lock_ref: inform callers of unavailable ref

One of the ways that locking might fail is that there is a
DF conflict between two refs (e.g., you want to lock
"foo/bar" but "foo" already exists). In this case, we return
an error, but there is no way for the caller to know the
specific problem.

This patch sets errno to ENOTDIR, which is the most sensible
code. It's what we would see if the refs were stored purely
in the filesystem (but these days we must check the
namespace manually due to packed refs).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/refs.c b/refs.c
index e65a3b4c4ef57863a1055108d2598777cabc2c8d..8679c17e0d2902e6264d0d0b1d6fd36bcb85fecb 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -893,8 +893,10 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
         * name is a proper prefix of our refname.
         */
        if (missing &&
-            !is_refname_available(ref, NULL, get_packed_refs(), 0))
+            !is_refname_available(ref, NULL, get_packed_refs(), 0)) {
+               last_errno = ENOTDIR;
                goto error_return;
+       }
 
        lock->lk = xcalloc(1, sizeof(struct lock_file));