Fix for #130376

[Evan Carroll]

> - I think we'd still need to patch our XML::SAX::save_parsers(),
>  otherwise people installing (say) XML::SAX::Expat from CPAN over our
>  libxml-sax-perl will write in /usr/share/perl5/XML/SAX/ParserDetails.ini
>  while the active file is in /etc/perl and managed by update-perl-sax-aparsers

No, no you're missing the point here entirely. it isn't Debians job to
bork cpan modules by telling them how to run their own show. XML::SAX
*should* read/write from /usr/share/perl5/XML/SAX/ParserDetails.ini
this is how it was designed!!! Debian on the other hand is hellbent on
making it so *their* utilities are configured through /etc/ (which is
arguably a *better* idea). However, this is Debian's variant not real
XML::SAX. So don't make Debian pretend to be XML::SAX by polluting the
namespace of vanilla CPAN.

Create your own XML::SAX fork, and make Debian modules use it, this
right and wrong is simply black-and-white.

Lets say I subclassed XML::SAX into XML::SAX::OOConfig and I depended
on the configuration file being in the same place.. Suddenly, that
subclass won't work (it would probably silently fail) to configure the
ini because other Debian modules using XML::SAX are unknowingly using
the ini file in a hacked location.

-- 
Evan Carroll
System Lord of the Internets