963214 - Shrunken tabs resize prematurely upon closing if mouse lands between the last tab and new tab button at top of window

Status: NEW

(Firefox :: Theme, defect)

Description

[Jared Wein [:jaws] (please needinfo? me)]

+++ This bug was initially created as a clone of Bug #823237 +++

STR:
Use a build with the Australis tabs
Maximize the window
Open enough tabs that the tab size shrinks
Move the mouse to the vertical center of a tab **that is in the middle of the tab strip**
Middle click on the tab to close the tab (about 5 pixels from the top and on one of the curves)
->  Close enough of these tabs such that moving the
    mouse out of the tabbar would cause them to grow in size
Move the mouse to the top of the screen and between tabs

Expected:
The tabs should not resize since the cursor is still over the tabbar

Actual:
The tabs resize since the cursor is not on top of a tab