merge: make usage of commit->util more extensible

The merge-recursive code uses the commit->util field directly to annotate
the commit objects given from the command line, i.e. the remote heads to
be merged, with a single string to be used to describe it in its trace
messages and conflict markers.

Correct this short-signtedness by redefining the field to be a pointer to
a structure "struct merge_remote_desc" that later enhancements can add
more information. Store the original objects we were told to merge in a
field "obj" in this struct, so that we can recover the tag we were told to
merge.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/commit.c b/commit.c
index 73b7e00292..83ff5035a7 100644
--- a/commit.c
+++ b/commit.c
@@ -894,3 +894,22 @@ int commit_tree(const char *msg, unsigned char *tree,
 	strbuf_release(&buffer);
 	return result;
 }
+
+struct commit *get_merge_parent(const char *name)
+{
+	struct object *obj;
+	struct commit *commit;
+	unsigned char sha1[20];
+	if (get_sha1(name, sha1))
+		return NULL;
+	obj = parse_object(sha1);
+	commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
+	if (commit && !commit->util) {
+		struct merge_remote_desc *desc;
+		desc = xmalloc(sizeof(*desc));
+		desc->obj = obj;
+		desc->name = strdup(name);
+		commit->util = desc;
+	}
+	return commit;
+}