From 7dca3ebc97661da9fe2945b9c65d58c234d10629 Mon Sep 17 00:00:00 2001
From: Thomas Heller <theller@ctypes.org>
Date: Thu, 29 May 2008 19:54:39 +0000
Subject: [PATCH] Merged revisions 63791-63792 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/trunk

........
  r63791 | thomas.heller | 2008-05-29 21:18:12 +0200 (Do, 29 Mai 2008) | 1 line

  Fix compiler warning.
........
  r63792 | thomas.heller | 2008-05-29 21:42:34 +0200 (Do, 29 Mai 2008) | 1 line

  ctypes NULL function pointers have a boolean False value now.
........
---
 Lib/ctypes/test/test_pointers.py |  8 ++++++
 Modules/_ctypes/_ctypes.c        | 42 ++++++++++++++++----------------
 2 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/Lib/ctypes/test/test_pointers.py b/Lib/ctypes/test/test_pointers.py
index df62d04675b..05b180e62ac 100644
--- a/Lib/ctypes/test/test_pointers.py
+++ b/Lib/ctypes/test/test_pointers.py
@@ -175,5 +175,13 @@ class PointersTestCase(unittest.TestCase):
         self.assertRaises(TypeError, c_void_p, 3.14) # make sure floats are NOT accepted
         self.assertRaises(TypeError, c_void_p, object()) # nor other objects
 
+    def test_pointers_bool(self):
+        # NULL pointers have a boolean False value, non-NULL pointers True.
+        self.failUnlessEqual(bool(POINTER(c_int)()), False)
+        self.failUnlessEqual(bool(pointer(c_int())), True)
+
+        self.failUnlessEqual(bool(CFUNCTYPE(None)(0)), False)
+        self.failUnlessEqual(bool(CFUNCTYPE(None)(42)), True)
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index fe332533a7a..b652319290b 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -474,7 +474,7 @@ GenericCData_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
 static PyObject *
 CDataType_from_buffer_copy(PyObject *type, PyObject *args)
 {
-	void *buffer;
+	const void *buffer;
 	Py_ssize_t buffer_len;
 	Py_ssize_t offset = 0;
 	PyObject *obj, *result;
@@ -3849,6 +3849,25 @@ CFuncPtr_repr(CFuncPtrObject *self)
 				   self);
 }
 
+static int
+Pointer_bool(CDataObject *self)
+{
+	return *(void **)self->b_ptr != NULL;
+}
+
+static PyNumberMethods Pointer_as_number = {
+	0, /* nb_add */
+	0, /* nb_subtract */
+	0, /* nb_multiply */
+	0, /* nb_remainder */
+	0, /* nb_divmod */
+	0, /* nb_power */
+	0, /* nb_negative */
+	0, /* nb_positive */
+	0, /* nb_absolute */
+	(inquiry)Pointer_bool, /* nb_bool */
+};
+
 PyTypeObject CFuncPtr_Type = {
 	PyVarObject_HEAD_INIT(NULL, 0)
 	"_ctypes.CFuncPtr",
@@ -3860,7 +3879,7 @@ PyTypeObject CFuncPtr_Type = {
 	0,					/* tp_setattr */
 	0,					/* tp_compare */
 	(reprfunc)CFuncPtr_repr,		/* tp_repr */
-	0,					/* tp_as_number */
+	&Pointer_as_number,			/* tp_as_number */
 	0,					/* tp_as_sequence */
 	0,					/* tp_as_mapping */
 	0,					/* tp_hash */
@@ -4933,25 +4952,6 @@ static PyMappingMethods Pointer_as_mapping = {
 	Pointer_subscript,
 };
 
-static int
-Pointer_bool(CDataObject *self)
-{
-	return *(void **)self->b_ptr != NULL;
-}
-
-static PyNumberMethods Pointer_as_number = {
-	0, /* nb_add */
-	0, /* nb_subtract */
-	0, /* nb_multiply */
-	0, /* nb_remainder */
-	0, /* nb_divmod */
-	0, /* nb_power */
-	0, /* nb_negative */
-	0, /* nb_positive */
-	0, /* nb_absolute */
-	(inquiry)Pointer_bool, /* nb_bool */
-};
-
 PyTypeObject Pointer_Type = {
 	PyVarObject_HEAD_INIT(NULL, 0)
 	"_ctypes._Pointer",