Make sure we have footprint courtyards before depending on DRC rules.

Fixes https://gitlab.com/kicad/code/kicad/issues/8291

pcbnew/edit_zone_helpers.cpp

@@ -134,8 +134,8 @@ void PCB_EDIT_FRAME::Edit_Zone_Params( ZONE* aZone )
         if( zones_to_refill.size() )
         {
             ZONE_FILLER filler( GetBoard(), &commit );
-            wxString    title =
-                    wxString::Format( _( "Refill %d Zones" ), (int) zones_to_refill.size() );
+            wxString    title = wxString::Format( _( "Refill %d Zones" ),
+                                                  (int) zones_to_refill.size() );
             filler.InstallNewProgressReporter( this, title, 4 );
 
             if( !filler.Fill( zones_to_refill ) )

pcbnew/zone_filler.cpp

@@ -135,6 +135,9 @@ bool ZONE_FILLER::Fill( std::vector<ZONE*>& aZones, bool aCheck, wxWindow* aPare
             zone->CacheBoundingBox();
             m_worstClearance = std::max( m_worstClearance, zone->GetLocalClearance() );
         }
+
+        // Rules may depend on insideCourtyard() or other expressions
+        footprint->BuildPolyCourtyards();
     }
 
     // Sort by priority to reduce deferrals waiting on higher priority zones.