Windows 7 compatibility

PC/getpathp.c

@@ -90,7 +90,6 @@
 #endif
 
 #include <windows.h>
-#include <pathcch.h>
 #include <shlwapi.h>
 
 #ifdef HAVE_SYS_TYPES_H
@@ -250,13 +249,42 @@ ismodule(wchar_t *filename, int update_filename)
    stuff as fits will be appended.
 */
 
+static int _PathCchCombineEx_Initialized = 0;
+typedef HRESULT(__stdcall *PPathCchCombineEx) (PWSTR pszPathOut, size_t cchPathOut,
+                                               PCWSTR pszPathIn, PCWSTR pszMore,
+                                               unsigned long dwFlags);
+static PPathCchCombineEx _PathCchCombineEx;
+
 static void
 join(wchar_t *buffer, const wchar_t *stuff)
 {
-    if (FAILED(PathCchCombineEx(buffer, MAXPATHLEN+1, buffer, stuff, 0))) {
+    if (_PathCchCombineEx_Initialized == 0) {
+        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
+                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
+        if (pathapi) {
+            _PathCchCombineEx = (PPathCchCombineEx)GetProcAddress(pathapi, "PathCchCombineEx");
+        }
+        else {
+            _PathCchCombineEx = NULL;
+        }
+        _PathCchCombineEx_Initialized = 1;
+    }
+
+    if (_PathCchCombineEx) {
+        if (FAILED(_PathCchCombineEx(buffer, MAXPATHLEN+1, buffer, stuff, 0))) {
         Py_FatalError("buffer overflow in getpathp.c's join()");
     }
+    } else {
+        if (!PathCombineW(buffer, buffer, stuff)) {
+            Py_FatalError("buffer overflow in getpathp.c's join()");
 }
+    }
+}
+
+static int _PathCchCanonicalizeEx_Initialized = 0;
+typedef HRESULT(__stdcall *PPathCchCanonicalizeEx) (PWSTR pszPathOut, size_t cchPathOut,
+    PCWSTR pszPathIn, unsigned long dwFlags);
+static PPathCchCanonicalizeEx _PathCchCanonicalizeEx;
 
 /* Call PathCchCanonicalizeEx(path): remove navigation elements such as "."
    and ".." to produce a direct, well-formed path. */
@@ -267,8 +295,27 @@ canonicalize(wchar_t *buffer, const wchar_t *path)
         return _PyStatus_NO_MEMORY();
     }
 
-    if (FAILED(PathCchCanonicalizeEx(buffer, MAXPATHLEN + 1, path, 0))) {
+    if (_PathCchCanonicalizeEx_Initialized == 0) {
+        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
+                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
+        if (pathapi) {
+            _PathCchCanonicalizeEx = (PPathCchCanonicalizeEx)GetProcAddress(pathapi, "PathCchCanonicalizeEx");
+        }
+        else {
+            _PathCchCanonicalizeEx = NULL;
+        }
+        _PathCchCanonicalizeEx_Initialized = 1;
+    }
+
+    if (_PathCchCanonicalizeEx) {
+        if (FAILED(_PathCchCanonicalizeEx(buffer, MAXPATHLEN + 1, path, 0))) {
         return INIT_ERR_BUFFER_OVERFLOW();
+        }
+    }
+    else {
+        if (!PathCanonicalizeW(buffer, path)) {
+            return INIT_ERR_BUFFER_OVERFLOW();
+        }
     }
     return _PyStatus_OK();
 }

PC/pyconfig.h

@@ -135,9 +135,9 @@ WIN32 is still required for the locale module.
 #endif /* MS_WIN64 */
 
 /* set the version macros for the windows headers */
-/* Python 3.9+ requires Windows 8 or greater */
-#define Py_WINVER 0x0602 /* _WIN32_WINNT_WIN8 */
-#define Py_NTDDI NTDDI_WIN8
+/* Python 3.5+ requires Windows Vista or greater */
+#define Py_WINVER 0x0600 /* _WIN32_WINNT_VISTA */
+#define Py_NTDDI NTDDI_VISTA
 
