Introduce get_octopus_merge_bases() in commit.c

This is like get_merge_bases() but it works for multiple heads, like
show-branch --merge-base.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/commit.c b/commit.c
index bbf9c75416537f4e64416d54b03cd00f9d0a56db..6052ca34c803e6af432309041c8e3201b71efca4 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -600,6 +600,33 @@ static struct commit_list *merge_bases(struct commit *one, struct commit *two)
        return result;
 }
 
+struct commit_list *get_octopus_merge_bases(struct commit_list *in)
+{
+       struct commit_list *i, *j, *k, *ret = NULL;
+       struct commit_list **pptr = &ret;
+
+       for (i = in; i; i = i->next) {
+               if (!ret)
+                       pptr = &commit_list_insert(i->item, pptr)->next;
+               else {
+                       struct commit_list *new = NULL, *end = NULL;
+
+                       for (j = ret; j; j = j->next) {
+                               struct commit_list *bases;
+                               bases = get_merge_bases(i->item, j->item, 1);
+                               if (!new)
+                                       new = bases;
+                               else
+                                       end->next = bases;
+                               for (k = bases; k; k = k->next)
+                                       end = k;
+                       }
+                       ret = new;
+               }
+       }
+       return ret;
+}
+
 struct commit_list *get_merge_bases(struct commit *one,
                                        struct commit *two, int cleanup)
 {

diff --git a/commit.h b/commit.h
index 7f8c5ee0fc15fd93c83a29d350d12fdb956657b9..dcec7fb9a2264d068037aa57894ba0a3ae43231a 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -121,6 +121,7 @@ int read_graft_file(const char *graft_file);
 struct commit_graft *lookup_commit_graft(const unsigned char *sha1);
 
 extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup);
+extern struct commit_list *get_octopus_merge_bases(struct commit_list *in);
 
 extern int register_shallow(const unsigned char *sha1);
 extern int unregister_shallow(const unsigned char *sha1);