cache: invalidate cache entries without INHERIT key

Detect cache entries missing INHERIT key and force cache invalidation
for them.  This fixes false positives from pkgcheck's InheritsCheck
if the repository contains up-to-date metadata cache entries generated
by Portage or PkgCore prior to the introduction of INHERIT key.
If _eclasses_ are non-empty, then we can reasonably assume that INHERIT
must be non-empty as well (i.e. at least one eclass was inherited
directly).

1 files changed, 7 insertions, 0 deletions

diff --git a/NEWS.rst b/NEWS.rst
index 78cc5fc8..5304d7f8 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -3,6 +3,13 @@ Release Notes
 =============
 
 ---------------------------
+pkgcore 0.12.6 (2021-??-??)
+---------------------------
+
+- pkgcore.cache: Invalidate cache entries if they are missing INHERIT
+  key, to avoid false positives from pkgcheck's InheritsCheck.
+
+---------------------------
 pkgcore 0.12.5 (2021-09-02)
 ---------------------------