From 7e262c06c7ec2457f84a19c4a1fdbb49aa8577a3 Mon Sep 17 00:00:00 2001
From: Fei Deng <duke8253@gmail.com>
Date: Wed, 21 Aug 2019 14:19:25 -0500
Subject: [PATCH] check for nullptr when locking

---
 iocore/eventsystem/I_Lock.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/iocore/eventsystem/I_Lock.h b/iocore/eventsystem/I_Lock.h
index b5bef2c40e0..d599be26b06 100644
--- a/iocore/eventsystem/I_Lock.h
+++ b/iocore/eventsystem/I_Lock.h
@@ -353,17 +353,19 @@ class MutexLock
     Ptr<ProxyMutex> &am, EThread *t)
     : m(am), locked_p(true)
   {
-    Mutex_lock(
+    if (am) {
+      Mutex_lock(
 #ifdef DEBUG
-      location, ahandler,
+        location, ahandler,
 #endif // DEBUG
-      m, t);
+        m, t);
+    }
   }
 
   void
   release()
   {
-    if (locked_p) {
+    if (locked_p && m) {
       Mutex_unlock(m, m->thread_holding);
     }
     locked_p = false;