Merge branch 'ah/doc-interpret-trailers-ifexists' into maint
[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 "remote.h"
18 #include "worktree.h"
19
20 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
21 static int config_update_recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
22 static int parallel_jobs = 1;
23 static struct string_list changed_submodule_paths = STRING_LIST_INIT_NODUP;
24 static int initialized_fetch_ref_tips;
25 static struct oid_array ref_tips_before_fetch;
26 static struct oid_array ref_tips_after_fetch;
27
28 /*
29  * The following flag is set if the .gitmodules file is unmerged. We then
30  * disable recursion for all submodules where .git/config doesn't have a
31  * matching config entry because we can't guess what might be configured in
32  * .gitmodules unless the user resolves the conflict. When a command line
33  * option is given (which always overrides configuration) this flag will be
34  * ignored.
35  */
36 static int gitmodules_is_unmerged;
37
38 /*
39  * This flag is set if the .gitmodules file had unstaged modifications on
40  * startup. This must be checked before allowing modifications to the
41  * .gitmodules file with the intention to stage them later, because when
42  * continuing we would stage the modifications the user didn't stage herself
43  * too. That might change in a future version when we learn to stage the
44  * changes we do ourselves without staging any previous modifications.
45  */
46 static int gitmodules_is_modified;
47
48 int is_staging_gitmodules_ok(void)
49 {
50         return !gitmodules_is_modified;
51 }
52
53 /*
54  * Try to update the "path" entry in the "submodule.<name>" section of the
55  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
56  * with the correct path=<oldpath> setting was found and we could update it.
57  */
58 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
59 {
60         struct strbuf entry = STRBUF_INIT;
61         const struct submodule *submodule;
62
63         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
64                 return -1;
65
66         if (gitmodules_is_unmerged)
67                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
68
69         submodule = submodule_from_path(null_sha1, oldpath);
70         if (!submodule || !submodule->name) {
71                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
72                 return -1;
73         }
74         strbuf_addstr(&entry, "submodule.");
75         strbuf_addstr(&entry, submodule->name);
76         strbuf_addstr(&entry, ".path");
77         if (git_config_set_in_file_gently(".gitmodules", entry.buf, newpath) < 0) {
78                 /* Maybe the user already did that, don't error out here */
79                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
80                 strbuf_release(&entry);
81                 return -1;
82         }
83         strbuf_release(&entry);
84         return 0;
85 }
86
87 /*
88  * Try to remove the "submodule.<name>" section from .gitmodules where the given
89  * path is configured. Return 0 only if a .gitmodules file was found, a section
90  * with the correct path=<path> setting was found and we could remove it.
91  */
92 int remove_path_from_gitmodules(const char *path)
93 {
94         struct strbuf sect = STRBUF_INIT;
95         const struct submodule *submodule;
96
97         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
98                 return -1;
99
100         if (gitmodules_is_unmerged)
101                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
102
103         submodule = submodule_from_path(null_sha1, path);
104         if (!submodule || !submodule->name) {
105                 warning(_("Could not find section in .gitmodules where path=%s"), path);
106                 return -1;
107         }
108         strbuf_addstr(&sect, "submodule.");
109         strbuf_addstr(&sect, submodule->name);
110         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
111                 /* Maybe the user already did that, don't error out here */
112                 warning(_("Could not remove .gitmodules entry for %s"), path);
113                 strbuf_release(&sect);
114                 return -1;
115         }
116         strbuf_release(&sect);
117         return 0;
118 }
119
120 void stage_updated_gitmodules(void)
121 {
122         if (add_file_to_cache(".gitmodules", 0))
123                 die(_("staging updated .gitmodules failed"));
124 }
125
126 static int add_submodule_odb(const char *path)
127 {
128         struct strbuf objects_directory = STRBUF_INIT;
129         int ret = 0;
130
131         ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
132         if (ret)
133                 goto done;
134         if (!is_directory(objects_directory.buf)) {
135                 ret = -1;
136                 goto done;
137         }
138         add_to_alternates_memory(objects_directory.buf);
139 done:
140         strbuf_release(&objects_directory);
141         return ret;
142 }
143
144 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
145                                              const char *path)
146 {
147         const struct submodule *submodule = submodule_from_path(null_sha1, path);
148         if (submodule) {
149                 if (submodule->ignore)
150                         handle_ignore_submodules_arg(diffopt, submodule->ignore);
151                 else if (gitmodules_is_unmerged)
152                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
153         }
154 }
155
156 int submodule_config(const char *var, const char *value, void *cb)
157 {
158         if (!strcmp(var, "submodule.fetchjobs")) {
159                 parallel_jobs = git_config_int(var, value);
160                 if (parallel_jobs < 0)
161                         die(_("negative values not allowed for submodule.fetchJobs"));
162                 return 0;
163         } else if (starts_with(var, "submodule."))
164                 return parse_submodule_config_option(var, value);
165         else if (!strcmp(var, "fetch.recursesubmodules")) {
166                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
167                 return 0;
168         }
169         return 0;
170 }
171
172 void gitmodules_config(void)
173 {
174         const char *work_tree = get_git_work_tree();
175         if (work_tree) {
176                 struct strbuf gitmodules_path = STRBUF_INIT;
177                 int pos;
178                 strbuf_addstr(&gitmodules_path, work_tree);
179                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
180                 if (read_cache() < 0)
181                         die("index file corrupt");
182                 pos = cache_name_pos(".gitmodules", 11);
183                 if (pos < 0) { /* .gitmodules not found or isn't merged */
184                         pos = -1 - pos;
185                         if (active_nr > pos) {  /* there is a .gitmodules */
186                                 const struct cache_entry *ce = active_cache[pos];
187                                 if (ce_namelen(ce) == 11 &&
188                                     !memcmp(ce->name, ".gitmodules", 11))
189                                         gitmodules_is_unmerged = 1;
190                         }
191                 } else if (pos < active_nr) {
192                         struct stat st;
193                         if (lstat(".gitmodules", &st) == 0 &&
194                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
195                                 gitmodules_is_modified = 1;
196                 }
197
198                 if (!gitmodules_is_unmerged)
199                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
200                 strbuf_release(&gitmodules_path);
201         }
202 }
203
204 void gitmodules_config_sha1(const unsigned char *commit_sha1)
205 {
206         struct strbuf rev = STRBUF_INIT;
207         unsigned char sha1[20];
208
209         if (gitmodule_sha1_from_commit(commit_sha1, sha1, &rev)) {
210                 git_config_from_blob_sha1(submodule_config, rev.buf,
211                                           sha1, NULL);
212         }
213         strbuf_release(&rev);
214 }
215
216 /*
217  * NEEDSWORK: With the addition of different configuration options to determine
218  * if a submodule is of interests, the validity of this function's name comes
219  * into question.  Once the dust has settled and more concrete terminology is
220  * decided upon, come up with a more proper name for this function.  One
221  * potential candidate could be 'is_submodule_active()'.
