From caa4a40d3d7cfaba3f501e3b36f474e32e76b9d7 Mon Sep 17 00:00:00 2001
From: Matt Sprague <uforic@users.noreply.github.com>
Date: Tue, 29 May 2018 15:30:44 -0700
Subject: [PATCH] Fix send / remove timing bug in Dispatcher

---
 src/util/dispatcher.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/util/dispatcher.js b/src/util/dispatcher.js
index b2f3b9b0adc..855b276c3a3 100644
--- a/src/util/dispatcher.js
+++ b/src/util/dispatcher.js
@@ -50,6 +50,10 @@ class Dispatcher {
      * @returns The ID of the worker to which the message was sent.
      */
     send(type: string, data: mixed, callback?: ?Function, targetID?: number): number {
+        if (this.actors.length === 0) {
+            // an async send call is getting executed but remove has been called
+            return -1;
+        }
         if (typeof targetID !== 'number' || isNaN(targetID)) {
             // Use round robin to send requests to web workers.
             targetID = this.currentActor = (this.currentActor + 1) % this.actors.length;