diff options
Diffstat (limited to 'submodule.c')
| -rw-r--r-- | submodule.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/submodule.c b/submodule.c index 61cb6e21dd..dcb4b5da71 100644 --- a/submodule.c +++ b/submodule.c @@ -6,6 +6,7 @@ #include "revision.h" #include "run-command.h" #include "diffcore.h" +#include "refs.h" static int add_submodule_odb(const char *path) { @@ -218,3 +219,163 @@ unsigned is_submodule_modified(const char *path, int ignore_untracked) strbuf_release(&buf); return dirty_submodule; } + +static int find_first_merges(struct object_array *result, const char *path, + struct commit *a, struct commit *b) +{ + int i, j; + struct object_array merges; + struct commit *commit; + int contains_another; + + char merged_revision[42]; + const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path", + "--all", merged_revision, NULL }; + struct rev_info revs; + struct setup_revision_opt rev_opts; + + memset(&merges, 0, sizeof(merges)); + memset(result, 0, sizeof(struct object_array)); + memset(&rev_opts, 0, sizeof(rev_opts)); + + /* get all revisions that merge commit a */ + snprintf(merged_revision, sizeof(merged_revision), "^%s", + sha1_to_hex(a->object.sha1)); + init_revisions(&revs, NULL); + rev_opts.submodule = path; + setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts); + + /* save all revisions from the above list that contain b */ + if (prepare_revision_walk(&revs)) + die("revision walk setup failed"); + while ((commit = get_revision(&revs)) != NULL) { + struct object *o = &(commit->object); + if (in_merge_bases(b, &commit, 1)) + add_object_array(o, NULL, &merges); + } + + /* Now we've got all merges that contain a and b. Prune all + * merges that contain another found merge and save them in + * result. + */ + for (i = 0; i < merges.nr; i++) { + struct commit *m1 = (struct commit *) merges.objects[i].item; + + contains_another = 0; + for (j = 0; j < merges.nr; j++) { + struct commit *m2 = (struct commit *) merges.objects[j].item; + if (i != j && in_merge_bases(m2, &m1, 1)) { + contains_another = 1; + break; + } + } + + if (!contains_another) + add_object_array(merges.objects[i].item, + merges.objects[i].name, result); + } + + free(merges.objects); + return result->nr; +} + +static void print_commit(struct commit *commit) +{ + struct strbuf sb = STRBUF_INIT; + struct pretty_print_context ctx = {0}; + ctx.date_mode = DATE_NORMAL; + format_commit_message(commit, " %h: %m %s", &sb, &ctx); + fprintf(stderr, "%s\n", sb.buf); + strbuf_release(&sb); +} + +#define MERGE_WARNING(path, msg) \ + warning("Failed to merge submodule %s (%s)", path, msg); + +int merge_submodule(unsigned char result[20], const char *path, + const unsigned char base[20], const unsigned char a[20], + const unsigned char b[20]) +{ + struct commit *commit_base, *commit_a, *commit_b; + int parent_count; + struct object_array merges; + + int i; + + /* store a in result in case we fail */ + hashcpy(result, a); + + /* we can not handle deletion conflicts */ + if (is_null_sha1(base)) + return 0; + if (is_null_sha1(a)) + return 0; + if (is_null_sha1(b)) + return 0; + + if (add_submodule_odb(path)) { + MERGE_WARNING(path, "not checked out"); + return 0; + } + + if (!(commit_base = lookup_commit_reference(base)) || + !(commit_a = lookup_commit_reference(a)) || + !(commit_b = lookup_commit_reference(b))) { + MERGE_WARNING(path, "commits not present"); + return 0; + } + + /* check whether both changes are forward */ + if (!in_merge_bases(commit_base, &commit_a, 1) || + !in_merge_bases(commit_base, &commit_b, 1)) { + MERGE_WARNING(path, "commits don't follow merge-base"); + return 0; + } + + /* Case #1: a is contained in b or vice versa */ + if (in_merge_bases(commit_a, &commit_b, 1)) { + hashcpy(result, b); + return 1; + } + if (in_merge_bases(commit_b, &commit_a, 1)) { + hashcpy(result, a); + return 1; + } + + /* + * Case #2: There are one or more merges that contain a and b in + * the submodule. If there is only one, then present it as a + * suggestion to the user, but leave it marked unmerged so the + * user needs to confirm the resolution. + */ + + /* find commit which merges them */ + parent_count = find_first_merges(&merges, path, commit_a, commit_b); + switch (parent_count) { + case 0: + MERGE_WARNING(path, "merge following commits not found"); + break; + + case 1: + MERGE_WARNING(path, "not fast-forward"); + fprintf(stderr, "Found a possible merge resolution " + "for the submodule:\n"); + print_commit((struct commit *) merges.objects[0].item); + fprintf(stderr, + "If this is correct simply add it to the index " + "for example\n" + "by using:\n\n" + " git update-index --cacheinfo 160000 %s \"%s\"\n\n" + "which will accept this suggestion.\n", + sha1_to_hex(merges.objects[0].item->sha1), path); + break; + + default: + MERGE_WARNING(path, "multiple merges found"); + for (i = 0; i < merges.nr; i++) + print_commit((struct commit *) merges.objects[i].item); + } + + free(merges.objects); + return 0; +} |