 /* We only set these values when building Python - we don't want to force
    these values on extensions, as that will affect the prototypes and

PCbuild/pythoncore.vcxproj

@@ -106,7 +106,7 @@
       <PreprocessorDefinitions Condition="$(IncludeExternals)">_Py_HAVE_ZLIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Link>
-      <AdditionalDependencies>version.lib;shlwapi.lib;ws2_32.lib;pathcch.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>version.lib;shlwapi.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>

Tools/msi/bundle/Default.wxl

@@ -121,9 +121,26 @@ Feel free to email <a href="mailto:python-list@python.org">python-list@pyt
   <String Id="FailureRestartButton">&amp;Restart</String>
   <String Id="FailureExistingInstall">Unable to install [WixBundleName] due to an existing install. Use Programs and Features to modify, repair or remove [WixBundleName].</String>
 
-  <String Id="FailureOldOS">At least Windows 8.1 or Windows Server 2012 are required to install [WixBundleName]
+  <String Id="FailureWin7MissingSP1">Windows 7 Service Pack 1 and all applicable updates are required to install [WixBundleName].
+
+Please &lt;a href="https://www.bing.com/search?q=how%20to%20install%20windows%207%20service%20pack%201"&gt;update your machine&lt;/a&gt; and then restart the installation.</String>
+  <String Id="FailureVistaMissingSP2">Windows Vista Service Pack 2 and all applicable updates are required to install [WixBundleName].
+
+Please &lt;a href="https://www.bing.com/search?q=how%20to%20install%20windows%20vista%20service%20pack%202"&gt;update your machine&lt;/a&gt; and then restart the installation.</String>
+  <String Id="FailureXPOrEarlier">Windows Vista or later is required to install and use [WixBundleName].
+
+Visit &lt;a href="https://www.python.org/"&gt;python.org&lt;/a&gt; to download Python 3.4.</String>
+
+  <String Id="FailureWS2K8R2MissingSP1">Windows Server 2008 R2 Service Pack 1 and all applicable updates are required to install [WixBundleName].
+
+Please &lt;a href="https://www.bing.com/search?q=how%20to%20install%20windows%20server%202008%20r2%20service%20pack%201"&gt;update your machine&lt;/a&gt; and then restart the installation.</String>
+  <String Id="FailureWS2K8MissingSP2">Windows Server 2008 Service Pack 2 and all applicable updates are required to install [WixBundleName].
+
+Please &lt;a href="https://www.bing.com/search?q=how%20to%20install%20windows%20server%202008%20service%20pack%202"&gt;update your machine&lt;/a&gt; and then restart the installation.</String>
+  <String Id="FailureWS2K3OrEarlier">Windows Server 2008 SP2 or later is required to install and use [WixBundleName].
+
+Visit &lt;a href="https://www.python.org/"&gt;python.org&lt;/a&gt; to download Python 3.4.</String>
 
-Visit &lt;a href="https://www.python.org/"&gt;python.org&lt;/a&gt; to download an earlier version of Python.</String>
   <String Id="SuccessMaxPathButton">Disable path length limit</String>
   <String Id="SuccessMaxPathButtonNote">Changes your machine configuration to allow programs, including Python, to bypass the 260 character "MAX_PATH" limitation.</String>
 </WixLocalization>

