From b25e0bb4c8c42c0313a4f971795e56cb31edcf0d Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@nestlabs.com>
Date: Thu, 17 Jan 2019 07:33:02 -0800
Subject: [PATCH] [coap] add NULL check in Message::Clone() (#3469)

---
 src/core/coap/coap_message.cpp | 12 ++++++++++++
 src/core/coap/coap_message.hpp |  9 +--------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/core/coap/coap_message.cpp b/src/core/coap/coap_message.cpp
index 44ea69cd7..f11e00416 100644
--- a/src/core/coap/coap_message.cpp
+++ b/src/core/coap/coap_message.cpp
@@ -365,6 +365,18 @@ void Message::SetDefaultResponseHeader(const Message &aRequest)
     SetToken(aRequest.GetToken(), aRequest.GetTokenLength());
 }
 
+Message *Message::Clone(uint16_t aLength) const
+{
+    Message *message = static_cast<Message *>(ot::Message::Clone(aLength));
+
+    VerifyOrExit(message != NULL);
+
+    memcpy(&message->GetHelpData(), &GetHelpData(), sizeof(GetHelpData()));
+
+exit:
+    return message;
+}
+
 #if OPENTHREAD_ENABLE_APPLICATION_COAP
 const char *Message::CodeToString(void) const
 {
diff --git a/src/core/coap/coap_message.hpp b/src/core/coap/coap_message.hpp
index 428e236c4..5e3d4f636 100644
--- a/src/core/coap/coap_message.hpp
+++ b/src/core/coap/coap_message.hpp
@@ -491,14 +491,7 @@ public:
      * @returns A pointer to the message or NULL if insufficient message buffers are available.
      *
      */
-    Message *Clone(uint16_t aLength) const
-    {
-        Message *message = static_cast<Message *>(ot::Message::Clone(aLength));
-
-        memcpy(&message->GetHelpData(), &GetHelpData(), sizeof(GetHelpData()));
-
-        return message;
-    }
+    Message *Clone(uint16_t aLength) const;
 
     /**
      * This method creates a copy of the message.