STR: 1. Open a bunch of tabs (more than enough that they cannot all be viewed at one time in the tab strip) 2. Scroll the tab strip so that the last/rightmost tab is visible, but is cut off by the edge of the tab strip 3. Close any visible tab using the 'X' At this point, another tab should shuffle into the place of the one that you just closed, so that its 'X' is exactly in the location that you just tapped. To see the correct/expected behavior, do the following: 1. Same step 1 as above 2. Scroll the tab strip so that the last/rightmost tab is either entirely visible (not cut off at all) or is entirely invisible 3. Same step 3 as above

Mass close of bugs in obsolete product https://bugzilla.mozilla.org/show_bug.cgi?id=1350354