440777 - user.js or similar should allow more general Javascript like autoconfig

Status: NEW

(Firefox :: Settings UI, enhancement)

Description

[Josh Triplett]

The autoconfig mechanism (somewhat documented at <http://mit.edu/~firefox/www/maintainers/autoconfig.html>) allows system administrators to write a Javascript configuration file which can run arbitrary Javascript, and which has functions designed to help configure Firefox based on its environment.  For example, an autoconfig file can get environment variables and set preferences based on them; it can also lock preferences (lockPref), set default preferences (defaultPref), and run any other Javascript that an extension could run.

However, no similar mechanism exists for individual Firefox user profiles.  I share my Firefox preferences in user.js between systems as part of my version-controlled home directory.  I'd like the additional flexibility provided by autoconfig, so I can set preferences based on environment variables such as $HOME, $EDITOR, and $EMAIL.

I can see two reasonable ways to implement this:
* Allow arbitrary Javascript in user.js
* Allow user.js to set some preference similar to general.config.filename, such as general.config.user_filename, and process that file as an autoconfig file *after* reading user.js.

The first option seems simplest.  The second option allows user.js to remain compatible with older versions of Firefox which do not support arbitrary Javascript in user.js.

This bug applies to more than just Firefox; please feel free to reassign it to a more appropriate underlying component.