to lookup the commit references, and determine if this is
447          * a fast forward or fast backwards update.
448          */
449         *left = lookup_commit_reference(one->hash);
450         *right = lookup_commit_reference(two->hash);
451
452         /*
453          * Warn about missing commits in the submodule project, but only if
454          * they aren't null.
455          */
456         if ((!is_null_oid(one) && !*left) ||
457              (!is_null_oid(two) && !*right))
458                 message = "(commits not present)";
459
460         *merge_bases = get_merge_bases(*left, *right);
461         if (*merge_bases) {
462                 if ((*merge_bases)->item == *left)
463                         fast_forward = 1;
464                 else if ((*merge_bases)->item == *right)
465                         fast_backward = 1;
466         }
467
468         if (!oidcmp(one, two)) {
469                 strbuf_release(&sb);
470                 return;
471         }
472
473 output_header:
474         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
475         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
476         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
477         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
478         if (message)
479                 strbuf_addf(&sb, " %s%s\n", message, reset);
480         else
481                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
482         fwrite(sb.buf, sb.len, 1, f);
483
484         strbuf_release(&sb);
485 }
486
487 void show_submodule_summary(FILE *f, const char *path,
488                 const char *line_prefix,
489                 struct object_id *one, struct object_id *two,
490                 unsigned dirty_submodule, const char *meta,
491                 const char *del, const char *add, const char *reset)
492 {
493         struct rev_info rev;
494         struct commit *left = NULL, *right = NULL;
495         struct commit_list *merge_bases = NULL;
496
497         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
498                               meta, reset, &left, &right, &merge_bases);
499
500         /*
501          * If we don't have both a left and a right pointer, there is no
502          * reason to try and display a summary. The header line should contain
503          * all the information the user needs.
504          */
505         if (!left || !right)
506                 goto out;
507
508         /* Treat revision walker failure the same as missing commits */
509         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
510                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
511                 goto out;
512         }
513
514         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
515
516 out:
517         if (merge_bases)
518                 free_commit_list(merge_bases);
519         clear_commit_marks(left, ~0);
520         clear_commit_marks(right, ~0);
521 }
522
523 void show_submodule_inline_diff(FILE *f, const char *path,
524                 const char *line_prefix,
525                 struct object_id *one, struct object_id *two,
526                 unsigned dirty_submodule, const char *meta,
527                 const char *del, const char *add, const char *reset,
528                 const struct diff_options *o)
529 {
530         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
531         struct commit *left = NULL, *right = NULL;
532         struct commit_list *merge_bases = NULL;
533         struct strbuf submodule_dir = STRBUF_INIT;
534         struct child_process cp = CHILD_PROCESS_INIT;
535
536         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
537                               meta, reset, &left, &right, &merge_bases);
538
539         /* We need a valid left and right commit to display a difference */
540         if (!(left || is_null_oid(one)) ||
541             !(right || is_null_oid(two)))
542                 goto done;
543
544         if (left)
545                 old = one;
546         if (right)
547                 new = two;
548
549         fflush(f);
550         cp.git_cmd = 1;
551         cp.dir = path;
552         cp.out = dup(fileno(f));
553         cp.no_stdin = 1;
554
555         /* TODO: other options may need to be passed here. */
556         argv_array_push(&cp.args, "diff");
557         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
558         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
559                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
560                                  o->b_prefix, path);
561                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
562                                  o->a_prefix, path);
563         } else {
564                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
565                                  o->a_prefix, path);
566                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
567                                  o->b_prefix, path);
568         }
569         argv_array_push(&cp.args, oid_to_hex(old));
570         /*
571          * If the submodule has modified content, we will diff against the
572          * work tree, under the assumption that the user has asked for the
573          * diff format and wishes to actually see all differences even if they
574          * haven't yet been committed to the submodule yet.
575          */
576         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
577                 argv_array_push(&cp.args, oid_to_hex(new));
578
579         prepare_submodule_repo_env(&cp.env_array);
580         if (run_command(&cp))
581                 fprintf(f, "(diff failed)\n");
582
583 done:
584         strbuf_release(&submodule_dir);
585         if (merge_bases)
586                 free_commit_list(merge_bases);
587         if (left)
588                 clear_commit_marks(left, ~0);
589         if (right)
590                 clear_commit_marks(right, ~0);
591 }
592
593 void set_config_fetch_recurse_submodules(int value)
594 {
595         config_fetch_recurse_submodules = value;
596 }
597
598 void set_config_update_recurse_submodules(int value)
599 {
600         config_update_recurse_submodules = value;
601 }
602
603 int should_update_submodules(void)
604 {
605         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
606 }
607
608 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
609 {
610         if (!S_ISGITLINK(ce->ce_mode))
611                 return NULL;
612
613         if (!should_update_submodules())
614                 return NULL;
615
616         return submodule_from_path(null_sha1, ce->name);
617 }
618
619 static int has_remote(const char *refname, const struct object_id *oid,
620                       int flags, void *cb_data)
621 {
622         return 1;
623 }
624
625 static int append_sha1_to_argv(const unsigned char sha1[20], void *data)
626 {
627         struct argv_array *argv = data;
628         argv_array_push(argv, sha1_to_hex(sha1));
629         return 0;
630 }
631
632 static int check_has_commit(const unsigned char sha1[20], void *data)
633 {
634         int *has_commit = data;
635
636         if (!lookup_commit_reference(sha1))
637                 *has_commit = 0;
638
639         return 0;
640 }
641
642 static int submodule_has_commits(const char *path, struct sha1_array *commits)
643 {
644         int has_commit = 1;
645
646         if (add_submodule_odb(path))
647                 return 0;
648
649         sha1_array_for_each_unique(commits, check_has_commit, &has_commit);
650         return has_commit;
651 }
652
653 static int submodule_needs_pushing(const char *path, struct sha1_array *commits)
654 {
655         if (!submodule_has_commits(path, commits))
656                 /*
657                  * NOTE: We do consider it safe to return "no" here. The
658                  * correct answer would be "We do not know" instead of
659                  * "No push needed", but it is quite hard to change
660                  * the submodule pointer without having the submodule
661                  * around. If a user did however change the submodules
662                  * without having the submodule around, this indicates
663                  * an expert who knows what they are doing or a
664                  * maintainer integrating work from other people. In
665                  * both cases it should be safe to skip this check.
