Replace _PyUnicode_AsString with PyUnicode_AsUTF8

Author: Avasam

CHANGES.txt

@@ -1,4 +1,4 @@
-Notable changes in recent builds.
+Notable changes in recent builds.
 
 Maintained by hand, so what's "notable" is subjective! Contributors are
 encouraged to add entries for their work.
@@ -17,7 +17,7 @@ Coming in build 311, as yet unreleased
 * Fixed `TypeError: cannot unpack non-iterable NoneType object` when registering an axscript client ScriptItem (#2513, @Avasam)
 * Fixed a memory leak when SafeArrays are used as out parameters (@the-snork)
 * Fixed dispatch handling for properties (@the-snork)
-* Resolved a handful of deprecation warnings (#2567, #2576, @Avasam)
+* Resolved a handful of deprecation warnings (#2567, #2576, #2591, @Avasam)
 * The following classes now produce a valid `eval` string representation when calling `repr`: (#2573, @Avasam)
   * `pywin.tools.browser.HLIPythonObject`
   * `win32com.server.exception.COMException`

win32/src/PyWinTypes.h

@@ -52,12 +52,8 @@
 // Macro to handle PyObject layout changes in Py3k
 #define PYWIN_OBJECT_HEAD PyVarObject_HEAD_INIT(NULL, 0)
 
-/* Attribute names are passed as Unicode in Py3k, so use a macro to
-    switch between string and unicode conversion.  This function is not
-    documented, but is used extensively in the Python codebase itself,
-    so it's reasonable to assume it won't disappear anytime soon.
-*/
-#define PYWIN_ATTR_CONVERT (char *)_PyUnicode_AsString
+// This macro is kept for legacy reason as it's casting from `const char *` to `char *`
+#define PYWIN_ATTR_CONVERT (char *)PyUnicode_AsUTF8
 
 typedef Py_ssize_t Py_hash_t;