From b1878fcc549685c86d27e8e7a251ae0ee7a9806a Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Sun, 21 Nov 2021 11:03:22 -0500
Subject: [PATCH] ClipVertexRange: fix fallout of NextShape API change

Fixes https://gitlab.com/kicad/code/kicad/-/issues/9711
---
 pcbnew/router/pns_line.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pcbnew/router/pns_line.cpp b/pcbnew/router/pns_line.cpp
index 7b1fefcff0..5447d354f0 100644
--- a/pcbnew/router/pns_line.cpp
+++ b/pcbnew/router/pns_line.cpp
@@ -1079,12 +1079,11 @@ void LINE::ClipVertexRange( int aStart, int aEnd )
      */
     int firstLink = 0;
     int lastLink  = std::max( 0, static_cast<int>( m_links.size() ) - 1 );
-    int arcIdx    = -1;
     int linkIdx   = 0;
 
     int numPoints = static_cast<int>( m_line.PointCount() );
 
-    for( int i = 0; i < m_line.PointCount(); i = m_line.NextShape( i ) )
+    for( int i = 0; i >= 0 && i < m_line.PointCount(); i = m_line.NextShape( i ) )
     {
         if( i <= aStart )
             firstLink = linkIdx;