give TypeError when trying to set T_STRING_INPLACE

Lib/test/test_structmembers.py

@@ -9,7 +9,7 @@ import unittest
 from test import test_support
 
 ts=test_structmembersType(False, 1, 2, 3, 4, 5, 6, 7, 8,
-                          9.99999, 10.1010101010)
+                          9.99999, 10.1010101010, "hi")
 
 class ReadWriteTests(unittest.TestCase):
 
@@ -68,6 +68,11 @@ class ReadWriteTests(unittest.TestCase):
         ts.T_ULONGLONG = 4
         self.assertEquals(ts.T_ULONGLONG, 4)
 
+    def test_inplace_string(self):
+        self.assertEquals(ts.T_STRING_INPLACE, "hi")
+        self.assertRaises(TypeError, setattr, ts, "T_STRING_INPLACE", "s")
+        self.assertRaises(TypeError, delattr, ts, "T_STRING_INPLACE")
+
 
 class TestWarnings(unittest.TestCase):
 

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.7 beta 1?
 Core and Builtins
 -----------------
 
+- Raise a TypeError when trying to delete a T_STRING_INPLACE struct member.
+
 - Issue #7994: Issue a PendingDeprecationWarning if object.__format__
   is called with a non-empty format string. This is an effort to
   future-proof user code. If a derived class does not currently

Modules/_testcapimodule.c

@@ -1712,6 +1712,7 @@ typedef struct {
 	unsigned long ulong_member;
 	float float_member;
 	double double_member;
+	char inplace_member[5];
 #ifdef HAVE_LONG_LONG
 	PY_LONG_LONG longlong_member;
 	unsigned PY_LONG_LONG ulonglong_member;
@@ -1735,6 +1736,7 @@ static struct PyMemberDef test_members[] = {
 	{"T_ULONG", T_ULONG, offsetof(test_structmembers, structmembers.ulong_member), 0, NULL},
 	{"T_FLOAT", T_FLOAT, offsetof(test_structmembers, structmembers.float_member), 0, NULL},
 	{"T_DOUBLE", T_DOUBLE, offsetof(test_structmembers, structmembers.double_member), 0, NULL},
+	{"T_STRING_INPLACE", T_STRING_INPLACE, offsetof(test_structmembers, structmembers.inplace_member), 0, NULL},
 #ifdef HAVE_LONG_LONG
 	{"T_LONGLONG", T_LONGLONG, offsetof(test_structmembers, structmembers.longlong_member), 0, NULL},
 	{"T_ULONGLONG", T_ULONGLONG, offsetof(test_structmembers, structmembers.ulonglong_member), 0, NULL},
@@ -1749,17 +1751,19 @@ test_structmembers_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 	static char *keywords[] = {
 		"T_BOOL", "T_BYTE", "T_UBYTE", "T_SHORT", "T_USHORT",
 		"T_INT", "T_UINT", "T_LONG", "T_ULONG",
-		"T_FLOAT", "T_DOUBLE",
+		"T_FLOAT", "T_DOUBLE", "T_INPLACE_STRING",
 #ifdef HAVE_LONG_LONG	
 		"T_LONGLONG", "T_ULONGLONG",
 #endif
 		NULL};
-	static char *fmt = "|bbBhHiIlkfd"
+	static char *fmt = "|bbBhHiIlkfds#"
 #ifdef HAVE_LONG_LONG
 		"LK"
 #endif
 		;
 	test_structmembers *ob;
+	const char *s;
+	Py_ssize_t string_len = 0;
 	ob = PyObject_New(test_structmembers, type);
 	if (ob == NULL)
 		return NULL;
@@ -1775,7 +1779,8 @@ test_structmembers_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 					 &ob->structmembers.long_member,
 					 &ob->structmembers.ulong_member,
 					 &ob->structmembers.float_member,
-					 &ob->structmembers.double_member
+					 &ob->structmembers.double_member,
+					 &s, &string_len
 #ifdef HAVE_LONG_LONG
 					 , &ob->structmembers.longlong_member,
 					 &ob->structmembers.ulonglong_member
@@ -1784,6 +1789,12 @@ test_structmembers_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 		Py_DECREF(ob);
 		return NULL;
 	}
+	if (string_len > 5) {
+		Py_DECREF(ob);
+		PyErr_SetString(PyExc_ValueError, "string too long");
+		return NULL;
+	}
+	strcpy(ob->structmembers.inplace_member, s);
 	return (PyObject *)ob;
 }
 

Python/structmember.c

@@ -172,7 +172,7 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
 
 	addr += l->offset;
 
-	if ((l->flags & READONLY) || l->type == T_STRING)
+	if ((l->flags & READONLY))
 	{
 		PyErr_SetString(PyExc_TypeError, "readonly attribute");
 		return -1;
@@ -329,6 +329,10 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
 			return -1;
 		}
 		break;
+	case T_STRING:
+        case T_STRING_INPLACE:
+		PyErr_SetString(PyExc_TypeError, "readonly attribute");
+		return -1;
 #ifdef HAVE_LONG_LONG
 	case T_LONGLONG:{
 		PY_LONG_LONG value;