A small tweak in navigation.

diff --git a/www/js/book.js b/www/js/book.js
index 9ed5ee5c7ae31491bf8a170252d27cf9b8755fff..fff27fc1f0a7a4756481a0725fcb55040ccc7ff0 100644 (file)
--- a/www/js/book.js
+++ b/www/js/book.js
@@ -216,9 +216,13 @@ var show_lines = function(data, game) {
 }
 
 var make_move = function(move) {
-       history.length = move_override;
-       history.push(move);
-       move_override = history.length;
+       if (move_override < history.length && history[move_override] == move) {
+               // User effectively only moved forward in history.
+               ++move_override;
+       } else {
+               history.push(move);
+               move_override = history.length;
+       }
        update();
 }
 window['make_move'] = make_move;