From 1cead3e9b9383af7caa4c48debf19d005f4af9fc Mon Sep 17 00:00:00 2001
From: Vladimir Sadov <vsadov@microsoft.com>
Date: Mon, 25 Mar 2024 21:53:04 -0700
Subject: [PATCH] Always zero-init if object contains pointers (#100265)

---
 src/coreclr/nativeaot/Runtime/gcrhenv.cpp            | 6 ++++++
 src/libraries/System.Runtime/tests/System/GCTests.cs | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/src/coreclr/nativeaot/Runtime/gcrhenv.cpp b/src/coreclr/nativeaot/Runtime/gcrhenv.cpp
index 379bf5003f9b2..a0f536b06420f 100644
--- a/src/coreclr/nativeaot/Runtime/gcrhenv.cpp
+++ b/src/coreclr/nativeaot/Runtime/gcrhenv.cpp
@@ -129,6 +129,12 @@ Object* GcAllocInternal(MethodTable *pEEType, uint32_t uFlags, uintptr_t numElem
     ASSERT(!pThread->IsDoNotTriggerGcSet());
     ASSERT(pThread->IsCurrentThreadInCooperativeMode());
 
+    if (pEEType->ContainsPointers())
+    {
+        uFlags |= GC_ALLOC_CONTAINS_REF;
+        uFlags &= ~GC_ALLOC_ZEROING_OPTIONAL;
+    }
+
     size_t cbSize = pEEType->get_BaseSize();
 
     if (pEEType->HasComponentSize())
diff --git a/src/libraries/System.Runtime/tests/System/GCTests.cs b/src/libraries/System.Runtime/tests/System/GCTests.cs
index d161b3bbdde5b..14b6e5de4065a 100644
--- a/src/libraries/System.Runtime/tests/System/GCTests.cs
+++ b/src/libraries/System.Runtime/tests/System/GCTests.cs
@@ -1100,6 +1100,8 @@ private unsafe static void AllocateArrayPinned_ManagedValueType_CanRoundtripThro
             byte* pointer = (byte*)Unsafe.AsPointer(ref array[0]);
             var size = Unsafe.SizeOf<EmbeddedValueType<string>>();
 
+            GC.Collect();
+
             for(int i = 0; i < length; ++i)
             {
                 int idx = rng.Next(length);