Fix bug with bad painting of view window when rubber band is empty

diff --git a/src/Qtx/QtxRubberBand.cxx b/src/Qtx/QtxRubberBand.cxx
index 16dca8b96c549c4883f48f8e8e74663a77ce2c6d..9a72c5846e9a3fdc32f11d876946ac41577a0d1f 100755 (executable)
--- a/src/Qtx/QtxRubberBand.cxx
+++ b/src/Qtx/QtxRubberBand.cxx
@@ -205,8 +205,8 @@ void QtxAbstractRubberBand::updateMask()
   if ( isClosed() )
     r += createRegion( myPoints.last(), myPoints.first() );
 
-  setMask( r );
-
+  if ( !r.isEmpty() )
+    setMask( r );
 }