From 40a09d74125535ae380f319d019d2074526bda51 Mon Sep 17 00:00:00 2001
From: Eugene Pankov <john.pankov@gmail.com>
Date: Sat, 2 May 2020 16:20:46 +0200
Subject: [PATCH] fixed ScreenDprListener never being fired

---
 src/browser/ScreenDprMonitor.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/browser/ScreenDprMonitor.ts b/src/browser/ScreenDprMonitor.ts
index ec8c6d8a..6bd4857e 100644
--- a/src/browser/ScreenDprMonitor.ts
+++ b/src/browser/ScreenDprMonitor.ts
@@ -44,12 +44,14 @@ export class ScreenDprMonitor extends Disposable {
   }
 
   private _updateDpr(): void {
-    if (!this._resolutionMediaMatchList || !this._outerListener) {
+    if (!this._outerListener) {
       return;
     }
 
     // Clear listeners for old DPR
-    this._resolutionMediaMatchList.removeListener(this._outerListener);
+    if (this._resolutionMediaMatchList) {
+      this._resolutionMediaMatchList.removeListener(this._outerListener);
+    }
 
     // Add listeners for new DPR
     this._currentDevicePixelRatio = window.devicePixelRatio;