IXR Server Warning

[EatonZ]

I've recently upgraded my site to PHP 7.2 and started getting these in the logs:

PHP Warning:  count(): Parameter must be an array or an object that implements Countable in \wp-includes\IXR\class-IXR-server.php on line 101

This is due to a PHP 7.2 change - you need to update this file for PHP 7.2.

PS: Not sure what IXR is, so I'm assigning it to "General".

[redsweater]

I'm assuming this is a runtime log message and not something that PHP logs while simply loading/parsing the file.

The line of code where it occurs indicates that the WordPress instance in question is being connected to by an XMLRPC client who invoking method with no parameters. The vast majority of supported XMLRPC methods require parameters, but for example "demo.sayHello" does not. I imagine invoking that method on such a system would exhibit the problem.

[dd32]

In 42652:

XML-RPC: Add default values to IXR_Message for PHP 7.2 compatibility to avoid PHP Warnings.

Fixes #43216 for trunk.

[dd32]

re-opening for 4.9 backport once verified fixed.

I used the following to trigger it:

curl -X POST http://wordpress-develop/src/xmlrpc.php -d '<?xml version="1.0"?><methodCall><methodName>demo.sayHello</methodName></methodCall>'

[dd32]

Bumping, 4.9.4 has been released.

[SergeyBiryukov]

In 42806:

XML-RPC: Add default values to IXR_Message for PHP 7.2 compatibility to avoid PHP Warnings.

Props dd32.
Merges [42652] to the 4.9 branch.
Fixes #43216.

[dd32]

It's been mentioned elsewhere that the changes in [42652] may not be compatible with existing uses, specifically the = false; additions.

Although there's unlikely to be any side effects of this, I'm commenting to say that only the = array() change was really needed here, and the rest was mostly just irrelevant.