From 71fba9ef0080a54dcd80fa5ff6c85c567101206d Mon Sep 17 00:00:00 2001
From: Naveen M K <naveen521kk@gmail.com>
Date: Thu, 17 Jun 2021 18:52:39 +0530
Subject: [PATCH 095/N] Add support for Windows 7 Python 3.9

---
 Modules/posixmodule.c | 22 +++++++++++------
 PC/getpathp.c         | 57 +++++++++++++++++++++++++++++++++++++++----
 configure.ac          |  2 +-
 3 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index bf19ac8..215c81f 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -18,7 +18,7 @@
 
       FSCTL_GET_REPARSE_POINT is not exported with WIN32_LEAN_AND_MEAN. */
 #  include <windows.h>
-#  include <pathcch.h>
+#  include <shlwapi.h>
 #endif
 
 #include "pycore_ceval.h"         // _PyEval_ReInitThreads()
@@ -4402,7 +4402,6 @@ os__path_splitroot_impl(PyObject *module, path_t *path)
     wchar_t *buffer;
     wchar_t *end;
     PyObject *result = NULL;
-    HRESULT ret;
 
     buffer = (wchar_t*)PyMem_Malloc(sizeof(wchar_t) * (wcslen(path->wide) + 1));
     if (!buffer) {
@@ -4414,18 +4413,26 @@ os__path_splitroot_impl(PyObject *module, path_t *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    ret = PathCchSkipRoot(buffer, &end);
+    if (buffer[0] && buffer[1] == L':') {
+        if (buffer[2] == L'\\') {
+            end = &buffer[3];
+        } else {
+            end = &buffer[2];
+        }
+    } else {
+        end = PathSkipRootW(buffer);
+    }
     Py_END_ALLOW_THREADS
-    if (FAILED(ret)) {
+    if (!end || end == buffer) {
         result = Py_BuildValue("sO", "", path->object);
-    } else if (end != buffer) {
+    } else if (!*end) {
+        result = Py_BuildValue("Os", path->object, "");
+    } else {
         size_t rootLen = (size_t)(end - buffer);
         result = Py_BuildValue("NN",
             PyUnicode_FromWideChar(path->wide, rootLen),
             PyUnicode_FromWideChar(path->wide + rootLen, -1)
         );
-    } else {
-        result = Py_BuildValue("Os", path->object, "");
     }
     PyMem_Free(buffer);
 
@@ -4433,6 +4440,7 @@ os__path_splitroot_impl(PyObject *module, path_t *path)
 }
 
 
+
 #endif /* MS_WINDOWS */
 
 
diff --git a/PC/getpathp.c b/PC/getpathp.c
index 53da3a6..40b0db3 100644
--- a/PC/getpathp.c
+++ b/PC/getpathp.c
@@ -90,7 +90,6 @@
 #endif
 
 #include <windows.h>
-#include <pathcch.h>
 #include <shlwapi.h>
 
 #ifdef HAVE_SYS_TYPES_H
@@ -250,14 +249,43 @@ 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))) {
-        Py_FatalError("buffer overflow in getpathp.c's join()");
+    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. */
 static PyStatus
@@ -267,8 +295,27 @@ canonicalize(wchar_t *buffer, const wchar_t *path)
         return _PyStatus_NO_MEMORY();
     }
 
-    if (FAILED(PathCchCanonicalizeEx(buffer, MAXPATHLEN + 1, path, 0))) {
-        return INIT_ERR_BUFFER_OVERFLOW();
+    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();
 }
diff --git a/configure.ac b/configure.ac
index d76db66..7cf6519 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5881,7 +5881,7 @@ AC_MSG_RESULT(done)
 # For mingw build need additional library for linking
 case $host in
   *-*-mingw*)
-    LIBS="$LIBS -lversion -lshlwapi -lpathcch"
+    LIBS="$LIBS -lversion -lshlwapi"
     RCFLAGS="$RCFLAGS -O COFF"
     case $host in
       i686*)  RCFLAGS="$RCFLAGS --target=pe-i386" ;;
-- 
2.32.0