url_for helper doesn't work for mailto link

[lookis]

https://github.com/hexojs/hexo-util/blob/master/lib/url_for.js#L28-L31

it will return origin path when met external link like http://example.com, but will not return origin path for mailto: someone@example.com. and lead to an issue when relative_link was set.

url_for('/category') => /relative_link/category <= OK!
url_for('http://example.com') => http://example.com <= OK!
url_for('mailto:someone@example.com') => /relative_link/mailto:someone@example.com <= Ops!

[SukkaW]

There is no better way to fix this. We might need to hardcode some whitelist protocols inside hexo-util, just as one of contributor of nodejs gives: nodejs/node#28482

https://github.com/nodejs/node/blob/49a5fa0d8b15cc50df833848bfc01d2260930dfd/lib/internal/url.js#L340-L348

[SukkaW]

@curbengh Any idea?

In isExternalLink() we use new URL(path)).origin === 'null' and consider mailto: javascript: links as an internal link, so that they won't be processed by external_link filter. But when at url_for and full_url_for, it requires to consider them as external links.

Currently I only come up with the idea of whitelist protocols.

[curbengh]

https://github.com/hexojs/hexo-util/blob/master/lib/url_for.js#L28-L31

The workaround is necessary to support path with a semicolon.

However, since encodeURL() never support path with semicolon, I'm ok dropping it from url_for() and full_url_for().

I'm assuming mailto: is more common than path with semicolon.

[curbengh]

When I created #114, I assumed url_for() would only be used for relative url, not data url (like mailto:) nor absolute url, which is why I made a leeway to support path with semicolon.

In relation to theme-next/hexo-theme-next#1260, I wonder why url_for(mailto:) exists (my apology, I don't understand 社交栏 and 检查单). I assume the theme dev also share my assumption.

Btw, this issue is still going to be fixed.

[lookis]

thx @curbengh
社交栏 means social account such as facebook or twitter account
检查单 is a check list for user to submit an issue

and I am not the author of theme-next, maybe they wrap every link with url_for :(

[stevenjoezhang]

https://github.com/theme-next/hexo-theme-next/blob/45148b265df579977a18bde6a908cf4977a75797/scripts/helpers/next-url.js#L16

theme-next is using a custom helper next_url. It is used to generate an <a> tag with a custom attributes.