1875572 - Page is sometimes initially laid out into a smaller rect than the screen, until you interact with the page

Status: UNCONFIRMED

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

Description

[csheany]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:123.0) Gecko/20100101 Firefox/123.0

Steps to reproduce:

Open this bug
Open https://issuetracker.google.com/issues/236167971

Actual results:

The page is smaller than the screen

Expected results:

The page is displayed properly

Comment 1

[csheany]

Attachment: Screenshot_Firefox Nightly.jpg

Comment 2

[csheany]

Only landscape seems to be affected. Portrait is fine.

Bug 1519013 doesn't trigger the reflow automatically

Bug 1509552 and Bug 1521359 don't trigger the reflow after zooming in

Bug 1523844 doesn't trigger the reflow after rotation

However scrolling the comments does trigger the reflow

Opening the link in a new tab displays the page properly (no reflow required)

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:botond, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Botond Ballo [:botond]]

I'm not able to reproduce this. I tested with a phone and two different tablets (Nexus 9, screen width 1024 CSS pixels in landscape mode; and Sony Xperia Z4, screen width 1280 CSS pixels in landscape mode).

Comment 5

[Botond Ballo [:botond]]

(In reply to Botond Ballo [:botond] from comment #4)

I'm not able to reproduce this. I tested with a phone and two different tablets (Nexus 9, screen width 1024 CSS pixels in landscape mode; and Sony Xperia Z4, screen width 1280 CSS pixels in landscape mode).

I did test with a more modern tablet as well (Samsung Galaxy Tab A9+, screen width 1152 CSS pixels in landscape mode), and was not able to reproduce there either.

Based on the described symptoms / screenshot alone, my best guess is that there is some sort of race condition that intermittently gets us stuck in a state where the page is not reflowed into the correct viewport size.

Based on comment 2, when this does happen it's a temporary state, as scrolling the comments triggers the reflow.