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 -N -r1.28 -r1.29
--- openacs-4/packages/chat/tcl/chat-ajax-procs.tcl	21 Nov 2018 12:32:18 -0000	1.28
+++ openacs-4/packages/chat/tcl/chat-ajax-procs.tcl	22 Nov 2018 09:08:33 -0000	1.29
@@ -37,7 +37,13 @@
             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
+            next -chat_id $chat_id \
+                -package_id $c(context_id) \
+                -mode $mode \
+                -path $path \
+                -logout_messages_p $c(logout_messages_p) \
+                -login_messages_p $c(login_messages_p) \
+                -timewindow $c(messages_time_window)
         }
     }
 
@@ -59,12 +65,6 @@
             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 -N -r1.49 -r1.50
--- openacs-4/packages/xowiki/tcl/chat-procs.tcl	21 Nov 2018 12:32:18 -0000	1.49
+++ openacs-4/packages/xowiki/tcl/chat-procs.tcl	22 Nov 2018 09:08:33 -0000	1.50
@@ -19,6 +19,7 @@
         {sweepinterval 5}
         {login_messages_p t}
         {logout_messages_p t}
+        {conf {}}
       }
 
   Chat instproc init {} {
@@ -48,10 +49,20 @@
     if {[:user_id] != 0 || [:session_id] != 0} {
       :init_user_color
     }
+    :set_options
   }
 
+  Chat instproc set_options {} {
+    dict for {key value} ${:conf} {
+      ::xo::clusterwide nsv_set ${:array}-options $key $value
+    }
+    if {[nsv_array exists ${:array}-options]} {
+      foreach {key value} [nsv_array get ${:array}-options] {
+        :set $key $value
+      }
+    }
+  }
 
-
   Chat instproc register_nsvs {msg_id user_id msg color secs} {
     # Tell the system we are back again, in case we were auto logged out
     if { ![nsv_exists ${:array}-login $user_id] } {
@@ -408,6 +419,9 @@
     {-package_id ""}
     {-mode ""}
     {-path ""}
+    -login_messages_p
+    -logout_messages_p
+    -timewindow
   } {
     #:log "--chat"
     if {![ns_conn isconnected]} return
@@ -521,11 +535,19 @@
       </div>
     }]
 
+    set conf [dict create]
+    foreach var [list login_messages_p logout_messages_p timewindow] {
+      if {[info exists $var]} {
+        dict set conf $var [set $var]
+      }
+    }
+
     [self] create c1 \
         -destroy_on_cleanup \
         -chat_id    $chat_id \
         -session_id $session_id \
-        -mode       $mode
+        -mode       $mode \
+        -conf       $conf
 
     set data [c1 login]
     if {$data ne ""} {
Index: openacs-4/packages/xowiki/tcl/includelet-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/includelet-procs.tcl,v
diff -u -N -r1.235 -r1.236
--- openacs-4/packages/xowiki/tcl/includelet-procs.tcl	21 Nov 2018 12:32:18 -0000	1.235
+++ openacs-4/packages/xowiki/tcl/includelet-procs.tcl	22 Nov 2018 09:08:33 -0000	1.236
@@ -4665,6 +4665,9 @@
           {-chat_id ""}
           {-mode ""}
           {-path ""}
+          -login_messages_p
+          -logout_messages_p
+          -timewindow
         }}
       }
   chat instproc render {} {
@@ -4673,10 +4676,21 @@
       # make the chat just for including page
       set chat_id [${:__including_page} item_id]
     }
-    set r [::xowiki::Chat login \
-               -chat_id $chat_id \
-               -mode $mode \
-               -path $path]
+    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]
 
     #ns_log notice chat=>$r