1255789 - [e10s] Soundcloud video sharing pop up is repositioning itself towards the edge of the display

Status: RESOLVED DUPLICATE of bug 1252262

(Core :: DOM: Animation, defect)

Description

[Iulia Cristescu, QA [:JuliaC] (away, please needinfo? [e-mail])]

Attachment: screencast showing the bug

[Note]:
Reproducible only with e10s enabled.

[Affected versions]:
- Aurora 47.0a2 (2016-03-10)
- Beta 46.0b1-build8

[Affected platforms]:
- Windows 10 x64 & x86
- Windows 7 x64

[Steps to reproduce]:
1. Launch Firefox.
2. Open https://soundcloud.com/ and choose a random track or recording from the menu. 
3. Click the Share button and from the sharing dialog, click the Facebook button.
4. Log into Facebook (if you haven't already) and check the pop up window's behavior.

[Expected result]:
The "Post on Facebook" window appears and stands in one (centered) place, allowing the user to complete its post.

[Actual result]:
The "Post on Facebook" pop-up window is brought up and it repositions itself towards the right-hand, bottom corner of the screen until it reaches it's margin.

[Regression range]:
I'll follow up with a regression range as soon as possible.

[Additional notes]:
- I was unable to reproduce this bug on the following builds: 48.0a2 (2016-03-10 with e10s) and 45.0-build2 (with e10s forcefully enabled via browser.tabs.remote.autostart pref change).
- This issue is also occurring while trying to share content from Pinterest and BlogSpot, from what I've managed to investigate so far. It's likely that other websites are also affected.
- I tried to replicate this exact behavior with other browser (e.g. Chrome) but was unable to.

Comment 1

[Ryan VanderMeulen [:RyanVM]]

Probably a dupe of bug 1252262.

Comment 2

[Iulia Cristescu, QA [:JuliaC] (away, please needinfo? [e-mail])]

(In reply to Ryan VanderMeulen [:RyanVM] from comment #1)
> Probably a dupe of bug 1252262.

This is indeed the same issue as Bug 1252262.