Conflict when dispatching batch from Ajax call

[koen12344]

The library checks the nonce arg in the get_chain_id() function when calling dispatch(). That arg is potentially overwritten by plugins, causing the nonce validation to fail, and the request to 403. The process will then not be dispatched and no healthcheck will be scheduled.

[koen12344]

Actually, diving deeper into the code, I think the issue is simply trying to dispatch a batch from any Ajax call. This will make the if ( empty( $this->chain_id ) && wp_doing_ajax() ) { line in get_chain_id() return true, and make it look for a nonce arg that isn't set, or doesn't apply to the library

[craigrileyuk]

Having this issue too. It's breaking the WooCommerce checkout since I'm using a queue to dispatch emails to a custom mail server.

Fix would be much appreciated.

[koen12344]

@craigrileyuk You can temporarily use my fixed branch by including the repo in your composer.json:

"repositories": [
    {
      "type": "vcs",
      "url": "https://github.com/koen12344/multisite-background-processing"
    }
  ],

"deliciousbrains/wp-background-processing": "dev-prod",

It fixes this issue, as well as the other issue I opened with processing batches on multisite. I use it in production on a few plugins

[remyperona]

Thank you for finding this issue and providing the fix, I was really wondering what was happening suddenly, and the update of this library turned up to be the culprit.