Replace GetVersionEx direct call

Author: jet2jet

Common/Common.vcxproj

@@ -151,6 +151,7 @@
     <ClCompile Include="MyFunc.cpp" />
     <ClCompile Include="MyProp.cpp" />
     <ClCompile Include="MyWindow.cpp" />
+    <ClCompile Include="OS.cpp" />
     <ClCompile Include="ShlItem.cpp" />
     <ClCompile Include="Splitter.cpp" />
     <ClCompile Include="stdafx.cpp">
@@ -181,6 +182,7 @@
     <ClInclude Include="MyFunc.h" />
     <ClInclude Include="MyProp.h" />
     <ClInclude Include="MyWindow.h" />
+    <ClInclude Include="OS.h" />
     <ClInclude Include="RefDelg.h" />
     <ClInclude Include="ShlItem.h" />
     <ClInclude Include="Splitter.h" />

Common/Common.vcxproj.filters

@@ -63,6 +63,9 @@
     <ClCompile Include="SyncUtil.cpp">
       <Filter>ソース ファイル</Filter>
     </ClCompile>
+    <ClCompile Include="OS.cpp">
+      <Filter>ソース ファイル</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="AppClass.h">
@@ -146,6 +149,9 @@
     <ClInclude Include="BitFlags.h">
       <Filter>ヘッダー ファイル</Filter>
     </ClInclude>
+    <ClInclude Include="OS.h">
+      <Filter>ヘッダー ファイル</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="ReadMe.txt" />

Common/OS.cpp

@@ -0,0 +1,26 @@
+/*
+ Copyright (C) 2026 jet (ジェット)
+
+ OS.cpp - implementations for OS-related functions
+ */
+
+#include "stdafx.h"
+#include "OS.h"
+
+static DWORD s_dwPlatformId = 0;
+
+EXTERN_C bool IsUnicodeAvailableOS()
+{
+	if (s_dwPlatformId == 0)
+	{
+		OSVERSIONINFO vi{};
+		vi.dwOSVersionInfoSize = sizeof(vi);
+#pragma warning(push)
+#pragma warning(disable:4996 28159)
+		if (!::GetVersionExA(&vi))
+#pragma warning(pop)
+			return false;
+		s_dwPlatformId = vi.dwPlatformId;
+	}
+	return (s_dwPlatformId != VER_PLATFORM_WIN32_WINDOWS);
+}

Common/OS.h

@@ -0,0 +1,9 @@
+/*
+ Copyright (C) 2026 jet (ジェット)
+
+ OS.h - declarations for OS-related functions
+ */
+
+#pragma once
+
+EXTERN_C bool IsUnicodeAvailableOS();

EasySFTP/EasySFTP.cpp

@@ -14,6 +14,7 @@
 
 #include "IDList.h"
 #include "FileStrm.h"
+#include "OS.h"
 #include "Logger.h"
 
 CMainApplication theApp;
@@ -514,22 +515,10 @@ HRESULT CMainApplication::InitSystemLibraries()
 	m_nCFShellIDList = ::RegisterClipboardFormat(CFSTR_SHELLIDLIST);
 
 	{
-		OSVERSIONINFO vi;
-		vi.dwOSVersionInfoSize = sizeof(vi);
-		if (!::GetVersionExA(&vi))
-		{
-			m_bUseOFNUnicode = false;
+		m_bUseOFNUnicode = IsUnicodeAvailableOS();
 #ifndef _WIN64
-			m_bIsWin9x = true;
+		m_bIsWin9x = !m_bUseOFNUnicode;
 #endif
-		}
-		else
-		{
-			m_bUseOFNUnicode = (vi.dwPlatformId == VER_PLATFORM_WIN32_NT);
-#ifndef _WIN64
-			m_bIsWin9x = !m_bUseOFNUnicode;
-#endif
-		}
 	}
 
 	return S_OK;

EasySFTP/RegHook.cpp

@@ -10,6 +10,7 @@
 #include "../ShellDLL/EasySFTP_h.h"
 #include "Array.h"
 #include "UString.h"
+#include "OS.h"
 
 #ifdef _DEBUG
 #define new DEBUG_NEW
@@ -482,12 +483,7 @@ static bool __stdcall InitOldRegFunctions()
 	s_pfnRegSetKeyValueW = (T_RegSetKeyValueW) ::GetProcAddress(hInstAdvapi32, "RegSetKeyValueW");
 #undef GetProcAddress
 
-	{
-		OSVERSIONINFO osvi;
-		osvi.dwOSVersionInfoSize = sizeof(osvi);
-		::GetVersionEx(&osvi);
-		s_bUnicodeSupported = (osvi.dwPlatformId == VER_PLATFORM_WIN32_NT);
-	}
+	s_bUnicodeSupported = IsUnicodeAvailableOS();
 
 	return true;
 }

ShellDLL/ShellDLL.cpp

@@ -12,6 +12,7 @@
 #include "CFactory.h"
 #include "INIFile.h"
 #include "MErrDlg.h"
+#include "OS.h"
 
 CMainDLL theApp;
 
@@ -1243,14 +1244,7 @@ bool CMainDLL::InitInstance()
 	::srand((unsigned int) (time(NULL) * GetTickCount()));
 
 	// Check whether we can use Unicode version of GetOpenFileName/GetSaveFileName
-	{
-		OSVERSIONINFO vi;
-		vi.dwOSVersionInfoSize = sizeof(vi);
-		if (!::GetVersionExA(&vi))
-			m_bUseOFNUnicode = false;
-		else
-			m_bUseOFNUnicode = (vi.dwPlatformId == VER_PLATFORM_WIN32_NT);
-	}
+	m_bUseOFNUnicode = IsUnicodeAvailableOS();
 
 	// Initializing system image lists
 	{