STEPS TO REPRODUCE: 1. Visit ftp://ftp.mozilla.org/pub/ 2. Click a link for some folder, and then click a link inside that folder. 3. Hit 'Back' browser button --> Now both "Back" and "Forward" buttons should be available. 4. File | Print Preview 5. Hit 'esc' key, or 'Close' button, to leave Print Preview. EXPECTED RESULTS: Back and Forward buttons should still be available. ACTUAL RESULTS: Back and Forward buttons are both grayed out now. (If I switch tabs away & back, the buttons become available again.) BROKEN: Mozilla/5.0 (X11; Linux x86_64; rv:7.0a1) Gecko/20110601 Firefox/7.0a1 WORKS: Mozilla/5.0 (X11; Linux x86_64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1 ('Print Preview' might not be the right component for this, but I'm filing it there to start.)

Nightly regression range: WORKS: Mozilla/5.0 (X11; Linux x86_64; rv:6.0a1) Gecko/20110503 Firefox/6.0a1 BROKEN: Mozilla/5.0 (X11; Linux x86_64; rv:6.0a1) Gecko/20110504 Firefox/6.0a1 http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=86248f7209b7&tochange=c3c4c902e9cd

(Based on regression date, this bug is present in mozilla-aurora, and it will be a new regression in Firefox 6 unless it's fixed.)

Confirmed that this was caused by the checkin for bug 451833, which added the pref "browser.urlbar.formatting.enabled". If I disable that pref in today's nightly, this bug goes away. (No restart needed). This is probably related to bug 660391 ("After closing Print preview, the favicon and the domain name highlighting disappears from the navigation bar")

In particular, from bug 660391 comment #3: > Error appears When closeing print preview: > > Error: [Exception... "Component returned failure code: 0x80004003 > (NS_ERROR_INVALID_POINTER) [nsISelectionController.getSelection]" nsresult: > "0x80004003 (NS_ERROR_INVALID_POINTER)" location: "JS frame :: > chrome://browser/content/urlbarBindings.xml :: formatValue :: line 152" > data: no] > Source File: chrome://browser/content/tabbrowser.xml > Line: 414

Just to get the ball rolling on this: the attached patch catches & squashes the exception that I quoted in comment 4, returning early from formatValue() instead of throwing. I've verified that this change is sufficient to fix this bug. (though it doesn't fix bug 660391) Dao, perhaps you can come up with an actual fix for this (or let me know if this patch is actually what we want, which I doubt)? This isn't a regression we should ship Firefox 6 with, IMHO.

Clearing Firefox 6 tracking due to bug dup.