This is just a list of the hacks or fixes that I currently have in place on Iceweasel. These were not my invention, and surely I owe a debt of thanks to various sites; unfortunately I have no way of knowing which sites.

Some of these hacks are too facilitate system wide control, others help to maximise performance on a thin client system.

Iceweasel Global Preferences

/etc/iceweasel/pref/iceweasel.js

// This is the Debian specific preferences file for Iceweasel
// You can make any change in here, it is the purpose of this file.
// You can, with this file and all files present in the
// /etc/iceweasel/pref directory, override any preference that is
// present in /usr/lib/iceweasel/defaults/preferences directory.
// While your changes will be kept on upgrade if you modify files in
// /etc/iceweasel/pref, please note that they won't be kept if you
// do make your changes in /usr/lib/iceweasel/defaults/preferences.
//
// Note that lockPref is allowed in these preferences files if you
// don't want users to be able to override some preferences.

lockPref("extensions.update.enabled", true);

// Use LANG environment variable to choose locale
lockPref("intl.locale.matchOS", true);

// Disable default browser checking.
lockPref("browser.shell.checkDefaultBrowser", false);

// ========= LTSP SPECIFIC HACKS ========

// Disable "safe browsing" feature that hogs CPU, HDD, etc. etc. in LTSP
lockPref("browser.safebrowsing.enabled", false);
lockPref("browser.safebrowsing.malware.enabled", false);

// Disable annoying location-bar suggestion "feature" that is sludgy with thin-clients
lockPref("browser.urlbar.maxRichResults", 0);

// Disable offline/disk caching of web pages
lockPref("browser.cache.offline.enable", false);
lockPref("browser.cache.disk.enable", false);
lockPref("browser.cache.memory.enable", false);

// ========= PROXY HACKS =========

lockPref("network.proxy.type", 1);
lockPref("network.proxy.share_proxy_settings", true);
lockPref("network.proxy.http", "192.168.1.254");
lockPref("network.proxy.http_port", 800);
lockPref("network.proxy.no_proxies_on", "localhost, 127.0.0.1, 192.168.1.0/24");

// ========= MISC HACKS ==========

lockPref("browser.startup.homepage", "http://www.example.co.uk/");
lockPref("app.update.enabled", false);

Iceweasel Image Caching

I understand that, on websites with certain size of image, that the thin client xorg starts to take a ridiculous amount of memory, resulting xorg dieing and the thin client returning to the login page. The following may help:

$ sudo echo "MOZ_DISABLE_IMAGE_OPTIMIZE=1" >> /etc/profile

References

I must apologise for the lack of references, if you recognise some of your work in the above, please do accept my apologies.

Iceweasel and Firefox do not use the KDE Print system, but instead print directly to CUPs. This works fine, but can be confusing, as it looks different and doesn’t offer all the same functions, like PDF etc.

Trying to resolve this issue, I came across this posting:

• How To: Make Firefox / Thunderbird print to kprinter automatically in KDE / Kubuntu by msak007

Single User

Step 1 Print to Postscript

First, if you haven’t done so, you need to print to PostScript in order for the needed entry in prefs.js to be populated. This will be done automatically the first time you print. Open any web page and go to:

File → Print → choose PostScript/default (it should be the default if you haven’t installed any printers yet) → click “Print”

Once you have done this and it prints, it’ll add the PostScript entry you need to edit.

Step 2 Change default postscript printer

In the URL bar, open the config by typing:

about:config

In the “Filter” bar, type

print.printer_PostScript/default.print_command

This should filter everything out but that line.

Right-click on the line, click on “Modify”, and change the entry from:

lpr ${MOZ_PRINTER_NAME:+-P"$MOZ_PRINTER_NAME"}

to:

kprinter

Then click OK. This will make Iceweasek print to kprinter any time you select the “PostScript/default” printer.

Step 3 Set it to print automatically

Right-click anywhere in the white space, then click on “New → Boolean” to add a new Boolean entry. Type:

print.always_print_silent

And set its value to “true”. This will force Iceweasel to print to the default printer without prompting you.

Step 4 Disable CUPs

If “PostScript/default” is the only printer you have and there are no local / network printers, it works great and you can stop here. But if you installed a printer through CUPS, it complicates things as Iceweasel will want to use that as a default and all your prints will go there without prompting you! So even if you don’t have a local printer, it’s a good idea to add the following line in case you add one later.

Once again, right-click and choose “New → Boolean”. Type:

print.postscript.cups.enabled

And set its value to “false”. That will disable CUPS printing in Iceweasel, and it will default to the “PostScript/default” printer. And since you’ve changed the output of that to kprinter, you’ll see a “processing” dialog for a split second when you print, after which kprinter will open up. There you can choose all your printers, including PDF, PostScript, and any CUPS installed printers.

Multi-user

There is a file that controls global settings, but it’s not prefs.js - it’s called (ironically) firefox.js, and is located in:

/usr/share/iceweasel/defaults/pref

Make sure you have Firefox closed and edit the file using your favorite editor.

$ cd /usr/share/iceweasel/defaults/pref/
$ sudo cp firefox.js firefox.js.backup
$ kdesu kate firefox.js

Enter your password, and when Kate opens up add the following to the very end of the file:

// Print to kprinter by default for all users
pref("print.postscript.print_command", "kprinter");
pref("print.print_command", "kprinter");
pref("print.always_print_silent", true);
pref("print.postscript.cups.enabled", false);

Save the file and launch Firefox. This will not overwrite or modify and user set entries (the entries in bold in about:config), so it will only affect new profiles. If you’ve already modified your profile, this will not change any of the settings in it.