Do not accept str8 type in function calls any longer.

Accept bytes instead of str8 in the (unexposed in ctypes) BSTR type.

Lib/ctypes/test/test_bytes.py

 """Test where byte objects are accepted"""
 import unittest
+import sys
 from ctypes import *
 
 class BytesTest(unittest.TestCase):
@@ -37,5 +38,14 @@ class BytesTest(unittest.TestCase):
         X("abc")
         X(b"abc")
 
+    if sys.platform == "win32":
+        def test_BSTR(self):
+            from _ctypes import _SimpleCData
+            class BSTR(_SimpleCData):
+                _type_ = "X"
+
+            BSTR("abc")
+            BSTR(b"abc")
+
 if __name__ == '__main__':
     unittest.main()

Modules/_ctypes/callproc.c

@@ -507,15 +507,6 @@ static int ConvParam(PyObject *obj, Py_ssize_t index, struct argument *pa)
 		return 0;
 	}
 
-	/* XXX struni remove later */
-	if (PyString_Check(obj)) {
-		pa->ffi_type = &ffi_type_pointer;
-		pa->value.p = PyString_AS_STRING(obj);
-		Py_INCREF(obj);
-		pa->keep = obj;
-		return 0;
-	}
-
 	if (PyBytes_Check(obj)) {
 		pa->ffi_type = &ffi_type_pointer;
 		pa->value.p = PyBytes_AsString(obj);

Modules/_ctypes/cfield.c

@@ -1501,7 +1501,7 @@ BSTR_set(void *ptr, PyObject *value, Py_ssize_t size)
 	/* convert value into a PyUnicodeObject or NULL */
 	if (Py_None == value) {
 		value = NULL;
-	} else if (PyString_Check(value)) {
+	} else if (PyBytes_Check(value)) {
 		value = PyUnicode_FromEncodedObject(value,
 						    conversion_mode_encoding,
 						    conversion_mode_errors);