User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:29.0) Gecko/20100101 Firefox/29.0 (Beta/Release) Build ID: 20140327140727 Steps to reproduce: OSX 10.8.5 Firefox Beta 29 + Trunk 31 1.) Drag a bookmark on the Bookmarks Bar and take a closer look on the Bookmarks Bar Actual results: The Bookmarks Bar grows up 1px Expected results: The Bookmarks Bar should not resize.

One more thing I noticed: This is probably caused, because the dragging indicator is no longer centered vertically. A screenshot is attached.

(In reply to Mehmet Sahin from comment #1) > Created attachment 8399497 [details] > separator_no_longer_vertically_centered.png > > One more thing I noticed: This is probably caused, because the dragging > indicator is no longer centered vertically. > > A screenshot is attached. Separator is maybe the wrong wording. I mean the indicator when you drag a bookmark on the Bookmarks Bar.

I thought bug 942600 had taken care of this...

(In reply to Marco Bonardo [:mak] from comment #3) > I thought bug 942600 had taken care of this... I think that one took care of horizontal overflow - this is about 1px vertical growth.

I can reproduce this, but only the first time you drag a bookmark in the bar in a window (ie the growth is permanent).

So I wanted to understand this better because of bug 982215 but I'm failing. Mike, do you know what's up here? It seems the size of the bookmarks in the bookmarks toolbar actually increases, but I don't know if that's because the outer size increases and it's just stretching, or something else...

Yeah, I think I see what's going on here (though not 100% sure why yet): PlacesToolbarDropIndicatorHolder doesn't have collapsed set on it in the 20px case. Manually setting collapsed on it puts the toolbar at the right height again. So we have to find the part of the code that's responsible for setting collapsed on PlacesToolbarDropIndicatorHolder, and find out why it's not happening.

Actually, correction - we have to find that PlacesToolbarDropIndicatorHolder causes the growth of 1px when uncollapsed. Just setting collapsed on it when collapsing the drop indicator will mean that we're still growing by 1px during the drag.

Ok, I think I've sorta figured it out. It has to do with the position: absolute on PlacesToolbarDropIndicatorHolder. If we reduce the ancestor chain up to the nearest positioned element (by setting position: relative on the hbox parent, or even on the PlacesToolbar itself), the 1px bump doesn't happen. This also doesn't seem to regress bug 942600, which is good. It does, however, make the top: 25% not work anymore - 25% from the top of the position: relative'd container is too much when in the bookmarks toolbar. Not so if the bookmarks toolbar items are in the nav-bar. *sigh*. Anyhow, that's my diagnosis. Did you want me to pick this up Gijs, since I've got a bunch of it swapped in? Or did you want to hack on it?

(In reply to Mike Conley (:mconley) from comment #9) > Anyhow, that's my diagnosis. Did you want me to pick this up Gijs, since > I've got a bunch of it swapped in? Or did you want to hack on it? Nope, go for it! I was just looking because I figured this intersected with bug 982215 but didn't make much headway, you seem to have this under control. :-)

Unfortunately, it's unlikely I'll get to this in the near future. I'll pick it up again eventually if nobody else does, but in the meantime, I won't hold it hostage.

This was fixed shortly in Photon Theme with bug 1389162. Merging into it.