Incorrect regular expression in links_add_target function

[antonlukin]

links_add_target function relies on a regular expression "!<($tags)([^>]*)>!i". It ignores cases where a tag is part of another tag, for example aside.

$content = 'test <aside>test</aside> test';
$content = links_add_target( $content, '_blank', array( 'a' ) );

This code return test <aside target="_blank">test</aside> test but it shouldn't.

Possible solution is to replace regexp with !<($tags)(\s[^>]*)?>!i

​https://developer.wordpress.org/reference/functions/links_add_target/

[antonlukin]

Patch to links_add_target function

[antonlukin]

My patch contains a bug. I will fix it shortly and send pull request to GitHub mirror.

[SergeyBiryukov]

In 48983:

Formatting: Make sure links_add_target() adds the target attribute to the correct tag.

Previously, the attribute could unintentionally be added to a tag that starts with the same characters, e.g. <aside> instead of <a>.

Props antonlukin.
Fixes #51313.

Merged into WP Core in https://core.trac.wordpress.org/changeset/48983