1579597 - Pinch zoom incorrectly renders top bar on reddit

Status: RESOLVED WORKSFORME

(Core :: Panning and Zooming, defect, P3)

Description

[Sound]

Attachment: Screen Shot 2019-09-06 at 11.23.30 PM.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:71.0) Gecko/20100101 Firefox/71.0

Steps to reproduce:

Open reddit: https://www.reddit.com/r/firefox/comments/d0fa5q/daily_nightly_discussion_for_20190906_post_about/

Actual results:

When you zoom in using pinch-zoom, the top navbar renders incorrectly (see the screenshot).

Comment 1

[Botond Ballo [:botond]]

To clarify, are you setting apz.allow_zooming=true? The article talks about doing that but you didn't mention it in your steps.

Comment 2

[Sound]

(In reply to Botond Ballo [:botond] from comment #1)

To clarify, are you setting apz.allow_zooming=true? The article talks about doing that but you didn't mention it in your steps.

Yes, apz.allow_zooming is set to true

Comment 3

[Daniel Holbert [:dholbert]]

(In reply to Sound from comment #0)

When you zoom in using pinch-zoom, the top navbar renders incorrectly (see the screenshot).

Just to clarify -- is the incorrect thing that the searchbar is cut off on the right side? Or is there something else broken there that you were meaning to highlight?

(I don't think this bug has to do with flexbox. That top bar might use flexbox, but it's sized to the viewport width, and we're likely just coming up with the wrong size for the viewport during the zoom operation, I think. Note that other content is cut off, too, e.g. the text at the bottom right of the screenshot.)

--> adjusting bug title based on my current understanding

Comment 4

[Sound]

Attachment: chrome-reddit.gif

Comment 5

[Sound]

(In reply to Daniel Holbert [:dholbert] from comment #3)

Just to clarify -- is the incorrect thing that the searchbar is cut off on the right side? Or is there something else broken there that you were meaning to highlight?

I shouldn't even be there. I've captured a video how Chrome does it (see attached chrome-reddit.gif) - basically it treats the whole page as an image, whereas Firefox tries to do something funky with the top bar.

Comment 6

[Botond Ballo [:botond]]

Thanks. Please note that pinch zooming support (apz.allow_zooming=true) on desktop is at a pretty early stage so some things like things are expected to be broken.

Comment 7

[Timothy Nikkel (:tnikkel)]

I don't think this reproduces anymore? Seems the same in firefox, chrome and safari for me.

Comment 8

[Botond Ballo [:botond]]

Yeah, I suspect this bug only occurred with WebRender enabled, and was fixed by bug 1609002.

Comment 9

[Sound]

Can confirm that this is fixed in Nightly with WR.

Comment 10

[Timothy Nikkel (:tnikkel)]

Thanks.