Let Older Add-Ons Work With Firefox 3.0

mask.of.sanity informs us of a hack that allows old add-ons to work with Firefox 3.0. Short form: in about:config, create a new boolean and set extensions.checkCompatibility to false. "The fix, which requires a little boolean creativity, great for anyone not afraid of taking risks. The idea is to stop Firefox checking its version history, allowing defunct extensions to work... [Those who do] get the fix working will have to remove the code from the prefs.js file once the stable Firefox comes out, but will enjoy their [favorite extensions] in the meantime."

Comments

Do not do this

[amake]

Not only is this not news, but it's a bad idea. Straight from the horse's mouth:

You can not make your extensions compatible by changing a Firefox preference. So don't do it unless you're fully prepared to deal with major breakage!

Re:Do not do this

[DuncanE]

While it may cause breakage its a great way for users of the beta and RC version of Firefox 3 to get some fairly major extensions work.

I need IEtab to get certain work pages to work and I really love stumbleupon... So when Firefox 3 upgraded automatically to RC1 and these broke it was quite annoying so i disabled the check.

An example of an extension this wont fix is Google Browser Sync. You will need to disable this in Firefox 3 otherwise you WILL see some major breakage if you disable the check.

Re:Do not do this

[GigaplexNZ]

Odd, IE Tab is working fine here on FF 3 RC 1 without any modifications. That said, I find a safer way to get your favourite extensions working is to edit the version number in install.rdf which is inside the .xpi file (xpi is just a renamed zip file). That way when the extension updates normally, the hack doesn't stick around ready to break something later.

Re:Do not do this

[The MAZZTer]

You DO realize safe-mode exists so you can uninstall and disable extensions without having them running, so they can't crash Firefox.

Takes a long time to filter

[IBBoard]

Obviously tips like this take a long time to filter through to Slashdot, for some reason. I saw that tip when first using Firefox 3 betas, and according to the Mozillazine knowledgebase it has been there since Firefox 2! It also covers an extra bit that the summary doesn't that might still stop extensions working in Firefox 3.

And after all that, I originally used the Nightly Tester Tools to check the compatibility of some extensions. Some of the simpler ones worked, but AdBlock Plus couldn't just have the FF2 version enabled (it wouldn't auto-fill the filter address, but they have an update) and neither could the Web Dev toolbar (the edit CSS tab wouldn't close, amongst other things). Both of them have now been updated for the RC.

I think this one is definitely tagged right - "!news". Now all it needs is "badidea".

Nightly Tester Tools

[DemonThing]

This addon lets you selectively override addons' compatibility, among other things.

This extension adds a few extras useful to those that regularly test nightly builds of Firefox, Thunderbird, Sunbird and Toolkit Seamonkey (Suiterunner).

The following is a brief list of the extension's features, for the full set of features please visit the extension home page.

• Extension compatibility fixing
• Titlebar customisation
• Build ID retrieval
• Screenshots
• Breakpad information
• Restoring tabs from previous session
• Leak log analysis

This is really, really stupid

[Idaho]

Sure you can disable the mechanism that checks whether plugins are compatible.

However, as is to be expected with major version changes, lots of API's will likely have changed, so if the plugins happen not to crash outright, they might fail in subtle ways that you don't discover until it's much too late.

This is pretty much exactly why the mechanism is there in the first place.

So if you do this, don't complain about "bugs" regarding crashes, memory leaks and pretty much any other problems you may experience with Firefox. There likely will be a lot, if you go down this road.

Re:A bit less strict disabling rules, please

[maxume]

There is a goal inside of Mozilla not to break extension compatibility for minor releases, and the documentation on their website suggests using maxVersion of the form 2.0.0.* for Firefox 2:

http://developer.mozilla.org/en/docs/Updating_extensions_for_Firefox_2#Step_1:_Update_the_install_manifest

For Firefox 3, they suggest moving to the form 3.0.*:

http://developer.mozilla.org/en/docs/Updating_extensions_for_Firefox_3#Step_1:_Update_the_install_manifest

So no, devs aren't breaking any rules when they mark their extension as being forward compatible.