bug#23871: 25.1.50; Undo unexpectedly leads to blank buffer

[Phillip Lord]

Markus Triska <triska@metalevel.at> writes:

>> I have pushed this to emacs-25, since Eli was happy with the last
>> version, and you're happy with this.
>
> One issue I noticed with the current undo system is that it behaves
> differently if the command that inserts text is invoked via a keyboard
> shortcut instead of via M-x ... RET.
>
> For example, in the recipe I gave, if you invoke Emacs via:
>
>    $ emacs -Q ceiled.pl -fn "Bitstream Vera Sans Mono 15" \
>        --eval "(progn (load \"$PWD/ediprolog.el\") \
>                       (global-set-key [f9] 'ediprolog-dwim))"
>
> (note the use of F9 as a shortcut for ediprolog-dwim), and then press F9
> instead of M-x ediprolog-dwim RET to invoke the query, then, after undo,
> point is placed at the *beginning* of line 15 instead of at the end.
>
> In fact, I find the former behaviour desirable since it puts point
> exactly where it was before the whole insertion started, and I hope that
> this can also be adopted if the command is invoked with M-x ... RET.

I'm amazed at how you spot all of these!

Can we start a new bug for this? We've been discussing about 4 different
bugs on this thread, and IIUC, Eli's fixed this one.

Phil