[PATCH 1/2] cache-tree.c::cache_tree_find(): simplify inernal API

Earlier cache_tree_find() needs to be called with a valid cache_tree,
but repeated look-up may find an invalid or missing cache_tree in between.
Help simplify the callers by returning NULL to mean "nothing appropriate
found" when the input is NULL.

Signed-off-by: Junio C Hamano <redacted>
---

 * This is a preliminary clean-up patch.  What comes next is much bigger.

 cache-tree.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/cache-tree.c b/cache-tree.c
index 6dd8411..5481e43 100644
--- a/cache-tree.c
+++ b/cache-tree.c

@@ -514,6 +514,8 @@ struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 
 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 {
+	if (!it)
+		return NULL;
 	while (*path) {
 		const char *slash;
 		struct cache_tree_sub *sub;

-- 
1.6.3.1.56.gd00e3.dirty