slot_collision: fix more for bug 374423

diff --git a/pym/_emerge/resolver/slot_collision.py b/pym/_emerge/resolver/slot_collision.py
index 0069d179d9c16c633bcfc95ed117338bfd71f427..0df8f20a28013ddbbdb9a86141843a7b85dbf466 100644 (file)
--- a/pym/_emerge/resolver/slot_collision.py
+++ b/pym/_emerge/resolver/slot_collision.py
@@ -588,6 +588,15 @@ class slot_conflict_handler(object):
                                else:
                                        violated_atom = atom.unevaluated_atom.violated_conditionals(_pkg_use_enabled(pkg), \
                                                pkg.iuse.is_valid_flag, parent_use=_pkg_use_enabled(ppkg))
+                                       if violated_atom.use is None:
+                                               # It's possible for autounmask to change
+                                               # parent_use such that the unevaluated form
+                                               # of the atom now matches, even though the
+                                               # earlier evaluated form (from before
+                                               # autounmask changed parent_use) does not.
+                                               # In this case (see bug #374423), it's
+                                               # expected that violated_atom.use is None.
+                                               continue
 
                                if pkg.installed and (violated_atom.use.enabled or violated_atom.use.disabled):
                                        #We can't change USE of an installed package (only of an ebuild, but that is already