Improper use of jQuery hasClass method

[kostasx]

According to the jQuery documentation (​https://api.jquery.com/hasclass/), the .hasClass() method accepts a class name without a prefixed . dot.
An improper use of the method's argument, that includes the dot, has been found in the following files:

/wp-includes/js/mediaelement/wp-mediaelement.js
Line #47

return ! $( this ).parent().hasClass( '.mejs-mediaelement' );

Should be:

return ! $( this ).parent().hasClass( 'mejs-mediaelement' );

/wp-includes/js/mediaelement/wp-mediaelement.min.js

Line #1

return!b(this).parent().hasClass(".mejs-mediaelement")

Should be:

return!b(this).parent().hasClass("mejs-mediaelement")

[SergeyBiryukov]

Hi @kostasx, welcome to WordPress Trac! Thanks for the report.

Introduced in [34346].

[kostasx]

Thank you @SergeyBiryukov.
It's nice to be able to contribute and give back to the community of WordPress.

[adamsilverstein]

@kostasx thanks for the report.

I was able to verify the selector doesn't work the way it is written. Did you discover this bug because of some unexpected behavior? The fix looks straightforward here, I want to make sure we are actually fixing and not breaking anything so it is helpful to be able to reproduce.

[kostasx]

Replying to adamsilverstein:

@kostasx thanks for the report.

I was able to verify the selector doesn't work the way it is written. Did you discover this bug because of some unexpected behavior? The fix looks straightforward here, I want to make sure we are actually fixing and not breaking anything so it is helpful to be able to reproduce.

Hello. Yes, I discovered the bug while working with multiple media elements (audio players) on a page. When the wrong selector was used, as is the case in the pre-patched version, an already activated media element was re-activated causing the element to start playing again. When the patch was applied, the already activated media element continued playing with any problem.

[adamsilverstein]

@kostasx great, thanks for clarifying - I thought it would cause something like this issue. Your description of the problem and the fact that you tested it and it resolved the issue gives me confidence that this is a valid fix.

[Presskopp]

the patch

[adamsilverstein]

In 40659:

Media: Fix improper use of jQuery hasClass method.

The jQuery hasClass method accepts a class name without a prefix '.' (period). Remove an errant class name with a '.' in wp-mediaelement.js that broke the selector in certain circumstances.

Props kostasx, Presskopp.
Fixes #40354.