Viewport resizes w/ upward scrolling

[joncole2014]

• Steps to reproduce
  • Use (or create) a webpage that uses the following CSS declaration:

#container {
  height: 100vh;
}

/* load this container at 100% the viewport height */

• Expected behavior

  • The viewport size does not change within iOS, as it's not a window, thus cannot resize

• Actual behavior

  • Downward scrolling is fine. When you scroll up, the viewport resizes. This messes with content that is designed mobile first.
  • This issue is not present on Safari. I am assuming this is because the navigation "floats" on top of the viewport in Safari.

• Device Information

  • iPhone XS
  • iOS version: 15.0.2
  • Firefox Daylight Version: 38.1 (6216)

• Other information

  • This may be by design.
  • I did not see other issues relating to this.

┆Issue is synchronized with this Jira Task

[karlcow]

create a webcompat issue. https://github.com/webcompat/web-bugs/issues/74844

[r-vdp]

Issue still present. This makes it very difficult to use Firefox on iOS since several websites are broken.

[ImpossibleReality]

This issue needs more attention. It makes many websites that depend on the viewport painful to use.

E.x. If a website were to have something like a hero at the top which had a size of 100vh, every time that you would change scroll direction, the hero would resize, causing the rest of the page to move with it.

[lmarceau]

From what I get, this probably relates to https://github.com/mozilla-mobile/firefox-ios/issues/11574. We should implement new APIs

[emilio]

Yes, these are related.

[github-actions[bot]]

This issue has been automatically marked as stale. Has the issue been fixed, or does it still require the community's attention? Please leave any comment to keep this issue opened. It will be closed automatically if no further update occurs in the next 30 days. Thank you for your contributions!

[struq]

not fixed

[github-actions[bot]]

This issue has been automatically marked as stale. Has the issue been fixed, or does it still require the community's attention? Please leave any comment to keep this issue opened. It will be closed automatically if no further update occurs in the next 30 days. Thank you for your contributions!

[emilio]

This is still an issue.