Merge pull request #1691 from matrix-org/t3chguy/lazy_save_relatedGroupSettings

only save RelatedGroupSettings if it was modified. Otherwise perms issue

src/components/views/room_settings/RelatedGroupSettings.js

@@ -19,6 +19,7 @@ import {MatrixEvent, MatrixClient} from 'matrix-js-sdk';
 import sdk from '../../../index';
 import { _t } from '../../../languageHandler';
 import Modal from '../../../Modal';
+import isEqual from 'lodash/isEqual';
 
 const GROUP_ID_REGEX = /\+\S+\:\S+/;
 
@@ -43,13 +44,25 @@ module.exports = React.createClass({
 
     getInitialState: function() {
         return {
-            newGroupsList: this.props.relatedGroupsEvent ?
+            newGroupsList: this.getInitialGroupList(),
-                (this.props.relatedGroupsEvent.getContent().groups || []) : [],
             newGroupId: null,
         };
     },
 
+    getInitialGroupList: function() {
+        return this.props.relatedGroupsEvent ? (this.props.relatedGroupsEvent.getContent().groups || []) : [];
+    },
+
+    needsSaving: function() {
+        const cli = this.context.matrixClient;
+        const room = cli.getRoom(this.props.roomId);
+        if (!room.currentState.maySendStateEvent('m.room.related_groups', cli.getUserId())) return false;
+        return isEqual(this.getInitialGroupList(), this.state.newGroupsList);
+    },
+
     saveSettings: function() {
+        if (!this.needsSaving()) return Promise.resolve();
+
         return this.context.matrixClient.sendStateEvent(
             this.props.roomId,
             'm.room.related_groups',
@@ -97,7 +110,7 @@ module.exports = React.createClass({
 
     onGroupDeleted: function(index) {
         const newGroupsList = this.state.newGroupsList.slice();
-        newGroupsList.splice(index, 1),
+        newGroupsList.splice(index, 1);
         this.setState({ newGroupsList });
     },