composite_db._visible: fix AttributeError

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index e6245598fc904fca301b176e7fcec4c3ac0b60cf..dfc9be9d020a7d9ec68f9628d6c51ba5cdc371e8 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -6858,7 +6858,7 @@ class _dep_check_composite_db(dbapi):
                        # Note: highest_visible is not necessarily the real highest
                        # visible, especially when --update is not enabled, so use
                        # < operator instead of !=.
-                       if pkg < highest_visible:
+                       if highest_visible is not None and pkg < highest_visible:
                                return False
                elif in_graph != pkg:
                        # Mask choices for packages that would trigger a slot