From f3271cb66b1222cfbce3a588858c5b0fe004dcf7 Mon Sep 17 00:00:00 2001
From: Sergey Fukanchik <fukanchik@gmail.com>
Date: Tue, 9 Feb 2021 13:09:36 -0500
Subject: [PATCH] Add unit test for swapEndiannessInplace(). Part of Bug #5837

---
 apps/openmw_test_suite/CMakeLists.txt         |   1 +
 .../misc/test_endianness.cpp                  | 122 ++++++++++++++++++
 components/misc/endianness.hpp                |   2 +-
 3 files changed, 124 insertions(+), 1 deletion(-)
 create mode 100644 apps/openmw_test_suite/misc/test_endianness.cpp

diff --git a/apps/openmw_test_suite/CMakeLists.txt b/apps/openmw_test_suite/CMakeLists.txt
index 5658a5eef..a3bb0c6f8 100644
--- a/apps/openmw_test_suite/CMakeLists.txt
+++ b/apps/openmw_test_suite/CMakeLists.txt
@@ -15,6 +15,7 @@ if (GTEST_FOUND AND GMOCK_FOUND)
         esm/test_fixed_string.cpp
 
         misc/test_stringops.cpp
+        misc/test_endianness.cpp
 
         nifloader/testbulletnifloader.cpp
 
diff --git a/apps/openmw_test_suite/misc/test_endianness.cpp b/apps/openmw_test_suite/misc/test_endianness.cpp
new file mode 100644
index 000000000..240e4a49a
--- /dev/null
+++ b/apps/openmw_test_suite/misc/test_endianness.cpp
@@ -0,0 +1,122 @@
+#include <gtest/gtest.h>
+#include "components/misc/endianness.hpp"
+
+struct EndiannessTest : public ::testing::Test {};
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace1)
+{
+  uint8_t zero=0x00;
+  uint8_t ff=0xFF;
+  uint8_t fortytwo=0x42;
+  uint8_t half=128;
+
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x00);
+
+  Misc::swapEndiannessInplace(ff);
+  EXPECT_EQ(ff, 0xFF);
+
+  Misc::swapEndiannessInplace(fortytwo);
+  EXPECT_EQ(fortytwo, 0x42);
+
+  Misc::swapEndiannessInplace(half);
+  EXPECT_EQ(half, 128);
+}
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace2)
+{
+  uint16_t zero = 0x0000;
+  uint16_t ffff = 0xFFFF;
+  uint16_t n12 = 0x0102;
+  uint16_t fortytwo = 0x0042;
+
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x0000);
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x0000);
+
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFF);
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFF);
+
+  Misc::swapEndiannessInplace(n12);
+  EXPECT_EQ(n12, 0x0201);
+  Misc::swapEndiannessInplace(n12);
+  EXPECT_EQ(n12, 0x0102);
+
+  Misc::swapEndiannessInplace(fortytwo);
+  EXPECT_EQ(fortytwo, 0x4200);
+  Misc::swapEndiannessInplace(fortytwo);
+  EXPECT_EQ(fortytwo, 0x0042);
+}
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace4)
+{
+  uint32_t zero = 0x00000000;
+  uint32_t n1234 = 0x01020304;
+  uint32_t ffff = 0xFFFFFFFF;
+
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x00000000);
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x00000000);
+
+  Misc::swapEndiannessInplace(n1234);
+  EXPECT_EQ(n1234, 0x04030201);
+  Misc::swapEndiannessInplace(n1234);
+  EXPECT_EQ(n1234, 0x01020304);
+  
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFFFFFF);
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFFFFFF);
+}
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace8)
+{
+  uint64_t zero = 0x0000'0000'0000'0000;
+  uint64_t n1234 = 0x0102'0304'0506'0708;
+  uint64_t ffff = 0xFFFF'FFFF'FFFF'FFFF;
+
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x0000'0000'0000'0000);
+  Misc::swapEndiannessInplace(zero);
+  EXPECT_EQ(zero, 0x0000'0000'0000'0000);
+  
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFF'FFFF'FFFF'FFFF);
+  Misc::swapEndiannessInplace(ffff);
+  EXPECT_EQ(ffff, 0xFFFF'FFFF'FFFF'FFFF);
+
+  Misc::swapEndiannessInplace(n1234);
+  EXPECT_EQ(n1234, 0x0807'0605'0403'0201);
+  Misc::swapEndiannessInplace(n1234);
+  EXPECT_EQ(n1234, 0x0102'0304'0506'0708);
+}
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace_float)
+{
+  const uint32_t original = 0x4023d70a;
+  const uint32_t expected = 0x0ad72340;
+
+  float number;
+  memcpy(&number, &original, sizeof(original));
+
+  Misc::swapEndiannessInplace(number);
+
+  EXPECT_TRUE(!memcmp(&number, &expected, sizeof(expected)));
+}
+
+TEST_F(EndiannessTest, test_swap_endianness_inplace_double)
+{
+  const uint64_t original = 0x040047ae147ae147ul;
+  const uint64_t expected = 0x47e17a14ae470004ul;
+
+  double number;
+  memcpy(&number, &original, sizeof(original));
+
+  Misc::swapEndiannessInplace(number);
+
+  EXPECT_TRUE(!memcmp(&number, &expected, sizeof(expected)) );
+}
diff --git a/components/misc/endianness.hpp b/components/misc/endianness.hpp
index 8019d33ed..ad8aba18c 100644
--- a/components/misc/endianness.hpp
+++ b/components/misc/endianness.hpp
@@ -26,7 +26,7 @@ namespace Misc
         {
             uint32_t v32;
             std::memcpy(&v32, &v, sizeof(T));
-            v32 = (v32 >> 24) | ((v32 >> 8) & 0xff00) | ((v32 & 0xff00) << 8) | v32 << 24;
+            v32 = (v32 >> 24) | ((v32 >> 8) & 0xff00) | ((v32 & 0xff00) << 8) | (v32 << 24);
             std::memcpy(&v, &v32, sizeof(T));
         }
         if constexpr (sizeof(T) == 8)