emacs: C-u C-space fix (setMark)

lib/ace/keyboard/emacs.js

@@ -421,6 +421,12 @@ exports.handler.addCommands({
             // "goto" commands become "select" commands.
             // Any insertion or mouse click resets mark-mode.
             // setMark twice in a row at the same place resets markmode
+            if (args && args.count) {
+                var mark = editor.popEmacsMark();
+                mark && editor.selection.moveCursorToPosition(mark);
+                return;
+            }
+
             var mark = editor.emacsMark(),
                 transientMarkModeActive = true;
 
@@ -448,6 +454,7 @@ exports.handler.addCommands({
             editor.selection.setSelectionAnchor(mark.row, mark.column);
         },
         readonly: true,
+        handlesCount: true,
         multiSelectAction: "forEach"
     },
     exchangePointAndMark: {