1052900 - (Windows Aero) Can't make content completely transparent anymore

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Luís Miguel [:quicksaver] (not reading bugmail)]

I actually have many examples for this particular "feature" that are now broken in Nightly. The simplest one is the following CSS excerpt to make about:blank completely transparent (to be able to see the desktop behind the firefox window):

> #appcontent,
> #appcontent > #content,
> #appcontent > #content > tabbox > tabpanels {
> 	background-color: transparent !important;
> }
> 
> #main-window[stylish-url="about:blank"]:not([onclose^="PrintUtils"]):not([title^="Source Chart"]):not([chromehidden="menubar toolbar directories extrachrome "]) #content browser:not([src]){ 
>    opacity: 0 !important;
> }

This works fine in all versions of firefox except for Nightly, where instead of a transparent tab I get a completely opaque and black tab. To get the previous behavior, I have to also set -moz-appearance:none on #appcontent, which wasn't necessary before (because it was already set like that?).

This issue appeared on the very first 34.a01 build. Looking at the pushlog, bug 1003425, bug 1022612 and bug 1037220 seem to be likely culprits as they seem to be somewhere in this neighborhood of graphics and layout, but I don't know enough to actually be sure. This might even be expected behavior, or even WONTFIX'able for some other reason. But I thought I'd mention it anyway.

Comment 1

[Luís Miguel [:quicksaver] (not reading bugmail)]

Regression range: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=9350909a3401&tochange=24a69de91baa

roc, do you agree that this is a regression and an unwanted side-effect of bug 1022612? If so, this becomes a bit urgent to fix, as it's in beta already.

Comment 2

[Luís Miguel [:quicksaver] (not reading bugmail)]

Also, setting -moz-appearance:none on #appcontent has many undesirable side-effects, and is not a good "fix": bug 672028 comment 9-11

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: fix

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/669b21a7bfd0

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

[Tracking Requested - why for this release]: Regression affecting addons.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8513083 [details] [diff] [review]
fix

Approval Request Comment
[Feature/regressing bug #]: 1022612
[User impact if declined]: Addons that try to manipulate window transparency on Windows 7 may be broken
[Describe test coverage new/current, TBPL]: very little test coverage
[Risks and why]: this mainly restores code to the way it worked before, so relatively low risk, except that other things changed underneath it in the meantime (namely, how we compute the opaque/transparent parts of a window) so it could theoretically regress addons or even Firefox UI. However, this should only affect users of -moz-win-exclude-glass, which in Firefox proper are the browser, the about box, and the downloads box (apparently), all of which seem to work fine.
[String/UUID change made/needed]: none

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/669b21a7bfd0

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/1fa602d38e6e

Needs rebasing for Beta uplift.

Comment 9

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: beta patch

Comment 10

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 8514758 [details] [diff] [review]
beta patch

applying 1052900-8514758
patching file layout/base/nsDisplayList.h
Hunk #2 FAILED at 796
1 out of 2 hunks FAILED -- saving rejects to file layout/base/nsDisplayList.h.rej
patching file layout/base/nsLayoutUtils.cpp
Hunk #1 FAILED at 3136
1 out of 1 hunks FAILED -- saving rejects to file layout/base/nsLayoutUtils.cpp.rej
patching file layout/xul/nsBoxFrame.cpp
Hunk #1 FAILED at 1324
1 out of 1 hunks FAILED -- saving rejects to file layout/xul/nsBoxFrame.cpp.rej

Are you sure your beta clone is current?

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: beta patch

I'm sure I didn't qref...

Comment 12

[Ryan VanderMeulen [:RyanVM]]

Thanks :)

Comment 13

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/73905ff57286