From 3bf1f55990e12e00aedd45e8e889f39ba73f40dd Mon Sep 17 00:00:00 2001
From: Alexander Shabalin <alexander.shabalin@jetbrains.com>
Date: Tue, 2 Feb 2021 09:24:37 +0300
Subject: [PATCH] Handle nullptr in StablePointer API (#4671)

---
 kotlin-native/runtime/src/mm/cpp/Memory.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/kotlin-native/runtime/src/mm/cpp/Memory.cpp b/kotlin-native/runtime/src/mm/cpp/Memory.cpp
index b6e68d734f3..7e43061f1ef 100644
--- a/kotlin-native/runtime/src/mm/cpp/Memory.cpp
+++ b/kotlin-native/runtime/src/mm/cpp/Memory.cpp
@@ -292,23 +292,35 @@ extern "C" RUNTIME_NOTHROW bool ClearSubgraphReferences(ObjHeader* root, bool ch
 }
 
 extern "C" RUNTIME_NOTHROW void* CreateStablePointer(ObjHeader* object) {
+    if (!object)
+        return nullptr;
+
     auto* threadData = mm::ThreadRegistry::Instance().CurrentThreadData();
     return mm::StableRefRegistry::Instance().RegisterStableRef(threadData, object);
 }
 
 extern "C" RUNTIME_NOTHROW void DisposeStablePointer(void* pointer) {
+    if (!pointer)
+        return;
+
     auto* threadData = mm::ThreadRegistry::Instance().CurrentThreadData();
     auto* node = static_cast<mm::StableRefRegistry::Node*>(pointer);
     mm::StableRefRegistry::Instance().UnregisterStableRef(threadData, node);
 }
 
 extern "C" RUNTIME_NOTHROW OBJ_GETTER(DerefStablePointer, void* pointer) {
+    if (!pointer)
+        RETURN_OBJ(nullptr);
+
     auto* node = static_cast<mm::StableRefRegistry::Node*>(pointer);
     ObjHeader* object = **node;
     RETURN_OBJ(object);
 }
 
 extern "C" RUNTIME_NOTHROW OBJ_GETTER(AdoptStablePointer, void* pointer) {
+    if (!pointer)
+        RETURN_OBJ(nullptr);
+
     auto* threadData = mm::ThreadRegistry::Instance().CurrentThreadData();
     auto* node = static_cast<mm::StableRefRegistry::Node*>(pointer);
     ObjHeader* object = **node;