666                  */
667                 return 0;
668
669         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
670                 struct child_process cp = CHILD_PROCESS_INIT;
671                 struct strbuf buf = STRBUF_INIT;
672                 int needs_pushing = 0;
673
674                 argv_array_push(&cp.args, "rev-list");
675                 sha1_array_for_each_unique(commits, append_sha1_to_argv, &cp.args);
676                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
677
678                 prepare_submodule_repo_env(&cp.env_array);
679                 cp.git_cmd = 1;
680                 cp.no_stdin = 1;
681                 cp.out = -1;
682                 cp.dir = path;
683                 if (start_command(&cp))
684                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
685                                         path);
686                 if (strbuf_read(&buf, cp.out, 41))
687                         needs_pushing = 1;
688                 finish_command(&cp);
689                 close(cp.out);
690                 strbuf_release(&buf);
691                 return needs_pushing;
692         }
693
694         return 0;
695 }
696
697 static struct sha1_array *submodule_commits(struct string_list *submodules,
698                                             const char *path)
699 {
700         struct string_list_item *item;
701
702         item = string_list_insert(submodules, path);
703         if (item->util)
704                 return (struct sha1_array *) item->util;
705
706         /* NEEDSWORK: should we have sha1_array_init()? */
707         item->util = xcalloc(1, sizeof(struct sha1_array));
708         return (struct sha1_array *) item->util;
709 }
710
711 static void collect_submodules_from_diff(struct diff_queue_struct *q,
712                                          struct diff_options *options,
713                                          void *data)
714 {
715         int i;
716         struct string_list *submodules = data;
717
718         for (i = 0; i < q->nr; i++) {
719                 struct diff_filepair *p = q->queue[i];
720                 struct sha1_array *commits;
721                 if (!S_ISGITLINK(p->two->mode))
722                         continue;
723                 commits = submodule_commits(submodules, p->two->path);
724                 sha1_array_append(commits, p->two->oid.hash);
725         }
726 }
727
728 static void find_unpushed_submodule_commits(struct commit *commit,
729                 struct string_list *needs_pushing)
730 {
731         struct rev_info rev;
732
733         init_revisions(&rev, NULL);
734         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
735         rev.diffopt.format_callback = collect_submodules_from_diff;
736         rev.diffopt.format_callback_data = needs_pushing;
737         diff_tree_combined_merge(commit, 1, &rev);
738 }
739
740 static void free_submodules_sha1s(struct string_list *submodules)
741 {
742         struct string_list_item *item;
743         for_each_string_list_item(item, submodules)
744                 sha1_array_clear((struct sha1_array *) item->util);
745         string_list_clear(submodules, 1);
746 }
747
748 int find_unpushed_submodules(struct sha1_array *commits,
749                 const char *remotes_name, struct string_list *needs_pushing)
750 {
751         struct rev_info rev;
752         struct commit *commit;
753         struct string_list submodules = STRING_LIST_INIT_DUP;
754         struct string_list_item *submodule;
755         struct argv_array argv = ARGV_ARRAY_INIT;
756
757         init_revisions(&rev, NULL);
758
759         /* argv.argv[0] will be ignored by setup_revisions */
760         argv_array_push(&argv, "find_unpushed_submodules");
761         sha1_array_for_each_unique(commits, append_sha1_to_argv, &argv);
762         argv_array_push(&argv, "--not");
763         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
764
765         setup_revisions(argv.argc, argv.argv, &rev, NULL);
766         if (prepare_revision_walk(&rev))
767                 die("revision walk setup failed");
768
769         while ((commit = get_revision(&rev)) != NULL)
770                 find_unpushed_submodule_commits(commit, &submodules);
771
772         reset_revision_walk();
773         argv_array_clear(&argv);
774
775         for_each_string_list_item(submodule, &submodules) {
776                 struct sha1_array *commits = (struct sha1_array *) submodule->util;
777
778                 if (submodule_needs_pushing(submodule->string, commits))
779                         string_list_insert(needs_pushing, submodule->string);
780         }
781         free_submodules_sha1s(&submodules);
782
783         return needs_pushing->nr;
784 }
785
786 static int push_submodule(const char *path, int dry_run)
787 {
788         if (add_submodule_odb(path))
789                 return 1;
790
791         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
792                 struct child_process cp = CHILD_PROCESS_INIT;
793                 argv_array_push(&cp.args, "push");
794                 if (dry_run)
795                         argv_array_push(&cp.args, "--dry-run");
796
797                 prepare_submodule_repo_env(&cp.env_array);
798                 cp.git_cmd = 1;
799                 cp.no_stdin = 1;
800                 cp.dir = path;
801                 if (run_command(&cp))
802                         return 0;
