Subject: 27.0.50; (apply ...) doesn't work with undo-in-region

From: Stefan Monnier <[email-masked]>
Date: Mon, 02 Apr 2018 19:54:28 -0400

Package: Emacs
Version: 27.0.50

As brought up by Johan, the (apply ...) elements in buffer-undo-list are
"too powerful".  Even though BEG/END/DELTA are provided, with the
intention to make it possible for undo-in-region to handle those
entries, undo-in-region does not handle those entries.

The main problem being that undo-in-region (as well as
erc-update-undo-list, incidentally) needs not just to know which part of
the buffer is modified and with which DELTA, but it also needs to be
able to create a new entry to apply the same change at another
buffer position.

        Stefan

In GNU Emacs 27.0.50 (build 1, x86_64-unknown-linux-gnu, GTK+ Version 3.22.26)
 of 2018-03-01 built on alfajor
Repository revision: 2d65141a5654c475746bd78d998877901a0ff065
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