bisect: quote pathnames for eval safety.

... and make sure they are on the same line.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-bisect.sh

 #!/bin/sh
 . git-sh-setup
 
+sq() {
+	perl -e '
+		for (@ARGV) {
+			s/'\''/'\'\\\\\'\''/g;
+			print " '\''$_'\''";
+		}
+		print "\n";
+	' "$@"
+}
+
 usage() {
     echo >&2 'usage: git bisect [start|bad|good|next|reset|visualize]
-git bisect start		reset bisect state and start bisection.
+git bisect start [<pathspec>]	reset bisect state and start bisection.
 git bisect bad [<rev>]		mark <rev> a known-bad revision.
 git bisect good [<rev>...]	mark <rev>... known-good revisions.
 git bisect next			find next bisection to test and check it out.
@@ -56,8 +66,11 @@ bisect_start() {
 	rm -f "$GIT_DIR/refs/heads/bisect"
 	rm -rf "$GIT_DIR/refs/bisect/"
 	mkdir "$GIT_DIR/refs/bisect"
-	echo "git-bisect start $@" >"$GIT_DIR/BISECT_LOG"
-	echo "$@" > "$GIT_DIR/BISECT_NAMES"
+	{
+	    echo -n "git-bisect start"
+	    sq "$@"
+	} >"$GIT_DIR/BISECT_LOG"
+	sq "$@" >"$GIT_DIR/BISECT_NAMES"
 }
 
 bisect_bad() {
@@ -142,7 +155,8 @@ bisect_next() {
 
 bisect_visualize() {
 	bisect_next_check fail
-	gitk bisect/bad --not `cd "$GIT_DIR/refs" && echo bisect/good-*` -- $(cat $GIT_DIR/BISECT_NAMES)
+	not=`cd "$GIT_DIR/refs" && echo bisect/good-*`
+	eval gitk bisect/bad --not $not -- $(cat "$GIT_DIR/BISECT_NAMES")
 }
 
 bisect_reset() {
@@ -173,7 +187,8 @@ bisect_replay () {
 		test "$bisect" = "git-bisect" || continue
 		case "$command" in
 		start)
-			bisect_start
+			cmd="bisect_start $rev"
+			eval "$cmd"
 			;;
 		good)
 			echo "$rev" >"$GIT_DIR/refs/bisect/good-$rev"