Files
middleclick-autoscroll/doc/middleclick-autoscroll.1.scd
T
Felitendo f42d80598f fix: keep Steam out of an endless update loop
Steam compares its installed files against its manifest at every start and
restores whatever differs, which is why its launcher entry carries
-noverifyfiles. The entry in ~/.config/autostart never got it: it points at
/usr/bin/steam, a shell script, so it fell through the Chromium filter in
mca_autostart_apply and was left alone.

A Steam started at login therefore verified, found the web helper script 46
bytes larger than the manifest says, restored it, and the path unit patched
it straight back - an update dialog that begins again every few seconds and
never finishes. The same client started from the menu was fine, which is
what made it look like a problem of Steam's own.

The autostart entry now carries the switch as well. It follows the Steam
setting rather than the autostart one, because leaving it out while Steam is
patched is exactly what causes the loop.

That covers the entry that exists; a terminal or a script still starts Steam
without the switch. So the patch no longer fights back either: a script that
was patched before, is not patched now, and belongs to a client that is
still running has just been restored by Steam, and doing it again would only
have the two of them undoing each other. It waits for the next apply with
Steam closed - the helper is started once, at the start, so patching it now
would not have helped that session anyway.

Also: Steam does not checksum that script, it compares sizes - the log says
"Verifying file sizes only" - while the comments and the documentation
claimed otherwise. And the status screen now tells a patch that is waiting
from one that is missing, instead of reporting both as not patched yet.
2026-08-24 10:01:27 +02:00

160 lines
5.8 KiB
Scdoc

middleclick-autoscroll(1)
# NAME
middleclick-autoscroll - middle-click autoscroll in every application that supports it
# SYNOPSIS
*middleclick-autoscroll* [_command_]
# DESCRIPTION
Blink, the engine inside Chromium, Electron and CEF, implements Windows-style
autoscroll: hold the middle mouse button and the page scrolls with the pointer.
On Linux it is switched off, because middle click is taken by primary-selection
paste. It can be turned back on with *--enable-blink-features=MiddleClickAutoscroll*
on the command line.
*middleclick-autoscroll* finds every Chromium-based application on the system
and puts that argument somewhere the application will actually read it, then
keeps doing so for anything installed later.
Run without a command it shows an interactive menu. Everything it can be told
is reachable from there; the configuration file behind it does not need to be
edited by hand.
Nothing outside the user's home directory is written to, and running it as root
is refused.
# COMMANDS
*enable*
Turn autoscroll on, apply it to everything installed, and start watching
for new applications.
*disable*
Turn it off and put every file that was changed back the way it was.
*apply* [*--rebuild*]
Apply to anything that has appeared since the last run. This is what the
watcher calls; running it by hand is only needed when the watcher is off.
Entries left behind by an application that has since been uninstalled are
removed here too - the entry shadowing it lives in the user's home, where
the package manager that removed the application cannot see it.
With *--rebuild* everything is taken back first and written again from
scratch. That is the repair: it does not care what looks correct already.
*status*
How many applications are covered, whether Steam is patched, and when the
last run was.
*list*
Every Chromium-based application that was found, and how each one is
handled.
*-h*, *--help*
Show a summary of the commands.
*-V*, *--version*
Show the version.
# HOW THE ARGUMENT GETS IN
Two ways, chosen per application.
*Flag file*
Arch's Electron and Chromium wrappers read extra arguments from
_$XDG_CONFIG_HOME/<name>-flags.conf_. This is the preferred route: it is
the supported way to pass arguments, it survives package upgrades, and it
applies to a launch from a terminal as much as one from the menu. An
*--enable-blink-features* line that is already in the file is extended
rather than duplicated - Chromium keeps only the last occurrence of that
option, so a second one would switch the first one off.
*Desktop entry*
For applications that ship their own binary with no wrapper, and for
Flatpaks, a copy of the desktop entry with the argument appended is written
to _~/.local/share/applications_, where it shadows the system one. Entries
that already live there - AppImages, web app shortcuts - are edited in
place, with the original kept.
A generated entry is marked *X-MCA-Generated* and an entry edited in place
*X-MCA-Patched*. The two are never confused: the first is deleted when
undoing, the second is restored from its backup. An entry with neither
marker belongs to somebody else and is left alone.
Programs that start themselves at login write their own entry into
_~/.config/autostart_ pointing straight at their binary, bypassing the menu
entry entirely. Those are patched in place as well.
# STEAM
Steam's interface is CEF and supports the feature, but Steam builds the command
line for its web helper itself. The only way in is the script that starts the
helper, inside Steam's own installation:
~/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
Steam compares the installed files against its manifest at every start - by
size, not by content - and restores whatever differs, so its launcher entry
gets *-noverifyfiles*. So does its entry in _~/.config/autostart_, which Steam
writes as soon as it is set to run at login: that entry bypasses the menu one
entirely, and without the switch a Steam started at login spends the session in
an update dialog. The trade-off is that Steam no longer repairs a damaged
installation on its own; that is why Steam is a switch of its own in the
settings.
Starting Steam some other way - from a terminal, from a script - leaves the
switch out, and Steam puts its own copy of the script back for that session.
The patch returns at the next apply with Steam closed. It is deliberately not
repeated while the client is running: the two would only undo each other, and
the helper is started once, at the start, so it would not help that session
anyway.
# SPOTIFY
The official client is CEF rather than Electron. Installed through
*spotify-launcher*, it is started by a program that builds its own command line
and has a configuration file with a slot for extra arguments; that slot is
where the flag goes. Installed as a plain package, it is an ordinary desktop
entry and needs nothing special.
# WHAT CANNOT BE DETECTED
An AppImage keeps its payload in a compressed filesystem, so there is no way to
tell from the outside whether it contains Chromium. Those are listed as *cannot
tell* and left alone until they are switched on from the applications screen.
# FILES
_~/.config/middleclick-autoscroll/config_
Written by the program. Every option in it is reachable from the menu.
_~/.local/state/middleclick-autoscroll/ledger_
One line per change, so *disable* can undo exactly what was done and
nothing else.
_~/.local/state/middleclick-autoscroll/backup/_
Copies of the files that are edited in place rather than shadowed.
_~/.cache/middleclick-autoscroll/detect_
Which programs were found to be Chromium, keyed by size and modification
time. Safe to delete.
# ENVIRONMENT
*NO_COLOR*
Disables colour.
# SEE ALSO
*systemctl*(1), *flatpak*(1)
# AUTHORS
Felitendo. Source and issue tracker at
https://github.com/Felitendo/middleclick-autoscroll