[BUG] When proxy is used in SimplePie, error is returned: A feed could not be found at https://www.newsblog.gr/feed/; the status code is 200 and content-type is ``

[sfatfarma]

Description

I am facing an interesting issue while using SimplePie. It manages to parse the following feed without issues https://www.newsblog.gr/feed/ , however, once I configure SimplePie to use a proxy, the following error is returned when trying to parse the above feed:

A feed could not be found at https://www.newsblog.gr/feed/; the status code is 200 and content-type is `` in \simplepie\library\SimplePie.php on line 1702

Steps to Reproduce

Steps to reproduce the behavior:

1. Set up SimplePie to get content from https://www.newsblog.gr/feed/ (this is working)

$feed = new SimplePie();
$feed->set_feed_url('https://www.newsblog.gr/feed/');
$feed->init();
$feed->handle_content_type();
if ($feed->error()) {
    error_log('feed error: '. $feed->error());
}

2. Add also the usage of a proxy to the request:

$feed = new SimplePie();
$prx_arr = array();
$prx_arr[CURLOPT_PROXY] = 'proxyIP:port';
$prx_arr[CURLOPT_PROXYUSERPWD] = 'proxyUser:pass';
$feed->set_curl_options($prx_arr);
$feed->set_feed_url('https://www.newsblog.gr/feed/');
$feed->init();
$feed->handle_content_type();
if ($feed->error()) {
    error_log('feed error: '. $feed->error());
}

Don't forget to replace the 'proxyIP:port' and 'proxyUser:pass' fields with working proxy server parameters.

Also, as a side note, while using the proxy, the following PHP warning is raised:

Undefined index: content-type in \simplepie\library\SimplePie.php on line 1643

Expected Behavior

Feed to be able to be loaded even if a proxy is used in SimplePie.

Actual Behavior

Feed failed to be loaded when a proxy is used.

[KW4NP]

I'm having this issue as well with a different feed. The feed works fine on the demo but occasionally returns errors, maybe an intermittent??
PHP Notice: Trying to access array offset on value of type bool in simplepie/library/SimplePie.php on line 1722
PHP Notice: A feed could not be found at https://tchadinfos.com/feed/; the status code is 200 and content-type is `` in /simplepie/library/SimplePie.php on line 1766
This link seems to be relevant but I'm not sure where to insert the code mentioned. https://stackoverflow.com/questions/42211661/simplepie-not-parsing-rss-feed
Using SimplePie 1.6