merge-base --octopus to mimic show-branch --merge-base

diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index 54e7ec22370ce63150ddc93ebe252bea09f5064a..c30128659f0e6edd9baf261e73c9da6b4a308964 100644 (file)
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -23,7 +23,7 @@ static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
 }
 
 static const char * const merge_base_usage[] = {
-       "git merge-base [-a|--all] <commit> <commit>...",
+       "git merge-base [-a|--all] [--octopus] <commit> <commit>...",
        NULL
 };
 
@@ -41,21 +41,50 @@ static struct commit *get_commit_reference(const char *arg)
        return r;
 }
 
+static int show_octopus_merge_bases(int count, const char **args, int show_all)
+{
+       struct commit_list *revs = NULL;
+       struct commit_list *result;
+       int i;
+
+       for (i = count - 1; i >= 0; i++)
+               commit_list_insert(get_commit_reference(args[i]), &revs);
+       result = get_octopus_merge_bases(revs);
+
+       if (!result)
+               return 1;
+
+       while (result) {
+               printf("%s\n", sha1_to_hex(result->item->object.sha1));
+               if (!show_all)
+                       return 0;
+               result = result->next;
+       }
+
+       return 0;
+}
+
 int cmd_merge_base(int argc, const char **argv, const char *prefix)
 {
        struct commit **rev;
        int rev_nr = 0;
        int show_all = 0;
+       int octopus = 0;
 
        struct option options[] = {
-               OPT_BOOLEAN('a', "all", &show_all, "outputs all common ancestors"),
+               OPT_BOOLEAN('a', "all", &show_all, "output all common ancestors"),
+               OPT_BOOLEAN(0, "octopus", &octopus, "find ancestors for a single n-way merge"),
                OPT_END()
        };
 
        git_config(git_default_config, NULL);
        argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0);
-       if (argc < 2)
+       if (!octopus && argc < 2)
                usage_with_options(merge_base_usage, options);
+
+       if (octopus)
+               return show_octopus_merge_bases(argc, argv, show_all);
+
        rev = xmalloc(argc * sizeof(*rev));
        while (argc-- > 0)
                rev[rev_nr++] = get_commit_reference(*argv++);