From 97dea6ede51deb9ee818fa00a0f32defd76a12c3 Mon Sep 17 00:00:00 2001
From: jean-pierre charras <jp.charras@wanadoo.fr>
Date: Thu, 7 May 2020 09:55:13 +0200
Subject: [PATCH] Gerbview: Fix a crash Don't try to close an empty polygon on
 G37 command. Can happens with malformed Gerber files. From Master, commit
 528ebf8.

---
 gerbview/rs274d.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gerbview/rs274d.cpp b/gerbview/rs274d.cpp
index 7c7629ec5e..210c562408 100644
--- a/gerbview/rs274d.cpp
+++ b/gerbview/rs274d.cpp
@@ -554,7 +554,10 @@ bool GERBER_FILE_IMAGE::Execute_G_Command( char*& text, int G_command )
         if( m_Exposure && GetItemsList() )    // End of polygon
         {
             GERBER_DRAW_ITEM * gbritem = m_Drawings.GetLast();
-            gbritem->m_Polygon.Append( gbritem->m_Polygon.Vertex( 0 ) );
+
+            if( gbritem->m_Polygon.VertexCount() )
+                gbritem->m_Polygon.Append( gbritem->m_Polygon.Vertex( 0 ) );
+
             StepAndRepeatItem( *gbritem );
         }
         m_Exposure = false;