richedit: Test to see if WM_SETREDRAW removes the windows visibility.

dlls/riched20/tests/editor.c

@@ -5186,7 +5186,10 @@ static void test_eventMask(void)
 
     /* check to see if EN_CHANGE is sent when redraw is turned off */
     SendMessage(eventMaskEditHwnd, WM_CLEAR, 0, 0);
+    ok(IsWindowVisible(eventMaskEditHwnd), "Window should be visible.\n");
     SendMessage(eventMaskEditHwnd, WM_SETREDRAW, FALSE, 0);
+    /* redraw is disabled by making the window invisible. */
+    todo_wine ok(!IsWindowVisible(eventMaskEditHwnd), "Window shouldn't be visible.\n");
     queriedEventMask = 0;  /* initialize to something other than we expect */
     SendMessage(eventMaskEditHwnd, EM_REPLACESEL, 0, (LPARAM) text);
     ok(queriedEventMask == (eventMask & ~ENM_CHANGE),