Cancel calls to rate-limited funcs on unmount

The tests were throwing up warnings about state being accessed, and null
MatrixClients being called, after component unmount.

src/components/structures/RoomView.js

@@ -273,6 +273,9 @@ module.exports = React.createClass({
 
         window.removeEventListener('resize', this.onResize);
 
+        // cancel any pending calls to the rate_limited_funcs
+        this._updateRoomMembers.cancelPendingCall();
+
         // no need to do this as Dir & Settings are now overlays. It just burnt CPU.
         // console.log("Tinter.tint from RoomView.unmount");
         // Tinter.tint(); // reset colourscheme

src/components/views/rooms/InviteMemberList.js

@@ -58,6 +58,8 @@ module.exports = React.createClass({
         if (cli) {
             cli.removeListener("RoomState.members", this.onRoomStateMember);
         }
+        // cancel any pending calls to the rate_limited_funcs
+        this._updateList.cancelPendingCall();
     },
 
     _updateList: new rate_limited_func(function() {
@@ -100,7 +102,7 @@ module.exports = React.createClass({
             <EntityTile key="dynamic_invite_tile" suppressOnHover={true} showInviteButton={true}
                 avatarJsx={ <BaseAvatar name="@" width={36} height={36} /> }
                 className="mx_EntityTile_invitePlaceholder"
-                presenceState="online" onClick={this.onThirdPartyInvite} name={"Invite by email"} 
+                presenceState="online" onClick={this.onThirdPartyInvite} name={"Invite by email"}
             />,
             function(query) {
                 return true; // always show this

src/components/views/rooms/MemberList.js

@@ -81,6 +81,9 @@ module.exports = React.createClass({
             cli.removeListener("User.lastPresenceTs", this.onUserLastPresenceTs);
             // cli.removeListener("Room.timeline", this.onRoomTimeline);
         }
+
+        // cancel any pending calls to the rate_limited_funcs
+        this._updateList.cancelPendingCall();
     },
 
 /*

src/components/views/rooms/RoomList.js

@@ -101,6 +101,8 @@ module.exports = React.createClass({
             MatrixClientPeg.get().removeListener("RoomState.events", this.onRoomStateEvents);
             MatrixClientPeg.get().removeListener("RoomMember.name", this.onRoomMemberName);
         }
+        // cancel any pending calls to the rate_limited_funcs
+        this._delayedRefreshRoomList.cancelPendingCall();
     },
 
     onRoom: function(room) {

src/ratelimitedfunc.js

@@ -21,13 +21,16 @@ limitations under the License.
  *
  * Note that the function must not take arguments, since the args
  * could be different for each invocarion of the function.
+ *
+ * The returned function has a 'cancelPendingCall' property which can be called
+ * on unmount or similar to cancel any pending update.
  */
 module.exports = function(f, minIntervalMs) {
     this.lastCall = 0;
     this.scheduledCall = undefined;
 
     var self = this;
-    return function() {
+    var wrapper = function() {
         var now = Date.now();
 
         if (self.lastCall < now - minIntervalMs) {
@@ -44,5 +47,23 @@ module.exports = function(f, minIntervalMs) {
             );
         }
     };
-};
 
+    // add the cancelPendingCall property
+    wrapper.cancelPendingCall = function() {
+        if (self.scheduledCall) {
+            clearTimeout(self.scheduledCall);
+            self.scheduledCall = undefined;
+        }
+    };
+
+    // make sure that cancelPendingCall is copied when react rebinds the
+    // wrapper
+    var _bind = wrapper.bind;
+    wrapper.bind = function() {
+        var rebound = _bind.apply(this, arguments);
+        rebound.cancelPendingCall = wrapper.cancelPendingCall;
+        return rebound;
+    };
+
+    return wrapper;
+};