From df830dab4cf9d010204234843138fe5db2463838 Mon Sep 17 00:00:00 2001
From: jean-pierre charras <jp.charras@wanadoo.fr>
Date: Wed, 27 Sep 2017 18:56:06 +0200
Subject: [PATCH] Add comments and a comment asking to fix a call to a GUI
 inside a io plugin, that is not allowed

---
 pcbnew/pcb_parser.cpp | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/pcbnew/pcb_parser.cpp b/pcbnew/pcb_parser.cpp
index b867490440..dfcc790dc9 100644
--- a/pcbnew/pcb_parser.cpp
+++ b/pcbnew/pcb_parser.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2012 CERN
- * Copyright (C) 2012-2016 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2012-2017 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -2820,15 +2820,16 @@ ZONE_CONTAINER* PCB_PARSER::parseZONE_CONTAINER()
             NeedRIGHT();
             break;
 
-        case T_layer:
+        case T_layer:   // keyword for zones that are on only one layer
             zone->SetLayer( parseBoardItemLayer() );
             NeedRIGHT();
             break;
 
-        case T_layers:
-            zone->SetLayerSet( parseBoardItemLayersAsMask() );
-            break;
-
+        case T_layers:  // keyword for zones that can live on a set of layer
+                        // currently: keepout zones
+            zone->SetLayerSet( parseBoardItemLayersAsMask() );
+            break;
+
         case T_tstamp:
             zone->SetTimeStamp( parseHex() );
             NeedRIGHT();
@@ -3079,7 +3080,7 @@ ZONE_CONTAINER* PCB_PARSER::parseZONE_CONTAINER()
             break;
 
         default:
-            Expecting( "net, layer/layers, tstamp, hatch, priority, connect_pads, min_thickness, "
+            Expecting( "net, layer/layers, tstamp, hatch, priority, connect_pads, min_thickness, "
                        "fill, polygon, filled_polygon, or fill_segments" );
         }
     }
@@ -3128,6 +3129,8 @@ ZONE_CONTAINER* PCB_PARSER::parseZONE_CONTAINER()
             // and update the zone netcode
             zone->SetNetCode( net->GetNet() );
 
+            // FIXME: a call to any GUI item is not allowed in io plugins:
+            // Change this code to generate a warning message outside this plugin
             // Prompt the user
             wxString msg;
             msg.Printf( _( "There is a zone that belongs to a not existing net\n"