Don't send a poll response event if you are voting for your current c…

src/components/views/messages/MPollBody.tsx

@@ -223,10 +223,13 @@ export default class MPollBody extends React.Component<IBodyProps, IState> {
     };
 
     private selectOption(answerId: string) {
-        if (answerId === this.state.selected) {
+        if (this.isEnded()) {
             return;
         }
-        if (this.isEnded()) {
+        const userVotes = this.collectUserVotes();
+        const userId = this.context.getUserId();
+        const myVote = userVotes.get(userId)?.answers[0];
+        if (answerId === myVote) {
             return;
         }
 

test/components/views/messages/MPollBody-test.tsx

@@ -497,6 +497,28 @@ describe("MPollBody", () => {
         ]);
     });
 
+    it("sends no vote event when I click what I already chose", () => {
+        const receivedEvents = [];
+        MatrixClientPeg.matrixClient.sendEvent = (
+            roomId: string,
+            eventType: string,
+            content: IContent,
+            txnId?: string,
+            callback?: Callback,
+        ): Promise<ISendEventResponse> => {
+            receivedEvents.push( { roomId, eventType, content, txnId, callback } );
+            return Promise.resolve({ "event_id": "fake_tracked_send_id" });
+        };
+
+        const votes = [responseEvent("@me:example.com", "wings")];
+        const body = newMPollBody(votes);
+        clickRadio(body, "wings");
+        clickRadio(body, "wings");
+        clickRadio(body, "wings");
+        clickRadio(body, "wings");
+        expect(receivedEvents).toEqual([]);
+    });
+
     it("sends several events when I click different options", () => {
         const receivedEvents = [];
         MatrixClientPeg.matrixClient.sendEvent = (