From 710962016b095e49404625ef92df57cb065e8f31 Mon Sep 17 00:00:00 2001
From: Jiaxin Wu <Jiaxin.wu@intel.com>
Date: Thu, 8 Nov 2018 15:30:16 +0800
Subject: [PATCH] MdeModulePkg/Dhcp4Dxe: Remove unnecessary NULL pointer check.

v3: Add the instance token check.

v2: The DHCP Instance might be destroyed in PxeDhcpDone. So,
we need safe-delete.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1469

Since the value of Instance is retrieved from the list Entry,
it can't be the NULL pointer, so just remove the unnecessary
check.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Wu Hao A <hao.a.wu@intel.com>
Cc: Gao Liming <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
Reviewed-by: Wu Hao A <hao.a.wu@intel.com>
---
 MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
index 98a22a77b4..360365ecc3 100644
--- a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
+++ b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
@@ -1,7 +1,7 @@
 /** @file
   EFI DHCP protocol implementation.
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -1648,12 +1648,9 @@ ON_EXIT:
   //
   NET_LIST_FOR_EACH_SAFE (Entry, Next, &DhcpSb->Children) {
     Instance = NET_LIST_USER_STRUCT (Entry, DHCP_PROTOCOL, Link);
-
-    if ((Instance != NULL) && (Instance->Token != NULL)) {
-      Instance->Timeout--;
-      if (Instance->Timeout == 0) {
-        PxeDhcpDone (Instance);
-      }
+    Instance->Timeout--;
+    if (Instance->Timeout == 0 && Instance->Token != NULL) {
+      PxeDhcpDone (Instance);
     }
   }
 
-- 
2.39.2