Merge branch '2.12' into 2.13

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -25,7 +25,7 @@ Active Maintainers:
   are disabled
  (contributed by Krzysztof D)
 
-2.12.4 (not yet released)
+2.12.4 (06-Jul-2021)
 
 #274: YAMLGenerator does not quote tilde (~) characters when MINIMIZE_QUOTES
   is enabled