1253042 - Compositor distorts 3d transformed blocks with "perspective" property

Status: RESOLVED DUPLICATE of bug 1269337

(Core :: Layout, defect)

Description

[Dan Callahan [:callahad]]

Attachment: screenshot.png

See screenshot.

Affected: 47 (nightly) and 46 (dev edition) on Mac OS X.
Not Affected: 44 (stable) or 45 (beta) on Mac OS X. Any version on Linux.
Unknown: Windows

STR:

1. Visit http://lab.hakim.se/reveal-js/
2. Press ESC to enter the slide overview mode
3. Press the right arrow a few times to change the selected slide

What should happen:

- The slide thumbnails translate across the screen, maintaining their aspect ratios

What actually happens:

- The rendered slide thumbnails stretch and distort

Other notes:

- Opening the DevTools Inspector and hovering over each child of the <div class="slides"> shows a correctly positioned and scaled outline for the element, even though the element itself is distorted when rendered.

- Injecting `.reveal.overview { perspective: none !important; }` in the Style Editor fixes the distortion at the cost of losing much of the scaling. The default stylesheet sets perspective: 700px;.

Comment 1

[Milan Sreckovic [:milan] (needinfo for best results)]

Not E10S specific.

Comment 2

[Cosmin Muntean [:cmuntean], Ecosystem QA]

Hi,

I have tested this issue on the latest Nightly (47.0a1) build on MAC OS 10.11 and I have managed to reproduce it. Firefox (44.0.2) release does not reproduce this issue. I have also tested on MAC OS 10.7, Windows 7 x64 but I was unable to reproduce it on Firefox (44.0.2) release or Nightly (47.0a1) build.

Firefox: 47.0a1, Build ID: 20160306030215
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:47.0) Gecko/20100101 Firefox/47.0

I have performed a regression and this is the obtained pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=37c7812ce0e6d10c7e7182f12e752832835e1d67&tochange=eb30e5ee32f0a11e3df594b5b3e69d0a5566bb63
Last good revision: 37c7812ce0e6d10c7e7182f12e752832835e1d67
First bad revision: eb30e5ee32f0a11e3df594b5b3e69d0a5566bb63

Thanks,
Cosmin.

Comment 3

[Dan Callahan [:callahad]]

This is now in Release. Bumping severity.

Rationale: Reveal.js is, by far, the most common HTML5 presentation framework, used by a majority of presenters at all conferences I've recently attended. This bug means that Reveal.js is severely degraded, and potentially unusable, on Firefox.

This disproportionately harms Firefox, since it makes it less likely that prominent members of the development community will be seen using Firefox while on stage. On a personal note, I work on the Developer Relations team. Presenting to engineers at conferences is literally my job. This bug makes it significantly more difficult for me to do my job, as I have to dance around my presentation software to avoid triggering this highly-visible bug and publicly embarrassing Mozilla.

:milan, do you have any suggestions for next steps, now that :CosminMCG has identified a regression window? As a temporary measure, I'd also be happy to work with the Reveal.js upstream (I've successfully done so in the past) to implement suitable workarounds.

Comment 4

[Milan Sreckovic [:milan] (needinfo for best results)]

This looks a lot like bug 1269337, with recent activity in there, and a regression from bug 1097464.