Comment 0 for bug 308605

User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081012 Minefield/3.1b2pre
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081012 Minefield/3.1b2pre

I have several different profiles for different purposes, e.g. one with only few selected addons and lots of security restrictions and one with "almost anything".
Some of the profiles use a proxy in order to access certain pages, others don't, etc. etc.
Instead of changing the preferences and addons every few minutes, I often need two instances of firefox running - each with a different profile of course.

Reproducible: Always

Steps to Reproduce:
1. Start firefox with an existing profile "default"
2. Start firefox with an existing profile "second" using 'firefox -P second'

Actual Results:
The running firefox instance using the profile "default" opens another window

Expected Results:
The started firefox instance should check whether any of the running firefox instances uses this profile already.
If there is an instance of firefox with the same (specified) profile running, it should open a new window
If there is no instance of firefox with the same (specified) profile running, it should startup one with the specified profile

Starting another firefox instance can be done by
 firefox -P second -no-remote
but there is no way to e.g. open a firefox window with a specified profile and a given url from e.g. command line or from other programs that allow to specify the browser command.
Running that very same command again if there is already a firefox instance using the profile "second" shows a dialog with the (only partially correct) message "Firefox is already running, but is not responding. [..]"