tree.h API: expose read_tree_1() as read_tree_at()

Rename the static read_tree_1() function to read_tree_at(). This
function works just like read_tree_recursive(), except you provide
your own strbuf.

This step doesn't make much sense now, but in follow-up commits I'll
remove the base/baselen/stage arguments to read_tree_recursive(). At
that point an anticipated in-tree user[1] for the old
read_tree_recursive() couldn't provide a path to start the
traversal.

Let's give them a function to do so with an API that makes more sense
for them, by taking a strbuf we should be able to avoid more casting
and/or reallocations in the future.

1. https://lore.kernel.org/git/xmqqft106sok.fsf@gitster.g

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

1 files changed, 6 insertions, 0 deletions

diff --git a/tree.h b/tree.h
index 6b0b1dc..123fc41 100644
--- a/tree.h
+++ b/tree.h
@@ -33,6 +33,12 @@ int cmp_cache_name_compare(const void *a_, const void *b_);
 #define READ_TREE_RECURSIVE 1
 typedef int (*read_tree_fn_t)(const struct object_id *, struct strbuf *, const char *, unsigned int, int, void *);
 
+int read_tree_at(struct repository *r,
+		 struct tree *tree, struct strbuf *base,
+		 int stage,
+		 const struct pathspec *pathspec,
+		 read_tree_fn_t fn, void *context);
+
 int read_tree_recursive(struct repository *r,
 			struct tree *tree,
 			const char *base, int baselen,