945682 - Video player is not displayed correctly on m.youtube.com

Status: RESOLVED DUPLICATE of bug 738926

(Core :: Layout: Floats, defect)

Description

[Catalin Suciu [:csuciu]]

Nightly 28.0a1 (2012-12-02)
Samsung Galaxy Note (4.0.4)
Nexus 4 (4.2)

1. Go to m.youtube.com and tap on a video while in portrait mode

Expected: The video player is centered

Actual: The video player is displayed on the right side of the screen 

Not reproducible on android stock browser

Comment 1

[Aaron Train [:aaronmt]]

Assume this is a regression, if so, please fine a range.

Comment 2

[Catalin Suciu [:csuciu]]

I don't think that this is a regression because:
- the issue is reproducible on Nightly builds from January 2013
- last week, I've checked youtube on Firefox 26 Beta 8 and I don't recall seeing this issue. Today, I verified again on Beta 8 and the issue is present

Maybe something changed on youtube's side.

Comment 3

[Aaron Train [:aaronmt]]

Attachment: YouTube (off-centred video) screenshot

Comment 4

[Hallvord R. M. Steen [:hallvors]]

Attachment: 945682.htm - TC

Comment 5

[Hallvord R. M. Steen [:hallvors]]

Attachment: 945682.htm - TC

Comment 6

[Hallvord R. M. Steen [:hallvors]]

David, could you have a look at this attachment? There's some CSS here that we don't render like Chrome and Opera do - I'm not sure why exactly.

Comment 7

[Hallvord R. M. Steen [:hallvors]]

(Also - I don't think this belongs in Tech Evangelism. There's nothing in that CSS that looks clearly wrong to me, and two other separate implementations disagree with our rendering)

Comment 8

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: simpler testcase

Comment 9

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Note that if I give the unstyle div (the container of the overflow:hidden div) padding-top:1px, the bug goes away.  The issue is related to (a) not matching the top edge correctly and (b) (a bug everyone has, I think -- bug 25888) only checking the top edge.

Comment 10

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The basic problem is that in nsBlockFrame::ReflowBlockFrame the call to ClearFloats is inside the applyTopMargin check, and applyTopMargin is false when we're reflowing the overflow:hidden frame.

(It's a bit unfortunate that a lot of the code here is totally different in my tree than in mozilla-central, due to the bug 25888 patches I've been carrying around for years.)

Comment 11

[Aaron Train [:aaronmt]]

Over to Core.