cast bytes to char* first, then to wchar_t

py_gd/py_gd.pyx

@@ -79,10 +79,11 @@ cdef FILE* open_file(file_path) except *:
 
     IF UNAME_SYSNAME == 'Windows':
         # convert pystring to wchar
-        cdef wchar_t* windows_filename
-        cdef wchar_t* flag = <wchar_t*> "wb".encode('utf-16')
-        windows_filename = <wchar_t*> file_path.encode('utf-16')
-        fp = _wfopen(windows_filename, flag)
+        # doing in two steps -- neccesary? it seems so.
+        # (Cython knows how to cast a bytes to a char*)
+        cdef char* windows_filename = file_path.encode('utf-16')
+        cdef char* flag = "wb".encode('utf-16')
+        fp = _wfopen(<wchar_t*> windows_filename, <wchar_t*> flag)
     ELSE:
         fp = fopen(file_path.encode('utf-8'), 'wb')