Index: openacs-4/packages/acs-subsite/tcl/group-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-subsite/tcl/group-procs.tcl,v
diff -u -N -r1.58 -r1.59
--- openacs-4/packages/acs-subsite/tcl/group-procs.tcl	29 Jan 2019 10:26:31 -0000	1.58
+++ openacs-4/packages/acs-subsite/tcl/group-procs.tcl	8 Feb 2019 12:37:08 -0000	1.59
@@ -797,6 +797,14 @@
         relation_add -member_state $member_state "membership_rel" $group_id $user_id
     }
     relation_add -member_state $member_state $rel_type $group_id $user_id
+
+    #
+    # Flush all permission checks pertaining to this user.
+    #
+    permission::cache_flush -party_id $user_id
+    #
+    # Flush all permission checks pertaining to the group
+    #
     flush_members_cache -group_id $group_id
 }