There is content_encoding parameter in YHttpWidgetsActionHandler::process_request() method. And it is set to 'application/json'. That is wrong, because The Content-Encoding entity header is used to compress the media-type.. So, it should be gzip or deflate if we need it at all.
Seems like we wanted to send 'Content-Type:application/json' header to notify client, that the response body is JSON.
Some clients do not show the response due to this issue, e.g. libcurl:
Unrecognized content encoding type. libcurl understands deflate, gzip content encodings.
- Investigate if we need the Content-Encoding, and in case we need it, change to correct value (e.g. gzip, deflate);
- Send 'Content-Type:application/json' header in case we need it.