[retro-gtk/core-fixes: 8/8] core: Check controller in retro_core_set_controller()

[Adrien Plazas <aplazas src gnome org>]

commit dc84f248aad6f4fd3abf65257a35b9fda838e9e6
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sun Feb 16 15:08:47 2020 +0100

    core: Check controller in retro_core_set_controller()
    
    The precondition should be checked to warn of wrong usages.

 retro-gtk/retro-core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/retro-gtk/retro-core.c b/retro-gtk/retro-core.c
index 556dbab..3820dce 100644
--- a/retro-gtk/retro-core.c
+++ b/retro-gtk/retro-core.c
@@ -1668,8 +1668,9 @@ retro_core_set_controller (RetroCore       *self,
   RetroCoreControllerInfo *info;
 
   g_return_if_fail (RETRO_IS_CORE (self));
+  g_return_if_fail (controller == NULL || RETRO_IS_CONTROLLER (controller));
 
-  if (RETRO_IS_CONTROLLER (controller)) {
+  if (controller != NULL) {
     info = g_new0 (RetroCoreControllerInfo, 1);
     gint fd;
     g_autofree gchar *name = NULL;