vcpkg/ports/python3/0006-restore-support-for-windows-7.patch

From e30a560527d17ae81685dd11d3268bc982af2048 Mon Sep 17 00:00:00 2001
From: Adam Johnson <AdamJohnso@gmail.com>
Date: Tue, 16 Feb 2021 18:03:07 -0500
Subject: [PATCH 7/7] restore support for windows 7

this backports the windows 7 compatible fix for bpo-39401 from gh-18234,
originally authored by Steve Dower, and removes explicit dependencies on
pathcch. 

The same mechanism is applied to fix posixmodule.c
---
index 25ddc82..ff51042 100644
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -44,6 +44,15 @@
 
 #include "pycore_runtime.h"       // _Py_ID
 
+// The Windws 7 patch lowers the API version such that these constants
+// are no longer defined by the Windows SDK. Debounce that.
+#ifndef LCMAP_SORTHANDLE
+#   define LCMAP_SORTHANDLE   0x20000000
+#endif
+#ifndef LCMAP_HASH
+#   define LCMAP_HASH         0x00040000
+#endif
+
 #if defined(MS_WIN32) && !defined(MS_WIN64)
 #define HANDLE_TO_PYNUM(handle) \
     PyLong_FromUnsignedLong((unsigned long) handle)
diff --git a/Modules/getpath.c b/Modules/getpath.c
index bc730fc..7d3d559 100644
--- a/Modules/getpath.c
+++ b/Modules/getpath.c
@@ -11,7 +11,7 @@
 
 #ifdef MS_WINDOWS
 #  include <windows.h>            // GetFullPathNameW(), MAX_PATH
-#  include <pathcch.h>
+#  include <Shlwapi.h>
 #endif
 
 #ifdef __APPLE__
@@ -217,6 +217,11 @@ getpath_isfile(PyObject *Py_UNUSED(self), PyObject *args)
     return r;
 }
 
+#ifdef MS_WINDOWS
+static int _PathCchFindExtension_Initialized = 0;
+typedef HRESULT (__stdcall *PPathCchFindExtension) (PCWSTR pszPath, size_t cchPath, PCWSTR *ppszExt);
+static PPathCchFindExtension _PathCchFindExtension;
+#endif
 
 static PyObject *
 getpath_isxfile(PyObject *Py_UNUSED(self), PyObject *args)
@@ -231,13 +235,51 @@ getpath_isxfile(PyObject *Py_UNUSED(self), PyObject *args)
     path = PyUnicode_AsWideCharString(pathobj, &cchPath);
     if (path) {
 #ifdef MS_WINDOWS
+
+        if (_PathCchFindExtension_Initialized == 0) {
+            HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
+                                             LOAD_LIBRARY_SEARCH_SYSTEM32);
+
+            if (pathapi) {
+                _PathCchFindExtension = (PPathCchFindExtension)GetProcAddress(pathapi, "PathCchFindExtension");
+            } else {
+                _PathCchFindExtension = NULL;
+            }
+
+            _PathCchFindExtension_Initialized = 1;
+        }
+
         const wchar_t *ext;
         DWORD attr = GetFileAttributesW(path);
-        r = (attr != INVALID_FILE_ATTRIBUTES) &&
-            !(attr & FILE_ATTRIBUTE_DIRECTORY) &&
-            SUCCEEDED(PathCchFindExtension(path, cchPath + 1, &ext)) &&
-            (CompareStringOrdinal(ext, -1, L".exe", -1, 1 /* ignore case */) == CSTR_EQUAL)
-            ? Py_True : Py_False;
+        if (attr == INVALID_FILE_ATTRIBUTES || (attr & FILE_ATTRIBUTE_DIRECTORY)) {
+            r = Py_False;
+        }
+        else {
+            HRESULT hr = S_OK;
+            if (_PathCchFindExtension) {
+                hr = _PathCchFindExtension(path, cchPath + 1, &ext);
+            }
+            else {
+                if (cchPath > MAX_PATH) {
+                    hr = E_FAIL;
+                }
+                else {
+                    ext = PathFindExtensionW(path);
+                    if (*ext == '\0')
+                        hr = E_FAIL;
+                }
+            }
+
+            if (!SUCCEEDED(hr)) {
+                r = Py_False;
+            }
+            else if (CompareStringOrdinal(ext, -1, L".exe", -1, 1 /* ignore case */) != CSTR_EQUAL) {
+                r = Py_False;
+            }
+            else {
+                r = Py_True;
+            }
+        }
 #else
         struct stat st;
         r = (_Py_wstat(path, &st) == 0) &&
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -15,7 +15,7 @@
 // whereas pycore_condvar.h defines the WIN32_LEAN_AND_MEAN macro.
 #ifdef MS_WINDOWS
 #  include <windows.h>
-#  include <pathcch.h>
+#  include <Shlwapi.h>
 #  include <lmcons.h>             // UNLEN
 #  include "osdefs.h"             // SEP
 #  define HAVE_SYMLINK
@@ -4471,6 +4471,11 @@ os__getvolumepathname_impl(PyObject *module, path_t *path)
     return result;
 }
 
+#ifdef MS_WINDOWS
+static int _PathCchSkipRoot_Initialized = 0;
+typedef HRESULT (__stdcall *PPathCchSkipRoot) (PCWSTR pszPath, PCWSTR *ppszRootEnd);
+static PPathCchSkipRoot _PathCchSkipRoot;
+#endif
 
 /*[clinic input]
 os._path_splitroot
@@ -4489,6 +4493,19 @@ os__path_splitroot_impl(PyObject *module, path_t *path)
     PyObject *result = NULL;
     HRESULT ret;
 
