[gnome-software] Add more assertions when setting GsApp properties

[Robert Ancell <rancell src gnome org>]

commit 45b25631e14ea51c4f44d9a2ab3185991ef656e5
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue May 15 15:35:00 2018 +1200

    Add more assertions when setting GsApp properties

 lib/gs-app.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/lib/gs-app.c b/lib/gs-app.c
index 3dde87c8..0cdfe5bc 100644
--- a/lib/gs-app.c
+++ b/lib/gs-app.c
@@ -1544,6 +1544,7 @@ gs_app_add_source_id (GsApp *app, const gchar *source_id)
        guint i;
 
        g_return_if_fail (GS_IS_APP (app));
+       g_return_if_fail (source_id != NULL);
 
        /* only add if not already present */
        for (i = 0; i < priv->source_ids->len; i++) {
@@ -3391,6 +3392,7 @@ gs_app_add_related (GsApp *app, GsApp *app2)
        g_autoptr(GMutexLocker) locker = NULL;
 
        g_return_if_fail (GS_IS_APP (app));
+       g_return_if_fail (GS_IS_APP (app2));
 
        locker = g_mutex_locker_new (&priv->mutex);
 
@@ -3447,6 +3449,7 @@ gs_app_add_history (GsApp *app, GsApp *app2)
        GsAppPrivate *priv = gs_app_get_instance_private (app);
        g_autoptr(GMutexLocker) locker = NULL;
        g_return_if_fail (GS_IS_APP (app));
+       g_return_if_fail (GS_IS_APP (app2));
        locker = g_mutex_locker_new (&priv->mutex);
        g_ptr_array_add (priv->history, g_object_ref (app2));
 }