X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=git-checkout-script;h=9feff149acc87326e13f96db17257235e78c42db;hb=1efdd27f54e42746c23944cfe77e568673b2a0fa;hp=dc1cffde0bd214b90f0c0b754f0e5f33bd3023b2;hpb=a79944d76cf4098e42d13e5743a3dccb61ebaca6;p=git.git

diff --git a/git-checkout-script b/git-checkout-script
index dc1cffde..9feff149 100755
--- a/git-checkout-script
+++ b/git-checkout-script
@@ -1,27 +1,55 @@
 #!/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
+old=$(git-rev-parse HEAD)
+new=
 force=
-update=
-while [ $i -lt ${#args} ]; do
-    case "${args[$i]}" in
+branch=
+newbranch=
+while [ "$#" != "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;;
-	"-u")
-		update=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 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
@@ -29,5 +57,21 @@ then
 	git-checkout-cache -q -f -u -a
 else
     git-read-tree -m -u $old $new
-fi && [ "$update" ] && echo $new > "$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