Optimize peel_ref for the current ref of a for_each_ref callback

diff --git a/git-clone.sh b/git-clone.sh
index b4e858c3885dab55398670d9497304eb83545d1f..0d686c3a03a15d73e086d3a54afeee269365ffcd 100755 (executable)
--- a/git-clone.sh
+++ b/git-clone.sh
@@ -409,11 +409,12 @@ else
        cd "$D" || exit
 fi
 
-if test -z "$bare" && test -f "$GIT_DIR/REMOTE_HEAD"
+if test -z "$bare"
 then
        # a non-bare repository is always in separate-remote layout
        remote_top="refs/remotes/$origin"
-       head_sha1=`cat "$GIT_DIR/REMOTE_HEAD"`
+       head_sha1=
+       test ! -r "$GIT_DIR/REMOTE_HEAD" || head_sha1=`cat "$GIT_DIR/REMOTE_HEAD"`
        case "$head_sha1" in
        'ref: refs/'*)
                # Uh-oh, the remote told us (http transport done against
@@ -470,9 +471,16 @@ then
                git config branch."$head_points_at".merge "refs/heads/$head_points_at"
                ;;
        '')
-               # Source had detached HEAD pointing nowhere
-               git update-ref --no-deref HEAD "$head_sha1" &&
-               rm -f "refs/remotes/$origin/HEAD"
+               if test -z "$head_sha1"
+               then
+                       # Source had nonexistent ref in HEAD
+                       echo >&2 "Warning: Remote HEAD refers to nonexistent ref, unable to checkout."
+                       no_checkout=t
+               else
+                       # Source had detached HEAD pointing nowhere
+                       git update-ref --no-deref HEAD "$head_sha1" &&
+                       rm -f "refs/remotes/$origin/HEAD"
+               fi
                ;;
        esac