1896007 - Dynamic toolbar causes glitches when scrolled away, when viewing certain content as app tabs (Bugzilla, substack, uBlock origin error page)

Status: RESOLVED FIXED

(Fenix :: PWA, defect)

Description

[Daniel Holbert [:dholbert]]

Steps to reproduce

1. Set Firefox Nightly as your default browser.
2. Install the uBlock origin extension in Nightly (in Firefox's menu "Extensions" section)
3. Switch apps to your email app, and tap a link to some domain that uBlock origin will intercept, like https://linksynergy.com/ . (You may want to send yourself an email with that URL in it, for you to tap in this step.)
   --> Firefox Nightly appears as an app tab, showing the uBlock origin interception page ("uBlock origin has prevented the following page from loading:")
4. Try to vertically scroll the uBlock origin interception page.

Expected behavior

Page shouldn't be scrollable (if there's no actual overflowing content); and if it is scrollable, the area that becomes visible should draw with the same background as the rest of the page.

Actual behavior

The dynamic toolbar scrolls out of view, leaving behind an empty space with a different background color from the rest of the page, which looks cosmetically weird.

Device information

• Firefox version: Nightly 127.0a1 2024-05-08
• Android device model: Pixel 6a, Pixel 8
• Android OS version: 15beta, 14 (on the two different phones listed above)

Any additional information?

I bisected to this 1-day range with mozregression:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=ea25d02dac47&tochange=7251b91515e4

In that range, it looks like this would probably be a regression from bug 1880747.

Comment 1

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

Set release status flags based on info from the regressing bug 1880747

:jackyzy823, since you are the author of the regressor, bug 1880747, could you take a look?

For more information, please visit BugBot documentation.

Comment 2

[Daniel Holbert [:dholbert]]

FWIW, here's what happened in "Good" builds before this regressed -- I think these are probably the expected-results:

• With the STR as-written, you end up at a PWA view where the dynamic toolbar simply does not scroll away at all.
• If I adjust the STR to produce an extremely tall uBlock origin page, by using a much longer intercepted URL like this one at https://linksynergy.com/aaaaa....[lots-of-characters-here]], then the page does scroll and the dynamic toolbar does auto-hide, and it doesn't leave behind any discolored area.

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug with a short uBlock interception page (where there's no reason for the page to be scrollable)

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug with a tall uBlock interception page (where the page is scrollable, but the dynamic toolbar auto-hides to reveal a solid opaque area instead of scrollable area)

Comment 5

[Daniel Holbert [:dholbert]]

Attachment: screencast of expected results wit ha tall uBlock interception page (captured in a Nightly from before this regressed)

Comment 6

[Daniel Holbert [:dholbert]]

Adding needinfo for twhite, since he reviewed/landed the regressing patch (and I don't want to put too much time pressure on jackyzy823).

twhite, given that current Nightly127 is about to move from Nightly to beta in a few days (and then release 4 weeks later), what do you think about backing out bug 1880747 for now, to avoid shipping this regression to 127beta/release (and to avoid putting relatively-tight time pressure on ourselves to mitigate this before 127 ships)?

This might seem small at first, since so far I (personally) have only seen this with this uBlock origin interception page; but:
(1) uBlock is one of the most popular add-ons, and this page does tend to get triggered pretty often (as a PWA) when tapping links in emails, for e.g. personalized links that use tracking services for analytics and such.
(2) I wouldn't be surprised if there's other content that's similarly-affected by the same issue, that we simply haven't discovered yet.

Comment 7

[Daniel Holbert [:dholbert]]

Attachment: screencaat of bug affecting Bugzilla opened as in-app tab from Gmail

Comment 8

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #6)

(2) I wouldn't be surprised if there's other content that's similarly-affected by the same issue, that we simply haven't discovered yet.

Update: this does indeed affect other content - see just-attached screencast showing this bug affecting this very Bugzilla page, when viewed as an app tab from a link tapped in the Gmail app. :)

Comment 9

[Daniel Holbert [:dholbert]]

I'm also seeing what I think is the same bug when scrolling substack newsletters like https://www.publicnotice.co/p/aaron-rupar-international-journalism-festival-24 (when viewed as an app tab).

In Nightly 127, the page's footer jumps up to an odd position when Firefox's dynamic toolbar appears; and the footer jumps off screen entirely when Firefox's dynamic toolbar autohides. No such issue in Beta 126.

Comment 10

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug affecting substack

Comment 11

[Daniel Holbert [:dholbert]]

[Tracking Requested - why for this release]: unintended regression, pretty noticeable depending on the site

Comment 12

[twhite]

what do you think about backing out bug 1880747 for now, to avoid shipping this regression to 127beta/release (and to avoid putting relatively-tight time pressure on ourselves to mitigate this before 127 ships)?

Thanks for reporting this Daniel, good catch. Yes I agree with the proposed backout and we can investigate an alternative fix for the original bug.

Comment 13

[Pascal Chevrel:pascalc]

https://hg.mozilla.org/releases/mozilla-beta/rev/9140e25b645b

Comment 14

[Pascal Chevrel:pascalc]

(In reply to Pascal Chevrel:pascalc from comment #13)

https://hg.mozilla.org/releases/mozilla-beta/rev/9140e25b645b

Fixed in beta by the backout of bug 1880747

Comment 15

[Daniel Holbert [:dholbert]]

Thanks! We can close this as fixed-by-backout then, I think.

Comment 16

[jackyzy823]

Hi All, Sorry for the late response . I was in the middle of business trip.

And also sorry for causing backout, I will try to find a proper alternative way to fix original bug and not causing this bug.

Comment 17

[Daniel Holbert [:dholbert]]

No worries, and thanks for taking a look!

Comment 18

[Petru-Mugurel Lingurar [:petru]]

Tried testing this but the scenario with using uBlock and https://linksynergy.com/ does not seem to work anymore
For other custom tabs the dynamic toolbar seem to have no issues - should I understand that the bug described in comment #1 happens on just specific pages?
This would be a strong indication of why the issue exists.

Comment 19

[jackyzy823]

This issue was introduced by the incomplete fix for bug 1880747 and was fixed by backout.

I just made a new patch https://phabricator.services.mozilla.com/D213415 with Bug 1901741.