[gnome-games] savestates-list: Add a type check in select_savestate_row()

[Alexander Mikhaylenko <alexm src gnome org>]

commit 24a5afbbf22596b91db680f891ce3165a21ff28c
Author: Yetizone <andreii lisita gmail com>
Date:   Fri Aug 16 16:00:39 2019 +0300

    savestates-list: Add a type check in select_savestate_row()

 src/ui/savestates-list.vala | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/ui/savestates-list.vala b/src/ui/savestates-list.vala
index 64b02758..6790d3ca 100644
--- a/src/ui/savestates-list.vala
+++ b/src/ui/savestates-list.vala
@@ -269,6 +269,9 @@ private class Games.SavestatesList : Gtk.Box {
                        state.selected_savestate = null;
                }
                else {
+                       if (!(row is SavestateListBoxRow))
+                               return;
+
                        var savestate_row = row as SavestateListBoxRow;
                        var savestate = savestate_row.savestate;