bug#68251: message-yank-buffer insert many copies of image

[Joseph Turner via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 68251@debbugs.gnu.org
>> Date: Fri, 05 Jan 2024 14:09:37 +0200
>> From: Eli Zaretskii <eliz@gnu.org>
>>
>> > Date: Thu, 04 Jan 2024 21:09:23 -0800
>> > From:  Joseph Turner via "Bug reports for GNU Emacs,
>> >  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> >
>> > To reproduce:
>> > - ~emacs -Q~
>> > - Open an image in a buffer
>> > - Create another buffer, call ~M-x message-mode~
>> > - Run ~message-yank-buffer~, select the buffer with the image
>> >
>> > Expected:
>> >
>> > One image is inserted into the buffer.
>> >
>> > Actual:
>> >
>> > Many images are inserted into the buffer.
>>
>> It isn't specific to images: it happens with any 'display' property
>> that spans more than one text line.  message-yank-buffer looks at
>> buffer text and ignores the 'display' properties, so it inserts every
>> line after quoting it, and this you get as many copies of the
>> 'display' property as there are newlines in the text covered by the
>> 'display' property.
>
> Btw: how is it useful to yank images into an email message?  What do
> you expect Emacs to send when the email with these citations is sent?
>
> To DTRT here Emacs would need to produce a MIME attachment with the
> image, won't it?

Yes, you're right.  I had wishful thinking for a WYSIWYG flow where
message-yank-buffer would insert an inline MIME attachment, and
message-mode would display it inline.