bug#21489: 25.0.50; Echoing and message interaction

bug#21489: 25.0.50; Echoing and message interaction

[Jay Belanger]

Emacs used to not always cover up messages with keystroke
echoing.  For example, in Emacs 24.5, setting

(local-set-key "ab"
	       (lambda ()
		 (interactive)
		 (message "Hello")
                 (push ?a unread-command-events)))

and then keying in "ab" would display
  Hello
in the minibuffer.  In the git master, it will display
  a-

The old behavior was useful.



In GNU Emacs 25.0.50.2 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.10)
 of 2015-07-07 on vh213601
Repository revision: 6aa1d7635c02e2268acc62ab3017621d83796467
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
System Description:	Debian GNU/Linux 7.8 (wheezy)

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GCONF GSETTINGS NOTIFY
GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS
GTK2 X11

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Article

Minor modes in effect:
  show-paren-mode: t
  display-time-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
nnimap read 51k from imap.gmail.com
Reading active file via nndraft...done
Checking new news...done
nnimap read 0k from imap.gmail.com
Processing kill file /home/belanger/.emacs.d/mail/KILL...
Starting new Ispell process /usr/bin/aspell with default dictionary...
Processing kill file /home/belanger/.emacs.d/mail/KILL...done
Mark set [4 times]
Quit
Making completion list...
Quit [3 times]

Load-path shadows:
None found.

Features:
(shadow emacsbug noutline outline easy-mmode nnir sort smiley ansi-color
gnus-cite mail-extr gnus-async gnus-bcklg flyspell ispell gnus-kill
gnus-ml disp-table gnus-topic nndraft nnmh utf-7 gnutls network-stream
nsm gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg
gnus-art mm-uu mml2015 epg-config mm-view mml-smime smime dig mailcap
nntp gnus-cache gnus-sum gnus-group gnus-undo gnus-start gnus-cloud
nnimap nnmail mail-source tls utf7 netrc nnoo parse-time gnus-spec
gnus-int gnus-range message dired-details advice dired-x dired
format-spec rfc822 mml mml-sec mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader gnus-win gnus gnus-ems nnheader
wid-edit server starttls smtpmail auth-source cl-seq eieio byte-opt
bytecomp byte-compile cl-extra seq cconv eieio-core cl-macs gv gnus-util
password-cache sendmail rfc2047 rfc2045 ietf-drums mm-util help-fns
help-mode easymenu mail-prsvr mail-utils tex-site auto-loads derived
paren time cus-start cus-load edmacro kmacro cl-loaddefs pcase cl-lib
time-date mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel x-win term/common-win x-dnd tool-bar dnd fontset
image regexp-opt fringe tabulated-list newcomment elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cl-generic cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese charscript case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer cl-preloaded nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote dbusbind gfilenotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 336645 20237)
 (symbols 48 30566 0)
 (miscs 40 235 365)
 (strings 32 45021 7896)
 (string-bytes 1 1520246)
 (vectors 16 23207)
 (vector-slots 8 558254 9089)
 (floats 8 337 253)
 (intervals 56 743 41)
 (buffers 976 28)
 (heap 1024 26597 6976))

bug#21489: 25.0.50; Echoing and message interaction (Bug#21489)

[Paul Eggert]

I'm following up on <http://bugs.gnu.org/21489> dated 2015-09-15.

I tried the example code you gave, and it behaved oddly for me under 
Emacs 24.5. I ran the program and typed "ab" and Emacs echoed "Hello" in 
the minibuffer. I then typed "bbbbbbbbbbb" and nothing happened. I then 
typed "c" and Emacs echoed "a c is undefined" in the minibuffer. (I 
didn't do this because I knew what would happen; I was just trying 
things idly.)

In contrast under Emacs 25.0.50, when I typed "ab" Emacs delayed and 
then echoed "a-". Then, each time I typed "b" it cleared the minibuffer, 
delayed, and then echoed "a-". When I finally typed "c" it it echoed "a 
c is undefined". This behavior more clearly indicated to me what was 
going on (which I figured out only after a bit of thought).

This exercise was unrealistic enough that I expect we shouldn't be 
basing design decisions on it. That being said, for this particular use 
case the 25.0.50 behavior appears to be a minor improvement over 24.5.

I suspect you filed this bug report because of some other, 
more-realistic code that behaves poorly with 25.0.50's echoing behavior. 
If so, could you please explain what the code is and what the 
misbehavior's symptoms are?

bug#21489: 25.0.50; Echoing and message interaction (Bug#21489)

[Jay Belanger]

> I'm following up on <http://bugs.gnu.org/21489> dated 2015-09-15.
...
> This exercise was unrealistic enough that I expect we shouldn't be
> basing design decisions on it. That being said, for this particular
> use case the 25.0.50 behavior appears to be a minor improvement over
> 24.5.
>
> I suspect you filed this bug report because of some other,
> more-realistic code that behaves poorly with 25.0.50's echoing
> behavior. If so, could you please explain what the code is and what
> the misbehavior's symptoms are?

I think it had to do with getting help for prefixes from within Calc.
I don't recall the details, though, and I may have found a workaround
for the problem I was having.
At any rate, unless someone else wants to keep it open, the bug might as
well be closed.

Jay

bug#21489: 25.0.50; Echoing and message interaction (Bug#21489)

[Paul Eggert]

Jay Belanger wrote:
> I think it had to do with getting help for prefixes from within Calc.
> I don't recall the details, though, and I may have found a workaround
> for the problem I was having.
> At any rate, unless someone else wants to keep it open, the bug might as
> well be closed.

Thanks, for now I'll close the bug since it's marked as a blocker for Emacs 25. 
We can reopen it later (or open a new one) if the problem turns up later for 
you, or for someone else.