PHP Notice in class-wp-xmlrpc-server.php when $matchtitle[1] is undefined

[RedSand]

We see this error fairly often when WP_DEBUG is enabled. (We use WP_DEBUG quite often - logging, no visual error display.)

PHP Notice:  Undefined offset: 1 in /XXXXXXXX/wp-includes/class-wp-xmlrpc-server.php on line 6329

Happens when $matchtitle[1] is undefined. It's an easy fix. See attached patch.

[markoheijnen]

Thank you for your patch and indeed it's a easy fix.

[RedSand]

@markoheijnen

You're welcome. Happy to help.

[SergeyBiryukov]

In 38620:

XML-RPC: Avoid a PHP notice in ::pingback_ping() if page title was not found.

Props RedSand.
Fixes #36727.