Segfault fixes. Switching scenes broke some assumptions. All PyObject calls from userspace now handle (discard) exceptions and return values.

src/GameEngine.cpp

@@ -162,7 +162,16 @@ void GameEngine::sUserInput()
         else if (currentScene()->key_callable != NULL && currentScene()->key_callable != Py_None)
         {
             PyObject* args = Py_BuildValue("(ss)", ActionCode::key_str(event.key.code).c_str(), actionType.c_str());
-            PyObject_Call(currentScene()->key_callable, args, NULL);
+            PyObject* retval = PyObject_Call(currentScene()->key_callable, args, NULL);
+            if (!retval)
+            {   
+                std::cout << "key_callable has raised an exception. It's going to STDERR and being dropped:" << std::endl;
+                PyErr_Print();
+                PyErr_Clear();
+            } else if (retval != Py_None)
+            {   
+                std::cout << "key_callable returned a non-None value. It's not an error, it's just not being saved or used." << std::endl;
+            }
         }
         else
         {

src/McRFPy_API.cpp

@@ -240,7 +240,16 @@ void McRFPy_API::doAction(std::string actionstr) {
         return;
     }
     //std::cout << " (" << PyUnicode_AsUTF8(PyObject_Repr(callbacks[actionstr])) << ")" << std::endl;
-    PyObject_Call(callbacks[actionstr], PyTuple_New(0), NULL);
+    PyObject* retval = PyObject_Call(callbacks[actionstr], PyTuple_New(0), NULL);
+    if (!retval)
+    {
+        std::cout << "doAction has raised an exception. It's going to STDERR and being dropped:" << std::endl;
+        PyErr_Print();
+        PyErr_Clear();
+    } else if (retval != Py_None)
+    {
+        std::cout << "doAction returned a non-None value. It's not an error, it's just not being saved or used." << std::endl;
+    }
 }
 
 /*

src/PyScene.cpp

@@ -27,7 +27,16 @@ void PyScene::do_mouse_input(std::string button, std::string type)
         if (target)
         {
             PyObject* args = Py_BuildValue("(iiss)", mousepos.x, mousepos.y, button.c_str(), type.c_str());
-            PyObject_Call(target->click_callable, args, NULL);
+            PyObject* retval = PyObject_Call(target->click_callable, args, NULL);
+            if (!retval)
+            {   
+                std::cout << "click_callable has raised an exception. It's going to STDERR and being dropped:" << std::endl;
+                PyErr_Print();
+                PyErr_Clear();
+            } else if (retval != Py_None)
+            {   
+                std::cout << "click_callable returned a non-None value. It's not an error, it's just not being saved or used." << std::endl;
+            }
         }
     }
 }

src/Scene.cpp

@@ -4,6 +4,7 @@
 //Scene::Scene() { game = 0; std::cout << "WARN: default Scene constructor called. (game = " << game << ")" << std::endl;};
 Scene::Scene(GameEngine* g)
 {
+    key_callable = Py_None;
     game = g; 
     ui_elements = std::make_shared<std::vector<std::shared_ptr<UIDrawable>>>();
 }

src/Timer.cpp

@@ -15,7 +15,16 @@ bool Timer::test(int now)
     {
         last_ran = now;
         PyObject* args = Py_BuildValue("(i)", now);
-        PyObject_Call(target, args, NULL);
+        PyObject* retval = PyObject_Call(target, args, NULL);
+        if (!retval)
+        {   
+            std::cout << "timer has raised an exception. It's going to STDERR and being dropped:" << std::endl;
+            PyErr_Print();
+            PyErr_Clear();
+        } else if (retval != Py_None)
+        {   
+            std::cout << "timer returned a non-None value. It's not an error, it's just not being saved or used." << std::endl;
+        }
         return true;
     }
     return false;