Re: [xml] correct version of libxml2

["Floodeenjr, Thomas" <thomas_floodeenjr mentor com>]

Daniel,

Yes indeed, we seem to be calling xmlCleanupParser() in many places. We will get with our engineering teams 
to investigate removing this call from our code. I would imagine that they thought at the time that this call 
was needed, as it appears to have had no ill side effects in the 2.6.x versions of libxml2.

Thanks,
-Tom


Thomas Floodeen, Jr.
Mentor Graphics BSD
720.494.1133


-----Original Message-----
From: Daniel Veillard [mailto:veillard redhat com] 
Sent: Monday, April 25, 2011 7:48 AM
To: Floodeenjr, Thomas
Cc: xml gnome org
Subject: Re: correct version of libxml2

  Hi Thomas,

 thanks for getting back to me on this issue, and in the proper forum !

On Mon, Apr 25, 2011 at 01:30:30PM +0000, Floodeenjr, Thomas wrote:
> Daniel,
>
> I believe you are correct. I found out that our code works with libxml2-2.7.2, but started to crash in 
> 2.7.3. I traced it down to a small change in threads.c:921 in 2.7.3:
>
> #elif defined HAVE_PTHREAD_H
>     if ((libxml_is_threaded)  && (pthread_key_delete != NULL))
>         pthread_key_delete(globalkey); #endif
>
> If I comment out the pthread_key_delete() call, our crash goes away. For expediency, I am doing this now. 
> However, we would like to track down why we are crashing.

  How did you end up calling xmlCleanupThreads() where that code is done.
It sounds very likely that you are calling xmlCleanupParser() while still using the library, and well in that 
case the crash is normal !
  http://xmlsoft.org/html/libxml-parser.html#xmlCleanupParser

see the documentation, you should call this function only once libxml2 is not in use anywhere in the 
application, which those days is very had to assert. Simplest is to just not call it.

Daniel

> -----Original Message-----
> From: Daniel Veillard [mailto:veillard redhat com]
> Sent: Sunday, April 24, 2011 8:17 PM
> To: Floodeenjr, Thomas
> Cc: Aleksey Sanin; xmlsec aleksey com
> Subject: Re: [xmlsec] correct version of libxml2
>
> On Wed, Apr 20, 2011 at 04:40:37PM +0000, Floodeenjr, Thomas wrote:
> > Aleksey,
> >
> > We are having problems with libxml2 that are not related to xmlsec.
> > Our xmlsec tests are working fine so far, but some of our core 
> > libxml2 usage is broken.
>
>   That's the wrong place to report such problems.
> 2.6.x releases are rather old and 2.6.12 is very old. I fixed a number of things in libxml2 since then. If 
> you got troubles, it may be due to a misuse of the library, compilation problems, or possibly a bug but 
> it's impossible to tell from your report, and this list ain't the right place for it:
>   http://xmlsoft.org/bugs.html
>
>   In my experience as libxml2 maintainer most of the time when people 
> report "bugs" appareing in recent libxml2 versions it is that they 
> relied upon broken behaviour usually not conformant to the 
> specification. Hiding the problem around by keeping an obsolete 
> version of the library rather than investigating the problem exposes 
> the user to risk including security ones. If you are embbeding libxml2 
> for any shipping product I urge you to actually report the problem and 
> get it solved instead of hiding this under the carpet by using an 
> obsolete
> libxml2 version,
>
>   thanks in advance,
>
> Daniel
>
> -- 
> Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
> daniel veillard com  | Rpmfind RPM search engine http://rpmfind.net/ 
> http://veillard.com/ | virtualization library  http://libvirt.org/

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