Tools/msi/bundle/bootstrap/PythonBootstrapperApplication.cpp

@@ -3011,35 +3011,65 @@ class PythonBootstrapperApplication : public CBalBaseBootstrapperApplication {
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows Server 2012 or later");
                 return;
             } else if (IsWindowsVersionOrGreater(6, 1, 1)) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Detected Windows Server 2008 R2");
+                HMODULE hKernel32 = GetModuleHandleW(L"kernel32");
+                if (hKernel32 && !GetProcAddress(hKernel32, "AddDllDirectory")) {
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Server 2008 R2 without KB2533623");
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "KB2533623 update is required to continue.");
+                    /* The "MissingSP1" error also specifies updates are required */
+                    LocGetString(_wixLoc, L"#(loc.FailureWS2K8R2MissingSP1)", &pLocString);
+                } else {
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows Server 2008 R2 or later");
+                    return;
+                }
             } else if (IsWindowsVersionOrGreater(6, 1, 0)) {
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Server 2008 R2");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Service Pack 1 is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureWS2K8R2MissingSP1)", &pLocString);
+            } else if (IsWindowsVersionOrGreater(6, 0, 2)) {
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Target OS is Windows Server 2008 SP2 or later");
+                return;
             } else if (IsWindowsVersionOrGreater(6, 0, 0)) {
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Server 2008");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Service Pack 2 is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureWS2K8MissingSP2)", &pLocString);
             } else {
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Server 2003 or earlier");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Windows Server 2008 SP2 or later is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureWS2K3OrEarlier)", &pLocString);
             }
-            BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Windows Server 2012 or later is required to continue installation");
         } else {
-            if (IsWindows10OrGreater()) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows 10 or later");
+            if (IsWindows8OrGreater()) {
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows 8 or later");
                 return;
-            } else if (IsWindows8Point1OrGreater()) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows 8.1");
+            } else if (IsWindows7SP1OrGreater()) {
+                HMODULE hKernel32 = GetModuleHandleW(L"kernel32");
+                if (hKernel32 && !GetProcAddress(hKernel32, "AddDllDirectory")) {
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows 7 SP1 without KB2533623");
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "KB2533623 update is required to continue.");
+                    /* The "MissingSP1" error also specifies updates are required */
+                    LocGetString(_wixLoc, L"#(loc.FailureWin7MissingSP1)", &pLocString);
+                } else {
+                    BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Target OS is Windows 7 SP1 or later");
                 return;
-            } else if (IsWindows8OrGreater()) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows 8");
+                }
             } else if (IsWindows7OrGreater()) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows 7");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows 7 RTM");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Service Pack 1 is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureWin7MissingSP1)", &pLocString);
+            } else if (IsWindowsVistaSP2OrGreater()) {
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Target OS is Windows Vista SP2");
+                return;
             } else if (IsWindowsVistaOrGreater()) {
-                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Vista");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows Vista RTM or SP1");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Service Pack 2 is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureVistaMissingSP2)", &pLocString);
             } else { 
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Detected Windows XP or earlier");
+                BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Windows Vista SP2 or later is required to continue installation");
+                LocGetString(_wixLoc, L"#(loc.FailureXPOrEarlier)", &pLocString);
             }
-            BalLog(BOOTSTRAPPER_LOG_LEVEL_ERROR, "Windows 8.1 or later is required to continue installation");
         }
 
-        LocGetString(_wixLoc, L"#(loc.FailureOldOS)", &pLocString);
         if (pLocString && pLocString->wzText) {
             BalFormatString(pLocString->wzText, &_failedMessage);
         }

Win7.rst

@@ -0,0 +1,24 @@
+============
+Python 3.9.1 fork for Windows 7 support
+============
+
+A lot of people still use Windows 7. End date of ESU support - 2023-01-10.
+
+***************
+Build instructions:
+***************
+
+You need Visual Studio 2017 and Python 3.8. Switch off vcpkg if it's installed
+(vcpkg integrate remove). Install everything related to Python in Visual Studio Installer.
+
+ 1.  Start your "x64 Native Tools Command Prompt for VS 2017"
+ 2.  Change current directory to the place with enough free space.
+ 3.  pip install -U sphinx
+ 4.  set PYTHON="C:\\Program Files\\Python38\\python.exe"
+ 5.  set SPHINXBUILD="C:\\Program Files\\Python38\\Scripts\\sphinx-build.exe"
+ 6.  git clone https://github.com/NulAsh/cpython.git
+ 7.  cd cpython\\Tools\\msi
+ 8.  buildrelease.bat -x64
+ 9.  cd ..\\..\\PCbuild\\amd64\\en-us
+
+ And in this folder we can see installer python-3.9.1-amd64.exe, install it as usual.