fix compilation for Python3.12

src/ctypes.pxd

@@ -11,6 +11,7 @@ from libc.stddef cimport wchar_t
 from libcpp.list cimport list
 from libcpp.map cimport map
 from libcpp.string cimport string
+from cpython.mem cimport PyMem_Free
 
 
 cdef extern from 'taglib/tstring.h' namespace 'TagLib::String':
@@ -62,10 +63,22 @@ cdef extern from 'taglib/tfile.h' namespace 'TagLib':
 
 cdef extern from 'taglib/fileref.h' namespace 'TagLib::FileRef':
     IF UNAME_SYSNAME == "Windows":
-        cdef File* create(const Py_UNICODE*) except +
+        cdef File* create(const wchar_t*) except +
     ELSE:
         cdef File* create(const char*) except +
 
+cdef extern from "Python.h":
+    IF UNAME_SYSNAME == "Windows":
+        cdef wchar_t *PyUnicode_AsWideCharString(char *path, Py_ssize_t *size)
+
+cdef inline File* create_wrapper(unicode path):
+    IF UNAME_SYSNAME == "Windows":
+        cdef wchar_t *wchar_path = PyUnicode_AsWideCharString(path, NULL)
+        cdef File* file = create(wchar_path)
+        PyMem_Free(wchar_path)
+        return file
+    ELSE:
+        return create(path.encode('utf-8'))
 
 cdef extern from 'taglib/taglib.h':
     int TAGLIB_MAJOR_VERSION

src/taglib.pyx

@@ -40,6 +40,7 @@ cdef dict propertyMapToDict(ctypes.PropertyMap map):
     return dct
 
 
+
 cdef class File:
     """Class representing an audio file with metadata ("tags").
     
@@ -80,12 +81,7 @@ cdef class File:
                 path = path.decode('utf8')
             path = Path(path)
         self.path = path
-        IF UNAME_SYSNAME == "Windows":
-            # create on windows takes wchar_t* which Cython automatically converts to
-            # from unicode strings
-            self.cFile = ctypes.create(str(self.path))
-        ELSE:
-            self.cFile = ctypes.create(str(self.path).encode('utf8'))
+        self.cFile = ctypes.create_wrapper(str(self.path))
         if not self.cFile or not self.cFile.isValid():
             raise OSError(f'Could not read file {path}')