From 5a33772f4141e44b96810596cf341a297381fda6 Mon Sep 17 00:00:00 2001
From: jean-pierre charras <jp.charras@wanadoo.fr>
Date: Thu, 6 Aug 2020 16:11:55 +0200
Subject: [PATCH] Pcbnew: avoid crash when saving a board having "orphan" nets.
 Sometimes tracks or zones can have "orphan" nets no longer existing in
 schematic after updating the board from the schematic (no pad belonging this
 net).

The fix does not save these broken nets having no info (no netname, no valid netcode)

Fixes #5087
https://gitlab.com/kicad/code/kicad/issues/5087
---
 pcbnew/kicad_plugin.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pcbnew/kicad_plugin.cpp b/pcbnew/kicad_plugin.cpp
index d617a81e7e..6686ae849b 100644
--- a/pcbnew/kicad_plugin.cpp
+++ b/pcbnew/kicad_plugin.cpp
@@ -579,6 +579,9 @@ void PCB_IO::formatNetInformation( BOARD* aBoard, int aNestLevel ) const
 {
     for( NETINFO_ITEM* net : *m_mapping )
     {
+        if( net == nullptr )    // Skip not actually existing nets (orphan nets)
+            continue;
+
         m_out->Print( aNestLevel, "(net %d %s)\n",
                                   m_mapping->Translate( net->GetNet() ),
                                   m_out->Quotew( net->GetNetname() ).c_str() );