If a caller of set-transient-map passes a suitable format string, this
is displayed as a message on activating the transient map.  An example
is text-scale-adjust, which displays the message "Use +, =, -, 0, C-+,
C-=, C--, C-0 for further adjustment".  So if after typing `C-x C-+' you
immediately type `+ + + - - -', the text size increases three times and
then decreases three times.  But on each key press the message is
redisplayed, which is slighty annoying (it actually looks like it stays
in the echo area but there is a brief flicker on each key press); the
message is helpful the first time, if you're unfamiliar with the
command, but on repeated uses, it becomes visual noise.  So I propose a
user option to suppress the message, as in the attached patch.

One thing I'm not sure about is whether the call to `message' in the
local function `clearfun' of set-transient-map, which is added to
pre-command-hook, should also be conditioned on the proposed user
option; I tested both with and without such conditioning and saw no
difference, so the patch omits it.  But I admit I don't see what the
purpose of clearfun is, so maybe it should be so conditioned.

If the patch (or a corrected version of it) is accepted, I will also
update the elisp manual and NEWS accordingly.

(An alternative to the above proposal is suppressing the message after
displaying it once (or perhaps n times, though that seems extravagant).
Or allowing both alternatives (or all three) as values of the user
option.  I prefer the simpler display-or-suppress proposal, but can
implement an alternative if desired.)


In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.43, cairo version 1.18.2) of 2024-10-21 built on strobelfssd
Repository revision: b3af195213518514f78ac6f66f9598e45befd1ec
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101013
System Description: Linux From Scratch r12.2-17-systemd

Configured using:
 'configure -C 'CFLAGS=-Og -g3' PKG_CONFIG_PATH=/opt/qt6/lib/pkgconfig'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG
RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER
WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB