Thanks for the pull request. Is there any reason for this PR? As far as I'm aware, PHP doesn't throw warnings or notices if you try to unset a non-existent variable/index, so it's safe to call this regardless.

Hello, on Ubuntu 14.04 LTS with Nginx 1.4.6 and PHP 5.5.9 i get this error everytime. So I solved the problem in this way

What error are you getting?

I get this error:

PHP Fatal error: Cannot unset string offsets in /usr/share/nginx/website/wp-content/plugins/rest-api/lib/endpoints/class-wp-rest-controller.php on line 193

@rmccue There are other places in the WP API where there is an isset check before unset like in WP_REST_Controller->get_public_item_schema(). I tested it without the check and get Fatal errors as well.

Thanks again @thebatclaudio

I tested it without the check and get Fatal errors as well.

Curious. I suspect it's probably if $data is '' or a similar default.

Thanks for the PR!