803                 close(cp.out);
804         }
805
806         return 1;
807 }
808
809 int push_unpushed_submodules(struct sha1_array *commits,
810                              const char *remotes_name,
811                              int dry_run)
812 {
813         int i, ret = 1;
814         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
815
816         if (!find_unpushed_submodules(commits, remotes_name, &needs_pushing))
817                 return 1;
818
819         for (i = 0; i < needs_pushing.nr; i++) {
820                 const char *path = needs_pushing.items[i].string;
821                 fprintf(stderr, "Pushing submodule '%s'\n", path);
822                 if (!push_submodule(path, dry_run)) {
823                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
824                         ret = 0;
825                 }
826         }
827
828         string_list_clear(&needs_pushing, 0);
829
830         return ret;
831 }
832
833 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
834 {
835         int is_present = 0;
836         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
837                 /* Even if the submodule is checked out and the commit is
838                  * present, make sure it is reachable from a ref. */
839                 struct child_process cp = CHILD_PROCESS_INIT;
840                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
841                 struct strbuf buf = STRBUF_INIT;
842
843                 argv[3] = sha1_to_hex(sha1);
844                 cp.argv = argv;
845                 prepare_submodule_repo_env(&cp.env_array);
846                 cp.git_cmd = 1;
847                 cp.no_stdin = 1;
848                 cp.dir = path;
849                 if (!capture_command(&cp, &buf, 1024) && !buf.len)
850                         is_present = 1;
851
852                 strbuf_release(&buf);
853         }
854         return is_present;
855 }
856
857 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
858                                          struct diff_options *options,
859                                          void *data)
860 {
861         int i;
862         for (i = 0; i < q->nr; i++) {
863                 struct diff_filepair *p = q->queue[i];
864                 if (!S_ISGITLINK(p->two->mode))
865                         continue;
866
867                 if (S_ISGITLINK(p->one->mode)) {
868                         /* NEEDSWORK: We should honor the name configured in
869                          * the .gitmodules file of the commit we are examining
870                          * here to be able to correctly follow submodules
871                          * being moved around. */
872                         struct string_list_item *path;
873                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
874                         if (!path && !is_submodule_commit_present(p->two->path, p->two->oid.hash))
875                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
876                 } else {
877                         /* Submodule is new or was moved here */
878                         /* NEEDSWORK: When the .git directories of submodules
879                          * live inside the superprojects .git directory some
880                          * day we should fetch new submodules directly into
881                          * that location too when config or options request
882                          * that so they can be checked out from there. */
883                         continue;
884                 }
885         }
886 }
887
888 static int add_sha1_to_array(const char *ref, const struct object_id *oid,
889                              int flags, void *data)
890 {
891         sha1_array_append(data, oid->hash);
892         return 0;
893 }
894
895 void check_for_new_submodule_commits(unsigned char new_sha1[20])
896 {
897         if (!initialized_fetch_ref_tips) {
898                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
899                 initialized_fetch_ref_tips = 1;
900         }
901
902         sha1_array_append(&ref_tips_after_fetch, new_sha1);
903 }
904
905 static int add_sha1_to_argv(const unsigned char sha1[20], void *data)
906 {
907         argv_array_push(data, sha1_to_hex(sha1));
908         return 0;
909 }
910
911 static void calculate_changed_submodule_paths(void)
912 {
913         struct rev_info rev;
914         struct commit *commit;
915         struct argv_array argv = ARGV_ARRAY_INIT;
916
917         /* No need to check if there are no submodules configured */
918         if (!submodule_from_path(NULL, NULL))
919                 return;
920
921         init_revisions(&rev, NULL);
922         argv_array_push(&argv, "--"); /* argv[0] program name */
923         sha1_array_for_each_unique(&ref_tips_after_fetch,
924                                    add_sha1_to_argv, &argv);
925         argv_array_push(&argv, "--not");
926         sha1_array_for_each_unique(&ref_tips_before_fetch,
927                                    add_sha1_to_argv, &argv);
928         setup_revisions(argv.argc, argv.argv, &rev, NULL);
929         if (prepare_revision_walk(&rev))
930                 die("revision walk setup failed");
931
932         /*
933          * Collect all submodules (whether checked out or not) for which new
934          * commits have been recorded upstream in "changed_submodule_paths".
