I suppose that is not good solution. Div reflects onClick and anchor is not necessary. What element/attribute need this anchor?
Under IE6 also we can see that collapsible got header structure (<div><a><div/></div>) .This sometimes generates collapsible header with double height.
Invalid anchor
<a onfocus="Ice.pnlClpFocus(this);" onblur="Ice.pnlClpBlur(this);" href="#">
<img \="" src="/oss-web/xmlhttp/css/xp/css-images/spacer.gif"/>
</a>
We got success with this code disabled (PanelCollapsibleRenderer.java Lines 72 to 78)
// Element anchor = domContext.createElement (HTML.ANCHOR_ELEM);
// anchor.setAttribute(HTML.ONFOCUS_ATTR, "Ice.pnlClpFocus (this);");
// anchor.setAttribute(HTML.ONBLUR_ATTR, "Ice.pnlClpBlur (this);");
// anchor.setAttribute(HTML.HREF_ATTR, "#");
// anchor.appendChild(domContext.createTextNode("<img src='"+ CoreUtils.resolveResourceURL(facesContext,
// "/xmlhttp/css/xp/css-images/spacer.gif") + "'
>"));
// header.appendChild(anchor);
Its a regression of
ICE-4674