222  *
223  * Determine if a submodule has been initialized at a given 'path'
224  */
225 int is_submodule_initialized(const char *path)
226 {
227         int ret = 0;
228         char *key = NULL;
229         char *value = NULL;
230         const struct string_list *sl;
231         const struct submodule *module = submodule_from_path(null_sha1, path);
232
233         /* early return if there isn't a path->module mapping */
234         if (!module)
235                 return 0;
236
237         /* submodule.<name>.active is set */
238         key = xstrfmt("submodule.%s.active", module->name);
239         if (!git_config_get_bool(key, &ret)) {
240                 free(key);
241                 return ret;
242         }
243         free(key);
244
245         /* submodule.active is set */
246         sl = git_config_get_value_multi("submodule.active");
247         if (sl) {
248                 struct pathspec ps;
249                 struct argv_array args = ARGV_ARRAY_INIT;
250                 const struct string_list_item *item;
251
252                 for_each_string_list_item(item, sl) {
253                         argv_array_push(&args, item->string);
254                 }
255
256                 parse_pathspec(&ps, 0, 0, NULL, args.argv);
257                 ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
258
259                 argv_array_clear(&args);
260                 clear_pathspec(&ps);
261                 return ret;
262         }
263
264         /* fallback to checking if the URL is set */
265         key = xstrfmt("submodule.%s.url", module->name);
266         ret = !git_config_get_string(key, &value);
267
268         free(value);
269         free(key);
270         return ret;
271 }
272
273 int is_submodule_populated_gently(const char *path, int *return_error_code)
274 {
275         int ret = 0;
276         char *gitdir = xstrfmt("%s/.git", path);
277
278         if (resolve_gitdir_gently(gitdir, return_error_code))
279                 ret = 1;
280
281         free(gitdir);
282         return ret;
283 }
284
285 int parse_submodule_update_strategy(const char *value,
286                 struct submodule_update_strategy *dst)
287 {
288         free((void*)dst->command);
289         dst->command = NULL;
290         if (!strcmp(value, "none"))
291                 dst->type = SM_UPDATE_NONE;
292         else if (!strcmp(value, "checkout"))
293                 dst->type = SM_UPDATE_CHECKOUT;
294         else if (!strcmp(value, "rebase"))
295                 dst->type = SM_UPDATE_REBASE;
296         else if (!strcmp(value, "merge"))
297                 dst->type = SM_UPDATE_MERGE;
298         else if (skip_prefix(value, "!", &value)) {
299                 dst->type = SM_UPDATE_COMMAND;
300                 dst->command = xstrdup(value);
301         } else
302                 return -1;
303         return 0;
304 }
305
306 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
307 {
308         struct strbuf sb = STRBUF_INIT;
309         switch (s->type) {
310         case SM_UPDATE_CHECKOUT:
311                 return "checkout";
312         case SM_UPDATE_MERGE:
313                 return "merge";
314         case SM_UPDATE_REBASE:
315                 return "rebase";
316         case SM_UPDATE_NONE:
317                 return "none";
318         case SM_UPDATE_UNSPECIFIED:
319                 return NULL;
320         case SM_UPDATE_COMMAND:
321                 strbuf_addf(&sb, "!%s", s->command);
322                 return strbuf_detach(&sb, NULL);
323         }
324         return NULL;
325 }
326
327 void handle_ignore_submodules_arg(struct diff_options *diffopt,
328                                   const char *arg)
329 {
330         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
331         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
332         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
333
334         if (!strcmp(arg, "all"))
335                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
336         else if (!strcmp(arg, "untracked"))
337                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
338         else if (!strcmp(arg, "dirty"))
339                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
340         else if (strcmp(arg, "none"))
341                 die("bad --ignore-submodules argument: %s", arg);
342 }
343
344 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
345                 struct commit *left, struct commit *right,
346                 struct commit_list *merge_bases)
347 {
348         struct commit_list *list;
349
350         init_revisions(rev, NULL);
351         setup_revisions(0, NULL, rev, NULL);
352         rev->left_right = 1;
353         rev->first_parent_only = 1;
354         left->object.flags |= SYMMETRIC_LEFT;
355         add_pending_object(rev, &left->object, path);
356         add_pending_object(rev, &right->object, path);
357         for (list = merge_bases; list; list = list->next) {
358                 list->item->object.flags |= UNINTERESTING;
359                 add_pending_object(rev, &list->item->object,
360                         oid_to_hex(&list->item->object.oid));
361         }
362         return prepare_revision_walk(rev);
363 }
364
365 static void print_submodule_summary(struct rev_info *rev, FILE *f,
366                 const char *line_prefix,
367                 const char *del, const char *add, const char *reset)
368 {
369         static const char format[] = "  %m %s";
370         struct strbuf sb = STRBUF_INIT;
371         struct commit *commit;
372
373         while ((commit = get_revision(rev))) {
374                 struct pretty_print_context ctx = {0};
375                 ctx.date_mode = rev->date_mode;
376                 ctx.output_encoding = get_log_output_encoding();
377                 strbuf_setlen(&sb, 0);
378                 strbuf_addstr(&sb, line_prefix);
379                 if (commit->object.flags & SYMMETRIC_LEFT) {
380                         if (del)
381                                 strbuf_addstr(&sb, del);
382                 }
383                 else if (add)
384                         strbuf_addstr(&sb, add);
385                 format_commit_message(commit, format, &sb, &ctx);
386                 if (reset)
387                         strbuf_addstr(&sb, reset);
388                 strbuf_addch(&sb, '\n');
389                 fprintf(f, "%s", sb.buf);
390         }
391         strbuf_release(&sb);
392 }
393
394 static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
395 {
396         const char * const *var;
397
398         for (var = local_repo_env; *var; var++) {
399                 if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
400                         argv_array_push(out, *var);
401         }
402 }
403
404 void prepare_submodule_repo_env(struct argv_array *out)
405 {
406         prepare_submodule_repo_env_no_git_dir(out);
407         argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
408                          DEFAULT_GIT_DIR_ENVIRONMENT);
409 }
410
411 /* Helper function to display the submodule header line prior to the full
412  * summary output. If it can locate the submodule objects directory it will
413  * attempt to lookup both the left and right commits and put them into the
414  * left and right pointers.
415  */
416 static void show_submodule_header(FILE *f, const char *path,
417                 const char *line_prefix,
418                 struct object_id *one, struct object_id *two,
419                 unsigned dirty_submodule, const char *meta,
420                 const char *reset,
421                 struct commit **left, struct commit **right,
422                 struct commit_list **merge_bases)
423 {
424         const char *message = NULL;
425         struct strbuf sb = STRBUF_INIT;
426         int fast_forward = 0, fast_backward = 0;
427
428         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
429                 fprintf(f, "%sSubmodule %s contains untracked content\n",
430                         line_prefix, path);
431         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
432                 fprintf(f, "%sSubmodule %s contains modified content\n",
433                         line_prefix, path);
434
435         if (is_null_oid(one))
436                 message = "(new submodule)";
437         else if (is_null_oid(two))
438                 message = "(submodule deleted)";
439
440         if (add_submodule_odb(path)) {
441                 if (!message)
442                         message = "(not initialized)";
443                 goto output_header;
444         }
445
446         /*
447          * Attempt to lookup the commit references, and determine if this is
448          * a fast forward or fast backwards update.
449          */
450         *left = lookup_commit_reference(one->hash);
451         *right = lookup_commit_reference(two->hash);
452
453         /*
454          * Warn about missing commits in the submodule project, but only if
455          * they aren't null.
456          */
457         if ((!is_null_oid(one) && !*left) ||
458              (!is_null_oid(two) && !*right))
459                 message = "(commits not present)";
460
461         *merge_bases = get_merge_bases(*left, *right);
462         if (*merge_bases) {
463                 if ((*merge_bases)->item == *left)
464                         fast_forward = 1;
465                 else if ((*merge_bases)->item == *right)
466                         fast_backward = 1;
467         }
468
469         if (!oidcmp(one, two)) {
470                 strbuf_release(&sb);
471                 return;
472         }
473
474 output_header:
475         strbuf_addf(&sb, "%s%sSubmodule %s ", line_prefix, meta, path);
476         strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
477         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
478         strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
479         if (message)
480                 strbuf_addf(&sb, " %s%s\n", message, reset);
481         else
482                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
483         fwrite(sb.buf, sb.len, 1, f);
484
485         strbuf_release(&sb);
486 }
487
488 void show_submodule_summary(FILE *f, const char *path,
489                 const char *line_prefix,
490                 struct object_id *one, struct object_id *two,
491                 unsigned dirty_submodule, const char *meta,
492                 const char *del, const char *add, const char *reset)
493 {
494         struct rev_info rev;
495         struct commit *left = NULL, *right = NULL;
496         struct commit_list *merge_bases = NULL;
497
498         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
499                               meta, reset, &left, &right, &merge_bases);
500
501         /*
502          * If we don't have both a left and a right pointer, there is no
503          * reason to try and display a summary. The header line should contain
504          * all the information the user needs.