+    if (_PathCchSkipRoot_Initialized == 0) {
+        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
+                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
+
+        if (pathapi) {
+            _PathCchSkipRoot = (PPathCchSkipRoot)GetProcAddress(pathapi, "PathCchSkipRoot");
+        } else {
+            _PathCchSkipRoot = NULL;
+        }
+
+        _PathCchSkipRoot_Initialized = 1;
+    }
+
     buffer = (wchar_t*)PyMem_Malloc(sizeof(wchar_t) * (wcslen(path->wide) + 1));
     if (!buffer) {
         return NULL;
@@ -4499,7 +4516,14 @@ os__path_splitroot_impl(PyObject *module, path_t *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    ret = PathCchSkipRoot(buffer, &end);
+    if (_PathCchSkipRoot) {
+        ret = _PathCchSkipRoot(buffer, &end);
+    } else {
+        end = PathSkipRootW(buffer);
+        if (!end) {
+            ret = E_FAIL;
+        }
+    }
     Py_END_ALLOW_THREADS
     if (FAILED(ret)) {
         result = Py_BuildValue("sO", "", path->object);
diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index d7d3cf0..6e9c090 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -130,8 +130,8 @@ WIN32 is still required for the locale module.
 
 /* 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
+#define Py_WINVER 0x0601 /* _WIN32_WINNT_WIN7 */
+#define Py_NTDDI NTDDI_WIN7
 
 /* 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
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 442e343..ef0a43e 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -94,7 +94,7 @@
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
-      <AdditionalDependencies>version.lib;ws2_32.lib;pathcch.lib;bcrypt.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>version.lib;ws2_32.lib;shlwapi.lib;bcrypt.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <LinkTimeCodeGeneration>Default</LinkTimeCodeGeneration>
     </Link>
   </ItemDefinitionGroup>
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index c39ba3e1a9..0ef3a05fb6 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -106,7 +106,7 @@
       <PreprocessorDefinitions Condition="$(IncludeExternals)">_Py_HAVE_ZLIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Link>
-      <AdditionalDependencies>version.lib;ws2_32.lib;pathcch.lib;bcrypt.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>version.lib;ws2_32.lib;shlwapi.lib;bcrypt.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
diff --git a/Python/fileutils.c b/Python/fileutils.c
index c86ed40..6b1535d 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -8,7 +8,7 @@
 #ifdef MS_WINDOWS
 #  include <malloc.h>
 #  include <windows.h>
-#  include <pathcch.h>            // PathCchCombineEx
+#  include <Shlwapi.h>
 extern int winerror_to_errno(int);
 #endif
 
@@ -1999,13 +1999,46 @@ _Py_wrealpath(const wchar_t *path,
 }
 #endif
 
+#ifdef MS_WINDOWS
+static int _PathCchSkipRoot_Initialized = 0;
+typedef HRESULT (__stdcall *PPathCchSkipRoot) (PCWSTR pszPath, PCWSTR *ppszRootEnd);
+static PPathCchSkipRoot _PathCchSkipRoot;
+
+#ifndef PATHCCH_ALLOW_LONG_PATHS
+#define PATHCCH_ALLOW_LONG_PATHS 0x00000001
+#endif
+#endif
 
 int
 _Py_isabs(const wchar_t *path)
 {
 #ifdef MS_WINDOWS
+    if (_PathCchSkipRoot_Initialized == 0) {
+        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
+                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
+
+        if (pathapi) {
+            _PathCchSkipRoot = (PPathCchSkipRoot)GetProcAddress(pathapi, "PathCchSkipRoot");
+        } else {
+            _PathCchSkipRoot = NULL;
+        }
+
+        _PathCchSkipRoot_Initialized = 1;
+    }
+
+    HRESULT hr;
     const wchar_t *tail;
-    HRESULT hr = PathCchSkipRoot(path, &tail);
+    if (_PathCchSkipRoot) {
+        hr = _PathCchSkipRoot(path, &tail);
+    } else {
+        tail = PathSkipRootW(path);
+        if (!tail) {
+            hr = E_FAIL;
+        } else {
+            hr = S_OK;
+        }
+    }
+
     if (FAILED(hr) || path == tail) {
         return 0;
     }
@@ -2086,6 +2117,11 @@ _Py_abspath(const wchar_t *path, wchar_t **abspath_p)
 #endif
 }
 
+#ifdef MS_WINDOWS
+static int _PathCchCombineEx_Initialized = 0;
+typedef HRESULT (__stdcall *PPathCchCombineEx) (PWSTR  pszPathOut, size_t cchPathOut, PCWSTR pszPathIn, PCWSTR pszMore, ULONG  dwFlags);
+static PPathCchCombineEx _PathCchCombineEx;
+#endif
 
 // The caller must ensure "buffer" is big enough.
 static int
@@ -2093,9 +2127,36 @@ join_relfile(wchar_t *buffer, size_t bufsize,
              const wchar_t *dirname, const wchar_t *relfile)
 {
 #ifdef MS_WINDOWS
-    if (FAILED(PathCchCombineEx(buffer, bufsize, dirname, relfile,
-        PATHCCH_ALLOW_LONG_PATHS))) {
-        return -1;
+
+    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, bufsize, dirname, relfile,
+            PATHCCH_ALLOW_LONG_PATHS))) {
+            return -1;
+        }
+    }
+    else {
+        size_t dirlen = wcslen(dirname);
+        size_t rellen = wcslen(relfile);
+        size_t maxlen = bufsize - 1;
+        if (maxlen > MAX_PATH || dirlen >= maxlen || rellen >= maxlen - dirlen) {
+            return -1;
+        }
+        wchar_t * r = PathCombineW(buffer, dirname, relfile);
+        if (!r)
+            return -1;
     }
 #else
     assert(!_Py_isabs(relfile));