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

diff --git a/git-checkout.sh b/git-checkout.sh
index 580a9e8a233f0a94c84792eba7c3dc653fccf3a0..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 $old_name 2>/dev/null)
 new=
 new_name=
 force=
@@ -22,7 +22,7 @@ while [ "$#" != "0" ]; do
                shift
                [ -z "$newbranch" ] &&
                        die "git checkout: -b needs a branch name"
-               [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
+               git-show-ref --verify --quiet -- "refs/heads/$newbranch" &&
                        die "git checkout: branch $newbranch already exists"
                git-check-ref-format "heads/$newbranch" ||
                        die "git checkout: we do not like '$newbranch' as a branch name."
@@ -51,7 +51,8 @@ while [ "$#" != "0" ]; do
                        fi
                        new="$rev"
                        new_name="$arg^0"
-                       if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+                       if git-show-ref --verify --quiet -- "refs/heads/$arg"
+                       then
                                branch="$arg"
                        fi
                elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
@@ -139,6 +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