505          */
506         if (!left || !right)
507                 goto out;
508
509         /* Treat revision walker failure the same as missing commits */
510         if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
511                 fprintf(f, "%s(revision walker failed)\n", line_prefix);
512                 goto out;
513         }
514
515         print_submodule_summary(&rev, f, line_prefix, del, add, reset);
516
517 out:
518         if (merge_bases)
519                 free_commit_list(merge_bases);
520         clear_commit_marks(left, ~0);
521         clear_commit_marks(right, ~0);
522 }
523
524 void show_submodule_inline_diff(FILE *f, const char *path,
525                 const char *line_prefix,
526                 struct object_id *one, struct object_id *two,
527                 unsigned dirty_submodule, const char *meta,
528                 const char *del, const char *add, const char *reset,
529                 const struct diff_options *o)
530 {
531         const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
532         struct commit *left = NULL, *right = NULL;
533         struct commit_list *merge_bases = NULL;
534         struct strbuf submodule_dir = STRBUF_INIT;
535         struct child_process cp = CHILD_PROCESS_INIT;
536
537         show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
538                               meta, reset, &left, &right, &merge_bases);
539
540         /* We need a valid left and right commit to display a difference */
541         if (!(left || is_null_oid(one)) ||
542             !(right || is_null_oid(two)))
543                 goto done;
544
545         if (left)
546                 old = one;
547         if (right)
548                 new = two;
549
550         fflush(f);
551         cp.git_cmd = 1;
552         cp.dir = path;
553         cp.out = dup(fileno(f));
554         cp.no_stdin = 1;
555
556         /* TODO: other options may need to be passed here. */
557         argv_array_push(&cp.args, "diff");
558         argv_array_pushf(&cp.args, "--line-prefix=%s", line_prefix);
559         if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
560                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
561                                  o->b_prefix, path);
562                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
563                                  o->a_prefix, path);
564         } else {
565                 argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
566                                  o->a_prefix, path);
567                 argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
568                                  o->b_prefix, path);
569         }
570         argv_array_push(&cp.args, oid_to_hex(old));
571         /*
572          * If the submodule has modified content, we will diff against the
573          * work tree, under the assumption that the user has asked for the
574          * diff format and wishes to actually see all differences even if they
575          * haven't yet been committed to the submodule yet.
576          */
577         if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
578                 argv_array_push(&cp.args, oid_to_hex(new));
579
580         prepare_submodule_repo_env(&cp.env_array);
581         if (run_command(&cp))
582                 fprintf(f, "(diff failed)\n");
583
584 done:
585         strbuf_release(&submodule_dir);
586         if (merge_bases)
587                 free_commit_list(merge_bases);
588         if (left)
589                 clear_commit_marks(left, ~0);
590         if (right)
591                 clear_commit_marks(right, ~0);
592 }
593
594 void set_config_fetch_recurse_submodules(int value)
595 {
596         config_fetch_recurse_submodules = value;
597 }
598
599 void set_config_update_recurse_submodules(int value)
600 {
601         config_update_recurse_submodules = value;
602 }
603
604 int should_update_submodules(void)
605 {
606         return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
607 }
608
609 const struct submodule *submodule_from_ce(const struct cache_entry *ce)
610 {
611         if (!S_ISGITLINK(ce->ce_mode))
612                 return NULL;
613
614         if (!should_update_submodules())
615                 return NULL;
616
617         return submodule_from_path(null_sha1, ce->name);
618 }
619
620 static int has_remote(const char *refname, const struct object_id *oid,
621                       int flags, void *cb_data)
622 {
623         return 1;
624 }
625
626 static int append_oid_to_argv(const struct object_id *oid, void *data)
627 {
628         struct argv_array *argv = data;
629         argv_array_push(argv, oid_to_hex(oid));
630         return 0;
631 }
632
633 static int check_has_commit(const struct object_id *oid, void *data)
634 {
635         int *has_commit = data;
636
637         if (!lookup_commit_reference(oid->hash))
638                 *has_commit = 0;
639
640         return 0;
641 }
642
643 static int submodule_has_commits(const char *path, struct oid_array *commits)
644 {
645         int has_commit = 1;
646
647         if (add_submodule_odb(path))
648                 return 0;
649
650         oid_array_for_each_unique(commits, check_has_commit, &has_commit);
651         return has_commit;
652 }
653
654 static int submodule_needs_pushing(const char *path, struct oid_array *commits)
655 {
656         if (!submodule_has_commits(path, commits))
657                 /*
658                  * NOTE: We do consider it safe to return "no" here. The
659                  * correct answer would be "We do not know" instead of
660                  * "No push needed", but it is quite hard to change
661                  * the submodule pointer without having the submodule
662                  * around. If a user did however change the submodules
663                  * without having the submodule around, this indicates
664                  * an expert who knows what they are doing or a
665                  * maintainer integrating work from other people. In
666                  * both cases it should be safe to skip this check.
667                  */
668                 return 0;
669
670         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
671                 struct child_process cp = CHILD_PROCESS_INIT;
672                 struct strbuf buf = STRBUF_INIT;
673                 int needs_pushing = 0;
674
675                 argv_array_push(&cp.args, "rev-list");
676                 oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
677                 argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
678
679                 prepare_submodule_repo_env(&cp.env_array);
680                 cp.git_cmd = 1;
681                 cp.no_stdin = 1;
682                 cp.out = -1;
683                 cp.dir = path;
684                 if (start_command(&cp))
685                         die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
686                                         path);
687                 if (strbuf_read(&buf, cp.out, 41))
688                         needs_pushing = 1;
689                 finish_command(&cp);
690                 close(cp.out);
691                 strbuf_release(&buf);
692                 return needs_pushing;
693         }
694
695         return 0;
696 }
697
698 static struct oid_array *submodule_commits(struct string_list *submodules,
699                                             const char *path)
700 {
701         struct string_list_item *item;
702
703         item = string_list_insert(submodules, path);
704         if (item->util)
705                 return (struct oid_array *) item->util;
706
707         /* NEEDSWORK: should we have oid_array_init()? */
708         item->util = xcalloc(1, sizeof(struct oid_array));
709         return (struct oid_array *) item->util;
710 }
711
712 static void collect_submodules_from_diff(struct diff_queue_struct *q,
713                                          struct diff_options *options,
714                                          void *data)
715 {
716         int i;
717         struct string_list *submodules = data;
718
719         for (i = 0; i < q->nr; i++) {
720                 struct diff_filepair *p = q->queue[i];
721                 struct oid_array *commits;
722                 if (!S_ISGITLINK(p->two->mode))
723                         continue;
724                 commits = submodule_commits(submodules, p->two->path);
725                 oid_array_append(commits, &p->two->oid);
726         }
727 }
728
729 static void find_unpushed_submodule_commits(struct commit *commit,
730                 struct string_list *needs_pushing)
731 {
732         struct rev_info rev;
733
734         init_revisions(&rev, NULL);
735         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
736         rev.diffopt.format_callback = collect_submodules_from_diff;
737         rev.diffopt.format_callback_data = needs_pushing;
738         diff_tree_combined_merge(commit, 1, &rev);
739 }
740
741 static void free_submodules_sha1s(struct string_list *submodules)
742 {
743         struct string_list_item *item;
744         for_each_string_list_item(item, submodules)
745                 oid_array_clear((struct oid_array *) item->util);
746         string_list_clear(submodules, 1);
747 }
748
749 int find_unpushed_submodules(struct oid_array *commits,
750                 const char *remotes_name, struct string_list *needs_pushing)
751 {
752         struct rev_info rev;
753         struct commit *commit;
754         struct string_list submodules = STRING_LIST_INIT_DUP;
755         struct string_list_item *submodule;
756         struct argv_array argv = ARGV_ARRAY_INIT;
757
758         init_revisions(&rev, NULL);
759
760         /* argv.argv[0] will be ignored by setup_revisions */
761         argv_array_push(&argv, "find_unpushed_submodules");
762         oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
