From d84b9c6337bab41ce0cd78969fccc8bc6c086ea0 Mon Sep 17 00:00:00 2001
From: Wawha <Wawha@users.noreply.github.com>
Date: Tue, 9 Jun 2020 18:21:31 +0200
Subject: [PATCH] fixed unique_ptr::reset() instructions order. Internal
 pointer must be updated before deleting object (#373)

---
 include/EASTL/unique_ptr.h   |  6 ++----
 test/source/TestSmartPtr.cpp | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/include/EASTL/unique_ptr.h b/include/EASTL/unique_ptr.h
index b39dd698..27f477ed 100644
--- a/include/EASTL/unique_ptr.h
+++ b/include/EASTL/unique_ptr.h
@@ -210,10 +210,8 @@ namespace eastl
 		{
 			if (pValue != mPair.first())
 			{
-				if (mPair.first())
-					get_deleter()(mPair.first());
-
-				mPair.first() = pValue;
+				if (auto first = exchange(mPair.first(), pValue))
+					get_deleter()(first);
 			}
 		}
 
diff --git a/test/source/TestSmartPtr.cpp b/test/source/TestSmartPtr.cpp
index 907c5b1e..031ea8c4 100644
--- a/test/source/TestSmartPtr.cpp
+++ b/test/source/TestSmartPtr.cpp
@@ -392,6 +392,20 @@ namespace SmartPtrTest
 		int mX;
 	};
 
+	struct CheckUPtrEmptyInDestructor
+	{
+		~CheckUPtrEmptyInDestructor()
+		{
+			if(mpUPtr)
+				mCheckUPtrEmpty = (*mpUPtr == nullptr);
+		}
+
+		eastl::unique_ptr<CheckUPtrEmptyInDestructor>* mpUPtr{};
+		static bool mCheckUPtrEmpty;
+	};
+
+	bool CheckUPtrEmptyInDestructor::mCheckUPtrEmpty = false;
+
 } // namespace SmartPtrTest
 
 
@@ -542,6 +556,16 @@ static int Test_unique_ptr()
 		}
 	}
 
+	{
+		// Test that unique_ptr internal pointer is reset before calling the destructor
+		CheckUPtrEmptyInDestructor::mCheckUPtrEmpty = false;
+
+		unique_ptr<CheckUPtrEmptyInDestructor> uptr(new CheckUPtrEmptyInDestructor);
+		uptr->mpUPtr = &uptr;
+		uptr.reset();
+		EATEST_VERIFY(CheckUPtrEmptyInDestructor::mCheckUPtrEmpty);
+	}
+
 	{
 		#if EASTL_CORE_ALLOCATOR_ENABLED
 			// Test EA::Allocator::EASTLICoreDeleter usage within eastl::shared_ptr.