From f61e1f212379f581daadaff8fc10107b8f9849f5 Mon Sep 17 00:00:00 2001
From: couriersud <couriersud@gmx.org>
Date: Thu, 2 Feb 2017 01:51:46 +0100
Subject: [PATCH] Fix a bug in pstring.cpp causing crash if moved object is
 reused. (nw)

---
 src/lib/netlist/plib/pstring.cpp | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/lib/netlist/plib/pstring.cpp b/src/lib/netlist/plib/pstring.cpp
index baeace1edb9..3369f23b6e2 100644
--- a/src/lib/netlist/plib/pstring.cpp
+++ b/src/lib/netlist/plib/pstring.cpp
@@ -415,16 +415,19 @@ static inline std::size_t countleadbits(std::size_t x)
 template<typename F>
 void pstring_t<F>::sfree(pstr_t *s)
 {
-	bool b = s->dec_and_check();
-	if ( b && s != &m_zero)
+	if (s != nullptr)
 	{
-		if (stk != nullptr)
+		bool b = s->dec_and_check();
+		if ( b && s != &m_zero)
 		{
-			size_type sn= ((32 - countleadbits(s->len())) + 1) / 2;
-			stk[sn].push(s);
+			if (stk != nullptr)
+			{
+				size_type sn= ((32 - countleadbits(s->len())) + 1) / 2;
+				stk[sn].push(s);
+			}
+			else
+				plib::pfree_array(reinterpret_cast<char *>(s));
 		}
-		else
-			plib::pfree_array(reinterpret_cast<char *>(s));
 	}
 }