erp5_web_jabber_client: Fix Scroll down on dialog page

bt5/erp5_web_jabber_client/PathTemplateItem/web_page_module/jabber_gadget_page_dialog_js.js

@@ -3,13 +3,14 @@
 (function (window, document, rJS, RSVP, Handlebars, loopEventListener) {
   "use strict";
 
-  function scroll() {
+  function scroll(g) {
+    var gadget = g;
     RSVP.Queue()
       .push(function () {
         return RSVP.delay(0);
       })
       .push(function () {
-        window.scrollTo(0, document.body.scrollHeight || document.documentElement.scrollHeight);
+        window.scrollTo(0, gadget.props.element.scrollHeight || document.body.scrollHeight || document.documentElement.scrollHeight);
       });
   }
 
@@ -176,7 +177,7 @@
 
           gadget.props.element.querySelector(".discussion-content").innerHTML = "";
           gadget.props.element.querySelector(".discussion-content").appendChild(ul);
-          scroll();
+          return scroll(gadget);
         });
     })
 
@@ -259,7 +260,7 @@
     })
 
     .declareService(function () {
-      scroll();
+      return scroll(this);
     });
 
 }(window, document, rJS, RSVP, Handlebars, loopEventListener));
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