convert: treat an empty string for clean/smudge filters as "cat"

diff --git a/cache.h b/cache.h
index 5ab6cb50a61e24dc418b351db8acc648b740c244..c63fcc113a6e511a53f0170a07bd5dbbf12cc120 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -831,6 +831,7 @@ extern const char *find_unique_abbrev(const unsigned char *sha1, int len);
 extern int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len);
 
 extern const unsigned char null_sha1[GIT_SHA1_RAWSZ];
+extern const struct object_id null_oid;
 
 static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 {