User Agent: Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.152 Safari/537.22 Steps to reproduce: Inputs with placeholder text e.g. <input placeholder="Title" type="text"> Actual results: The placeholder text shows through layers e.g. a hover drop down menu - see: (http://www.eflbooks.co.uk/index.php and mouse over the SEARCH box top left) Expected results: In all other browsers that I have tested, the placeholder text does not show through covering layers when it is covered.

Mounir?

Regression range is Last good nightly: 2012-11-09 First bad nightly: 2012-11-10 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=90cea19e27e2&tochange=a47525b93528

Thank you! So that's presumably a regression from bug 737786. In particular, giving the placeholder opacity may be giving it a stacking context... We probably need to make sure that the placeholder's display item ends up stacking inside the input's display item somehow.

Please nominate a fix for this regression for uplift if it's low risk enough but we don't need to track this as it doesn't seem to be a very popular use case or a serious UI breakage but more a mild annoyance (correct me if I'm wrong here).

Well, it makes it impossible to select some menu options on this site, at least for me...

Yeah, the opacity forms a new stacking context which gets put in our PositionedDescendants list (which is a bad name), so it escapes the text control and then gets sorted with the rest of the content on the page. If text controls weren't special than this testcase would be equivalent. But they are special.

This needs a reftest of course.

Yep, already in my queue.

https://hg.mozilla.org/integration/mozilla-inbound/rev/eaf894949611 https://hg.mozilla.org/integration/mozilla-inbound/rev/a67ca797279e

https://hg.mozilla.org/mozilla-central/rev/eaf894949611 https://hg.mozilla.org/mozilla-central/rev/a67ca797279e

Comment on attachment 721923 [details] [diff] [review] patch [Approval Request Comment] Bug caused by (feature/regressing bug #):bug 737786 User impact if declined: placeholder text in input textbox will appear over top other page content incorrectly, according to comment 5 this makes it impossible to use the menu options on http://www.eflbooks.co.uk/index.php Testing completed (on m-c, etc.): on m-c for about 4 days now Risk to taking this patch (and alternatives if risky): fairly low risk, the frame tree under text controls is fully under our control, and the kinds of things that are in it are limited, so the resulting display list should be pretty simple String or UUID changes made by this patch: none

Comment on attachment 721923 [details] [diff] [review] patch Will take this low risk fix since we're at our 4th beta of the cycle, please land today so it's in tomorrow's beta build.

https://hg.mozilla.org/releases/mozilla-aurora/rev/101247312576 https://hg.mozilla.org/releases/mozilla-aurora/rev/02c22d594266

https://hg.mozilla.org/releases/mozilla-beta/rev/5637f880eb77 https://hg.mozilla.org/releases/mozilla-beta/rev/0d32b5f317ec

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0 Verified on Firefox 21.0b5, on Windows 7, 64 bits using the two provided testcases.

Verified as fixed on Windows XP using FF 22.b1: Mozilla/5.0 (Windows NT 5.1; rv:22.0) Gecko/20100101 Firefox/22.0(20130514181517)

Verified as fixed on Win XP using FF 20.0.1 and FF 21.0 too: Mozilla/5.0 (Windows NT 5.1; rv:20.0) Gecko/20100101 Firefox/20.0(20130409194949) Mozilla/5.0 (Windows NT 5.1; rv:21.0) Gecko/20100101 Firefox/21.0 (20130511120803)