Subject: Archive (e.g. tarball) file buffers are editable, but have no undo information

From: Paul Pogonyshev <[email-masked]>
Date: Thu, 28 Aug 2014 19:11:29 +0200

1) Visit any '.tar.gz' archve;
2) Open any contained file within that archive;
3) Press 'x' or any other self-inserting key;
4) Buffer is now in 'modified' state, but you cannot undo your modification.

Paul