Links broken with (at least) two underscores in URL

AI-generated summary

A discussion is ongoing about broken links in Discourse when URLs contain at least two underscores. Steven shared examples of broken Twitter links with underscores, while codinghorror suggested using angle brackets to fix the issue, although this prevents oneboxing.

Steven found a temporary solution by replacing underscores with the URL-encoded version %5F. sam suggested reporting the issue to markdown.it for linkify, but Vitaly mentioned it’s a known issue with a workaround available.

sam asked if Vitaly has revisited the issue, and supermathie proposed fixing the issue by percent-encoding underscores in the query string in the paste handler. However, sam expressed concerns about fiddling with the clipboard. codinghorror disagreed, suggesting that fiddling with the clipboard is safe when dealing with URLs starting with https://.

i don’t know if this is an issue regarding Discourse exactly or if it’s coming from twitter API but I wanted to share this little bug, when we share a tweet from a account that has a underscore in its username, the link is broken on Discourse, here is an example :

https://twitter.com/_miss_ives_/status/923667180201414658
https://twitter.com/_miss_ives_/status/923667180201414658


Another example

https://twitter.com/_FARTIGAS_/status/914070638561767425
https://twitter.com/_FARTIGAS_/status/914070638561767425

when it’s not coming from twitter, a link with underscore works fine :

Put angle brackets on either side of the link. <like this>

That prevents oneboxing though. The link works, but it won’t onebox.
<https://twitter.com/_miss_ives_/status/923667180201414658>
https://twitter.com/_miss_ives_/status/923667180201414658

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Then it’s something @sam will have to add to his list for later. In the meantime, replace the underscore with the URL-encoded version of the character.

I’ll leave that as an excercise for the reader..

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It’s pretty rare so that’s not a hurry at all. No worry

I tried with %5F and works perfectly, that’ll do it nicely for now.

Thanks!

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@Vitaly Is this issue something you would like reported to markdown.it for linkify ?

( https://twitter.com/_miss_ives_/status/923667180201414658 not auto linking )

I am not sure we can even fix this properly cause we would have to push linkify forward in the pipeline?

Especially since this is default CommonMark http://spec.commonmark.org/dingus/?text=https%3A%2F%2Ftwitter.com%2F_miss_ives_%2Fstatus%2F923667180201414658 @codinghorror

That’s a known issue:

https://github.com/markdown-it/markdown-it/issues/38

It’s possible to fix, but not easy. Workaround available.

Correct solution is to make linkifier part of tokenizer process. That’s expensive (for example, email lookahead check for every character). Tradeoff is to listen : then do look behind for http(s), and lookahead for the rest. That’s not universal, but will cover all real cases:

  • http/https links will be parsed with other tokens, with higher priority than emphasis
  • everything else will be detected via text scan & regexps (as linkifier works now), probability of collision is very low.

I have no plans to do this, but if anyone wish to implement - see explanation above. Or use < > :slight_smile:

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Можно ли исправить это, выполнив работу в нашем обработчике вставки и, если мы вставляем URL, кодируя символы подчеркивания в строке запроса с помощью процентного кодирования?

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Работа с буфером обмена почти всегда заканчивается плачевно.

@Vitaly, интересно, удалось ли тебе недавно взглянуть на эту проблему? В данном случае речь идёт о линкере https://....

Думаю, правильно выстроить порядок в движке и минимизировать затраты здесь — настоящий кошмар.

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Я не согласен; https:// — это НАСТОЛЬКО редкая комбинация символов, что, на мой взгляд, такие манипуляции обычно вполне безопасны.

(За исключением блоков кода, но если в буфере обмена ТОЛЬКО URL, то это, по моему мнению, довольно безопасно. Так что, если вы создадите якорь «начинается с https://», я могу на 99,99% гарантировать, что это будет безопасно.)

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