I want to confirm this bug, and show how to easily reproduce.

The Ubuntu repositories contain sword module...

sword-text-kjv

includes an xml version of the KJV bible.

Use the command 

mod2osis KJV

to extract a 23 MB xml file which causes the reproduceable bug.

(The mod2osis cmd line util is in package libsword6, also in the
ubuntu repositories.)

To force a crash try parsing the the kjv.osis file, I'm using php5
which uses libxml2, the following short php file that uses
the php command line environment that will trigger this
bug reliably, with a php wrapper around the original libxml2 error
indicating that this parm is to small.  

(I'm using php 5.1.6 but that should
not matter here, any 5.1.X will use libxml2)

---------------------
#!/usr/bin/php
<?php

// Set $in to whatever location you put kjv.osis

// $in = '/tmp/kjv.osis';
$in = '~/kjv.osis';

$reader = new XMLReader();
$reader->open($in);
while ($reader->read()) 
{
   switch ($reader->nodeType) 
   {
     default:
          // do nothing, just waiting for a crash.
      break;
   }
}

?>
---

Clearly xml files that are very deep are being distributed with 
current linux systems, and the 1024 depth is not big enough to handle
them.

I would recommend a quick fix, setting it to, say 4096 or whatever, to cover
normal use and I would also recommend a parm somewhere to set this.

I would argue about the sanity of whoever produced that XML ... 
It has to be a recursive kind of structure and I don't see how a
normal text, no matter the size can be that deep with a significant
structure, I mean something which makes sense to an human.
What is the DTD for that kind of document ? How are you sure it's
not an instance building error or a logical error in the design.

I'm not sure I want to add yet another global variable to libxml2.
I'm not sure going from 1024 to 4096 would solve the problem in any
way either.

Daniel

Actually this is fixed, cause xmlParserMaxDepth is available trough parserInternals.h.

I've got another improvement request on this. Will it be accepted to add per parser context depth limit? (I mean if I send a patch for that).

It's useful to do this some times when we have several contexts and want to limit depth a particular one.

This is a question to Daniel obviously.

I'm not sure, on one hand it's cleaner to use per parser context
than a global variable, on the other hand it's yet another knob
at the parser level, I think it's acceptable though,

Daniel

GNOME is going to shut down bugzilla.gnome.org in favor of gitlab.gnome.org.
As part of that, we are mass-closing older open tickets in bugzilla.gnome.org
which have not seen updates for a longer time (resources are unfortunately
quite limited so not every ticket can get handled).

If you can still reproduce the situation described in this ticket in a recent
and supported software version, then please follow
  https://wiki.gnome.org/GettingInTouch/BugReportingGuidelines
and create a new ticket at
  https://gitlab.gnome.org/GNOME/libxml2/-/issues/

Thank you for your understanding and your help.