763         argv_array_push(&argv, "--not");
764         argv_array_pushf(&argv, "--remotes=%s", remotes_name);
765
766         setup_revisions(argv.argc, argv.argv, &rev, NULL);
767         if (prepare_revision_walk(&rev))
768                 die("revision walk setup failed");
769
770         while ((commit = get_revision(&rev)) != NULL)
771                 find_unpushed_submodule_commits(commit, &submodules);
772
773         reset_revision_walk();
774         argv_array_clear(&argv);
775
776         for_each_string_list_item(submodule, &submodules) {
777                 struct oid_array *commits = (struct oid_array *) submodule->util;
778
779                 if (submodule_needs_pushing(submodule->string, commits))
780                         string_list_insert(needs_pushing, submodule->string);
781         }
782         free_submodules_sha1s(&submodules);
783
784         return needs_pushing->nr;
785 }
786
787 static int push_submodule(const char *path,
788                           const struct remote *remote,
789                           const char **refspec, int refspec_nr,
790                           const struct string_list *push_options,
791                           int dry_run)
792 {
793         if (add_submodule_odb(path))
794                 return 1;
795
796         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
797                 struct child_process cp = CHILD_PROCESS_INIT;
798                 argv_array_push(&cp.args, "push");
799                 if (dry_run)
800                         argv_array_push(&cp.args, "--dry-run");
801
802                 if (push_options && push_options->nr) {
803                         const struct string_list_item *item;
804                         for_each_string_list_item(item, push_options)
805                                 argv_array_pushf(&cp.args, "--push-option=%s",
806                                                  item->string);
807                 }
808
809                 if (remote->origin != REMOTE_UNCONFIGURED) {
810                         int i;
811                         argv_array_push(&cp.args, remote->name);
812                         for (i = 0; i < refspec_nr; i++)
813                                 argv_array_push(&cp.args, refspec[i]);
814                 }
815
816                 prepare_submodule_repo_env(&cp.env_array);
817                 cp.git_cmd = 1;
818                 cp.no_stdin = 1;
819                 cp.dir = path;
820                 if (run_command(&cp))
821                         return 0;
822                 close(cp.out);
823         }
824
825         return 1;
826 }
827
828 /*
829  * Perform a check in the submodule to see if the remote and refspec work.
830  * Die if the submodule can't be pushed.
831  */
832 static void submodule_push_check(const char *path, const struct remote *remote,
833                                  const char **refspec, int refspec_nr)
834 {
835         struct child_process cp = CHILD_PROCESS_INIT;
836         int i;
837
838         argv_array_push(&cp.args, "submodule--helper");
839         argv_array_push(&cp.args, "push-check");
840         argv_array_push(&cp.args, remote->name);
841
842         for (i = 0; i < refspec_nr; i++)
843                 argv_array_push(&cp.args, refspec[i]);
844
845         prepare_submodule_repo_env(&cp.env_array);
846         cp.git_cmd = 1;
847         cp.no_stdin = 1;
848         cp.no_stdout = 1;
849         cp.dir = path;
850
851         /*
852          * Simply indicate if 'submodule--helper push-check' failed.
853          * More detailed error information will be provided by the
854          * child process.
855          */
856         if (run_command(&cp))
857                 die("process for submodule '%s' failed", path);
858 }
859
860 int push_unpushed_submodules(struct oid_array *commits,
861                              const struct remote *remote,
862                              const char **refspec, int refspec_nr,
863                              const struct string_list *push_options,
864                              int dry_run)
865 {
866         int i, ret = 1;
867         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
868
869         if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
870                 return 1;
871
872         /*
873          * Verify that the remote and refspec can be propagated to all
874          * submodules.  This check can be skipped if the remote and refspec
875          * won't be propagated due to the remote being unconfigured (e.g. a URL
876          * instead of a remote name).
877          */
878         if (remote->origin != REMOTE_UNCONFIGURED)
879                 for (i = 0; i < needs_pushing.nr; i++)
880                         submodule_push_check(needs_pushing.items[i].string,
881                                              remote, refspec, refspec_nr);
882
883         /* Actually push the submodules */
884         for (i = 0; i < needs_pushing.nr; i++) {
885                 const char *path = needs_pushing.items[i].string;
886                 fprintf(stderr, "Pushing submodule '%s'\n", path);
887                 if (!push_submodule(path, remote, refspec, refspec_nr,
888                                     push_options, dry_run)) {
889                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
890                         ret = 0;
891                 }
892         }
893
894         string_list_clear(&needs_pushing, 0);
895
896         return ret;
897 }
898
899 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
900 {
901         int is_present = 0;
902         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
903                 /* Even if the submodule is checked out and the commit is
904                  * present, make sure it is reachable from a ref. */
905                 struct child_process cp = CHILD_PROCESS_INIT;
906                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
907                 struct strbuf buf = STRBUF_INIT;
908
909                 argv[3] = sha1_to_hex(sha1);
910                 cp.argv = argv;
911                 prepare_submodule_repo_env(&cp.env_array);
912                 cp.git_cmd = 1;
913                 cp.no_stdin = 1;
914                 cp.dir = path;
915                 if (!capture_command(&cp, &buf, 1024) && !buf.len)
916                         is_present = 1;
917
918                 strbuf_release(&buf);
919         }
920         return is_present;
921 }
922
923 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
924                                          struct diff_options *options,
925                                          void *data)
926 {
927         int i;
928         for (i = 0; i < q->nr; i++) {
929                 struct diff_filepair *p = q->queue[i];
930                 if (!S_ISGITLINK(p->two->mode))
931                         continue;
932
933                 if (S_ISGITLINK(p->one->mode)) {
934                         /* NEEDSWORK: We should honor the name configured in
935                          * the .gitmodules file of the commit we are examining
936                          * here to be able to correctly follow submodules
937                          * being moved around. */
938                         struct string_list_item *path;
939                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
940                         if (!path && !is_submodule_commit_present(p->two->path, p->two->oid.hash))
941                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
942                 } else {
943                         /* Submodule is new or was moved here */
944                         /* NEEDSWORK: When the .git directories of submodules
945                          * live inside the superprojects .git directory some
946                          * day we should fetch new submodules directly into
947                          * that location too when config or options request
948                          * that so they can be checked out from there. */
949                         continue;
950                 }
951         }
952 }
953
954 static int add_sha1_to_array(const char *ref, const struct object_id *oid,
955                              int flags, void *data)
956 {
957         oid_array_append(data, oid);
958         return 0;
959 }
960
961 void check_for_new_submodule_commits(struct object_id *oid)
962 {
963         if (!initialized_fetch_ref_tips) {
964                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
965                 initialized_fetch_ref_tips = 1;
966         }
967
968         oid_array_append(&ref_tips_after_fetch, oid);
969 }
970
971 static int add_oid_to_argv(const struct object_id *oid, void *data)
972 {
973         argv_array_push(data, oid_to_hex(oid));
974         return 0;
975 }
976
977 static void calculate_changed_submodule_paths(void)
978 {
979         struct rev_info rev;
980         struct commit *commit;
981         struct argv_array argv = ARGV_ARRAY_INIT;
982
983         /* No need to check if there are no submodules configured */
984         if (!submodule_from_path(NULL, NULL))
985                 return;
986
987         init_revisions(&rev, NULL);
988         argv_array_push(&argv, "--"); /* argv[0] program name */
989         oid_array_for_each_unique(&ref_tips_after_fetch,
990                                    add_oid_to_argv, &argv);
991         argv_array_push(&argv, "--not");
992         oid_array_for_each_unique(&ref_tips_before_fetch,
993                                    add_oid_to_argv, &argv);
994         setup_revisions(argv.argc, argv.argv, &rev, NULL);
995         if (prepare_revision_walk(&rev))
996                 die("revision walk setup failed");
997
998         /*
999          * Collect all submodules (whether checked out or not) for which new
1000          * commits have been recorded upstream in "changed_submodule_paths".
