This works correctly:
[my link](mailto:alice@alice.com&subject=Hi)
This doesn’t work (an empty <a> tag is generated):
[my link](mailto:&subject=Hi)
The later formatting allows a user to send a message to whoever he wants. It is used in Discourse, for example, when sharing a post (see the code here).
Same issue with the email bbcode. This works correctly:
[email=alice@alice.com&subject=Hi]my link[/email]
But not this:
[email=&subject=Hi]my link[/email]
Weird it works on plain markdown-it and on commonmark dingus, so I guess it’s an spec violation.
Most likely related to our sanitizer, I am guessing we are stripping due to a potential security issue. Maybe a bit too aggressively.
I support a fix here but it is likely to be very very tricky.
Is there a workaround for this? I notice that writing as HTML doesn’t change anything.:
<a href="mailto:?subject=alfa&body=bravo">charlie</a>