AutoLink extension links invalid protocol-only (no host) URIs

[peckjon]

It is common to type only "http://" (not followed by any hostname etc) in the process of creating technical documentation.

The AutoLink extension incorrectly attempts to link these, resulting in ugly documentation.

URIs are invalid without a host portion:

URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]

hier-part = "//" authority path-abempty
                 / path-absolute
                 / path-rootless
                 / path-empty

authority = [ userinfo "@" ] host [ ":" port ]

• https://tools.ietf.org/html/rfc3986#appendix-A (brackets indicate optionality)

[robinst]

http:// by itself should not get autolinked. Do you type "http://" (including the quotes)? If so, that's a bug in autolink-java which I should fix.

[peckjon]

Thanks for the quick response! The line I typed was:

* **(Required):** Images ("images": ["data://...", "http://...", ...])

...and on more careful inspection (sorry!), the linked portion includes [only] the first dot (eg, http://.)

Is http://. a valid URL? Technically, I'm not sure (one could perhaps argue that unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~" makes it valid). Logically, no, but I suppose that's because . is an invalid TLD.

PS md in context: https://algorithmia.com/algorithms/web/SocialMediaImageRecommender

[robinst]

Thanks for including the full source :).

Yeah, I think it's valid because host can just be a single unreserved character. Having said that, even just http:// is valid according to RFC 3986, but we don't autolink it. And for valid URLs that end with a ., we don't include . either.

I've raised robinst/autolink-java#15 to fix it there, but we can also leave this one open until we bump the dependency here.

[peckjon]

Wow that was fast @robinst -- I see robinst/autolink-java#15 is already fixed!

Thanks for being awesome. Closing out.

[robinst]

Released in 0.10.0 now: https://github.com/atlassian/commonmark-java/blob/master/CHANGELOG.md#0100---2017-09-14

[peckjon]

Awesome, Robin! Thanks!!