Fossil

          if( isCP ){
            drawCherrypickLine(x0,y0,x1+dx,null);
            cls = "arrow cherrypick " + (x1<x0 ? "l" : "r");
          }else{
            drawMergeLine(x0,y0,x1+dx,null);
            cls = "arrow merge " + (x1<x0 ? "l" : "r");
          }
          if( p.mu==p.cu ){
          if( !isCP || p.mu==p.cu ){
            dx = x1<x0 ? mLine.w : -(mArrow.w + mLine.w/2);
            drawBox(cls,null,x1+dx,y0+(mLine.w-mArrow.h)/2);
          }
          y1 = y0;
        }else{
          drawMergeLine(x0,y0,x1+(x0<x1 ? mLine.w : 0),null);
          drawMergeLine(x1,y0+mLine.w,null,y1);