From e3b21dfe249f5d5a46802e0811ff6d05330ea362 Mon Sep 17 00:00:00 2001
From: Sandeep Mistry <sandeep.mistry@gmail.com>
Date: Mon, 12 Mar 2018 01:41:40 +0000
Subject: [PATCH] Check if attribute handle supports emit before calling

Origin: https://github.com/noble/bleno/pull/369
Change-Id: Icdc68c129ab7b165f5b30e15812e9d7316346146
---
 lib/hci-socket/gatt.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/hci-socket/gatt.js b/lib/hci-socket/gatt.js
index 18dc52b..c5b2fe8 100644
--- a/lib/hci-socket/gatt.js
+++ b/lib/hci-socket/gatt.js
@@ -911,7 +911,9 @@ Gatt.prototype.handleWriteRequestOrCommand = function(request) {
               handleAttribute.emit('subscribe', this._mtu - 3, updateValueCallback);
             }
           } else {
-            handleAttribute.emit('unsubscribe');
+            if (handleAttribute.emit) {
+              handleAttribute.emit('unsubscribe');
+            }
           }
 
           result = ATT_ECODE_SUCCESS;