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, 13 insertions, 0 deletions

diff --git a/commit.h b/commit.h
index 009b113..5b57eab 100644
--- a/commit.h
+++ b/commit.h
@@ -185,4 +185,17 @@ extern int commit_tree(const char *msg, unsigned char *tree,
 		struct commit_list *parents, unsigned char *ret,
 		const char *author);
 
+struct merge_remote_desc {
+	struct object *obj; /* the named object, could be a tag */
+	const char *name;
+};
+#define merge_remote_util(commit) ((struct merge_remote_desc *)((commit)->util))
+
+/*
+ * Given "name" from the command line to merge, find the commit object
+ * and return it, while storing merge_remote_desc in its ->util field,
+ * to allow callers to tell if we are told to merge a tag.
+ */
+struct commit *get_merge_parent(const char *name);
+
 #endif /* COMMIT_H */