1001          */
1002         while ((commit = get_revision(&rev))) {
1003                 struct commit_list *parent = commit->parents;
1004                 while (parent) {
1005                         struct diff_options diff_opts;
1006                         diff_setup(&diff_opts);
1007                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
1008                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
1009                         diff_opts.format_callback = submodule_collect_changed_cb;
1010                         diff_setup_done(&diff_opts);
1011                         diff_tree_sha1(parent->item->object.oid.hash, commit->object.oid.hash, "", &diff_opts);
1012                         diffcore_std(&diff_opts);
1013                         diff_flush(&diff_opts);
1014                         parent = parent->next;
1015                 }
1016         }
1017
1018         argv_array_clear(&argv);
1019         oid_array_clear(&ref_tips_before_fetch);
1020         oid_array_clear(&ref_tips_after_fetch);
1021         initialized_fetch_ref_tips = 0;
1022 }
1023
1024 struct submodule_parallel_fetch {
1025         int count;
1026         struct argv_array args;
1027         const char *work_tree;
1028         const char *prefix;
1029         int command_line_option;
1030         int quiet;
1031         int result;
1032 };
1033 #define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0}
1034
1035 static int get_next_submodule(struct child_process *cp,
1036                               struct strbuf *err, void *data, void **task_cb)
1037 {
1038         int ret = 0;
1039         struct submodule_parallel_fetch *spf = data;
1040
1041         for (; spf->count < active_nr; spf->count++) {
1042                 struct strbuf submodule_path = STRBUF_INIT;
1043                 struct strbuf submodule_git_dir = STRBUF_INIT;
1044                 struct strbuf submodule_prefix = STRBUF_INIT;
1045                 const struct cache_entry *ce = active_cache[spf->count];
1046                 const char *git_dir, *default_argv;
1047                 const struct submodule *submodule;
1048
1049                 if (!S_ISGITLINK(ce->ce_mode))
1050                         continue;
1051
1052                 submodule = submodule_from_path(null_sha1, ce->name);
1053                 if (!submodule)
1054                         submodule = submodule_from_name(null_sha1, ce->name);
1055
1056                 default_argv = "yes";
1057                 if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1058                         if (submodule &&
1059                             submodule->fetch_recurse !=
1060                                                 RECURSE_SUBMODULES_NONE) {
1061                                 if (submodule->fetch_recurse ==
1062                                                 RECURSE_SUBMODULES_OFF)
1063                                         continue;
1064                                 if (submodule->fetch_recurse ==
1065                                                 RECURSE_SUBMODULES_ON_DEMAND) {
1066                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1067                                                 continue;
1068                                         default_argv = "on-demand";
1069                                 }
1070                         } else {
1071                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
1072                                     gitmodules_is_unmerged)
1073                                         continue;
1074                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
1075                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1076                                                 continue;
1077                                         default_argv = "on-demand";
1078                                 }
1079                         }
1080                 } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1081                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
1082                                 continue;
1083                         default_argv = "on-demand";
1084                 }
1085
1086                 strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1087                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1088                 strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1089                 git_dir = read_gitfile(submodule_git_dir.buf);
1090                 if (!git_dir)
1091                         git_dir = submodule_git_dir.buf;
1092                 if (is_directory(git_dir)) {
1093                         child_process_init(cp);
1094                         cp->dir = strbuf_detach(&submodule_path, NULL);
1095                         prepare_submodule_repo_env(&cp->env_array);
1096                         cp->git_cmd = 1;
1097                         if (!spf->quiet)
1098                                 strbuf_addf(err, "Fetching submodule %s%s\n",
1099                                             spf->prefix, ce->name);
1100                         argv_array_init(&cp->args);
1101                         argv_array_pushv(&cp->args, spf->args.argv);
1102                         argv_array_push(&cp->args, default_argv);
1103                         argv_array_push(&cp->args, "--submodule-prefix");
1104                         argv_array_push(&cp->args, submodule_prefix.buf);
1105                         ret = 1;
1106                 }
1107                 strbuf_release(&submodule_path);
1108                 strbuf_release(&submodule_git_dir);
1109                 strbuf_release(&submodule_prefix);
1110                 if (ret) {
1111                         spf->count++;
1112                         return 1;
1113                 }
1114         }
1115         return 0;
1116 }
1117
1118 static int fetch_start_failure(struct strbuf *err,
1119                                void *cb, void *task_cb)
1120 {
1121         struct submodule_parallel_fetch *spf = cb;
1122
1123         spf->result = 1;
1124
1125         return 0;
1126 }
1127
1128 static int fetch_finish(int retvalue, struct strbuf *err,
1129                         void *cb, void *task_cb)
1130 {
1131         struct submodule_parallel_fetch *spf = cb;
1132
1133         if (retvalue)
1134                 spf->result = 1;
1135
1136         return 0;
1137 }
1138
1139 int fetch_populated_submodules(const struct argv_array *options,
1140                                const char *prefix, int command_line_option,
1141                                int quiet, int max_parallel_jobs)
1142 {
1143         int i;
1144         struct submodule_parallel_fetch spf = SPF_INIT;
1145
1146         spf.work_tree = get_git_work_tree();
1147         spf.command_line_option = command_line_option;
1148         spf.quiet = quiet;
1149         spf.prefix = prefix;
1150
1151         if (!spf.work_tree)
1152                 goto out;
1153
1154         if (read_cache() < 0)
1155                 die("index file corrupt");
1156
1157         argv_array_push(&spf.args, "fetch");
1158         for (i = 0; i < options->argc; i++)
1159                 argv_array_push(&spf.args, options->argv[i]);
1160         argv_array_push(&spf.args, "--recurse-submodules-default");
1161         /* default value, "--submodule-prefix" and its value are added later */
1162
1163         if (max_parallel_jobs < 0)
1164                 max_parallel_jobs = parallel_jobs;
1165
1166         calculate_changed_submodule_paths();
1167         run_processes_parallel(max_parallel_jobs,
1168                                get_next_submodule,
1169                                fetch_start_failure,
1170                                fetch_finish,
1171                                &spf);
1172
1173         argv_array_clear(&spf.args);
1174 out:
1175         string_list_clear(&changed_submodule_paths, 1);
1176         return spf.result;
1177 }
1178
1179 unsigned is_submodule_modified(const char *path, int ignore_untracked)
1180 {
1181         struct child_process cp = CHILD_PROCESS_INIT;
1182         struct strbuf buf = STRBUF_INIT;
1183         FILE *fp;
1184         unsigned dirty_submodule = 0;
1185         const char *git_dir;
1186         int ignore_cp_exit_code = 0;
1187
1188         strbuf_addf(&buf, "%s/.git", path);
1189         git_dir = read_gitfile(buf.buf);
1190         if (!git_dir)
1191                 git_dir = buf.buf;
1192         if (!is_git_directory(git_dir)) {
1193                 if (is_directory(git_dir))
1194                         die(_("'%s' not recognized as a git repository"), git_dir);
1195                 strbuf_release(&buf);
1196                 /* The submodule is not checked out, so it is not modified */
1197                 return 0;
1198         }
1199         strbuf_reset(&buf);
1200
1201         argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1202         if (ignore_untracked)
1203                 argv_array_push(&cp.args, "-uno");
1204
1205         prepare_submodule_repo_env(&cp.env_array);
1206         cp.git_cmd = 1;
1207         cp.no_stdin = 1;
1208         cp.out = -1;
1209         cp.dir = path;
1210         if (start_command(&cp))
1211                 die("Could not run 'git status --porcelain=2' in submodule %s", path);
1212
1213         fp = xfdopen(cp.out, "r");
1214         while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1215                 /* regular untracked files */
1216                 if (buf.buf[0] == '?')
