Close/Blank last tab w/ middle-click?

Question

I have only one tab open in Firefox (the page that's showing this question, for example). I'm using (what I think is) a stock 3.6.6 install, and there's no close button on that one tab. Here's the current behavior when I middle-click on that tab:

• nothing happens

Here's the behavior I want when I middle-click on that tab:

• web page disappears
• same tab remains, but it's now blank

How can I make Firefox behave this way? I've had it before, but I don't know if it was an addon (likely TabMix Plus) or a tweak I made to the stock browser?

EDIT: I really want this without installing addons, but I accept that an addon may be required.

Answer 1

In about:config, set

browser.tabs.closeWindowWithLastTab

to false.

Edit: This works on my iMac; doesn't on my macbook. No idea what's different, YMMV.

Answer 2

Tab mix plus does this, but you have to do a little tweak to it go to Tab Mix Plus Options -> Events -> Tab Closing -> Closing Last tab, and check "Do not close window when closing last tab".

EDIT: There is no way to do this without tab mix plus.