From ce21019c7d2640877ded25a53c5d51231829d12c Mon Sep 17 00:00:00 2001
From: Yury Semikhatsky <yurys@chromium.org>
Date: Wed, 11 Dec 2019 13:06:11 -0700
Subject: [PATCH] fix(webkit): make sure each message is dispatch in separate
 task (#212)

---
 src/webkit/Connection.ts | 12 ++++++++++--
 src/webkit/Target.ts     |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/webkit/Connection.ts b/src/webkit/Connection.ts
index d3a93c88d0..ef0eafc5bf 100644
--- a/src/webkit/Connection.ts
+++ b/src/webkit/Connection.ts
@@ -36,6 +36,7 @@ export class Connection extends EventEmitter {
   private readonly _sessions = new Map<string, TargetSession>();
   private _incomingMessageQueue: string[] = [];
   private _dispatchTimerId?: NodeJS.Timer;
+  private _sameDispatchTask: boolean = false;
 
   _closed = false;
 
@@ -71,10 +72,15 @@ export class Connection extends EventEmitter {
   }
 
   private _onMessage(message: string) {
-    if (this._incomingMessageQueue.length || this._delay)
+    if (this._sameDispatchTask || this._incomingMessageQueue.length || this._delay)
       this._enqueueMessage(message);
-    else
+    else {
+      this._sameDispatchTask = true;
+      // This is for the case when several messages come in a batch and read
+      // in a loop by transport ending up in the same task.
+      Promise.resolve().then(() => this._sameDispatchTask = false);
       this._dispatchMessage(message);
+    }
   }
 
   private _enqueueMessage(message: string) {
@@ -100,6 +106,8 @@ export class Connection extends EventEmitter {
   }
 
   private _dispatchOneMessageFromQueue() {
+    if (this._closed)
+      return;
     const message = this._incomingMessageQueue.shift();
     try {
       this._dispatchMessage(message);
diff --git a/src/webkit/Target.ts b/src/webkit/Target.ts
index 338cf94caf..31e577ccb5 100644
--- a/src/webkit/Target.ts
+++ b/src/webkit/Target.ts
@@ -57,7 +57,7 @@ export class Target {
     await (this._page._delegate as FrameManager)._initializeSession(session).catch(e => {
       // Swallow initialization errors due to newer target swap in,
       // since we will reinitialize again.
-      if (!isSwappedOutError(e))
+      if (this._page)
         throw e;
     });
   }