Okay, I think I've got a minimal repro (appended). It's possible the
fault lies in the Perl interface, in which case this should be
reassigned to the `libxml-libxslt-perl' package.
The bug only seems to be triggered if we pass nodes from exsl:node-set()
into an unrelated extension function; changing the select to not call
local:uc() causes the program to run to completion.
Also of interest: if I change the definition of local:uc to
{ $_ = shift; return uc; }
then the crash doesn't happen until after the output is written. I'm
guessing that this means it's possibly Perl's garbage collection
interfering? I'm not sure whether that's usable for a workaround in my
production code or not - I'm dealing with many more calls there.
Here's the code:
#!/usr/bin/perl -w
use strict;
use warnings;
use XML::LibXSLT;
use XML::LibXML;
my $xslt = XML::LibXSLT->new();
my $ext_uri = "urn:local";
XML::LibXSLT->register_function($ext_uri, "uc", sub { return uc shift; } );
my $stylesheet = $xslt->parse_stylesheet(XML::LibXML->load_xml(string => <<'EOF'));
<xsl:stylesheet version="1.0"
extension-element-prefixes="exsl local"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:exsl="http://exslt.org/common";
xmlns:local="urn:local">
<xsl:template match="/">
<xsl:variable name="foo">
<foo a="foo"/>
</xsl:variable>
<bar><xsl:value-of select="local:uc(exsl:node-set($foo)//@a)"/></bar>
</xsl:template>
</xsl:stylesheet>
EOF
my $input = XML::LibXML->load_xml(string => "<input/>");
print $stylesheet->transform($input)->toString;
