A bug in WordPress that was more likely to affect left-handed users is finally being fixed after seven years.
It has been discovered that a bug that causes the comment reply section to suddenly open when scrolling a page while browsing a WordPress site on a smartphone is more likely to occur for users who operate the screen with their left hand. This issue was reported in 2019, but developer Terence Eden proposed a fix, and it has finally been incorporated into the WordPress core after about seven years.
A bug which only affected left-handed users – Terence Eden's Blog
Eden said that he received reports from readers of his blog that 'while scrolling through the page, a comment input field suddenly appears, interrupting the viewing experience.' However, Eden himself, who regularly checks his own site, had never experienced this problem.
The cause lay in the difference in how they used their smartphones. Eden was swiping the right side of the screen with his right thumb, while the reporter was using the left side of the screen with his left thumb, where the 'reply' link for comments was located.
WordPress's comment function has an event called 'touchstart' that detects the moment a reply link is touched. Because touchstart executes as soon as a finger touches the screen, it opens the comment reply field before the browser can determine whether it's a normal tap or a scroll operation.
Therefore, if your thumb touches a reply link when you start scrolling, the reply field will appear even if you didn't intend to click the link. Since reply links are generally located on the left side of the screen, people who scroll with their left thumb were more likely to experience this malfunction. It should be noted that the same problem can occur even for right-handed people who operate their smartphone with their left hand, so it is not strictly a bug limited to left-handed people.
The problematic code was added in 2017 as part of a change to revamp the JavaScript for the comment reply feature. The code at the time performed the same action with `touchstart` in addition to the 'click' event that occurred when a link was selected as usual.
Older mobile browsers had a mechanism that delayed the occurrence of a click event by about 300 milliseconds to determine whether a tap on the screen was a double tap for zooming. While the use of `touchstart` was once employed to circumvent this delay, by 2017, when the code was added to WordPress, this delay was virtually negligible in major browsers.
The bug itself was reported to WordPress's bug tracking system in 2019, with the complaint that 'when you try to scroll, touchstart reacts and the reply field opens.' It remained unfixed until July 2026, when Eden submitted a fix that removed touchstart and used only click.
The WordPress development team determined that `touchstart` was unnecessary because tapping a link on a touchscreen triggers a normal click event. The fix involved deleting just a few lines of code and was adopted as a change for WordPress 7.1, thus resolving the long-standing issue.
Remove touchstart from reply links by edent · Pull Request #12168 · WordPress/wordpress-develop
https://github.com/WordPress/wordpress-develop/pull/12168
This bug demonstrates that testing solely based on the developer's own usage can lead to overlooking issues that are concentrated in specific user groups. Furthermore, it highlights how compatibility measures that were once necessary can now be meaningless and even detract from the user experience.
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in Software, Web Service, Posted by log1i_yk