935          */
936         while ((commit = get_revision(&rev))) {
937                 struct commit_list *parent = commit->parents;
938                 while (parent) {
939                         struct diff_options diff_opts;
940                         diff_setup(&diff_opts);
941                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
942                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
943                         diff_opts.format_callback = submodule_collect_changed_cb;
944                         diff_setup_done(&diff_opts);
945                         diff_tree_sha1(parent->item->object.oid.hash, commit->object.oid.hash, "", &diff_opts);
946                         diffcore_std(&diff_opts);
947                         diff_flush(&diff_opts);
948                         parent = parent->next;
949                 }
950         }
951
952         argv_array_clear(&argv);
953         sha1_array_clear(&ref_tips_before_fetch);
954         sha1_array_clear(&ref_tips_after_fetch);
955         initialized_fetch_ref_tips = 0;
956 }
957
958 struct submodule_parallel_fetch {
959         int count;
960         struct argv_array args;
961         const char *work_tree;
962         const char *prefix;
963         int command_line_option;
964         int quiet;
965         int result;
966 };
967 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0}
968
969 static int get_next_submodule(struct child_process *cp,
970                               struct strbuf *err, void *data, void **task_cb)
971 {
972         int ret = 0;
973         struct submodule_parallel_fetch *spf = data;
974
975         for (; spf->count < active_nr; spf->count++) {
976                 struct strbuf submodule_path = STRBUF_INIT;
977                 struct strbuf submodule_git_dir = STRBUF_INIT;
978                 struct strbuf submodule_prefix = STRBUF_INIT;
979                 const struct cache_entry *ce = active_cache[spf->count];
980                 const char *git_dir, *default_argv;
981                 const struct submodule *submodule;
982
983                 if (!S_ISGITLINK(ce->ce_mode))
984                         continue;
985
986                 submodule = submodule_from_path(null_sha1, ce->name);
987                 if (!submodule)
988                         submodule = submodule_from_name(null_sha1, ce->name);
989
990                 default_argv = "yes";
991                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
992                         if (submodule &&
993                             submodule->fetch_recurse !=
994                                                 RECURSE_SUBMODULES_NONE) {
995                                 if (submodule->fetch_recurse ==
996                                                 RECURSE_SUBMODULES_OFF)
997                                         continue;
998                                 if (submodule->fetch_recurse ==
999                                                 RECURSE_SUBMODULES_ON_DEMAND) {
1000                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1001                                                 continue;
1002                                         default_argv = "on-demand";
1003                                 }
1004                         } else {
1005                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
1006                                     gitmodules_is_unmerged)
1007                                         continue;
1008                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
1009                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1010                                                 continue;
1011                                         default_argv = "on-demand";
1012                                 }
1013                         }
1014                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1015                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1016                                 continue;
1017                         default_argv = "on-demand";
1018                 }
1019
1020                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1021                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1022                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1023                 git_dir = read_gitfile(submodule_git_dir.buf);
1024                 if (!git_dir)
1025                         git_dir = submodule_git_dir.buf;
1026                 if (is_directory(git_dir)) {
1027                         child_process_init(cp);
1028                         cp->dir = strbuf_detach(&submodule_path, NULL);
1029                         prepare_submodule_repo_env(&cp->env_array);
1030                         cp->git_cmd = 1;
1031                         if (!spf->quiet)
1032                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1033                                             spf->prefix, ce->name);
1034                         argv_array_init(&cp->args);
1035                         argv_array_pushv(&cp->args, spf->args.argv);
1036                         argv_array_push(&cp->args, default_argv);
1037                         argv_array_push(&cp->args, "--submodule-prefix");
1038                         argv_array_push(&cp->args, submodule_prefix.buf);
1039                         ret = 1;
1040                 }
1041                 strbuf_release(&submodule_path);
1042                 strbuf_release(&submodule_git_dir);
1043                 strbuf_release(&submodule_prefix);
1044                 if (ret) {
1045                         spf->count++;
1046                         return 1;
1047                 }
1048         }
1049         return 0;
1050 }
1051
1052 static int fetch_start_failure(struct strbuf *err,
1053                                void *cb, void *task_cb)
1054 {
1055         struct submodule_parallel_fetch *spf = cb;
1056
1057         spf->result = 1;
1058
1059         return 0;
1060 }
1061
1062 static int fetch_finish(int retvalue, struct strbuf *err,
1063                         void *cb, void *task_cb)
1064 {
1065         struct submodule_parallel_fetch *spf = cb;
1066
1067         if (retvalue)
1068                 spf->result = 1;
1069
1070         return 0;
1071 }
1072
1073 int fetch_populated_submodules(const struct argv_array *options,
1074                                const char *prefix, int command_line_option,
1075                                int quiet, int max_parallel_jobs)
1076 {
1077         int i;
1078         struct submodule_parallel_fetch spf = SPF_INIT;
1079
1080         spf.work_tree = get_git_work_tree();
1081         spf.command_line_option = command_line_option;
1082         spf.quiet = quiet;
1083         spf.prefix = prefix;
1084
1085         if (!spf.work_tree)
1086                 goto out;
1087
1088         if (read_cache() < 0)
1089                 die("index file corrupt");
1090
1091         argv_array_push(&spf.args, "fetch");
1092         for (i = 0; i < options->argc; i++)
1093                 argv_array_push(&spf.args, options->argv[i]);
1094         argv_array_push(&spf.args, "--recurse-submodules-default");
1095         /* default value, "--submodule-prefix" and its value are added later */
1096
1097         if (max_parallel_jobs < 0)
1098                 max_parallel_jobs = parallel_jobs;
1099
1100         calculate_changed_submodule_paths();
1101         run_processes_parallel(max_parallel_jobs,
1102                                get_next_submodule,
1103                                fetch_start_failure,
