url protection

[Patrice Dumas]

Hello,

In general, hrefs generated by texi2any to Texinfo manuals, be it the
current manual or external manual, only contain ascii characters
acceptable in hrefs.  However, for some other href, for <img> file
names, or from @url{}, there could be any characters.

I think that it would be cleaner to percent encode those hrefs.  I tries
to read the URL specification, https://url.spec.whatwg.org/, but I could
not understand much, and there is no exposition at all, only pseudo
code.

My proposal would be to follow the perl faq,
https://perldoc.perl.org/perlfaq9#How-do-I-decode-or-create-those-%25-encodings-on-the-web?
To encode a string yourself, use the URI::Escape module. The uri_escape 
function returns the escaped string

This would add the URI::Escape module as dependency.  This is a rather
common module, but it does not seems to be in perl core.  To me
documenting that the module is needed should be enough.

The standard does not seems to clear on the encoding to use for the %
encodings.  URI::Escape has uri_escape() and uri_escape_utf8.  My
feeling is that the best would be to use first encode to the output
encoding and then call URI::Escape uri_escape().


Any comment?

-- 
Pat