Problem timing out XML::LibXML parse_html_string call

Sam Tregar <[email protected]>
Newsgroups gmane.comp.lang.perl.xml
Message-ID <[email protected]>
Hello all.  I'm using XML::LibXML to parse some HTML.  Mostly it's working
great - fast and very useful XPath support.  My problem is that it's choking
on some very bad HTML in a very bad way - it's sitting on the CPU until
killed manually.  I expected some HTML wouldn't parse, so this isn't such a
tragedy.  What is a big problem is that my attempt to work around this with
alarm() aren't working!

Here's my code:

use strict;
use warnings;
use XML::LibXML;

my $html = do { local $/; <> };

my $libxml = XML::LibXML->new();
#$libxml->recover(2);

eval {
    local $SIG{ALRM} = sub { die "TIMEOUT\n" };
    alarm(10);
    $libxml->parse_html_string($html);
    alarm(0);
};
if ($@ and $@ eq "TIMEOUT\n") {
    warn "Timed out ok.\n";
} elsif ($@) {
    die $@;
}

If I replace the parse call with sleep(20) then it works as expected - the
alarm triggers and the timeout is caught.  If I run it as-is with my sample
HTML then it never stops until killed.  If you want to play along at home
here's the test file:

http://sam.tregar.com/libxml-fail.html

BEWARE: that's some really bad HTML and it not only breaks XML::LibXML but
it also crashed Firefox on me.  You probably don't want to load it in your
browser.

I've never had alarm() fail like this.  Is there an alternative I can try?
Any other ideas about how to handle this?

Thanks!
-sam

_______________________________________________
Perl-XML mailing list
[email protected]
To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.