Merge with gitk --parents change.

diff --git a/git-checkout-script b/git-checkout-script
index 870b1a3ef9ad71699ee0a6c967e91eaab0932573..a37740713ed747a18b7ee5415e41e5bd57834c48 100755 (executable)
--- a/git-checkout-script
+++ b/git-checkout-script
@@ -1,18 +1,28 @@
 #!/bin/sh
-: ${GIT_DIR=.git}
+. git-sh-setup-script || die "Not a git archive"
+
 old=$(git-rev-parse HEAD)
 new=
 force=
 branch=
+newbranch=
 while [ "$#" != "0" ]; do
     arg="$1"
     shift
     case "$arg" in
+       "-b")
+               newbranch="$1"
+               shift
+               [ -z "$newbranch" ] &&
+                       die "git checkout: -b needs a branch name"
+               [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
+                       die "git checkout: branch $newbranch already exists"
+               ;;
        "-f")
                force=1
                ;;
        *)
-               rev=$(git-rev-parse "$arg")
+               rev=$(git-rev-parse --verify "$arg^0") || exit
                if [ -z "$rev" ]; then
                        echo "unknown flag $arg"
                        exit 1
@@ -22,7 +32,7 @@ while [ "$#" != "0" ]; do
                        exit 1
                fi
                new="$rev"
-               if [ -f "$GIT_DIR/revs/heads/$arg" ]; then
+               if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
                        branch="$arg"
                fi
                ;;
@@ -31,6 +41,16 @@ while [ "$#" != "0" ]; do
 done
 [ -z "$new" ] && new=$old
 
+#
+# If we don't have an old branch that we're switching to,
+# and we don't have a new branch name for the target we
+# are switching to, then we'd better just be checking out
+# what we already had
+#
+[ -z "$branch$newbranch" ] &&
+       [ "$new" != "$old" ] &&
+       die "git checkout: you need to specify a new branch name"
+
 if [ "$force" ]
 then
     git-read-tree --reset $new &&
@@ -46,6 +66,10 @@ fi
 # be based on them, since we re-set the index)
 #
 if [ "$?" -eq 0 ]; then
+       if [ "$newbranch" ]; then
+               echo $new > "$GIT_DIR/refs/heads/$newbranch"
+               branch="$newbranch"
+       fi
        [ "$branch" ] && ln -sf "refs/heads/$branch" "$GIT_DIR/HEAD"
        rm -f "$GIT_DIR/MERGE_HEAD"
 fi