Show hole clearance lines around NPTH pads.

Also make the clearance line NONPLATED_HOLES colour, not the PADS_TH
colour.

pcbnew/pad.cpp

@@ -755,6 +755,32 @@ int PAD::GetLocalClearance( wxString* aSource ) const
 }
 
 
+int PAD::GetOwnClearance( PCB_LAYER_ID aLayer, wxString* aSource ) const
+{
+    DRC_CONSTRAINT c;
+
+    if( GetBoard() && GetBoard()->GetDesignSettings().m_DRCEngine )
+    {
+        BOARD_DESIGN_SETTINGS& bds = GetBoard()->GetDesignSettings();
+
+        if( GetAttribute() == PAD_ATTRIB::NPTH )
+            c = bds.m_DRCEngine->EvalRules( HOLE_CLEARANCE_CONSTRAINT, this, nullptr, aLayer );
+        else
+            c = bds.m_DRCEngine->EvalRules( CLEARANCE_CONSTRAINT, this, nullptr, aLayer );
+    }
+
+    if( c.Value().HasMin() )
+    {
+        if( aSource )
+            *aSource = c.GetName();
+
+        return c.Value().Min();
+    }
+
+    return 0;
+}
+
+
 int PAD::GetSolderMaskExpansion() const
 {
     // The pad inherits the margin only to calculate a default shape,

pcbnew/pad.h

@@ -397,6 +397,8 @@ public:
     double GetLocalSolderPasteMarginRatio() const { return m_localSolderPasteMarginRatio; }
     void SetLocalSolderPasteMarginRatio( double aRatio ) { m_localSolderPasteMarginRatio = aRatio; }
 
+    int GetOwnClearance( PCB_LAYER_ID aLayer, wxString* aSource = nullptr ) const override;
+
     /**
      * Convert the pad shape to a closed polygon. Circles and arcs are approximated by segments.
      *

pcbnew/pcb_painter.cpp

@@ -1327,6 +1327,9 @@ void PCB_PAINTER::draw( const PAD* aPad, int aLayer )
 
         if( flashActiveLayer || aPad->GetDrillSize().x )
         {
+            if( aPad->GetAttribute() == PAD_ATTRIB::NPTH )
+                color = m_pcbSettings.GetLayerColor( LAYER_NON_PLATEDHOLES );
+
             m_gal->SetLineWidth( m_pcbSettings.m_outlineWidth );
             m_gal->SetIsStroke( true );
             m_gal->SetIsFill( false );