A script somebody puts in front of the client to add a switch of its own is
still a way of starting Steam, but nothing recognised it as one: the check is
by name, and the script is not called steam.
Such a script tends to name the flag it exists to add, and that flag is one of
the markers the hint scan reads as "this is Chromium". The entry was therefore
handled as an application and had the flag appended to every Exec line of it,
where Steam ignores it, instead of being handed to the Steam module - so the
interface it was pointing at never got autoscroll, and the launcher entry never
got Steam's own switch either.
The handover a launcher script makes is now followed one step, and a script
that hands over to Steam counts as Steam. One step is all there is: the
client's own launcher is recognised by name already.
Felitendo
c1841ec169