699722 - "ASSERTION: Framesets should not be positioned and should not float" when full-screening a <frameset>

Status: NEW

(Core :: DOM: Core & HTML, defect, P5)

Description

[Jesse Ruderman]

1. Set user_pref("full-screen-api.enabled", true);
2. Load the testcase
3. Click anywhere

Result: 

###!!! ASSERTION: Framesets should not be positioned and should not float: '!disp->IsAbsolutelyPositioned() && !disp->IsFloating()', file layout/generic/nsFrameSetFrame.cpp, line 1566

Comment 1

[Jesse Ruderman]

Attachment: testcase

Comment 2

[Jesse Ruderman]

Attachment: stack trace

Comment 3

[Boris Zbarsky [:bzbarsky]]

Hrm.  So the issue is that we have some existing !important position/float rules in the UA stylesheet, but the full-screen rules are more specific...

The assertion here dates back to bug 263406, but positioning of framesets was disallowed even before that....

We can probably remove this assertion for <frameset>, I suspect; I don't know of any obvious reasons why it can't be positioned/floated in the particular way that fullscreen stuff does it.

But this raises an interesting question: what should happen for <frame>?  Per spec, the insides of <frameset> don't participate in CSS layout at all, iirc; I'm pretty sure that trying to apply the fullscreen styles to <frame> won't work.  Since I expect no one will ever do that, maybe the spec could just forbid fullscreening <frame>?

And a similar question about <option>, actually.

Comment 4

[Jesse Ruderman]

Still happens on trunk after b99801e9a0c0 and friends modified the assertion condition:

###!!! ASSERTION: Framesets should not be positioned and should not float: '!disp->IsAbsolutelyPositionedStyle() && !disp->IsFloatingStyle()', file ../../../layout/generic/nsFrameSetFrame.cpp, line 1520

Comment 5

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046

Move all DOM bugs that haven't been updated in more than 3 years and has no one currently assigned to P5.

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