ishikawa <address@hidden> writes:
It is only that I am a little puzzled that I didn't get this warning
in the previous versions 21.x (and prior), and I am wondering
if there is a better memory allocation/checking introduced in 22.0
which causes this warning to appear. In the older versions, say 21.x
(and prior), I have not seen this message.
Those warnings are new in Emacs 22.
In Emacs 21 and before, there is a risk of running out of memory and
Emacs crashing.
In Emacs 22, more checks and automatic measures like undo-outer-limit
have been added to prevent running out of memory, and to give feedback
to the user when those measures kick in.
Here's what C-h C-n (aka NEWS) says about it:
** When the undo information of the current command gets really large
(beyond the value of `undo-outer-limit'), Emacs discards it and warns
you about it.