From 9baa649389881043919c748192d9ad1461c7234a Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 30 Oct 2020 16:44:56 +0100
Subject: [PATCH] LibGUI: Fix null parent deref in
 AbstractButton::set_checked()

If a button is orphaned, there are no siblings anyway, so there's no
need to try to update them.
---
 Libraries/LibGUI/AbstractButton.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Libraries/LibGUI/AbstractButton.cpp b/Libraries/LibGUI/AbstractButton.cpp
index 02e66e20b5..d4fba8c293 100644
--- a/Libraries/LibGUI/AbstractButton.cpp
+++ b/Libraries/LibGUI/AbstractButton.cpp
@@ -68,7 +68,7 @@ void AbstractButton::set_checked(bool checked)
         return;
     m_checked = checked;
 
-    if (is_exclusive() && checked) {
+    if (is_exclusive() && checked && parent_widget()) {
         parent_widget()->for_each_child_of_type<AbstractButton>([&](auto& sibling) {
             if (!sibling.is_exclusive() || !sibling.is_checked())
                 return IterationDecision::Continue;