1217                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1218
1219                 if (buf.buf[0] == 'u' ||
1220                     buf.buf[0] == '1' ||
1221                     buf.buf[0] == '2') {
1222                         /* T = line type, XY = status, SSSS = submodule state */
1223                         if (buf.len < strlen("T XY SSSS"))
1224                                 die("BUG: invalid status --porcelain=2 line %s",
1225                                     buf.buf);
1226
1227                         if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1228                                 /* nested untracked file */
1229                                 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1230
1231                         if (buf.buf[0] == 'u' ||
1232                             buf.buf[0] == '2' ||
1233                             memcmp(buf.buf + 5, "S..U", 4))
1234                                 /* other change */
1235                                 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1236                 }
1237
1238                 if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1239                     ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1240                      ignore_untracked)) {
1241                         /*
1242                          * We're not interested in any further information from
1243                          * the child any more, neither output nor its exit code.
1244                          */
1245                         ignore_cp_exit_code = 1;
1246                         break;
1247                 }
1248         }
1249         fclose(fp);
1250
1251         if (finish_command(&cp) && !ignore_cp_exit_code)
1252                 die("'git status --porcelain=2' failed in submodule %s", path);
1253
1254         strbuf_release(&buf);
1255         return dirty_submodule;
1256 }
1257
1258 int submodule_uses_gitfile(const char *path)
1259 {
1260         struct child_process cp = CHILD_PROCESS_INIT;
1261         const char *argv[] = {
1262                 "submodule",
1263                 "foreach",
1264                 "--quiet",
1265                 "--recursive",
1266                 "test -f .git",
1267                 NULL,
1268         };
1269         struct strbuf buf = STRBUF_INIT;
1270         const char *git_dir;
1271
1272         strbuf_addf(&buf, "%s/.git", path);
1273         git_dir = read_gitfile(buf.buf);
1274         if (!git_dir) {
1275                 strbuf_release(&buf);
1276                 return 0;
1277         }
1278         strbuf_release(&buf);
1279
1280         /* Now test that all nested submodules use a gitfile too */
1281         cp.argv = argv;
1282         prepare_submodule_repo_env(&cp.env_array);
1283         cp.git_cmd = 1;
1284         cp.no_stdin = 1;
1285         cp.no_stderr = 1;
1286         cp.no_stdout = 1;
1287         cp.dir = path;
1288         if (run_command(&cp))
1289                 return 0;
1290
1291         return 1;
1292 }
1293
1294 /*
1295  * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1296  * when doing so.
1297  *
1298  * Return 1 if we'd lose data, return 0 if the removal is fine,
1299  * and negative values for errors.
1300  */
1301 int bad_to_remove_submodule(const char *path, unsigned flags)
1302 {
1303         ssize_t len;
1304         struct child_process cp = CHILD_PROCESS_INIT;
1305         struct strbuf buf = STRBUF_INIT;
1306         int ret = 0;
1307
1308         if (!file_exists(path) || is_empty_dir(path))
1309                 return 0;
1310
1311         if (!submodule_uses_gitfile(path))
1312                 return 1;
1313
1314         argv_array_pushl(&cp.args, "status", "--porcelain",
1315                                    "--ignore-submodules=none", NULL);
1316
1317         if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1318                 argv_array_push(&cp.args, "-uno");
1319         else
1320                 argv_array_push(&cp.args, "-uall");
1321
1322         if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1323                 argv_array_push(&cp.args, "--ignored");
1324
1325         prepare_submodule_repo_env(&cp.env_array);
1326         cp.git_cmd = 1;
1327         cp.no_stdin = 1;
1328         cp.out = -1;
1329         cp.dir = path;
1330         if (start_command(&cp)) {
1331                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1332                         die(_("could not start 'git status' in submodule '%s'"),
1333                                 path);
1334                 ret = -1;
1335                 goto out;
1336         }
1337
1338         len = strbuf_read(&buf, cp.out, 1024);
1339         if (len > 2)
1340                 ret = 1;
1341         close(cp.out);
1342
1343         if (finish_command(&cp)) {
1344                 if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1345                         die(_("could not run 'git status' in submodule '%s'"),
1346                                 path);
1347                 ret = -1;
1348         }
1349 out:
1350         strbuf_release(&buf);
1351         return ret;
1352 }
1353
1354 static const char *get_super_prefix_or_empty(void)
1355 {
1356         const char *s = get_super_prefix();
1357         if (!s)
1358                 s = "";
1359         return s;
1360 }
1361
1362 static int submodule_has_dirty_index(const struct submodule *sub)
1363 {
1364         struct child_process cp = CHILD_PROCESS_INIT;
1365
1366         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1367
1368         cp.git_cmd = 1;
1369         argv_array_pushl(&cp.args, "diff-index", "--quiet",
1370                                    "--cached", "HEAD", NULL);
1371         cp.no_stdin = 1;
1372         cp.no_stdout = 1;
1373         cp.dir = sub->path;
1374         if (start_command(&cp))
1375                 die("could not recurse into submodule '%s'", sub->path);
1376
1377         return finish_command(&cp);
1378 }
1379
1380 static void submodule_reset_index(const char *path)
1381 {
1382         struct child_process cp = CHILD_PROCESS_INIT;
1383         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1384
1385         cp.git_cmd = 1;
1386         cp.no_stdin = 1;
1387         cp.dir = path;
1388
1389         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1390                                    get_super_prefix_or_empty(), path);
1391         argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1392
1393         argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1394
1395         if (run_command(&cp))
1396                 die("could not reset submodule index");
1397 }
1398
1399 /**
1400  * Moves a submodule at a given path from a given head to another new head.
1401  * For edge cases (a submodule coming into existence or removing a submodule)
1402  * pass NULL for old or new respectively.
