[PATCH] sha1_file: fix delta_stack memory leak in unpack_entry

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This delta_stack array can grow to any length depending on the actual
delta chain, but we forget to free it. Normally it does not matter
because we use small_delta_stack[] from stack and small_delta_stack
can hold 64-delta chains, more than standard --depth=50 in pack-objects.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Found when trying to see if making some objects loose at this phase
 could help git-blame and how many objects will be loosened. Gotta go
 soon, didn't really test it, but I bet it'll work.

 sha1_file.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sha1_file.c b/sha1_file.c
index 6e8c05d..57ab15d 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2289,6 +2289,10 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
 	*final_size = size;
 
 	unuse_pack(&w_curs);
+
+	if (delta_stack != small_delta_stack)
+		free(delta_stack);
+
 	return data;
 }
 
-- 
1.9.0.40.gaa8c3ea