436003 - <xul:panel noautohide="true" style="background:transparent"> shows black background on Windows

Status: RESOLVED DUPLICATE of bug 432460

(Core :: XUL, defect)

Description

[Mook (songbird dead account)]

Attachment: test case (launch with firefox -chrome)

This appears to be Windows only; Mac and Linux look fine.

With a <xul:panel> with noautohide="true", transparent background shows up as black instead.  If noautohide is not set (i.e. default, false), it works as expected.

See testcase; must launch as chrome (otherwise the transparency doesn't want to apply, as evidenced by having drop shadow).  Clicking any of the two buttons in the panel closes the window.

Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0

Comment 1

[:Mook]

Some random notes:
As far as I can tell, this happens because, on Windows, <panel noautohide> gets parented (i.e. it has a HWND parent) so that it doesn't get on top of other windows.  But the transparency setting walks up the HWND tree to find the window to set layer window on.  Which means it ends up being set on the wrong window.

Just hacking things there so that it sets layered window on the panel HWND didn't quite seem to work, but it's possible that my hacks weren't done correctly.