core.logallrefupdates create new log file only for branch heads.

diff --git a/git-checkout.sh b/git-checkout.sh
index f03620b054ea81554e293dabf0884cac12bb73e4..119bca1ffbfb8fb0dae404a8e7389f577aebc42c 100755 (executable)
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -4,8 +4,8 @@ USAGE='[-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
 SUBDIRECTORY_OK=Sometimes
 . git-sh-setup
 
-old=$(git-rev-parse HEAD)
 old_name=HEAD
+old=$(git-rev-parse --verify $old_name 2>/dev/null)
 new=
 new_name=
 force=
@@ -140,6 +140,13 @@ fi
        die "git checkout: to checkout the requested commit you need to specify 
               a name for a new branch which is created and switched to"
 
+if [ "X$old" = X ]
+then
+       echo "warning: You do not appear to currently be on a branch." >&2
+       echo "warning: Forcing checkout of $new_name." >&2
+       force=1
+fi
+
 if [ "$force" ]
 then
     git-read-tree --reset -u $new