Loic Reporter
	Description • 8 years ago

Bug #2 from bug 1249664.

STR:
1) Open the testcase
2) Browse the dropdown list of the <select>
3) Without clicking on option, move the mouse outside the dropdown

Result: highlighted option is selected and dropdown disappears.

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 1 • 8 years ago

Also looks like a regression from 44. Tracking for 46+. 

Is this also only a problem if e10s is disabled?

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 2 • 8 years ago

jet, can you help find an owner for this recent regression? Thanks.

	Jet Villegas (inactive)
	Comment 3 • 8 years ago

Appears to be regressed by the fix for bug Bug 506815. I've asked for a backout:
https://bugzilla.mozilla.org/show_bug.cgi?id=1249664#c19

	Loic Reporter
	Comment 4 • 8 years ago

It's not a recent regression, the bug is here for ages. I tested with FF4 and FF8 and the bug is present.

On the other hand, bug 1249664 is a recent regression.

	Jet Villegas (inactive)
	Comment 5 • 8 years ago

I see. This bug is also fixed in e10s builds. Marking dependency.

	Mats Palmgren (inactive)
	Comment 6 • 8 years ago

The underlying issue is that the :hover rule makes us destroy the current CSS box
for the element and create a new box of a different type (aka reframing).  We have
never supported keeping the dropdown menu open across reframing.

	Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)
	Comment 7 • 8 years ago

Untracking for 46/47, since this  isn't actually a recent regression. Sounds promising too that e10s fixes the issue!  Thanks for investigating loic, mats, and jet!