From 2af6d01fdfce2e3df68887f98fc58fc7b30e5726 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Sat, 25 Jul 2020 17:31:17 +0100
Subject: [PATCH] Add some defensive code for empty polygons.

Fixes https://gitlab.com/kicad/code/kicad/issues/4947
---
 pcbnew/class_pad.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pcbnew/class_pad.cpp b/pcbnew/class_pad.cpp
index 63b398ae43..c7bf625f8e 100644
--- a/pcbnew/class_pad.cpp
+++ b/pcbnew/class_pad.cpp
@@ -801,6 +801,11 @@ bool D_PAD::HitTest( const wxPoint& aPosition, int aAccuracy ) const
 
 bool D_PAD::HitTest( const EDA_RECT& aRect, bool aContained, int aAccuracy ) const
 {
+    auto getArea = []( const SHAPE_POLY_SET& aPoly ) -> double
+                   {
+                       return aPoly.OutlineCount() ? aPoly.COutline( 0 ).Area() : 0;
+                   };
+
     EDA_RECT arect = aRect;
     arect.Normalize();
     arect.Inflate( aAccuracy );
@@ -823,8 +828,8 @@ bool D_PAD::HitTest( const EDA_RECT& aRect, bool aContained, int aAccuracy ) con
 
     selRect.BooleanIntersection( *GetEffectivePolygon(), SHAPE_POLY_SET::PM_FAST );
 
-    double padArea = GetEffectivePolygon()->Outline( 0 ).Area();
-    double intersection = selRect.Outline( 0 ).Area();
+    double padArea = getArea( *GetEffectivePolygon() );
+    double intersection = getArea( selRect );
 
     if( intersection > ( padArea * 0.99 ) )
         return true;