From d9501d7cbab1ea4b1bf6b51f8eda178f6dad6ddb Mon Sep 17 00:00:00 2001
From: Jan Kotas <jkotas@microsoft.com>
Date: Sat, 29 Apr 2017 07:43:23 -0700
Subject: [PATCH] Fetch secondary handle only if primary is non-null

The GC is not tracking the secondary handle once primary gets cleared.

Fixes dotnet/coreclr#11270


Commit migrated from https://github.com/dotnet/coreclr/commit/d9b076c50a6781418a01c1baa166cba0ab15e229
---
 src/coreclr/src/vm/comdependenthandle.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/src/vm/comdependenthandle.cpp b/src/coreclr/src/vm/comdependenthandle.cpp
index 0f33821..4763e48 100644
--- a/src/coreclr/src/vm/comdependenthandle.cpp
+++ b/src/coreclr/src/vm/comdependenthandle.cpp
@@ -69,8 +69,14 @@ FCIMPLEND
 FCIMPL2(Object*, DependentHandle::nGetPrimaryAndSecondary, OBJECTHANDLE handle, Object **outSecondary)
 {
     FCALL_CONTRACT;
-    *outSecondary = OBJECTREFToObject(GetDependentHandleSecondary(handle));
-    return OBJECTREFToObject(ObjectFromHandle(handle));
+    _ASSERTE(handle != NULL && outSecondary != NULL);
+
+    OBJECTREF primary = ObjectFromHandle(handle);
+
+    // Secondary is tracked only if primary is non-null
+    *outSecondary = (primary != NULL) ? OBJECTREFToObject(GetDependentHandleSecondary(handle)) : NULL;
+
+    return OBJECTREFToObject(primary);
 }
 FCIMPLEND
 
-- 
2.7.4