depgraph: fix KeyError in select_atoms

This happens if depstring evaluates to nothing.

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 17405b06dc1c72b502f6a50d2860fc3f9c014588..f569b18158820515e0f17c2b855e7cc9cbfb8a1d 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -2233,6 +2233,8 @@ class depgraph(object):
                                raise portage.exception.InvalidDependString(mycheck[1])
                if parent is None:
                        selected_atoms = mycheck[1]
+               elif parent not in atom_graph:
+                       selected_atoms = {parent : mycheck[1]}
                else:
                        # Recursively traversed virtual dependencies, and their
                        # direct dependencies, are considered to have the same