Subject: bug#54472: 29.0.50; mouse-wheel-scroll-amount inconsistency

From: Po Lu <[email-masked]>
Date: Sun, 20 Mar 2022 21:06:20 +0800

Ergus <[email-masked]> writes:

> (setq-default mouse-wheel-scroll-amount '(3             ;; No modifier
> 					((control) . 6)
> 					((meta) . hscroll)
>                                         ;; Either Shift+mouse not text-scale work in terminal,
>                                         ;; so put them together
> 					((shift) . text-scale))
> 	    mouse-wheel-progressive-speed nil
> 	    mouse-scroll-delay 0)
>
> And I have noticed that the scroll speed on xterm doubles the one in
> gui: with 1 mouse wheel tick 
>
> on gui: the buffer scrolls 3 lines (seems correct with the config).
> in xterm: (emacs -nw) it scrolls 6 lines.
>
> Is this a known issue? I have a workaround for it, but maybe there is a
> real issue to solve?

> Configured using:
>  'configure --prefix=/home/ergo/.local/ --with-mailutils --with-json
>  --with-x-toolkit=gtk3 --with-xft --with-wide-int --with-modules
>  --with-cairo --with-harfbuzz --with-native-compilation --with-pgtk'
>
> Configured features:
> ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
> JSON LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER
> PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
> WEBP XIM GTK3 ZLIB

You seem to be using a PGTK build.  Please see if you get different
behavior differently on a build with the regular X Windows support.

Thanks.

If you're using X, don't use PGTK.  It lacks certain features, such as
drag and drop support, which will require a rewrite of the selection
handling code to use GDK selections instead of the GTK clipboard,
working `yank-media', and is known to cause many problems related to
input.

BTW, some of your configuration options are redundant or make no sense:
--with-wide-int does nothing on a 64-bit system, and --with-xft,
--with-cairo and --with-x-toolkit=gtk3 are ignored when PGTK is enabled.

You might want to correct them.