1277044 - Firefox handling of taskbar preview is inconsistent.

Status: UNCONFIRMED

(Core :: Widget, defect)

Description

[Robert Claypool]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:49.0) Gecko/20100101 Firefox/49.0
Build ID: 20160520030251

Steps to reproduce:

One thing i did was check and uncheck Options|Tabs|Show tab previews in the Windows taskbar, which didn't change anything.

I've tried going back to older builds, but it seems that there are specific builds that change settings that persist until another specific build changes the setting again, so just going back a few builds doesn't make it work again.


Actual results:

When I hovered over the taskbar as Nightly was loading, it showed a list correspondning to many tabs, but as the load progressed the taskbar previews switched to the active tab in each window. In an earlier release it worked but in an even earlier release trying to close a single tab through the taskbar, caused a message that closing the window would close individual tabs. That subcondition got reported in another bug.


Expected results:

When "Show tab previews in the Windows taskbar" is checked, until the list gets too wide, tab taskbar previews should show all tabs, and when the list does get too wide, a list of all tabs should appear. Bonus if you could show a tab preview to the side of the list expansive list.