bindings: python: fix segfault when calling Line.request()

When Line.request() is called without the required 'consumer=value'
argument, the module attempts access an empty dictionary object
resulting in a segfault. This patch avoids such access when the
dictionary is empty and maintains the current design where the
LineBulk object is responsible for validation of arguments.

Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

diff --git a/bindings/python/gpiodmodule.c b/bindings/python/gpiodmodule.c
index 00f624b47a47a1c21e2f91e72c9e26342cf3f521..27a8118a90ba04adb5fe7c98e1b5e93b9e978271 100644 (file)
--- a/bindings/python/gpiodmodule.c
+++ b/bindings/python/gpiodmodule.c
@@ -472,8 +472,12 @@ static PyObject *gpiod_Line_request(gpiod_LineObject *self,
        gpiod_LineBulkObject *bulk_obj;
        int rv;
 
-       def_val = PyDict_GetItemString(kwds, "default_val");
-       def_vals = PyDict_GetItemString(kwds, "default_vals");
+       if (PyDict_Size(kwds) > 0) {
+               def_val = PyDict_GetItemString(kwds, "default_val");
+               def_vals = PyDict_GetItemString(kwds, "default_vals");
+       } else {
+               def_val = def_vals = NULL;
+       }
 
        if (def_val && def_vals) {
                PyErr_SetString(PyExc_TypeError,