From f493f7d480610aff6ad90119c0265dec5636a592 Mon Sep 17 00:00:00 2001
From: Markus Gans <guru@server.home.net>
Date: Sun, 21 Aug 2016 22:47:45 +0200
Subject: [PATCH] Fix: Dereference of null pointer in FButtonGroup

---
 src/fbuttongroup.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/fbuttongroup.cpp b/src/fbuttongroup.cpp
index 3beababc..997cdaa6 100644
--- a/src/fbuttongroup.cpp
+++ b/src/fbuttongroup.cpp
@@ -70,6 +70,9 @@ void FButtonGroup::init()
 //----------------------------------------------------------------------
 bool FButtonGroup::isRadioButton(FToggleButton* button) const
 {
+  if ( ! button )
+    return false;
+
   return bool ( strcmp ( button->getClassName()
                        , const_cast<char*>("FRadioButton") ) == 0 );
 }
@@ -333,7 +336,10 @@ void FButtonGroup::hide()
 //----------------------------------------------------------------------
 void FButtonGroup::insert (FToggleButton* button)
 {
-  if ( button && button->group() )
+  if ( ! button )
+    return;
+
+  if ( button->group() )
     button->group()->remove(button);
 
   // setChecked the first FRadioButton
@@ -355,7 +361,7 @@ void FButtonGroup::remove (FToggleButton* button)
 {
   FButtonGroup::FButtonList::iterator iter;
 
-  if ( buttonlist.empty() )
+  if ( ! button || buttonlist.empty() )
     return;
 
   iter = buttonlist.begin();