1403  */
1404 int submodule_move_head(const char *path,
1405                          const char *old,
1406                          const char *new,
1407                          unsigned flags)
1408 {
1409         int ret = 0;
1410         struct child_process cp = CHILD_PROCESS_INIT;
1411         const struct submodule *sub;
1412
1413         sub = submodule_from_path(null_sha1, path);
1414
1415         if (!sub)
1416                 die("BUG: could not get submodule information for '%s'", path);
1417
1418         if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1419                 /* Check if the submodule has a dirty index. */
1420                 if (submodule_has_dirty_index(sub))
1421                         return error(_("submodule '%s' has dirty index"), path);
1422         }
1423
1424         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1425                 if (old) {
1426                         if (!submodule_uses_gitfile(path))
1427                                 absorb_git_dir_into_superproject("", path,
1428                                         ABSORB_GITDIR_RECURSE_SUBMODULES);
1429                 } else {
1430                         struct strbuf sb = STRBUF_INIT;
1431                         strbuf_addf(&sb, "%s/modules/%s",
1432                                     get_git_common_dir(), sub->name);
1433                         connect_work_tree_and_git_dir(path, sb.buf);
1434                         strbuf_release(&sb);
1435
1436                         /* make sure the index is clean as well */
1437                         submodule_reset_index(path);
1438                 }
1439         }
1440
1441         prepare_submodule_repo_env_no_git_dir(&cp.env_array);
1442
1443         cp.git_cmd = 1;
1444         cp.no_stdin = 1;
1445         cp.dir = path;
1446
1447         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1448                         get_super_prefix_or_empty(), path);
1449         argv_array_pushl(&cp.args, "read-tree", NULL);
1450
1451         if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1452                 argv_array_push(&cp.args, "-n");
1453         else
1454                 argv_array_push(&cp.args, "-u");
1455
1456         if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1457                 argv_array_push(&cp.args, "--reset");
1458         else
1459                 argv_array_push(&cp.args, "-m");
1460
1461         argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1462         argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1463
1464         if (run_command(&cp)) {
1465                 ret = -1;
1466                 goto out;
1467         }
1468
1469         if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1470                 if (new) {
1471                         struct child_process cp1 = CHILD_PROCESS_INIT;
1472                         /* also set the HEAD accordingly */
1473                         cp1.git_cmd = 1;
1474                         cp1.no_stdin = 1;
1475                         cp1.dir = path;
1476
1477                         argv_array_pushl(&cp1.args, "update-ref", "HEAD", new, NULL);
1478
1479                         if (run_command(&cp1)) {
1480                                 ret = -1;
1481                                 goto out;
1482                         }
1483                 } else {
1484                         struct strbuf sb = STRBUF_INIT;
1485
1486                         strbuf_addf(&sb, "%s/.git", path);
1487                         unlink_or_warn(sb.buf);
1488                         strbuf_release(&sb);
1489
1490                         if (is_empty_dir(path))
1491                                 rmdir_or_warn(path);
1492                 }
1493         }
1494 out:
1495         return ret;
1496 }
1497
1498 static int find_first_merges(struct object_array *result, const char *path,
1499                 struct commit *a, struct commit *b)
1500 {
1501         int i, j;
1502         struct object_array merges = OBJECT_ARRAY_INIT;
1503         struct commit *commit;
1504         int contains_another;
1505
1506         char merged_revision[42];
1507         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1508                                    "--all", merged_revision, NULL };
1509         struct rev_info revs;
1510         struct setup_revision_opt rev_opts;
1511
1512         memset(result, 0, sizeof(struct object_array));
1513         memset(&rev_opts, 0, sizeof(rev_opts));
1514
1515         /* get all revisions that merge commit a */
1516         xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1517                         oid_to_hex(&a->object.oid));
1518         init_revisions(&revs, NULL);
1519         rev_opts.submodule = path;
1520         setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1521
1522         /* save all revisions from the above list that contain b */
1523         if (prepare_revision_walk(&revs))
1524                 die("revision walk setup failed");
1525         while ((commit = get_revision(&revs)) != NULL) {
1526                 struct object *o = &(commit->object);
1527                 if (in_merge_bases(b, commit))
1528                         add_object_array(o, NULL, &merges);
1529         }
1530         reset_revision_walk();
1531
1532         /* Now we've got all merges that contain a and b. Prune all
1533          * merges that contain another found merge and save them in
1534          * result.
1535          */
1536         for (i = 0; i < merges.nr; i++) {
1537                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1538
1539                 contains_another = 0;
1540                 for (j = 0; j < merges.nr; j++) {
1541                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1542                         if (i != j && in_merge_bases(m2, m1)) {
1543                                 contains_another = 1;
1544                                 break;
1545                         }
1546                 }
1547
1548                 if (!contains_another)
1549                         add_object_array(merges.objects[i].item, NULL, result);
1550         }
1551
1552         free(merges.objects);
1553         return result->nr;
1554 }
1555
1556 static void print_commit(struct commit *commit)
1557 {
1558         struct strbuf sb = STRBUF_INIT;
1559         struct pretty_print_context ctx = {0};
1560         ctx.date_mode.type = DATE_NORMAL;
1561         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1562         fprintf(stderr, "%s\n", sb.buf);
1563         strbuf_release(&sb);
1564 }
1565
1566 #define MERGE_WARNING(path, msg) \
1567         warning("Failed to merge submodule %s (%s)", path, msg);
1568
1569 int merge_submodule(unsigned char result[20], const char *path,
1570                     const unsigned char base[20], const unsigned char a[20],
1571                     const unsigned char b[20], int search)
1572 {
1573         struct commit *commit_base, *commit_a, *commit_b;
1574         int parent_count;
1575         struct object_array merges;
1576
1577         int i;
1578
1579         /* store a in result in case we fail */
1580         hashcpy(result, a);
1581
1582         /* we can not handle deletion conflicts */
1583         if (is_null_sha1(base))
1584                 return 0;
1585         if (is_null_sha1(a))
1586                 return 0;
1587         if (is_null_sha1(b))
1588                 return 0;
1589
1590         if (add_submodule_odb(path)) {
1591                 MERGE_WARNING(path, "not checked out");
1592                 return 0;
1593         }
1594
1595         if (!(commit_base = lookup_commit_reference(base)) ||
1596             !(commit_a = lookup_commit_reference(a)) ||
1597             !(commit_b = lookup_commit_reference(b))) {
1598                 MERGE_WARNING(path, "commits not present");
1599                 return 0;
1600         }
1601
1602         /* check whether both changes are forward */
1603         if (!in_merge_bases(commit_base, commit_a) ||
1604             !in_merge_bases(commit_base, commit_b)) {
1605                 MERGE_WARNING(path, "commits don't follow merge-base");
1606                 return 0;
1607         }
1608
1609         /* Case #1: a is contained in b or vice versa */
1610         if (in_merge_bases(commit_a, commit_b)) {
1611                 hashcpy(result, b);
1612                 return 1;
1613         }
1614         if (in_merge_bases(commit_b, commit_a)) {
1615                 hashcpy(result, a);
1616                 return 1;
1617         }
1618
1619         /*
1620          * Case #2: There are one or more merges that contain a and b in
1621          * the submodule. If there is only one, then present it as a
1622          * suggestion to the user, but leave it marked unmerged so the
1623          * user needs to confirm the resolution.
1624          */
1625
1626         /* Skip the search if makes no sense to the calling context.  */
1627         if (!search)
1628                 return 0;
1629
1630         /* find commit which merges them */
1631         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1632         switch (parent_count) {
1633         case 0:
1634                 MERGE_WARNING(path, "merge following commits not found");
1635                 break;
1636
1637         case 1:
1638                 MERGE_WARNING(path, "not fast-forward");
1639                 fprintf(stderr, "Found a possible merge resolution "
1640                                 "for the submodule:\n");
1641                 print_commit((struct commit *) merges.objects[0].item);
1642                 fprintf(stderr,
1643                         "If this is correct simply add it to the index "
1644                         "for example\n"
1645                         "by using:\n\n"
1646                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1647                         "which will accept this suggestion.\n",
1648                         oid_to_hex(&merges.objects[0].item->oid), path);
1649                 break;
1650
1651         default:
1652                 MERGE_WARNING(path, "multiple merges found");
1653                 for (i = 0; i < merges.nr; i++)
1654                         print_commit((struct commit *) merges.objects[i].item);
1655         }
1656
1657         free(merges.objects);
1658         return 0;
1659 }
1660
1661 int parallel_submodules(void)
1662 {
1663         return parallel_jobs;
1664 }
1665
1666 /*
1667  * Embeds a single submodules git directory into the superprojects git dir,
1668  * non recursively.
