Hi Gareth,
I have solved it.
The solution: *drumroll* Switch from Ubuntu to Bookworm.
[...]
There is no "[-]-private" option according to the grep I performed, and [-]-private produces a non-private window when run here from the command line.
Thanks Brad, Max, Greg, Jeffrey, Tomas and the unnamed Briton.
I have used Bookworm earlier, but the apt policy bit and Max's
reply
drove me to return.
Some confusion may still be in order though:
Nikulin's suspicion that a copy of the file is used seems true:
changing
non-pinned icons in Ubuntu's panel worked without a reboot, but
not
Firefox. I tried looking into the GNOME source (grep-ing into that
address)
but in vain.
The desktop-file-validate tool threw no error. Incidentally, the
Ubuntu
desktop file had a single hyphen in the sub-entry for private
windows
(Bookworm does not have sub-entries), but I've used both single
and double
hyphens earlier. But I am using double hyphens now, as Brad
warned.
I don't think *I* should raise a bug as Max suggested: unless a
significant
number of users is interested, I wouldn't want to, although not
having
your data out there is better IMHO. Perhaps some day I'll
contribute the
feature myself.
Thanks again,
Pranjal