Animated emojis causing scroll issues in Reader comments

[guarani]

Expected behavior

All emojis in Reader content, even animated emojis such as :highfive: and :nailbiting:, should be rendered at their correct size (i.e. roughly of height equal to the line height).

Actual behavior

Animated emojis such as :highfive: and :nailbiting: can cause scroll position in the Reader to jump about. The reason the scroll jumps about (and sometimes gets into a loop) appears to be because these animated emojis arbitrarily and rapidly change in size. This fluctuating size changes the content size of the scroll view, causing scroll to occur and in turn making the app difficult to use.

Steps to reproduce the behavior

These steps to reproduce are not 100% reliable so might take some more investigation until better steps are uncovered.

Prerequisites:

• The site you test on must support animated emojis. These are not available on all types of sites.
• A post with a comment that contains an animated emoji such as :highfive: and :nailbiting:, preferably there should enough comments on the site so that there is scroll (overflow) when viewed in the iOS app.

Steps

1. Tap on a link to a post comment
2. The link should open the WordPress for iOS app and display the comment in Reader
3. Notice the animated emoji appears larger than expected
4. Scroll up and down (to the end of the comment thread)
5. Expect that the scroll position starts jumping on its own

Tested on iPhone 11, iOS 14, WPiOS 17.5 beta

[philnick206]

Looks like it might be related: #4275587-zen

[sami9v]

Looks like it might be related: #4275587-zen

[sami9v]

sami9v

[sami9v]

Bcy

[metabreakr]

Possible case in 35990442-hc / 5357042-zen