Would it be possible to include an option or something to the PortableFirefox launcher that would add a line to the user.js file in the profile directory?
Firefox is running fine from my USB key, but it's very sluggish when I have caching turned on (and it causes a lot of writes to the key, which apparently isn't very good for it). I've tried turning caching off, but that makes FF sluggish as well.
I then set the caching directory to the user's TEMP directory on the local hard drive, and then it works fine. However, this presents the following issues:
* The TEMP folder on several machines (or for different user accounts on the same machine) varies.
* The 'caching directory' preference doesn't support environment variables (like %TEMP%)
That's why I'd like to have the launcher append the line
user_pref('browser.cache.disk.parent_directory', %TEMP%) with of course %TEMP% replaced by the corresponding environment value... And taking JS escaping into account, as well...