Consistently save/restore exception indicator when called from C code

Signed-off-by: Simon McVittie <smcv@collabora.com>

3 files changed, 43 insertions, 16 deletions

diff --git a/dbus_bindings/conn-methods.c b/dbus_bindings/conn-methods.c
index 62bdf86..ddd0766 100644
--- a/dbus_bindings/conn-methods.c
+++ b/dbus_bindings/conn-methods.c
@@ -34,9 +34,12 @@ static void
 _object_path_unregister(DBusConnection *conn, void *user_data)
 {
     PyGILState_STATE gil = PyGILState_Ensure();
+    PyObject *et, *ev, *tb;
     PyObject *tuple = NULL;
     Connection *conn_obj = NULL;
-    PyObject *callable;
+    PyObject *callable = NULL;
+
+    PyErr_Fetch(&et, &ev, &tb);
 
     conn_obj = (Connection *)DBusPyConnection_ExistingFromDBusConnection(conn);
     if (!conn_obj) goto out;
@@ -59,13 +62,15 @@ _object_path_unregister(DBusConnection *conn, void *user_data)
         Py_XDECREF(PyObject_CallFunctionObjArgs(callable, conn_obj, NULL));
     }
 out:
+    if (PyErr_Occurred()) {
+        PyErr_WriteUnraisable(callable);
+    }
+
     Py_CLEAR(conn_obj);
     Py_CLEAR(tuple);
     /* the user_data (a Python str) is no longer ref'd by the DBusConnection */
     Py_CLEAR(user_data);
-    if (PyErr_Occurred()) {
-        PyErr_Print();
-    }
+    PyErr_Restore(et, ev, tb);
     PyGILState_Release(gil);
 }
 
@@ -75,10 +80,13 @@ _object_path_message(DBusConnection *conn, DBusMessage *message,
 {
     DBusHandlerResult ret;
     PyGILState_STATE gil = PyGILState_Ensure();
+    PyObject *et, *ev, *tb;
     Connection *conn_obj = NULL;
     PyObject *tuple = NULL;
     PyObject *msg_obj;
-    PyObject *callable;             /* borrowed */
+    PyObject *callable = NULL;      /* borrowed */
+
+    PyErr_Fetch(&et, &ev, &tb);
 
     dbus_message_ref(message);
     msg_obj = DBusPyMessage_ConsumeDBusMessage(message);
@@ -123,12 +131,14 @@ _object_path_message(DBusConnection *conn, DBusMessage *message,
     }
 
 out:
+    if (PyErr_Occurred()) {
+        PyErr_WriteUnraisable(callable);
+    }
+
     Py_CLEAR(msg_obj);
     Py_CLEAR(conn_obj);
     Py_CLEAR(tuple);
-    if (PyErr_Occurred()) {
-        PyErr_Print();
-    }
+    PyErr_Restore(et, ev, tb);
     PyGILState_Release(gil);
     return ret;
 }
@@ -143,6 +153,7 @@ _filter_message(DBusConnection *conn, DBusMessage *message, void *user_data)
 {
     DBusHandlerResult ret;
     PyGILState_STATE gil = PyGILState_Ensure();
+    PyObject *et, *ev, *tb;
     Connection *conn_obj = NULL;
     PyObject *callable = NULL;
     PyObject *msg_obj;
@@ -150,6 +161,8 @@ _filter_message(DBusConnection *conn, DBusMessage *message, void *user_data)
     Py_ssize_t i, size;
 #endif
 
+    PyErr_Fetch(&et, &ev, &tb);
+
     dbus_message_ref(message);
     msg_obj = DBusPyMessage_ConsumeDBusMessage(message);
     if (!msg_obj) {
@@ -201,9 +214,14 @@ _filter_message(DBusConnection *conn, DBusMessage *message, void *user_data)
 
     ret = DBusPyConnection_HandleMessage(conn_obj, msg_obj, callable);
 out:
+    if (PyErr_Occurred()) {
+        PyErr_WriteUnraisable(callable);
+    }
+
     Py_CLEAR(msg_obj);
     Py_CLEAR(conn_obj);
     Py_CLEAR(callable);
+    PyErr_Restore(et, ev, tb);
     PyGILState_Release(gil);
     return ret;
 }
diff --git a/dbus_bindings/pending-call.c b/dbus_bindings/pending-call.c
index 636095f..50b2998 100644
--- a/dbus_bindings/pending-call.c
+++ b/dbus_bindings/pending-call.c
@@ -79,15 +79,20 @@ _pending_call_notify_function(DBusPendingCall *pc,
                               PyObject *list)
 {
     PyGILState_STATE gil = PyGILState_Ensure();
+    PyObject *et, *ev, *tb;
+    PyObject *handler;
+    DBusMessage *msg;
+
+    PyErr_Fetch(&et, &ev, &tb);
+
     /* BEGIN CRITICAL SECTION
      * While holding the GIL, make sure the callback only gets called once
      * by deleting it from the 1-item list that's held by libdbus.
      */
-    PyObject *handler = PyList_GetItem(list, 0);
-    DBusMessage *msg;
+    handler = PyList_GetItem(list, 0);
 
     if (!handler) {
-        PyErr_Print();
+        PyErr_WriteUnraisable(list);
         goto release;
     }
     if (handler == Py_None) {
@@ -113,7 +118,7 @@ _pending_call_notify_function(DBusPendingCall *pc,
             PyObject *ret = PyObject_CallFunctionObjArgs(handler, msg_obj, NULL);
 
             if (!ret) {
-                PyErr_Print();
+                PyErr_WriteUnraisable(handler);
             }
             Py_CLEAR(ret);
             Py_CLEAR(msg_obj);
@@ -124,6 +129,7 @@ _pending_call_notify_function(DBusPendingCall *pc,
 
 release:
     Py_CLEAR(handler);
+    PyErr_Restore(et, ev, tb);
     PyGILState_Release(gil);
 }
 
diff --git a/dbus_bindings/server.c b/dbus_bindings/server.c
index dfbfa53..2080d6b 100644
--- a/dbus_bindings/server.c
+++ b/dbus_bindings/server.c
@@ -190,9 +190,12 @@ DBusPyServer_new_connection_cb(DBusServer *server,
                                void *data UNUSED)
 {
     PyGILState_STATE gil = PyGILState_Ensure();
+    PyObject *et, *ev, *tb;
     PyObject *self = NULL;
     PyObject *method = NULL;
 
+    PyErr_Fetch(&et, &ev, &tb);
+
     self = DBusPyServer_ExistingFromDBusServer(server);
     if (!self) goto out;
     TRACE(self);
@@ -224,12 +227,12 @@ DBusPyServer_new_connection_cb(DBusServer *server,
     }
 
 out:
-    Py_CLEAR(method);
-    Py_CLEAR(self);
-
     if (PyErr_Occurred())
-        PyErr_Print();
+        PyErr_WriteUnraisable(method);
 
+    Py_CLEAR(self);
+    Py_CLEAR(method);
+    PyErr_Restore(et, ev, tb);
     PyGILState_Release(gil);
 }