Index: openacs-4/packages/chat/tcl/chat-ajax-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/chat/tcl/chat-ajax-procs.tcl,v
diff -u -r1.27 -r1.28
--- openacs-4/packages/chat/tcl/chat-ajax-procs.tcl	21 Nov 2018 09:56:37 -0000	1.27
+++ openacs-4/packages/chat/tcl/chat-ajax-procs.tcl	21 Nov 2018 12:32:18 -0000	1.28
@@ -37,14 +37,7 @@
             return [_ chat.Room_not_found]
         } else {
             chat_room_get -room_id $chat_id -array c
-            next \
-                -chat_id $chat_id \
-                -package_id $c(context_id) \
-                -mode $mode \
-                -path $path \
-                -login_messages_p $c(login_messages_p) \
-                -logout_messages_p $c(logout_messages_p) \
-                -timewindow $c(messages_time_window)
+            next -chat_id $chat_id -package_id $c(context_id) -mode $mode -path $path
         }
     }
 
@@ -66,6 +59,12 @@
             ad_return_forbidden
             ad_script_abort
         }
+        if {[chat_room_exists_p ${:chat_id}]} {
+            chat_room_get -room_id ${:chat_id} -array c
+            set :login_messages_p  $c(login_messages_p)
+            set :logout_messages_p $c(logout_messages_p)
+            set :timewindow        $c(messages_time_window)
+        }
         next
     }
 
Index: openacs-4/packages/xowiki/tcl/chat-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/chat-procs.tcl,v
diff -u -r1.48 -r1.49
--- openacs-4/packages/xowiki/tcl/chat-procs.tcl	21 Nov 2018 11:20:31 -0000	1.48
+++ openacs-4/packages/xowiki/tcl/chat-procs.tcl	21 Nov 2018 12:32:18 -0000	1.49
@@ -408,9 +408,6 @@
     {-package_id ""}
     {-mode ""}
     {-path ""}
-    -login_messages_p
-    -logout_messages_p
-    -timewindow
   } {
     #:log "--chat"
     if {![ns_conn isconnected]} return
@@ -524,22 +521,11 @@
       </div>
     }]
 
-    set chat_cmd [list \
-                      [self] create c1 \
-                      -destroy_on_cleanup \
-                      -chat_id    $chat_id \
-                      -session_id $session_id \
-                      -mode       $mode]
-    # We don't want to override Chat class default with our own and
-    # therefore we build the command dynamically depending if these
-    # variables are there or not.
-    set optional_vars [list login_messages_p logout_messages_p timewindow]
-    foreach var $optional_vars {
-      if {[info exists $var]} {
-        lappend chat_cmd -${var} [set $var]
-      }
-    }
-    {*}$chat_cmd
+    [self] create c1 \
+        -destroy_on_cleanup \
+        -chat_id    $chat_id \
+        -session_id $session_id \
+        -mode       $mode
 
     set data [c1 login]
     if {$data ne ""} {
Index: openacs-4/packages/xowiki/tcl/includelet-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/includelet-procs.tcl,v
diff -u -r1.234 -r1.235
--- openacs-4/packages/xowiki/tcl/includelet-procs.tcl	21 Nov 2018 09:56:37 -0000	1.234
+++ openacs-4/packages/xowiki/tcl/includelet-procs.tcl	21 Nov 2018 12:32:18 -0000	1.235
@@ -4665,9 +4665,6 @@
           {-chat_id ""}
           {-mode ""}
           {-path ""}
-          -login_messages_p
-          -logout_messages_p
-          -timewindow
         }}
       }
   chat instproc render {} {
@@ -4676,21 +4673,10 @@
       # make the chat just for including page
       set chat_id [${:__including_page} item_id]
     }
-    set chat_cmd [list \
-                      ::xowiki::Chat login \
-                      -chat_id $chat_id \
-                      -mode $mode \
-                      -path $path]
-    # We don't want to override Chat class default with our own and
-    # therefore we build the command dynamically depending if these
-    # variables are there or not.
-    set optional_vars [list login_messages_p logout_messages_p timewindow]
-    foreach var $optional_vars {
-      if {[info exists $var]} {
-        lappend chat_cmd -${var} [set $var]
-      }
-    }
-    set r [{*}$chat_cmd]
+    set r [::xowiki::Chat login \
+               -chat_id $chat_id \
+               -mode $mode \
+               -path $path]
 
     #ns_log notice chat=>$r