X-Git-Url: https://git.octo.it/?a=blobdiff_plain;ds=sidebyside;f=git-checkout-script;h=a37740713ed747a18b7ee5415e41e5bd57834c48;hb=623c8a1460125f66274f451691b3576b0d0f7a4c;hp=e8e777f1f23e71fde909ce0d831d4a319993c0ab;hpb=303e5f4c325d008c68e5e70e901ab68b289ade2e;p=git.git

diff --git a/git-checkout-script b/git-checkout-script
index e8e777f1..a3774071 100755
--- a/git-checkout-script
+++ b/git-checkout-script
@@ -1,30 +1,75 @@
 #!/bin/sh
-: ${GIT_DIR=.git}
-old=$(git-rev-parse HEAD)
-new=$(git-rev-parse --revs-only "$@")
-new=${new:-$old}
-args=($(git-rev-parse --no-revs "$@"))
+. git-sh-setup-script || die "Not a git archive"
 
-i=0
-force=0
-while [ $i -lt ${#args} ]; do
-    case "${args[$i]}" in
+old=$(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;;
-	"")
+		force=1
 		;;
 	*)
-		echo "unknown flag ${args[$i]}"
-		exit 1;;
+		rev=$(git-rev-parse --verify "$arg^0") || exit
+		if [ -z "$rev" ]; then
+			echo "unknown flag $arg"
+			exit 1
+		fi
+		if [ "$new" ]; then
+			echo "Multiple revisions?"
+			exit 1
+		fi
+		new="$rev"
+		if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+			branch="$arg"
+		fi
+		;;
     esac
     i=$(($i+1))
 done
+[ -z "$new" ] && new=$old
 
-if $force
+#
+# If we don't have an old branch that we're switching to,
+# and we don't have a new branch name for the target we
+# are switching to, then we'd better just be checking out
+# what we already had
+#
+[ -z "$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 &&
-	echo $new > "$GIT_DIR/HEAD"
+	git-checkout-cache -q -f -u -a
 else
-    git-read-tree -m -u $old $new && echo $new > "$GIT_DIR/HEAD"
+    git-read-tree -m -u $old $new
+fi
+
+# 
+# Switch the HEAD pointer to the new branch if it we
+# checked out a branch head, and remove any potential
+# old MERGE_HEAD's (subsequent commits will clearly not
+# be based on them, since we re-set the index)
+#
+if [ "$?" -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"
 fi