Web compatibility issue with various unknown (external) protocols like ed2k about url

[annevk]

Are these web compatibility issues or issues with extensions? It seems any website breakage would also impact Safari and I haven't seen any reports about breakage.

[evilpie]

These are issues with external applications, not extensions, which are supposed to be opened as external protocol handlers. I assume most users of e.g. eDonkey are on Windows, which might affect Safari less.

[valenting]

I think there are two different issues with these schemes.

1. Schemes that wrap another URL with the intention of passing that URL to an external protocol handler.
2. Schemes such as ed2k which have a totally different definition. Even with RFC 3986 rules ed2k://|file|The_Two_Towers-The_Purist_Edit-Trailer.avi|14997504|965c013e991ee246d63d45ea71954c4d|/ is not a valid URI as | is not a valid host character, but as it happens it used to work. The question is how much effort should we expend in keeping these URLs functioning on the web?

While I don't have any experience with ed2k I think it's also supposed to be passed to an external protocol handler. But that doesn't work unless it's successfully parsed.

[karwa]

The ed2k issue seems to come from U+007C (vertical bar) being listed as a forbidden host code-point. Personally I think it would be very low-risk to allow that character in opaque hostnames.

Failing that, it would be reasonable to at least percent-encode the character -- it's very possible that the application's processing would be tolerant to such a change.

[evilpie]

BMO 1878295 has an other example with vscode:///{'cmd':'openFile'} ({ and } are escaped)

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