bug#43865: mml-attach-file could call system file chooser

[Robert Pluim]

>>>>> On Thu, 08 Oct 2020 15:55:06 +0300, Eli Zaretskii <eliz@gnu.org> said:

    >> From: Robert Pluim <rpluim@gmail.com>
    >> Cc: 積丹尼 Dan Jacobson <jidanni@jidanni.org>,
    >> 43865@debbugs.gnu.org
    >> Date: Thu, 08 Oct 2020 14:28:16 +0200
    >> 
    >> True, but I think this was more of a feature request. How about we
    >> allow use-dialog-box and use-file-dialog to have a value of 'always?

    Eli> Does that really work?  Doesn't the mouse click even bring some
    Eli> information needed by the dialog?  I guess it's okay if not, although
    Eli> I wouldn't be building such a new feature on a single request.  But
    Eli> that's me.

Based on hacking 'next-read-file-uses-dialog-p' to always return t,
things work fine for at least 'find-file' and 'mml-attach-file'

Robert
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