what's wrong with the following?

From: Paul Holverda (_paulholverda__at_hotmail.com)
Date: 12/31/03 

Date: Wed, 31 Dec 2003 10:41:22 +0100

Hey all I got a problem with the following code, somehow i got in an
endless Loop when i enter the "polyList2.addPoly( newPolygon )" area
so basically the error is in the Poly class I believe?
But why is polyList1.addPoly( newPolygon ) working correctly??! I did some
debuggin and the endless loop is in the addPoly method, to be more
specific in while(!isLast() ) part of it.

//SNIPPET OF CSG CLASS

         for ( int i = 0; i < WorldLoader.compiledBrushList.length; i++ )
         {
             // Clear the clip flag for each new brush to be clipped.
             clip = false;
             brush1 = WorldLoader.compiledBrushList[i];
             // Copy the polygons from brush1 to polylist1
             for ( int loop = 0; loop < brush1.polys.length; loop++ )
             {
                 Poly newPolygon = new Poly();
                 newPolygon = brush1.polys[loop];
                 if ( polyList1 != null )
                 {
                     polyList1.addPoly( newPolygon );
                 }
                 else
                     polyList1 = newPolygon;
             }

             for ( int j = 0; j < WorldLoader.compiledBrushList.length;
i++ )
             {
                 brush2 = WorldLoader.compiledBrushList[j];
                 // If brush1 is the same as brush2 then we are halfway
through
                 // clipping the brushes against each other so we set the
clip
                 // flag for further operations and continue.
                 if ( brush1.equals( brush2 ) )
                 {
                     clip = true;
                     continue;
                 }
                 for ( int loop = 0; loop < brush2.polys.length; loop++ )
                 {
                     Poly newPolygon = new Poly();
                     newPolygon = brush2.polys[loop];
                     if ( polyList2 != null )
                     {
                         polyList2.addPoly( newPolygon );
                     }
                     else
                         polyList2 = newPolygon;
                 }

And for completeness here is a snippet of the POLY class:
    /**
      * This method will add a polygon to a linked list
      * @param p Poly
      */
     public void addPoly( Poly p )
     {
         if ( p != null )
         {
             if ( isLast() )
             {
                 next = p;
                 return;
             }

             Poly pPoly = next;

             while ( !pPoly.isLast() )
             {
                 pPoly = pPoly.getNext();
             }

             pPoly.next = p;
         }
    }

     public Poly getNext()
     {
         return next;
     }

     public boolean isLast()
     {
         if ( next == null )
         {
             return true;
         }
         return false;
     }

thanks in advance,

Paul