Bugzilla

(In reply to Harald van Dijk from comment #8)
> +++ thunderbird-91.0b6/comm/mail/app/profile/all-thunderbird.js
> +// prevent web pages from registering mailnews protocol handlers
> +pref("network.protocol-handler.external.mid", false);
> And indeed, after setting network.protocol-handler.external.mid to true in 91.0b6, the links work again.

Thanks much Harald for investigating, that's valuable information. What exactly happened after you first clicked on a mid: link after enabling the pref?

For me, changing the pref causes TB to ask which app should handle mid: protocol links (see screenshot), so it's not *just working* again but needs more non-trivial user input. This hint is probably going in the right direction, but it doesn't look like a sufficient fix to me yet.
Looks like we're not succeeding to register ourselves for handling mid: protocol.
Or maybe one of my other installations overwrote that?

Changing the other related pref, `network.protocol-handler.expose.mid = true` did not seem to have any effect, with or without the `...external.mid` pref set.
https://support.mozilla.org/en-US/questions/1005638

(In reply to Harald van Dijk from comment #8)
> +++ thunderbird-91.0b6/comm/mail/app/profile/all-thunderbird.js
> +// prevent web pages from registering mailnews protocol handlers
> +pref("network.protocol-handler.external.mid", false);
> And indeed, after setting network.protocol-handler.external.mid to true in 91.0b6, the links work again.

Thanks much Harald for investigating, that's valuable information. What exactly happened after you first clicked on a mid: link after enabling the pref?

For me, changing the pref causes TB to ask which app should handle mid: protocol links (see screenshot), so it's not *just working* again but needs more non-trivial user input. This hint is probably going in the right direction, but it doesn't look like a sufficient fix to me yet.
Looks like we're not succeeding to register ourselves for handling mid: protocol.
Or maybe one of my other installations overwrote that?

Creating and setting the other related pref, `network.protocol-handler.expose.mid = true` did not seem to have any effect, with or without the `...external.mid` pref set.
https://support.mozilla.org/en-US/questions/1005638