Fix missing dummy stroke for undo event. Fix typo in listener

client/client_recv.js

@@ -448,6 +448,7 @@ function handle_event(state, context, event, options = {}) {
         }
 
         case EVENT.ERASER: {
+            geometry_add_dummy_stroke(context);
             need_draw = true;
             const stroke = state.events[event.stroke_id];
             stroke.deleted = true;

client/webgl_listeners.js

@@ -151,7 +151,7 @@ function keydown(e, state, context) {
         document.querySelector('.debug-window').classList.toggle('dhide');
     } else if (e.code === 'KeyZ') {
         if (e.ctrlKey) {
-            queue_event(state, endo_event(state));
+            queue_event(state, undo_event(state));
         } else {
             state.zoomdown = true;
         }