1197621 - Popup menus from toolbar have wrong placement of triangle if window size is narrow enough

Status: NEW

(Firefox :: Menus, defect)

Description

[arni2033]

Attachment: Popup menus from toolbar have wrong placement of triangle if window size is narrow enough.png

STR:   (Win7, Nightly 43.0a1 (2015-08-20))
1. Place Pocket button and History button on toolbar.
2. Doch the window to the left side of screen, place mouse over right border of the window and
   drag it to the left to make window's width as small as possible (to cause overflow)
3. Click #nav-bar-overflow-button to view hidden buttons in toolbar
4. Click Pocket/History button

Result:       Triangle is placed at the right top of menu popup
Expectations: Triangle should be placed at the left top of menu popup

Note:   I can reproduce it with Pocket and History buttons. However, it may and WILL happen with
        add-ons that provide wide popups, and user may set HiDPI on his mashine. In these cases you
        don't even need to make the window too narrow to reproduce it.