1104                                fetch_finish,
1105                                &spf);
1106
1107         argv_array_clear(&spf.args);
1108 out:
1109         string_list_clear(&changed_submodule_paths, 1);
1110         return spf.result;
1111 }
1112
1113 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1114 {
1115         ssize_t len;
1116         struct child_process cp = CHILD_PROCESS_INIT;
1117         const char *argv[] = {
1118                 "status",
1119                 "--porcelain",
1120                 NULL,
1121                 NULL,
1122         };
1123         struct strbuf buf = STRBUF_INIT;
1124         unsigned dirty_submodule = 0;
1125         const char *line, *next_line;
1126         const char *git_dir;
1127
1128         strbuf_addf(&buf, "%s/.git", path);
1129         git_dir = read_gitfile(buf.buf);
1130         if (!git_dir)
1131                 git_dir = buf.buf;
1132         if (!is_directory(git_dir)) {
1133                 strbuf_release(&buf);
1134                 /* The submodule is not checked out, so it is not modified */
1135                 return 0;
1136
1137         }
1138         strbuf_reset(&buf);
1139
1140         if (ignore_untracked)
1141                 argv[2] = "-uno";
1142
1143         cp.argv = argv;
1144         prepare_submodule_repo_env(&cp.env_array);
1145         cp.git_cmd = 1;
1146         cp.no_stdin = 1;
1147         cp.out = -1;
1148         cp.dir = path;
1149         if (start_command(&cp))
1150                 die("Could not run 'git status --porcelain' in submodule %s", path);
1151
1152         len = strbuf_read(&buf, cp.out, 1024);
1153         line = buf.buf;
1154         while (len > 2) {
1155                 if ((line[0] == '?') && (line[1] == '?')) {
1156                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1157                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
1158                                 break;
1159                 } else {
1160                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1161                         if (ignore_untracked ||
1162                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
1163                                 break;
1164                 }
1165                 next_line = strchr(line, '\n');
1166                 if (!next_line)
1167                         break;
1168                 next_line++;
1169                 len -= (next_line - line);
1170                 line = next_line;
1171         }
1172         close(cp.out);
1173
1174         if (finish_command(&cp))
1175                 die("'git status --porcelain' failed in submodule %s", path);
1176
1177         strbuf_release(&buf);
1178         return dirty_submodule;
1179 }
1180
1181 int submodule_uses_gitfile(const char *path)
1182 {
1183         struct child_process cp = CHILD_PROCESS_INIT;
1184         const char *argv[] = {
1185                 "submodule",
1186                 "foreach",
1187                 "--quiet",
1188                 "--recursive",
1189                 "test -f .git",
1190                 NULL,
1191         };
1192         struct strbuf buf = STRBUF_INIT;
1193         const char *git_dir;
1194
1195         strbuf_addf(&buf, "%s/.git", path);
1196         git_dir = read_gitfile(buf.buf);
1197         if (!git_dir) {
1198                 strbuf_release(&buf);
1199                 return 0;
1200         }
1201         strbuf_release(&buf);
1202
1203         /* Now test that all nested submodules use a gitfile too */
1204         cp.argv = argv;
1205         prepare_submodule_repo_env(&cp.env_array);
1206         cp.git_cmd = 1;
1207         cp.no_stdin = 1;
1208         cp.no_stderr = 1;
1209         cp.no_stdout = 1;
1210         cp.dir = path;
1211         if (run_command(&cp))
1212                 return 0;
1213
1214         return 1;
1215 }
1216
1217 /*
1218  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1219  * when doing so.
1220  *
1221  * Return 1 if we'd lose data, return 0 if the removal is fine,
1222  * and negative values for errors.
1223  */
1224 int bad_to_remove_submodule(const char *path, unsigned flags)
1225 {
1226         ssize_t len;
1227         struct child_process cp = CHILD_PROCESS_INIT;
1228         struct strbuf buf = STRBUF_INIT;
1229         int ret = 0;
1230
1231         if (!file_exists(path) || is_empty_dir(path))
1232                 return 0;
1233
1234         if (!submodule_uses_gitfile(path))
1235                 return 1;
1236
1237         argv_array_pushl(&cp.args, "status", "--porcelain",
1238                                    "--ignore-submodules=none", NULL);
1239
1240         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1241                 argv_array_push(&cp.args, "-uno");
1242         else
1243                 argv_array_push(&cp.args, "-uall");
1244
1245         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1246                 argv_array_push(&cp.args, "--ignored");
1247
1248         prepare_submodule_repo_env(&cp.env_array);
1249         cp.git_cmd = 1;
1250         cp.no_stdin = 1;
1251         cp.out = -1;
1252         cp.dir = path;
1253         if (start_command(&cp)) {
1254                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1255                         die(_("could not start 'git status in submodule '%s'"),
1256                                 path);
1257                 ret = -1;
1258                 goto out;
1259         }
1260
1261         len = strbuf_read(&buf, cp.out, 1024);
1262         if (len > 2)
1263                 ret = 1;
1264         close(cp.out);
1265
1266         if (finish_command(&cp)) {
1267                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1268                         die(_("could not run 'git status in submodule '%s'"),
1269                                 path);
1270                 ret = -1;
1271         }
1272 out:
1273         strbuf_release(&buf);
1274         return ret;
1275 }
1276
1277 static const char *get_super_prefix_or_empty(void)
1278 {
1279         const char *s = get_super_prefix();
1280         if (!s)
1281                 s = "";
1282         return s;
1283 }
1284
1285 static int submodule_has_dirty_index(const struct submodule *sub)
1286 {
1287         struct child_process cp = CHILD_PROCESS_INIT;
1288
1289         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1290
1291         cp.git_cmd = 1;
1292         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1293                                    "--cached", "HEAD", NULL);
1294         cp.no_stdin = 1;
1295         cp.no_stdout = 1;
1296         cp.dir = sub->path;
1297         if (start_command(&cp))
1298                 die("could not recurse into submodule '%s'", sub->path);
1299
1300         return finish_command(&cp);
1301 }
1302
1303 static void submodule_reset_index(const char *path)
1304 {
1305         struct child_process cp = CHILD_PROCESS_INIT;
1306         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1307
1308         cp.git_cmd = 1;
1309         cp.no_stdin = 1;
1310         cp.dir = path;
1311
1312         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1313                                    get_super_prefix_or_empty(), path);
1314         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1315
1316         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1317
1318         if (run_command(&cp))
1319                 die("could not reset submodule index");
1320 }
1321
1322 /**
1323  * Moves a submodule at a given path from a given head to another new head.
