From 59412aba513e6b28263e81d39be9a0d9df545e7d Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@matrix.org>
Date: Wed, 29 Apr 2020 15:45:51 +0200
Subject: [PATCH] handle race between sending and await next event from other
 party

---
 src/crypto/verification/Base.js                        | 5 +++++
 src/crypto/verification/request/VerificationRequest.js | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/src/crypto/verification/Base.js b/src/crypto/verification/Base.js
index c3a8e0ec6..d9580aa49 100644
--- a/src/crypto/verification/Base.js
+++ b/src/crypto/verification/Base.js
@@ -122,6 +122,11 @@ export class VerificationBase extends EventEmitter {
         if (this._done) {
             return Promise.reject(new Error("Verification is already done"));
         }
+        const existingEvent = this.request.getEventFromOtherParty(type);
+        if (existingEvent) {
+            return Promise.resolve(existingEvent);
+        }
+
         this._expectedEvent = type;
         return new Promise((resolve, reject) => {
             this._resolveEvent = resolve;
diff --git a/src/crypto/verification/request/VerificationRequest.js b/src/crypto/verification/request/VerificationRequest.js
index 47fa44657..a0d0998d9 100644
--- a/src/crypto/verification/request/VerificationRequest.js
+++ b/src/crypto/verification/request/VerificationRequest.js
@@ -877,4 +877,8 @@ export class VerificationRequest extends EventEmitter {
             this._setPhase(newTransitions[newTransitions.length - 1].phase);
         }
     }
+
+    getEventFromOtherParty(type) {
+        return this._eventsByThem.get(type);
+    }
 }