Start moving unpack-trees to "struct tree_desc"

This doesn't actually change any real code, but it changes the interface
to unpack_trees() to take an array of "struct tree_desc" entries, the same
way the tree-walk.c functions do.

The reason for this is that we would be much better off if we can do the
tree-unpacking using the generic "traverse_trees()" functionality instead
of having to the special "unpack" infrastructure.

This really is a pretty minimal diff, just to change the calling
convention. It passes all the tests, and looks sane. There were only two
users of "unpack_trees()": builtin-read-tree and merge-recursive, and I
tried to keep the changes minimal.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/merge-recursive.c b/merge-recursive.c
index c8539ec0ba..f7d1b84999 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -216,13 +216,19 @@ static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
  */
 static int index_only = 0;
 
+static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
+{
+	parse_tree(tree);
+	init_tree_desc(desc, tree->buffer, tree->size);
+}
+
 static int git_merge_trees(int index_only,
 			   struct tree *common,
 			   struct tree *head,
 			   struct tree *merge)
 {
 	int rc;
-	struct object_list *trees = NULL;
+	struct tree_desc t[3];
 	struct unpack_trees_options opts;
 
 	memset(&opts, 0, sizeof(opts));
@@ -234,11 +240,11 @@ static int git_merge_trees(int index_only,
 	opts.head_idx = 2;
 	opts.fn = threeway_merge;
 
-	object_list_append(&common->object, &trees);
-	object_list_append(&head->object, &trees);
-	object_list_append(&merge->object, &trees);
+	init_tree_desc_from_tree(t+0, common);
+	init_tree_desc_from_tree(t+1, head);
+	init_tree_desc_from_tree(t+2, merge);
 
-	rc = unpack_trees(trees, &opts);
+	rc = unpack_trees(3, t, &opts);
 	cache_tree_free(&active_cache_tree);
 	return rc;
 }