diff --git a/pcbnew/class_zone.h b/pcbnew/class_zone.h
index 87d9727085..17c51cfcf9 100644
--- a/pcbnew/class_zone.h
+++ b/pcbnew/class_zone.h
@@ -342,13 +342,15 @@ public:
      * Used in filling zones calculations
      * Circles (vias) and arcs (ends of tracks) are approximated by segments
      * @param aCornerBuffer = a buffer to store the polygon
-     * @param aClearanceValue = the clearance around the pad
-     * @param aAddClearance = true to add a clearance area to the polygon
-     *                      false to create the outline polygon.
+     * @param aMinClearanceValue = the min clearance around outlines
+     * @param aUseNetClearance = true to use a clearance which is the max value between
+     *          aMinClearanceValue and the net clearance
+     *          false to use aMinClearanceValue only
+     * if both aMinClearanceValue = 0 and aUseNetClearance = false: create the zone outline polygon.
      */
     void TransformOutlinesShapeWithClearanceToPolygon( CPOLYGONS_LIST& aCornerBuffer,
-                                               int                    aClearanceValue,
-                                               bool                   aAddClearance );
+                                               int                    aMinClearanceValue,
+                                               bool                   aUseNetClearance );
     /**
      * Function HitTestForCorner
      * tests if the given wxPoint near a corner
diff --git a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
index a4c22752dc..803f2cc356 100644
--- a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
+++ b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
@@ -376,7 +376,7 @@ void ZONE_CONTAINER::AddClearanceAreasPolygonsToPolysList( BOARD* aPcb )
         if( zone->GetIsKeepout() && ! zone->GetDoNotAllowCopperPour() )
             continue;
 
-        // A highter priority zone or keepout area is found: remove its area
+        // A highter priority zone or keepout area is found: remove this area
         item_boundingbox = zone->GetBoundingBox();
         if( !item_boundingbox.Intersects( zone_boundingbox ) )
             continue;
@@ -386,18 +386,21 @@ void ZONE_CONTAINER::AddClearanceAreasPolygonsToPolysList( BOARD* aPcb )
         // do not add clearance.
         // the zone will be connected to the current zone, but filled areas
         // will use different parameters (clearance, thermal shapes )
-        bool addclearance = GetNetCode() != zone->GetNetCode();
-        int clearance = zone_clearance;
+        bool same_net = GetNetCode() == zone->GetNetCode();
+        int min_clearance = zone_clearance;
+        bool use_net_clearance = true;
 
-        if( zone->GetIsKeepout() )
+        if( zone->GetIsKeepout() || same_net )
         {
-            addclearance = true;
-            clearance = m_ZoneMinThickness / 2;
+            // Just take in account the fact the outline has a thickness, so
+            // the actual area to substract is inflated to take in account this fact
+            min_clearance = m_ZoneMinThickness / 2;
+            use_net_clearance = false;
         }
 
         zone->TransformOutlinesShapeWithClearanceToPolygon(
                     cornerBufferPolysToSubstract,
-                    clearance, addclearance );
+                    min_clearance, use_net_clearance );
     }
 
    // Remove thermal symbols
diff --git a/pcbnew/zones_convert_to_polygons_aux_functions.cpp b/pcbnew/zones_convert_to_polygons_aux_functions.cpp
index 985d0db48f..bdd789bf3a 100644
--- a/pcbnew/zones_convert_to_polygons_aux_functions.cpp
+++ b/pcbnew/zones_convert_to_polygons_aux_functions.cpp
@@ -48,22 +48,22 @@
   *                      false to create the outline polygon.
   */
 void ZONE_CONTAINER::TransformOutlinesShapeWithClearanceToPolygon(
-            CPOLYGONS_LIST& aCornerBuffer,
-            int aClearanceValue, bool aAddClearance )
+        CPOLYGONS_LIST& aCornerBuffer, int aMinClearanceValue, bool aUseNetClearance )
 {
     // Creates the zone outline polygon (with linked holes if any)
     CPOLYGONS_LIST zoneOutline;
     BuildFilledSolidAreasPolygons( NULL, &zoneOutline );
 
     // add clearance to outline
-    int clearance = 0;
+    int clearance = aMinClearanceValue;
 
-    if( aAddClearance )
+    if( aUseNetClearance )
     {
         clearance = GetClearance();
-        if( aClearanceValue > clearance )
-            clearance = aClearanceValue;
+        if( aMinClearanceValue > clearance )
+            clearance = aMinClearanceValue;
     }
+
     // Calculate the polygon with clearance
     // holes are linked to the main outline, so only one polygon is created.
     if( clearance )
diff --git a/polygon/PolyLine.cpp b/polygon/PolyLine.cpp
index b9b23ef76e..e207f35282 100644
--- a/polygon/PolyLine.cpp
+++ b/polygon/PolyLine.cpp
@@ -1501,7 +1501,7 @@ void ConvertPolysListWithHolesToOnePolygon( const CPOLYGONS_LIST& aPolysListWith
     // If polycount<= 1, there is no holes found, and therefore just copy the polygon.
     if( polycount <= 1 )
     {
-        aOnePolyList = aPolysListWithHoles;
+        aOnePolyList.Append( aPolysListWithHoles );
         return;
     }