From 7842ba3ab4b975c394be526da5452bd727dccef1 Mon Sep 17 00:00:00 2001
From: Mike McLaughlin <mikem@microsoft.com>
Date: Wed, 30 Mar 2016 14:57:18 -0700
Subject: [PATCH] Fixed issue #3987 "Debugger fails to stop on entry due to
 stack walk failure"

By initializing m_rgHijackFunction to NULL.
---
 src/debug/daccess/dacdbiimpl.cpp | 3 +++
 src/debug/ee/debugger.cpp        | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/src/debug/daccess/dacdbiimpl.cpp b/src/debug/daccess/dacdbiimpl.cpp
index 41ecde63ec74..8ff1ecd9daba 100644
--- a/src/debug/daccess/dacdbiimpl.cpp
+++ b/src/debug/daccess/dacdbiimpl.cpp
@@ -5081,6 +5081,9 @@ void DacDbiInterfaceImpl::Hijack(
     // (The hijack function already has the context)
     _ASSERTE((pOriginalContext == NULL) == (cbSizeContext == 0));
     _ASSERTE(EHijackReason::IsValid(reason));
+#ifdef PLATFORM_UNIX
+    _ASSERTE(!"Not supported on this platform");
+#endif
 
     //
     // If we hijack a thread which might not be managed we can set vmThread = NULL
diff --git a/src/debug/ee/debugger.cpp b/src/debug/ee/debugger.cpp
index c063eb829f25..7422f7baaeca 100644
--- a/src/debug/ee/debugger.cpp
+++ b/src/debug/ee/debugger.cpp
@@ -983,6 +983,7 @@ Debugger::Debugger()
 
     m_fShutdownMode = false;
     m_fDisabled = false;
+    m_rgHijackFunction = NULL;
 
 #ifdef _DEBUG
     InitDebugEventCounting();
@@ -17092,6 +17093,7 @@ Debugger::EnumMemoryRegions(CLRDataEnumMemoryFlags flags)
 {
     DAC_ENUM_VTHIS();
     SUPPORTS_DAC;
+    _ASSERTE(m_rgHijackFunction != NULL);
 
     if ( flags != CLRDATA_ENUM_MEM_TRIAGE)
     {