[jdarwood007]

Additionally resolves not getting a error back

[albertlast]

Letting a new post (no message yet) skip canModifyMsg() looks right. Editing an existing post still fails on 3.0, though, and it is in the same check.

canModifyMsg() calls a bare allowedTo() inside namespace SMF\Actions. The global allowedTo() lives in Subs-Compat.php and only exists when $backward_compatibility is on, and off is the default. On a forum with it off, I called canModifyMsg() with this PR applied, as the admin, for an existing message:

backward_compatibility=0 user=1 msg=1 board=1
THROW Error: Call to undefined function SMF\Actions\allowedTo()

So uploading an attachment while editing a post still fatals. User::$me->allowedTo('modify_any', $id_board) and User::$me->allowedTo('modify_own', $id_board) would avoid that.

The $this->msg === 0 test at the top of canModifyMsg() reads the property rather than the $id_msg parameter, but those are the same value at the only call site.

[jdarwood007]

Its what happens when you write for one and copy the code between them.