X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=git-checkout-script;h=9feff149acc87326e13f96db17257235e78c42db;hb=10d781b9caa4f71495c7b34963bef137216f86a8;hp=5b49662e623a4f68f2796458daea3875911afb68;hpb=dc14841102bb364c2be200e8456146fc8df970b9;p=git.git

diff --git a/git-checkout-script b/git-checkout-script
index 5b49662e..9feff149 100755
--- 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
 		;;
@@ -31,10 +41,37 @@ 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 &&
 	git-checkout-cache -q -f -u -a
 else
     git-read-tree -m -u $old $new
-fi && [ "$branch" ] && ln -sf "refs/heads/$branch" "$GIT_DIR/HEAD"
+fi
+
+# 
+# Switch the HEAD pointer to the new branch if it we
+# checked out a branch head, and remove any potential
+# old MERGE_HEAD's (subsequent commits will clearly not
+# 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"
+else
+	exit 1
+fi