From 311cde098498f38e740b5344e6a1b57bff71cb1f Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Mon, 12 Apr 2021 20:42:50 -0400
Subject: [PATCH] Safety check suggested by Coverity

---
 pcbnew/router/pns_line.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pcbnew/router/pns_line.cpp b/pcbnew/router/pns_line.cpp
index 254340a72c..97cb189070 100644
--- a/pcbnew/router/pns_line.cpp
+++ b/pcbnew/router/pns_line.cpp
@@ -613,6 +613,8 @@ void LINE::dragCornerFree( const VECTOR2I& aP, int aIndex )
 
 void LINE::DragCorner( const VECTOR2I& aP, int aIndex, bool aFreeAngle )
 {
+    wxCHECK_RET( aIndex >= 0, "Negative index passed to LINE::DragCorner" );
+
     if( aFreeAngle )
     {
         dragCornerFree( aP, aIndex );