Dunno whether this bug belongs in XBL or Layout... Elements with XBL bindings and display style 'block' are not rendered, because we hit an unimplemented case in nsCSSFrameConstructor::WipeContainingBlock(): ... else { //uh oh. the block we need to reframe has no parent! } ... A testcase is at http://www.croczilla.com/svg/xbl-block-bug/bug.xml: bug.xml ------- <?xml?> <?xml-stylesheet href="bug-bindings.css" type="text/css"?> <doc> <blockelement/> </doc> bug-bindings.css ---------------- blockelement { display: block; -moz-binding: url("bug-bindings.xml#blockelement"); } bug-bindings.xml ---------------- <?xml?> <bindings xmlns="http://www.mozilla.org/xbl"> <binding id="blockelement"> <content>foopy</content> </binding> </bindings> If the 'display: block;' declaration is left out, the element renders ok.

Some more comments: 1) If the binding document is loaded synchronously (from the xul cache), the problem disappears. Only the first load in a session is problematic in these cases. 2) Elements that can't have bindings because of this bug include <html:div> and <svg:svg>.

Adding dependency to 142585. I don't think it's worth the time to really fix this properly (if such a thing is even possible in the current code), although if you need it to work in some subset of cases, it might not be too hard.

Testcase is here no more. There's a way to reproduce or we can close this 8 years old bug?

Testcase is still in comment 0, no?

This is fixed by one of the numerous root frame and ib changes since then.

But it might be good to add a testcase.