Improve behavior of calling reply command when point is on username using "Elemental" message format

[rgri]

To reproduce:

1. Open the room list
2. Enter a room
3. Attempt to use S-RET or M-x ement-room-write-reply to reply to a message point

This fails with the following trace:

Debugger entered--Lisp error: (cl-assertion-failed ((ement-event-p (ewoc-data (ewoc-locate ement-ewoc))) nil))
  cl--assertion-failed((ement-event-p (ewoc-data (ewoc-locate ement-ewoc))))
  ement-room-write-reply()
  #<subr funcall-interactively>(ement-room-write-reply)
  apply(#<subr funcall-interactively> ement-room-write-reply)
  funcall-interactively(ement-room-write-reply)
  #<subr call-interactively>(ement-room-write-reply nil nil)
  apply(#<subr call-interactively> (ement-room-write-reply nil nil))
  explain-pause--wrap-call-interactively(#<subr call-interactively> ement-room-write-reply nil nil)
  apply(explain-pause--wrap-call-interactively #<subr call-interactively> (ement-room-write-reply nil nil))
  call-interactively(ement-room-write-reply nil nil)
  command-execute(ement-room-write-reply)

Specifically, I am using Nix's emacs29-pgtk package.

[alphapapa]

The backtrace would seem to indicate that you called the command to write a reply when point was not on a message event.

[rgri]

Yes, I must have thought that the username associated with a message is included in the region defined as the message. I'll close this now.

Though is it perhaps worthwhile to add a catch for such an error? So far nothing else while using ement has spit such an ugly message at me.

[alphapapa]

Yes, I must have thought that the username associated with a message is included in the region defined as the message. I'll close this now.

The default message display format puts the usernames and timestamps in the margins; the point can't move into the margins. Point can be in the message body, reactions, etc.

Though is it perhaps worthwhile to add a catch for such an error? So far nothing else while using ement has spit such an ugly message at me.

What you saw was the catch, the assertion. I don't understand how you could have tried to call that command thinking point was on a username shown in a margin, though.

Maybe it should be improved, but this is the first I've heard of this problem, and at least a few hundred people are using Ement now, so we'll see.

[rgri]

I maybe should have clarified: the issue only appears while in the "Elemental" room format: with ement-room-message-format-spec set to "%B%r%R%t".

[alphapapa]

Ok, that makes sense, yes. Probably point was on the username rather than the message below it. I'll repurpose this issue to improve that behavior. Thanks.