Micropub: Error responses are not JSON

[cweiske]

While trying to do this:

Send an invalid micropub request to create a new post

I encountered this error:

Server responded with a status code of 500 and plain-text error message "Couldn't create note"

Some other notes:

The micropub draft specification section 3.8 Error Response states:

If an error body is returned, the response body must be encoded as a [JSON] object and include at least a single property named error with the value set to one of the below:

Such an error can be forced by making the content POST parameter an array:

$ curl -X POST -H 'Authorization: Bearer foo' -d h=entry -d 'content[]=test' http://known.example.org/micropub/endpoint
HTTP/1.0 500 Internal Server Error
...
Content-Type: text/html

Couldn't create note

[cweiske]

Same error occurs when the access token is invalid