modedit: Mirror custom pads

Fixes mirror command to correctly handle custom pads.

Fixes: lp:1808135
* https://bugs.launchpad.net/kicad/+bug/1808135

pcbnew/class_pad.cpp

@@ -481,6 +481,40 @@ void D_PAD::FlipPrimitives()
 }
 
 
+void D_PAD::MirrorXPrimitives( int aX )
+{
+    // Mirror custom shapes
+    for( unsigned ii = 0; ii < m_basicShapes.size(); ++ii )
+    {
+        PAD_CS_PRIMITIVE& primitive = m_basicShapes[ii];
+
+        MIRROR( primitive.m_Start.x, aX );
+        MIRROR( primitive.m_End.x, aX );
+        primitive.m_ArcAngle = -primitive.m_ArcAngle;
+
+        switch( primitive.m_Shape )
+        {
+        case S_POLYGON:         // polygon
+            for( unsigned jj = 0; jj < primitive.m_Poly.size(); jj++ )
+                MIRROR( primitive.m_Poly[jj].x, aX );
+            break;
+
+        default:
+            break;
+        }
+    }
+
+    // Mirror the local coordinates in merged Polygon
+    for( int cnt = 0; cnt < m_customShapeAsPolygon.OutlineCount(); ++cnt )
+    {
+        SHAPE_LINE_CHAIN& poly = m_customShapeAsPolygon.Outline( cnt );
+
+        for( int ii = 0; ii < poly.PointCount(); ++ii )
+            MIRROR( poly.Point( ii ).x, aX );
+    }
+}
+
+
 void D_PAD::AppendConfigs( PARAM_CFG_ARRAY* aResult )
 {
     // Parameters stored in config are only significant parameters

pcbnew/class_pad.h

@@ -347,6 +347,13 @@ public:
      */
     void FlipPrimitives();
 
+    /**
+     * Mirror the primitives about a coordinate
+     *
+     * @param aX the x coordinate about which to mirror
+     */
+    void MirrorXPrimitives( int aX );
+
     /**
      * Import to the basic shape list
      * @return true if OK, false if issues

pcbnew/tools/edit_tool.cpp

@@ -731,6 +731,9 @@ static void mirrorPadX( D_PAD& aPad, const wxPoint& aMirrorPoint )
 {
     wxPoint tmpPt = mirrorPointX( aPad.GetPosition(), aMirrorPoint );
 
+    if( aPad.GetShape() == PAD_SHAPE_CUSTOM )
+        aPad.MirrorXPrimitives( tmpPt.x );
+
     aPad.SetPosition( tmpPt );
 
     aPad.SetX0( aPad.GetPosition().x );