1324  * For edge cases (a submodule coming into existence or removing a submodule)
1325  * pass NULL for old or new respectively.
1326  */
1327 int submodule_move_head(const char *path,
1328                          const char *old,
1329                          const char *new,
1330                          unsigned flags)
1331 {
1332         int ret = 0;
1333         struct child_process cp = CHILD_PROCESS_INIT;
1334         const struct submodule *sub;
1335         int *error_code_ptr, error_code;
1336
1337         if (!is_submodule_initialized(path))
1338                 return 0;
1339
1340         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1341                 /*
1342                  * Pass non NULL pointer to is_submodule_populated_gently
1343                  * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1344                  * to fixup the submodule in the force case later.
1345                  */
1346                 error_code_ptr = &error_code;
1347         else
1348                 error_code_ptr = NULL;
1349
1350         if (old && !is_submodule_populated_gently(path, error_code_ptr))
1351                 return 0;
1352
1353         sub = submodule_from_path(null_sha1, path);
1354
1355         if (!sub)
1356                 die("BUG: could not get submodule information for '%s'", path);
1357
1358         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1359                 /* Check if the submodule has a dirty index. */
1360                 if (submodule_has_dirty_index(sub))
1361                         return error(_("submodule '%s' has dirty index"), path);
1362         }
1363
1364         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1365                 if (old) {
1366                         if (!submodule_uses_gitfile(path))
1367                                 absorb_git_dir_into_superproject("", path,
1368                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1369                 } else {
1370                         char *gitdir = xstrfmt("%s/modules/%s",
1371                                     get_git_common_dir(), sub->name);
1372                         connect_work_tree_and_git_dir(path, gitdir);
1373                         free(gitdir);
1374
1375                         /* make sure the index is clean as well */
1376                         submodule_reset_index(path);
1377                 }
1378
1379                 if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1380                         char *gitdir = xstrfmt("%s/modules/%s",
1381                                     get_git_common_dir(), sub->name);
1382                         connect_work_tree_and_git_dir(path, gitdir);
1383                         free(gitdir);
1384                 }
1385         }
1386
1387         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1388
1389         cp.git_cmd = 1;
1390         cp.no_stdin = 1;
1391         cp.dir = path;
1392
1393         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1394                         get_super_prefix_or_empty(), path);
1395         argv_array_pushl(&cp.args, "read-tree", NULL);
1396
1397         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1398                 argv_array_push(&cp.args, "-n");
1399         else
1400                 argv_array_push(&cp.args, "-u");
1401
1402         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1403                 argv_array_push(&cp.args, "--reset");
1404         else
1405                 argv_array_push(&cp.args, "-m");
1406
1407         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1408         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1409
1410         if (run_command(&cp)) {
1411                 ret = -1;
1412                 goto out;
1413         }
1414
1415         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1416                 if (new) {
1417                         struct child_process cp1 = CHILD_PROCESS_INIT;
1418                         /* also set the HEAD accordingly */
1419                         cp1.git_cmd = 1;
1420                         cp1.no_stdin = 1;
1421                         cp1.dir = path;
1422
1423                         argv_array_pushl(&cp1.args, "update-ref", "HEAD",
1424                                          new ? new : EMPTY_TREE_SHA1_HEX, NULL);
1425
1426                         if (run_command(&cp1)) {
1427                                 ret = -1;
1428                                 goto out;
1429                         }
1430                 } else {
1431                         struct strbuf sb = STRBUF_INIT;
1432
1433                         strbuf_addf(&sb, "%s/.git", path);
1434                         unlink_or_warn(sb.buf);
1435                         strbuf_release(&sb);
1436
1437                         if (is_empty_dir(path))
1438                                 rmdir_or_warn(path);
1439                 }
1440         }
1441 out:
1442         return ret;
1443 }
1444
1445 static int find_first_merges(struct object_array *result, const char *path,
1446                 struct commit *a, struct commit *b)
1447 {
1448         int i, j;
1449         struct object_array merges = OBJECT_ARRAY_INIT;
1450         struct commit *commit;
1451         int contains_another;
1452
1453         char merged_revision[42];
1454         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1455                                    "--all", merged_revision, NULL };
1456         struct rev_info revs;
1457         struct setup_revision_opt rev_opts;
1458
1459         memset(result, 0, sizeof(struct object_array));
1460         memset(&rev_opts, 0, sizeof(rev_opts));
1461
1462         /* get all revisions that merge commit a */
1463         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1464                         oid_to_hex(&a->object.oid));
1465         init_revisions(&revs, NULL);
1466         rev_opts.submodule = path;
1467         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1468
1469         /* save all revisions from the above list that contain b */
1470         if (prepare_revision_walk(&revs))
1471                 die("revision walk setup failed");
1472         while ((commit = get_revision(&revs)) != NULL) {
1473                 struct object *o = &(commit->object);
1474                 if (in_merge_bases(b, commit))
1475                         add_object_array(o, NULL, &merges);
1476         }
1477         reset_revision_walk();
1478
1479         /* Now we've got all merges that contain a and b. Prune all
1480          * merges that contain another found merge and save them in
1481          * result.
