+2015-12-23 Katsumi Yamaoka <yamaoka@jpl.org>
+
+ Fix `gnus-union' so as to behave like `cl-union'.
+
+ * gnus-group.el (gnus-group-prepare-flat):
+ Make gnus-union use `equal' to compare items in lists.
+
+ * gnus-util.el (gnus-union): Make it behave like cl-union partially.
+
2015-12-17 Eli Zaretskii <eliz@gnu.org>
* auth-source.el (auth-source-ensure-strings):