Do not redraw the dialog on activate

doc/TODO

@@ -20,10 +20,12 @@ Missing Features
      └──► tmp
 ---------------------------------------
 
+- Screen characters should get the options transparent 
+  and transparent with color
 - FDialog title button [▲] and [▼] should maximized or restore 
   the window size on a resizeable dialog
 - A possibility to change the window size dynamically with the mouse
 - Add a scrolling area with on-demand scroll bars for FButtonGroup
-- Adding for flexible layouts a FGrid widget container that organizes
+- Adding for flexible layouts a FGrid widget container that organizes 
   its child widgets in rows and columns
 

src/fdialog.cpp

@@ -1033,7 +1033,8 @@ void FDialog::activateDialog()
     if ( ! focusFirstChild() )
       old_focus->unsetFocus();
 
-    old_focus->redraw();
+    if ( ! old_focus->isWindow() )
+      old_focus->redraw();
   }
 
   if ( statusBar() )