1669  */
1670 static void relocate_single_git_dir_into_superproject(const char *prefix,
1671                                                       const char *path)
1672 {
1673         char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1674         const char *new_git_dir;
1675         const struct submodule *sub;
1676
1677         if (submodule_uses_worktrees(path))
1678                 die(_("relocate_gitdir for submodule '%s' with "
1679                       "more than one worktree not supported"), path);
1680
1681         old_git_dir = xstrfmt("%s/.git", path);
1682         if (read_gitfile(old_git_dir))
1683                 /* If it is an actual gitfile, it doesn't need migration. */
1684                 return;
1685
1686         real_old_git_dir = real_pathdup(old_git_dir, 1);
1687
1688         sub = submodule_from_path(null_sha1, path);
1689         if (!sub)
1690                 die(_("could not lookup name for submodule '%s'"), path);
1691
1692         new_git_dir = git_path("modules/%s", sub->name);
1693         if (safe_create_leading_directories_const(new_git_dir) < 0)
1694                 die(_("could not create directory '%s'"), new_git_dir);
1695         real_new_git_dir = real_pathdup(new_git_dir, 1);
1696
1697         fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1698                 get_super_prefix_or_empty(), path,
1699                 real_old_git_dir, real_new_git_dir);
1700
1701         relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1702
1703         free(old_git_dir);
1704         free(real_old_git_dir);
1705         free(real_new_git_dir);
1706 }
1707
1708 /*
1709  * Migrate the git directory of the submodule given by path from
1710  * having its git directory within the working tree to the git dir nested
1711  * in its superprojects git dir under modules/.
1712  */
1713 void absorb_git_dir_into_superproject(const char *prefix,
1714                                       const char *path,
1715                                       unsigned flags)
1716 {
1717         int err_code;
1718         const char *sub_git_dir;
1719         struct strbuf gitdir = STRBUF_INIT;
1720         strbuf_addf(&gitdir, "%s/.git", path);
1721         sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1722
1723         /* Not populated? */
1724         if (!sub_git_dir) {
1725                 const struct submodule *sub;
1726
1727                 if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1728                         /* unpopulated as expected */
1729                         strbuf_release(&gitdir);
1730                         return;
1731                 }
1732
1733                 if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1734                         /* We don't know what broke here. */
1735                         read_gitfile_error_die(err_code, path, NULL);
1736
1737                 /*
1738                 * Maybe populated, but no git directory was found?
1739                 * This can happen if the superproject is a submodule
1740                 * itself and was just absorbed. The absorption of the
1741                 * superproject did not rewrite the git file links yet,
1742                 * fix it now.
1743                 */
1744                 sub = submodule_from_path(null_sha1, path);
1745                 if (!sub)
1746                         die(_("could not lookup name for submodule '%s'"), path);
1747                 connect_work_tree_and_git_dir(path,
1748                         git_path("modules/%s", sub->name));
1749         } else {
1750                 /* Is it already absorbed into the superprojects git dir? */
1751                 char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1752                 char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1753
1754                 if (!starts_with(real_sub_git_dir, real_common_git_dir))
1755                         relocate_single_git_dir_into_superproject(prefix, path);
1756
1757                 free(real_sub_git_dir);
1758                 free(real_common_git_dir);
1759         }
1760         strbuf_release(&gitdir);
1761
1762         if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1763                 struct child_process cp = CHILD_PROCESS_INIT;
1764                 struct strbuf sb = STRBUF_INIT;
1765
1766                 if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1767                         die("BUG: we don't know how to pass the flags down?");
1768
1769                 strbuf_addstr(&sb, get_super_prefix_or_empty());
1770                 strbuf_addstr(&sb, path);
1771                 strbuf_addch(&sb, '/');
1772
1773                 cp.dir = path;
1774                 cp.git_cmd = 1;
1775                 cp.no_stdin = 1;
1776                 argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1777                                            "submodule--helper",
1778                                            "absorb-git-dirs", NULL);
1779                 prepare_submodule_repo_env(&cp.env_array);
1780                 if (run_command(&cp))
1781                         die(_("could not recurse into submodule '%s'"), path);
1782
1783                 strbuf_release(&sb);
1784         }
1785 }
1786
1787 const char *get_superproject_working_tree(void)
1788 {
1789         struct child_process cp = CHILD_PROCESS_INIT;
1790         struct strbuf sb = STRBUF_INIT;
1791         const char *one_up = real_path_if_valid("../");
1792         const char *cwd = xgetcwd();
1793         const char *ret = NULL;
1794         const char *subpath;
1795         int code;
1796         ssize_t len;
1797
1798         if (!is_inside_work_tree())
1799                 /*
1800                  * FIXME:
1801                  * We might have a superproject, but it is harder
1802                  * to determine.
1803                  */
1804                 return NULL;
1805
1806         if (!one_up)
1807                 return NULL;
1808
1809         subpath = relative_path(cwd, one_up, &sb);
1810
1811         prepare_submodule_repo_env(&cp.env_array);
1812         argv_array_pop(&cp.env_array);
1813
1814         argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
1815                         "ls-files", "-z", "--stage", "--full-name", "--",
1816                         subpath, NULL);
1817         strbuf_reset(&sb);
1818
1819         cp.no_stdin = 1;
1820         cp.no_stderr = 1;
1821         cp.out = -1;
1822         cp.git_cmd = 1;
1823
1824         if (start_command(&cp))
1825                 die(_("could not start ls-files in .."));
1826
1827         len = strbuf_read(&sb, cp.out, PATH_MAX);
1828         close(cp.out);
1829
1830         if (starts_with(sb.buf, "160000")) {
1831                 int super_sub_len;
1832                 int cwd_len = strlen(cwd);
1833                 char *super_sub, *super_wt;
1834
1835                 /*
1836                  * There is a superproject having this repo as a submodule.
1837                  * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
1838                  * We're only interested in the name after the tab.
1839                  */
1840                 super_sub = strchr(sb.buf, '\t') + 1;
1841                 super_sub_len = sb.buf + sb.len - super_sub - 1;
1842
1843                 if (super_sub_len > cwd_len ||
1844                     strcmp(&cwd[cwd_len - super_sub_len], super_sub))
1845                         die (_("BUG: returned path string doesn't match cwd?"));
1846
1847                 super_wt = xstrdup(cwd);
1848                 super_wt[cwd_len - super_sub_len] = '\0';
1849
1850                 ret = real_path(super_wt);
1851                 free(super_wt);
1852         }
1853         strbuf_release(&sb);
1854
1855         code = finish_command(&cp);
1856
1857         if (code == 128)
1858                 /* '../' is not a git repository */
1859                 return NULL;
1860         if (code == 0 && len == 0)
1861                 /* There is an unrelated git repository at '../' */
1862                 return NULL;
1863         if (code)
1864                 die(_("ls-tree returned unexpected return code %d"), code);
1865
1866         return ret;
1867 }
1868
1869 int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
1870 {
1871         const struct submodule *sub;
1872         const char *git_dir;
1873         int ret = 0;
1874
1875         strbuf_reset(buf);
1876         strbuf_addstr(buf, submodule);
1877         strbuf_complete(buf, '/');
1878         strbuf_addstr(buf, ".git");
1879
1880         git_dir = read_gitfile(buf->buf);
1881         if (git_dir) {
1882                 strbuf_reset(buf);
1883                 strbuf_addstr(buf, git_dir);
1884         }
1885         if (!is_git_directory(buf->buf)) {
1886                 gitmodules_config();
1887                 sub = submodule_from_path(null_sha1, submodule);
1888                 if (!sub) {
1889                         ret = -1;
1890                         goto cleanup;
1891                 }
1892                 strbuf_reset(buf);
1893                 strbuf_git_path(buf, "%s/%s", "modules", sub->name);
1894         }
1895
1896 cleanup:
1897         return ret;
1898 }