[Xcb] Question about XML spec, and QueryExtension

Barton C Massey bart at cs.pdx.edu
Tue Aug 26 23:04:32 PDT 2008


In message <48B2BC85.50304 at hummingbird.com> you wrote:
> Antoine Latter wrote:
> > The XCB xproto.h doesn't include the padding either - and it's used
> > extensively in xcb_ext.c, which makes me think that if QueryExtension
> > were broken extensions in general would be broken.
> > 
> > Am I missing something here?  Presumably extensions work in XCB.
> 
> There is a bug in the XML (missing padding), but the C compiler
> fortuitously papers-over the bug by automatically aligning the
> structure. Not all C compilers do this, so the bug needs to be fixed
> regardless.

I thought it might be something like that.  THanks for the diagnosis!

I agree that the patch should be inserted here. I'd do it right now, but I'm 
on an eeePC on a weak link in a foreign country. Anyone?

> It would be interesting to compile all of XCB with -Wpadded to see what 
> other bugs there are in the XML definitions.  

Indeed.  Someone want to try this?  I suppose I'll get to it eventually
if no one else does, but it may be a long while.  I think it just amounts
to some kind of compile with and without followed by a diff?

> (See also:
> http://lists.freedesktop.org/archives/xcb/2008-January/003186.html -
> which hasn't been applied yet).

Sigh.  Our apologies.

Peter, we would love it if you would please apply for commit privileges
so you can apply this patch yourself. :-)  Also make sure it's in
Bugzilla, if you would be so kind, even if you fix it right away.

And again, thanks hugely for your attention to this stuff.

	Bart


More information about the Xcb mailing list