Unexpected handling of dollar signs ($) in URL during conversion.

[janzankowski]

Steps to reproduce:

1. Paste the following string into the conversion box:
   curl 'http://sejm.gov.pl/Sejm8.nsf/posel.xsp?id=001&type=A&$$ajaxid=view%3A_id1%3A_id2%3AfacetMain%3A_id187%3AholdBiura'
2. Wait until result is produced.

Result:

// Generated by curl-to-PHP: http://incarnate.github.io/curl-to-php/
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $_ENV["http://sejm.gov.pl/Sejm8.nsf/posel.xsp?id=001&type=A&ajaxid=view%3A_id1%3A_id2%3AfacetMain%3A_id187%3AholdBiura"]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

$result = curl_exec($ch);
if (curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
}
curl_close ($ch);

In particular, please note the part: $_ENV["http://sejm.gov.pl/Sejm8.nsf/posel.xsp?id=001&type=A&ajaxid=view%3A_id1%3A_id2%3AfacetMain%3A_id187%3AholdBiura"].

I see there's something clever going on here, because of adding the $_ENV bit. This is easy to catch because on executing this, PHP will complain about 'no index found' (in array $_ENV). However, only after quite some time I also realized the dollar signs ($) in the bit $$ajaxid in the input string were dropped in the resulting code, and caused the requests not to work. If this needs to be done to prevent some XSS, etc, then could the converter be more explicit about it?

Proposed solution:
Provide a warning label if dollar characters are removed from input URL.

Thank you for a great tool.