From 5b887396c3e7f135a71d891ca29ffa55f5aa98a9 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Mon, 19 Oct 2020 14:19:07 -0400
Subject: [PATCH] pad: Check for null collabClient in socket.io event handlers

---
 src/static/js/pad.js | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/static/js/pad.js b/src/static/js/pad.js
index ac591ca52..1768f63c7 100644
--- a/src/static/js/pad.js
+++ b/src/static/js/pad.js
@@ -189,23 +189,37 @@ function handshake()
   });
 
   socket.on('reconnect', function () {
-    pad.collabClient.setChannelState("CONNECTED");
+    // pad.collabClient might be null if the hanshake failed (or it never got that far).
+    if (pad.collabClient != null) {
+      pad.collabClient.setChannelState('CONNECTED');
+    }
     sendClientReady(receivedClientVars);
   });
 
   socket.on('reconnecting', function() {
-    pad.collabClient.setStateIdle();
-    pad.collabClient.setIsPendingRevision(true);
-    pad.collabClient.setChannelState("RECONNECTING");
+    // pad.collabClient might be null if the hanshake failed (or it never got that far).
+    if (pad.collabClient != null) {
+      pad.collabClient.setStateIdle();
+      pad.collabClient.setIsPendingRevision(true);
+      pad.collabClient.setChannelState('RECONNECTING');
+    }
   });
 
   socket.on('reconnect_failed', function(error) {
-    pad.collabClient.setChannelState("DISCONNECTED", "reconnect_timeout");
+    // pad.collabClient might be null if the hanshake failed (or it never got that far).
+    if (pad.collabClient != null) {
+      pad.collabClient.setChannelState('DISCONNECTED', 'reconnect_timeout');
+    } else {
+      throw new Error('Reconnect timed out');
+    }
   });
 
   socket.on('error', function(error) {
-    pad.collabClient.setStateIdle();
-    pad.collabClient.setIsPendingRevision(true);
+    // pad.collabClient might be null if the error occurred before the hanshake completed.
+    if (pad.collabClient != null) {
+      pad.collabClient.setStateIdle();
+      pad.collabClient.setIsPendingRevision(true);
+    }
   });
 
   var initalized = false;