One set of Mozilla autoconfig rules for both Firefox & Thunderbird

In case anyone might find this technique useful or have interesting ideas of their own to add (hopefully this still works in the latest versions, I'm using 16.02/WinXP on this machine)...

1] Close all instances of Firefox and Thunderbird

2] In Mozilla Firefox installation dir, create \defaults\preferences\autoconfig.js containing:

Code:

//
pref("general.config.obscure_value", 0);
pref("general.config.filename", "FirefoxCfg.js");

3] In Mozilla Firefox installation dir, create FirefoxCfg.js containing:

Code:

//
try
{
  // Read config filename pref set by autoconfig.js earlier
  var cfgFile = getPref("general.config.filename");
  
  // Set a context independent pref, I'll demo pref() here
  pref("bogus.pref.common", "I am a common pref");
  
  // Set a context specific pref, I'll demo lockPref() here
  if(cfgFile == "FirefoxCfg.js")
    lockPref("bogus.pref.switched", "I am a Firefox specific pref");
  else if(cfgFile == "ThunderbirdCfg.js")
    lockPref("bogus.pref.switched", "I am a Thunderbird specific pref");
  else throw("Unknown cfgFile value: " + cfgFile);
  
  // Display set prefs
  var msg = "bogus.pref.common=" + getPref("bogus.pref.common")+
            "\nbogus.pref.switched=" + getPref("bogus.pref.switched");
  Components.utils.import("resource://gre/modules/Services.jsm");
  Services.prompt.alert(null, "AutoConfig", msg); 
}
catch(e)
{
  displayError(cfgFile, e);
  throw("");  // Terminate startup, msg is not displayed 
}

4] In Mozilla Thunderbird installation dir, create \defaults\preferences\autoconfig.js containing:

Code:

//
pref("general.config.obscure_value", 0);
pref("general.config.filename", "ThunderbirdCfg.js");

5] In Mozilla Thunderbird installation dir, create ThunderbirdCfg.js containing the same code put into FirefoxCfg.js (up above).

6] Launch Firefox, you should see an alert window popup saying:

hit OK button and Firefox should launch normally.

7] Launch Thunderbird, you should see an alert window popup saying:

hit OK button and Thunderbird should launch normally.

8] To unwind this demo, close all instances of Firefox and Thunderbird, delete both autoconfig.js files, the FirefoxCfg.js file, and the ThunderbirdCfg.js file.