Merge branch 'release/wap-im' of http://git.yoho.cn/fe/yohobuywap-node into release/wap-im

@@ -696,7 +696,8 @@ var chat = {
 
 
                 // records.reverse();
-
+                let oldFister = self.$chatWin.find('.msg-wrap:first')[0];
+                let grap = oldFister ? oldFister.offsetTop : 0 ;
                 let $docFragment = $(document.createDocumentFragment());
 
                 records.forEach((chatMessage, index, arr) => {
@@ -727,6 +728,10 @@ var chat = {
 
                 self.$historyLoader.after($docFragment);
 
+                oldFister && self.$chatWin.scrollTop(oldFister.offsetTop - grap );
+
+
+
 
                 if (records.length) {
                     msgHistory.endTime = records[records.length - 1].sendTime;