From dc2ecf35f8608a8b38ac4563a3cd0f40188f4799 Mon Sep 17 00:00:00 2001
From: "R. Timothy Edwards" <tim@opencircuitdesign.com>
Date: Wed, 1 Jul 2026 11:53:47 -0400
Subject: [PATCH] Corrected a crash condition in extresist where ResNodeList is
 not checked for being NULL before inserting a new node at the front of it.

---
 VERSION          | 2 +-
 resis/ResMerge.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/VERSION b/VERSION
index ed183db6..5743627f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.668
+8.3.669
diff --git a/resis/ResMerge.c b/resis/ResMerge.c
index 79463d89..0dac96a9 100644
--- a/resis/ResMerge.c
+++ b/resis/ResMerge.c
@@ -645,7 +645,7 @@ ResTriangleCheck(resptr)
 
 		    n3->rn_less = NULL;
 		    n3->rn_more = ResNodeList;
-		    ResNodeList->rn_less = n3;
+		    if (ResNodeList != NULL) ResNodeList->rn_less = n3;
 		    ResNodeList = n3;
 		    if (resptr == rr1->rr_connection1)
 		    {
@@ -780,7 +780,7 @@ ResTriangleCheck(resptr)
 
 		n3->rn_less = NULL;
 		n3->rn_more = ResNodeList;
-		ResNodeList->rn_less = n3;
+		if (ResNodeList != NULL) ResNodeList->rn_less = n3;
 		ResNodeList = n3;
 		if (resptr == rr1->rr_connection1)
 		{