Fix bug in _remove_pkg logic (bug 505422)
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 04d7aae..f27e855 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -2431,7 +2431,8 @@
 		self._dynamic_config._blocked_world_pkgs.pop(pkg, None)
 
 		for child in children:
-			if not self._dynamic_config.digraph.parent_nodes(child):
+			if child in self._dynamic_config.digraph and \
+				not self._dynamic_config.digraph.parent_nodes(child):
 				self._remove_pkg(child)
 
 		# Clear caches.