Bug#617362: iceweasel can't run two sessions simultaneously

[Zefram]

Package: iceweasel
Version: 3.5.16-4
Severity: normal

Suppose one already has Iceweasel running.  Now run it again by typing
"firefox" in a terminal window.  A new Iceweasel window pops up, but
the second firefox process terminates immediately instead of waiting for
the end of the session with the new window.  In fact, the two Iceweasel
windows are not only being managed by the same instance of the program,
they're actually treated as part of the same session, and things done
with one window will affect the other: changes to preferences (such as
preferred background colour) in one window affect the other, and selecting
the "Quit" menu option in one window will close both.  Finally, closing
the original Iceweasel window (by the "Close Window" menu option or an X
"delete window" request) won't terminate the original firefox process --
the process stays around to manage the second window.

I realise that managing both windows with the same process is intentional,
and done for performance reasons, but merging state of the two sessions
and losing the usual correspondence between processes and sessions
is an undesirable side effect.  I don't mind waiting the extra second
it takes to start a fresh session rather than add a new window to the
existing session.

If it's desired to have a way to open a new window in an existing
session from the command line, which I can see being useful to some
people, then that should be an option, not mandatory.  In fact, there's
already such an option (-new-window), it appears that it's being treated
as always on.  There's also an option that looks like it should disable
this behaviour (-no-remote), but if that's used while there's an existing
Iceweasel process then it fails to bring up a browser window at all,
instead producing a small window titled "Close Iceweasel", containing
a road-sign-like icon and the text

	Iceweasel is already running, but is not responding. To open a
	new window, you must first close the existing Iceweasel process,
	or restart your system.

and an "OK" button.  Clicking on that button terminates the new process
without ever bringing up a real browser window.

See also Bug#187138, concerning nearly-identical behaviour of Galeon.

-zefram