[PATCH 17/38] resolve_gitlink_ref(): avoid memory allocation in many cases

[Michael Haggerty <mhagger@alum.mit.edu>]

If we don't have to strip trailing '/' from the submodule path, then
don't allocate and copy the submodule name.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/refs.c b/refs.c
index 5e0777a..7a8ef6d 100644
--- a/refs.c
+++ b/refs.c
@@ -1301,19 +1301,25 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 
 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
 {
-	int len = strlen(path);
-	struct strbuf submodule = STRBUF_INIT;
+	size_t len, orig_len = strlen(path);
 	struct ref_store *refs;
 	int flags;
 
-	while (len && path[len-1] == '/')
-		len--;
+	for (len = orig_len; len && path[len - 1] == '/'; len--)
+		;
+
 	if (!len)
 		return -1;
 
-	strbuf_add(&submodule, path, len);
-	refs = get_ref_store(submodule.buf);
-	strbuf_release(&submodule);
+	if (len == orig_len) {
+		refs = get_ref_store(path);
+	} else {
+		char *stripped = xmemdupz(path, len);
+
+		refs = get_ref_store(stripped);
+		free(stripped);
+	}
+
 	if (!refs)
 		return -1;
 
-- 
2.8.1