Merge branch 'release/6.2'

# Conflicts:
#	.bumpversion.cfg
#	CHANGELOG.md
#	CMakeLists.txt
#	bindings/rust/evmc-sys/Cargo.toml
#	bindings/rust/evmc-vm/Cargo.toml

CHANGELOG.md

@@ -7,6 +7,13 @@
   [#263](https://github.com/ethereum/evmc/pull/263)]
   The `vmtester` tool now builds with MSVC with `/std:c++17`.
 
+## [6.2.2] - 2019-05-16
+
+- Fixed: [[#281](https://github.com/ethereum/evmc/pull/281)]
+  Compilation error of `evmc::result::raw()` in Visual Studio fixed.
+- Fixed: [[#282](https://github.com/ethereum/evmc/pull/282)]
+  The `evmc::result`'s move assignment operator fixed.
+
 ## [6.2.1] - 2019-04-29
 
 - Fixed:
@@ -159,6 +166,7 @@
 
 
 [6.3.0]: https://github.com/ethereum/evmc/compare/v6.2.1...master
+[6.2.2]: https://github.com/ethereum/evmc/releases/tag/v6.2.2
 [6.2.1]: https://github.com/ethereum/evmc/releases/tag/v6.2.1
 [6.2.0]: https://github.com/ethereum/evmc/releases/tag/v6.2.0
 [6.1.1]: https://github.com/ethereum/evmc/releases/tag/v6.1.1

include/evmc/evmc.hpp

@@ -39,16 +39,20 @@ public:
     /// Move constructor.
     result(result&& other) noexcept : evmc_result{other}
     {
-        // Disable releaser of the rvalue object.
-        other.release = nullptr;
+        other.release = nullptr;  // Disable releasing of the rvalue object.
     }
 
-    result(result const&) = delete;
-
-    /// Move-and-swap assignment operator.
-    result& operator=(result other) noexcept
+    /// Move assignment operator.
+    ///
+    /// The self-assigment MUST never happen.
+    ///
+    /// @param other The other result object.
+    /// @return      The reference to the left-hand side object.
+    result& operator=(result&& other) noexcept
     {
-        std::swap(*this, other);
+        this->~result();                           // Release this object.
+        static_cast<evmc_result&>(*this) = other;  // Copy data.
+        other.release = nullptr;                   // Disable releasing of the rvalue object.
         return *this;
     }
 
@@ -56,8 +60,8 @@ public:
     /// releases the ownership of the resources and invalidates this object.
     evmc_result raw() noexcept
     {
-        auto out = evmc_result{};
-        std::swap<evmc_result>(out, *this);
+        const auto out = evmc_result{*this};  // Copy data.
+        this->release = nullptr;              // Disable releasing of this object.
         return out;
     }
 };

test/unittests/test_cpp.cpp

@@ -2,6 +2,10 @@
 // Copyright 2018-2019 The EVMC Authors.
 // Licensed under the Apache License, Version 2.0.
 
+// The vector is not used here, but including it was causing compilation issues
+// previously related to using explicit template argument (SFINAE disabled).
+#include <vector>
+
 #include "../../examples/example_host.h"
 #include "../../examples/example_vm.h"
 
@@ -120,3 +124,77 @@ TEST(cpp, host_call)
 
     example_host_destroy_context(host_context);
 }
+
+TEST(cpp, result_raii)
+{
+    static auto release_called = 0;
+    release_called = 0;
+    auto release_fn = [](const evmc_result*) noexcept { ++release_called; };
+
+    {
+        auto raw_result = evmc_result{};
+        raw_result.status_code = EVMC_INTERNAL_ERROR;
+        raw_result.release = release_fn;
+
+        auto raii_result = evmc::result{raw_result};
+        EXPECT_EQ(raii_result.status_code, EVMC_INTERNAL_ERROR);
+        EXPECT_EQ(raii_result.gas_left, 0);
+        raii_result.gas_left = -1;
+
+        auto raw_result2 = raii_result.raw();
+        EXPECT_EQ(raw_result2.status_code, EVMC_INTERNAL_ERROR);
+        EXPECT_EQ(raw_result.status_code, EVMC_INTERNAL_ERROR);
+        EXPECT_EQ(raw_result2.gas_left, -1);
+        EXPECT_EQ(raw_result.gas_left, 0);
+        EXPECT_EQ(raw_result2.release, release_fn);
+        EXPECT_EQ(raw_result.release, release_fn);
+    }
+    EXPECT_EQ(release_called, 0);
+
+    {
+        auto raw_result = evmc_result{};
+        raw_result.status_code = EVMC_INTERNAL_ERROR;
+        raw_result.release = release_fn;
+
+        auto raii_result = evmc::result{raw_result};
+        EXPECT_EQ(raii_result.status_code, EVMC_INTERNAL_ERROR);
+    }
+    EXPECT_EQ(release_called, 1);
+}
+
+TEST(cpp, result_move)
+{
+    static auto release_called = 0;
+    auto release_fn = [](const evmc_result*) noexcept { ++release_called; };
+
+    release_called = 0;
+    {
+        auto raw = evmc_result{};
+        raw.gas_left = -1;
+        raw.release = release_fn;
+
+        auto r0 = evmc::result{raw};
+        EXPECT_EQ(r0.gas_left, raw.gas_left);
+
+        auto r1 = std::move(r0);
+        EXPECT_EQ(r1.gas_left, raw.gas_left);
+    }
+    EXPECT_EQ(release_called, 1);
+
+    release_called = 0;
+    {
+        auto raw1 = evmc_result{};
+        raw1.gas_left = 1;
+        raw1.release = release_fn;
+
+        auto raw2 = evmc_result{};
+        raw2.gas_left = 1;
+        raw2.release = release_fn;
+
+        auto r1 = evmc::result{raw1};
+        auto r2 = evmc::result{raw2};
+
+        r2 = std::move(r1);
+    }
+    EXPECT_EQ(release_called, 2);
+}