Bug: Undefined variable $http_response_header in Client->send()

[cmanley]

Here it is:

php-json-rpc-http/src/Client.php

Line 226 in db15a07

$this->throwHttpExceptionOnHttpError($http_response_header);

and a few lines down too.
That gets converted into an ErrorException in onError() so the proper send() HTTP exception handling is effectively bypassed.

[cmanley]

More info:

See:

php-json-rpc-http/src/Client.php

Line 229 in db15a07

$this->throwHttpExceptionOnHttpError($http_response_header);

and on line 226 too.

That triggered this exception in my code:
ErrorException: Undefined variable: http_response_header at .../vendor/datto/json-rpc-http/src/Client.php line 229.

$http_response_header is a reserved variable, but it doesn't seem to always exist. See the note at the bottom of this page for the cause and solution:
https://www.php.net/manual/en/reserved.variables.httpresponseheader.php
Quoted below just in case it disappears in the future:

Bear in mind this special variable is somehow protected and not populated in some situation when the peer server close the connection early on (ssl reset)
=> Undefined variable: http_response_header

A code like this one:
$response = @file_get_contents($url);
empty($http_response_header) && $http_response_header = array('HTTP/1.1 400 Bad request');

Will return a cryptic error message:
Fatal error: Call to undefined function array() on line 2

--
Should you want to cope with this situation:
$hdrs = array('HTTP/1.1 400 Bad request');
!empty($htp_response_header) && $hdrs = $http_response_headers;

Now use $hdrs in place of $http_response_header

[pfeigl]

We are seeing this same error when using https://github.com/fiskaly/fiskaly-sdk-php (which is based on this library).

While there is obviously a root problem which needs to be fixed, this makes it practically impossible to actually debug it, because all real error details are hidden from the surface