From e26c912b86651b9c8062f529f2225b10de7a69f3 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Wed, 3 Feb 2021 11:56:15 +0000
Subject: [PATCH] Don't apply electrical clearance to non-copper zones.

Also removes a very old (and somewhat confusing) comment.

Fixes https://gitlab.com/kicad/code/kicad/issues/7404
---
 pcbnew/zone.cpp        | 21 ++++++++++++++-------
 pcbnew/zone_filler.cpp |  7 +------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/pcbnew/zone.cpp b/pcbnew/zone.cpp
index 1f0a131cd2..a8c5618131 100644
--- a/pcbnew/zone.cpp
+++ b/pcbnew/zone.cpp
@@ -1165,12 +1165,19 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
     if( GetNumCorners() <= 2 )  // malformed zone. polygon calculations will not like it ...
         return false;
 
+    int zoneClearance = m_ZoneClearance;
+
     if( GetIsRuleArea() )
     {
         // We like keepouts just the way they are....
         aSmoothedPoly = *m_Poly;
         return true;
     }
+    else if( !IsOnCopperLayer() )
+    {
+        // Non-copper zones don't have electrical clearances
+        zoneClearance = 0;
+    }
 
     BOARD* board = GetBoard();
     int    edgeClearance = 0;
@@ -1229,21 +1236,21 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
     for( ZONE* zone : interactingZones )
         aSmoothedPoly.BooleanAdd( *zone->Outline(), SHAPE_POLY_SET::PM_FAST );
 
-    if( !GetIsRuleArea() && aBoardOutline )
+    if( aBoardOutline )
     {
-        SHAPE_POLY_SET bufferedOutline = *aBoardOutline;
-        bufferedOutline.Deflate( std::max( m_ZoneClearance, edgeClearance ), 16 );
-        aSmoothedPoly.BooleanIntersection( bufferedOutline, SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
+        SHAPE_POLY_SET poly = *aBoardOutline;
+        poly.Deflate( std::max( zoneClearance, edgeClearance ), 16 );
+        aSmoothedPoly.BooleanIntersection( poly, SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
     }
 
     smooth( aSmoothedPoly );
 
     if( aSmoothedPolyWithApron )
     {
-        SHAPE_POLY_SET bufferedExtents = *maxExtents;
-        bufferedExtents.Inflate( m_ZoneMinThickness, 16 );
+        SHAPE_POLY_SET poly = *maxExtents;
+        poly.Inflate( m_ZoneMinThickness, 16 );
         *aSmoothedPolyWithApron = aSmoothedPoly;
-        aSmoothedPolyWithApron->BooleanIntersection( bufferedExtents, SHAPE_POLY_SET::PM_FAST );
+        aSmoothedPolyWithApron->BooleanIntersection( poly, SHAPE_POLY_SET::PM_FAST );
     }
 
     aSmoothedPoly.BooleanIntersection( *maxExtents, SHAPE_POLY_SET::PM_FAST );
diff --git a/pcbnew/zone_filler.cpp b/pcbnew/zone_filler.cpp
index b0091c3966..03b3b95933 100644
--- a/pcbnew/zone_filler.cpp
+++ b/pcbnew/zone_filler.cpp
@@ -1193,11 +1193,6 @@ bool ZONE_FILLER::fillSingleZone( ZONE* aZone, PCB_LAYER_ID aLayer, SHAPE_POLY_S
         aLayer = F_Cu;
     }
 
-    /*
-     * convert outlines + holes to outlines without holes (adding extra segments if necessary)
-     * m_Poly data is expected normalized, i.e. NormalizeAreaOutlines was used after building
-     * this zone
-     */
     if ( !aZone->BuildSmoothedPoly( maxExtents, aLayer, boardOutline, &smoothedPoly ) )
         return false;
 
@@ -1234,7 +1229,7 @@ bool ZONE_FILLER::fillSingleZone( ZONE* aZone, PCB_LAYER_ID aLayer, SHAPE_POLY_S
         }
         else if( half_min_width - epsilon > epsilon )
         {
-            smoothedPoly.Deflate( -( half_min_width - epsilon ), numSegs );
+            smoothedPoly.Inflate( half_min_width - epsilon, numSegs );
         }
 
         aRawPolys = smoothedPoly;