base: callback fixes

base/sources/iron_sys.c

@@ -397,7 +397,9 @@ f32 sys_real_delta(void) {
 static void _sys_run_callbacks(any_array_t *cbs, i32 len) {
 	for (i32 i = 0; i < len; ++i) {
 		callback_t *cb = cbs->buffer[i];
-		cb->f(cb->data);
+		if (cb != NULL) { // Callback may have been removed
+			cb->f(cb->data);
+		}
 	}
 }
 
@@ -459,10 +461,6 @@ void sys_remove_update(void (*f)(void *data)) {
 	_sys_remove_callback(_sys_on_updates, f);
 }
 
-void sys_remove_end_frame(void (*f)(void *data)) {
-	_sys_remove_callback(_sys_on_end_frames, f);
-}
-
 void video_unload(video_t *self) {}
 
 char *sys_buffer_to_string(buffer_t *b) {

base/sources/iron_sys.h

@@ -65,7 +65,6 @@ void sys_notify_on_update(void (*f)(void *data), void *data);
 void sys_notify_on_next_frame(void (*f)(void *data), void *data);
 void sys_notify_on_end_frame(void (*f)(void *data), void *data);
 void sys_remove_update(void (*f)(void *data));
-void sys_remove_end_frame(void (*f)(void *data));
 
 void sys_render(void);
 void sys_foreground(void);