Re: [xml] debugging outputbuffer code in libxml

[Igor Zlatkovic <igor zlatkovic com>]

On Mon, Mar 03, 2003 at 12:32:27PM -0500, Gennady Feldman wrote:
> [clipped]
> > Either you or me are misunderstanding the encoder code. Can you send me
> > your test program, along with the XML it was parsing, or tell me what to
> > do to provoke libxml to write beyond the end of the buffer it
> > allocated?
> >
> > Ciao,
> > Igor
>
> Ok, here is the latest/smallest patch that I put together. I wasn't sure
> what was better just pasting the new piece of code or doing a "diff -u".
> The fix is a rather simple one and fixes most of the problems that I
> stumbled onto. I am still tracing as to why we got that condition in
> place. One of the major reasons is that the new UTF8toUTF8 encoder
> function got added which triggered the condition because it returns -1
> and doesn't reset the written value. What I did was just put a safety
> check around the code and it runs great now.
>
> [clipped]
>
> P.S. I am attaching my test file source file and I am pretty sure that
> you can use any XML file bigger than 4kb to test it on. Actually in some
> cases any XML file will do.
>
> [clipped]

Thanks. As far as I can see with the debugger, you are right, the thing
really writes beyond the end of the allocated buffer, within the call to
xmlAllocOutputBuffer().

However, I would rather not mess with the code so basic to libxml
without having heard Daniel's opinion. I have nothing better to do at
the moment, true enough, but this will have to wait for the end of
Daniel's looooong weekend. :-)

Ciao,
Igor