Remove the special casing of Py_None when converting the return value
of the Python part of a callback function to C. If it cannot be
converted, call PyErr_WriteUnraisable with the exception we got.
Before, arbitrary data has been passed to the calling C code in this
case.
(I'm not really sure the NEWS entry is understandable, but I cannot
find better words)
diff --git a/Lib/ctypes/test/test_as_parameter.py b/Lib/ctypes/test/test_as_parameter.py
index 5716f16..0581059 100644
--- a/Lib/ctypes/test/test_as_parameter.py
+++ b/Lib/ctypes/test/test_as_parameter.py
@@ -61,6 +61,7 @@
def callback(v):
args.append(v)
+ return v
CallBack = CFUNCTYPE(c_int, c_int)
diff --git a/Lib/ctypes/test/test_functions.py b/Lib/ctypes/test/test_functions.py
index bfa0cad..759aea7 100644
--- a/Lib/ctypes/test/test_functions.py
+++ b/Lib/ctypes/test/test_functions.py
@@ -222,6 +222,7 @@
def callback(v):
args.append(v)
+ return v
CallBack = CFUNCTYPE(c_int, c_int)
diff --git a/Misc/NEWS b/Misc/NEWS
index ab40d3d..dc99ff7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -64,6 +64,11 @@
Library
-------
+- If a the Python part of a ctypes callback function returns None,
+ and this cannot be converted to the required C type, an exception is
+ printed with PyErr_WriteUnraisable. Before this change, the C
+ callback did return arbitrary values to the calling code.
+
- The __repr__ method of a NULL ctypes.py_object() no longer raises
an exception.
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index cbe3d03..c8e669a 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -205,7 +205,7 @@
result = PyObject_CallObject(callable, arglist);
CHECK("'calling callback function'", result);
- if ((restype != &ffi_type_void) && result && result != Py_None) {
+ if ((restype != &ffi_type_void) && result) {
PyObject *keep;
assert(setfunc);
#ifdef WORDS_BIGENDIAN