1482          */
1483         for (i = 0; i < merges.nr; i++) {
1484                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1485
1486                 contains_another = 0;
1487                 for (j = 0; j < merges.nr; j++) {
1488                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1489                         if (i != j && in_merge_bases(m2, m1)) {
1490                                 contains_another = 1;
1491                                 break;
1492                         }
1493                 }
1494
1495                 if (!contains_another)
1496                         add_object_array(merges.objects[i].item, NULL, result);
1497         }
1498
1499         free(merges.objects);
1500         return result->nr;
1501 }
1502
1503 static void print_commit(struct commit *commit)
1504 {
1505         struct strbuf sb = STRBUF_INIT;
1506         struct pretty_print_context ctx = {0};
1507         ctx.date_mode.type = DATE_NORMAL;
1508         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1509         fprintf(stderr, "%s\n", sb.buf);
1510         strbuf_release(&sb);
1511 }
1512
1513 #define MERGE_WARNING(path, msg) \
1514         warning("Failed to merge submodule %s (%s)", path, msg);
1515
1516 int merge_submodule(unsigned char result[20], const char *path,
1517                     const unsigned char base[20], const unsigned char a[20],
1518                     const unsigned char b[20], int search)
1519 {
1520         struct commit *commit_base, *commit_a, *commit_b;
1521         int parent_count;
1522         struct object_array merges;
1523
1524         int i;
1525
1526         /* store a in result in case we fail */
1527         hashcpy(result, a);
1528
1529         /* we can not handle deletion conflicts */
1530         if (is_null_sha1(base))
1531                 return 0;
1532         if (is_null_sha1(a))
1533                 return 0;
1534         if (is_null_sha1(b))
1535                 return 0;
1536
1537         if (add_submodule_odb(path)) {
1538                 MERGE_WARNING(path, "not checked out");
1539                 return 0;
1540         }
1541
1542         if (!(commit_base = lookup_commit_reference(base)) ||
1543             !(commit_a = lookup_commit_reference(a)) ||
1544             !(commit_b = lookup_commit_reference(b))) {
1545                 MERGE_WARNING(path, "commits not present");
1546                 return 0;
1547         }
1548
1549         /* check whether both changes are forward */
1550         if (!in_merge_bases(commit_base, commit_a) ||
1551             !in_merge_bases(commit_base, commit_b)) {
1552                 MERGE_WARNING(path, "commits don't follow merge-base");
1553                 return 0;
1554         }
1555
1556         /* Case #1: a is contained in b or vice versa */
1557         if (in_merge_bases(commit_a, commit_b)) {
1558                 hashcpy(result, b);
1559                 return 1;
1560         }
1561         if (in_merge_bases(commit_b, commit_a)) {
1562                 hashcpy(result, a);
1563                 return 1;
1564         }
1565
1566         /*
1567          * Case #2: There are one or more merges that contain a and b in
1568          * the submodule. If there is only one, then present it as a
1569          * suggestion to the user, but leave it marked unmerged so the
1570          * user needs to confirm the resolution.
1571          */
1572
1573         /* Skip the search if makes no sense to the calling context.  */
1574         if (!search)
1575                 return 0;
1576
1577         /* find commit which merges them */
1578         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1579         switch (parent_count) {
1580         case 0:
1581                 MERGE_WARNING(path, "merge following commits not found");
1582                 break;
1583
1584         case 1:
1585                 MERGE_WARNING(path, "not fast-forward");
1586                 fprintf(stderr, "Found a possible merge resolution "
1587                                 "for the submodule:\n");
1588                 print_commit((struct commit *) merges.objects[0].item);
1589                 fprintf(stderr,
1590                         "If this is correct simply add it to the index "
1591                         "for example\n"
1592                         "by using:\n\n"
1593                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1594                         "which will accept this suggestion.\n",
1595                         oid_to_hex(&merges.objects[0].item->oid), path);
1596                 break;
1597
1598         default:
1599                 MERGE_WARNING(path, "multiple merges found");
1600                 for (i = 0; i < merges.nr; i++)
1601                         print_commit((struct commit *) merges.objects[i].item);
1602         }
1603
1604         free(merges.objects);
1605         return 0;
1606 }
1607
1608 int parallel_submodules(void)
1609 {
1610         return parallel_jobs;
1611 }
1612
1613 /*
1614  * Embeds a single submodules git directory into the superprojects git dir,
1615  * non recursively.
1616  */
1617 static void relocate_single_git_dir_into_superproject(const char *prefix,
1618                                                       const char *path)
1619 {
1620         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1621         const char *new_git_dir;
1622         const struct submodule *sub;
1623
1624         if (submodule_uses_worktrees(path))
1625                 die(_("relocate_gitdir for submodule '%s' with "
1626                       "more than one worktree not supported"), path);
1627
1628         old_git_dir = xstrfmt("%s/.git", path);
1629         if (read_gitfile(old_git_dir))
1630                 /* If it is an actual gitfile, it doesn't need migration. */
1631                 return;
1632
1633         real_old_git_dir = real_pathdup(old_git_dir, 1);
1634
1635         sub = submodule_from_path(null_sha1, path);
1636         if (!sub)
1637                 die(_("could not lookup name for submodule '%s'"), path);
1638
1639         new_git_dir = git_path("modules/%s", sub->name);
1640         if (safe_create_leading_directories_const(new_git_dir) < 0)
1641                 die(_("could not create directory '%s'"), new_git_dir);
1642         real_new_git_dir = real_pathdup(new_git_dir, 1);
1643
1644         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1645                 get_super_prefix_or_empty(), path,
1646                 real_old_git_dir, real_new_git_dir);
1647
1648         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1649
1650         free(old_git_dir);
1651         free(real_old_git_dir);
1652         free(real_new_git_dir);
1653 }
1654
1655 /*
1656  * Migrate the git directory of the submodule given by path from
1657  * having its git directory within the working tree to the git dir nested
1658  * in its superprojects git dir under modules/.
