fix bluescreen ... i hope this is okay

diff --git a/lib/python/Components/Element.py b/lib/python/Components/Element.py
index 884c87d393d920f0b1bec8a2e012be0b80d25e0e..54a1cc251cce6239537eec090249279db409d0d8 100644 (file)
--- a/lib/python/Components/Element.py
+++ b/lib/python/Components/Element.py
@@ -29,7 +29,8 @@ class Element:
                # we should not disconnect from upstream if
                # there are still elements depending on us.
                assert len(self.downstream_elements) == 0, "there are still downstream elements left"
-               self.source.disconnectDownstream(self)
+               if self.source:
+                       self.source.disconnectDownstream(self)
        
        def disconnectDownstream(self, downstream):
                self.downstream_elements.remove(downstream)