#2895: don't crash with bytes as keyword argument names.

Lib/test/test_grammar.py

@@ -265,6 +265,14 @@ class GrammarTests(unittest.TestCase):
         d22v(*(1, 2, 3, 4))
         d22v(1, 2, *(3, 4, 5))
         d22v(1, *(2, 3), **{'d': 4})
+
+        # keyword argument type tests
+        try:
+            str('x', **{b'foo':1 })
+        except TypeError:
+            pass
+        else:
+            self.fail('Bytes should not work as keyword argument names')
         # keyword only argument tests
         def pos0key1(*, key): return key
         pos0key1(key=100)

Misc/NEWS

@@ -12,6 +12,8 @@ What's new in Python 3.0b1?
 Core and Builtins
 -----------------
 
+- Issue 2895: Don't crash when given bytes objects as keyword names.
+
 - Issue 2798: When parsing arguments with PyArg_ParseTuple, the "s" code now
   allows any unicode string and returns a utf-8 encoded buffer, just like the
   "s#" code already does.  The "z" code was corrected as well.

Python/getargs.c

@@ -1532,7 +1532,7 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
 		while (PyDict_Next(keywords, &pos, &key, &value)) {
 			int match = 0;
 			char *ks;
-			if (!PyString_Check(key) && !PyUnicode_Check(key)) {
+			if (!PyUnicode_Check(key)) {
 				PyErr_SetString(PyExc_TypeError,
 					        "keywords must be strings");
 				return cleanreturn(0, freelist);