1659  */
1660 void absorb_git_dir_into_superproject(const char *prefix,
1661                                       const char *path,
1662                                       unsigned flags)
1663 {
1664         int err_code;
1665         const char *sub_git_dir;
1666         struct strbuf gitdir = STRBUF_INIT;
1667         strbuf_addf(&gitdir, "%s/.git", path);
1668         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1669
1670         /* Not populated? */
1671         if (!sub_git_dir) {
1672                 const struct submodule *sub;
1673
1674                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1675                         /* unpopulated as expected */
1676                         strbuf_release(&gitdir);
1677                         return;
1678                 }
1679
1680                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1681                         /* We don't know what broke here. */
1682                         read_gitfile_error_die(err_code, path, NULL);
1683
1684                 /*
1685                 * Maybe populated, but no git directory was found?
1686                 * This can happen if the superproject is a submodule
1687                 * itself and was just absorbed. The absorption of the
1688                 * superproject did not rewrite the git file links yet,
1689                 * fix it now.
1690                 */
1691                 sub = submodule_from_path(null_sha1, path);
1692                 if (!sub)
1693                         die(_("could not lookup name for submodule '%s'"), path);
1694                 connect_work_tree_and_git_dir(path,
1695                         git_path("modules/%s", sub->name));
1696         } else {
1697                 /* Is it already absorbed into the superprojects git dir? */
1698                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1699                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1700
1701                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1702                         relocate_single_git_dir_into_superproject(prefix, path);
1703
1704                 free(real_sub_git_dir);
1705                 free(real_common_git_dir);
1706         }
1707         strbuf_release(&gitdir);
1708
1709         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1710                 struct child_process cp = CHILD_PROCESS_INIT;
1711                 struct strbuf sb = STRBUF_INIT;
1712
1713                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1714                         die("BUG: we don't know how to pass the flags down?");
1715
1716                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1717                 strbuf_addstr(&sb, path);
1718                 strbuf_addch(&sb, '/');
1719
1720                 cp.dir = path;
1721                 cp.git_cmd = 1;
1722                 cp.no_stdin = 1;
1723                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1724                                            "submodule--helper",
1725                                            "absorb-git-dirs", NULL);
1726                 prepare_submodule_repo_env(&cp.env_array);
1727                 if (run_command(&cp))
1728                         die(_("could not recurse into submodule '%s'"), path);
1729
1730                 strbuf_release(&sb);
1731         }
1732 }
1733
1734 const char *get_superproject_working_tree(void)
1735 {
1736         struct child_process cp = CHILD_PROCESS_INIT;
1737         struct strbuf sb = STRBUF_INIT;
1738         const char *one_up = real_path_if_valid("../");
1739         const char *cwd = xgetcwd();
1740         const char *ret = NULL;
1741         const char *subpath;
1742         int code;
1743         ssize_t len;
1744
1745         if (!is_inside_work_tree())
1746                 /*
1747                  * FIXME:
1748                  * We might have a superproject, but it is harder
1749                  * to determine.
1750                  */
1751                 return NULL;
1752
1753         if (!one_up)
1754                 return NULL;
1755
1756         subpath = relative_path(cwd, one_up, &sb);
1757
1758         prepare_submodule_repo_env(&cp.env_array);
1759         argv_array_pop(&cp.env_array);
1760
1761         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1762                         "ls-files", "-z", "--stage", "--full-name", "--",
1763                         subpath, NULL);
1764         strbuf_reset(&sb);
1765
1766         cp.no_stdin = 1;
1767         cp.no_stderr = 1;
1768         cp.out = -1;
1769         cp.git_cmd = 1;
1770
1771         if (start_command(&cp))
1772                 die(_("could not start ls-files in .."));
1773
1774         len = strbuf_read(&sb, cp.out, PATH_MAX);
1775         close(cp.out);
1776
1777         if (starts_with(sb.buf, "160000")) {
1778                 int super_sub_len;
1779                 int cwd_len = strlen(cwd);
1780                 char *super_sub, *super_wt;
1781
1782                 /*
1783                  * There is a superproject having this repo as a submodule.
1784                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1785                  * We're only interested in the name after the tab.
1786                  */
1787                 super_sub = strchr(sb.buf, '\t') + 1;
1788                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1789
1790                 if (super_sub_len > cwd_len ||
1791                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1792                         die (_("BUG: returned path string doesn't match cwd?"));
1793
1794                 super_wt = xstrdup(cwd);
1795                 super_wt[cwd_len - super_sub_len] = '\0';
1796
1797                 ret = real_path(super_wt);
1798                 free(super_wt);
1799         }
1800         strbuf_release(&sb);
1801
1802         code = finish_command(&cp);
1803
1804         if (code == 128)
1805                 /* '../' is not a git repository */
1806                 return NULL;
1807         if (code == 0 && len == 0)
1808                 /* There is an unrelated git repository at '../' */
1809                 return NULL;
1810         if (code)
1811                 die(_("ls-tree returned unexpected return code %d"), code);
1812
1813         return ret;
1814 }