1869801 - "Write a comment" option overlaps the last comment at m.facebook.com

Status: NEW

(Web Compatibility :: Site Reports, defect, P1)

Description

[Raul Bucata]

Attachment: Screenshot_6.png

Environment:
Operating system: Android 12/ Android 13
Firefox version: Firefox Nightly 122.0a1 (2015991335-🦎122.0a1-20231212092611🦎)

Preconditions:
Clean profile

Steps to reproduce:

1. Navigate to: https://www.facebook.com/
2. Perform account login.
3. Select a desired post and tap on the "Comment" button.
4. Scroll towards the last comment and observe the result.

Expected Behavior:
The comment is not truncated

Actual Behavior:
The comment is truncated by the "Write a comment" option

Notes:

• Reproducible regardless of the status of ETP
• Reproducible on the latest build of Firefox Nightly and Firefox Release
• Works as expected using Chrome
• Screenshot attached
• Issue found during WebCompat team [Top100] websites testing

Comment 1

[Raul Bucata]

Verified this issue and still reproduces on Firefox 123 and 125.

Tested with:

Browser / Version: Firefox Release 123.0 (2016003223-🦎123.0-20240212203859🦎)/ Firefox Nightly 125.0a1 (2016005351-🦎125.0a1-20240223095502🦎)/ Firefox Beta 124.0b3 (2016005255-🦎124.0-20240223091706🦎)/ Chrome Mobile Version 121.0.6167.180
Operating System: Google Pixel 3 (Android 12) -1080 x 2160 pixels, 18:9 ratio (~443 ppi density)
Operating System: Oppo Find X5 (Android 13) - 1080 x 2400 pixels, 20:9 ratio (~402 ppi density)

Comment 2

[Ksenia Berezina [:ksenia]]

Leaving a ni for myself to test if it's breaking functionality

Comment 3

[Daniel Holbert [:dholbert] (mostly-away until Aug 19)]

I was briefly able to reproduce in old Nightly 2023-12-13 on a Pixel 6a (that's the datestamp from the day this was filed, which I ran in the hopes of being able to repro), but after some more testing, it stopped reproducing for me.

Here's what I was doing that did seem to make this reproduce for me, for a little hwile:

1. Tap the "comment" icon below a post to view the post-and-comments view (as in the STR).
2. Scroll downwards to see the last comment.
3. Now do a rapid top-to-bottom finger-swipe to kick off a rapid upwards scroll.
4. While the page is still scrolling upwards, do a rapid bottom-to-top finger-swipe to scroll downwards again.

When I followed these^ STR:

• In step 2 (i.e. the end of the original STR), the dynamic toolbar would always disappear for me, which makes the bug not reproduce.
• Then the dynamic toolbar reappears in step 3 as I scroll back upwards.
• However, in step 4, the dynamic toolbar does sometimes stick around (not autohide) even though I've gone back to scrolling down the page -- at least, it sticks around until I do an additional final scroll operation, which does then hide it. (So for that part, I have to e.g. scroll once, and then scrolling stops at the bottom of the document with the dynamic scrollbar still in view; and then I do another gentle scroll to make the toolbar hide.)

As I was typing these STR, though, the bug stopped reproducing for me with these STR, so there's definitely some weirdness here.

I'm not sure this is a huge usability problem since you can still scroll a bit further to avoid the bug, though, and at least for me, I have to really try to make it repro (and even then it stopped reproducing for me).

I tested in current Nightly too and wasn't able to repro, but I'm not sure if that's because it's fixed vs. because it's so intermittently-reproducible for me.

Raul, can you still reproduce, and if so, do you have any tips for making it reproduce more reliably? (And does your experience match mine, where e.g. the initial scroll down the page doesn't reliably trigger it, and when it does happen you can work around it by doing an additional tiny scroll to hide the dynamic toolbar?)

Comment 4

[Daniel Holbert [:dholbert] (mostly-away until Aug 19)]

Also: if you can still reproduce, could you check whether disabling the dynamic toolbar helps at all? (Settings|Customize|Scroll-to-hide-toolbar:off)

Comment 5

[Raul Bucata]

Hi Daniel. I can still reproduce, but it seems that "Scroll to hide toolbar" enabled helps in this situation: no overlapping elements