STEPS TO REPRODUCE: 1. Start Firefox [with a fresh profile, for simplicity] 2(a). Click "most visited" or "latest headlines" pseudo-folders on your bookmarks toolbar. OR: 2(b) Right-click bookmarks toolbar, and choose "New Folder", click "Add", and then try to open the folder. ACTUAL RESULTS: Folder takes ~1 sec to open. First bad build is: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.3a5pre) Gecko/20100506 Minefield/3.7a5pre Regression range: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=29bc8f25685d&tochange=014349e11696 in which this push looks most suspicious: http://hg.mozilla.org/mozilla-central/pushloghtml?changeset=d7393e28fb2d

We special handle toolbar menus opening on Linux to allow drag&drop without a key modifier, could be something broke there in the bindings rewrite.

Here's a screencast of the broken behavior, with the 20100506 nightly. The menu item "blinks" when I click it -- note the delay from the "blink" to the menu actually opening. (Maybe it's ~1/2 second rather than a full second, but it's still very tangible & slow from a user's perspective.)

Yeah, if it's half a second, is what i was talking about in comment 1, we delay menu opening to allow drag&drop, but as soon as you mouseup it should open instantly (and this is probably the part that broke)

and here's the working behavior, with the 20100502 nightly. (I meant record the 20100505 nightly, but accidentally did this one -- I've verified that the 20100505 behavior matches this, though.) Here, the menu opens before the "blink" even completes, I think.

yep there is a missing onMouseUp handler in http://mxr.mozilla.org/mozilla-central/source/browser/components/places/content/browserPlacesViews.js#982 Actually we should not even have those on other platforms, thus that probably needs some ifdef love too. I'll take this for now.

This should make it, but I have to test it

Comment on attachment 444874 [details] [diff] [review] patch v1.0 ok, tested on ubuntu 64, looks good. I guess a test for this timings would be hard or too much prone to randomness.

Comment on attachment 444874 [details] [diff] [review] patch v1.0 r=mano