Description:
------------
I'm using a stream filter to process data.

The test case below (also available at https://3v4l.org/kaeRJ) shows a stream filter that reverses the text on each line.

Since PHP 7.2, the final block of data is not included in the output.

My initial debugging suggests an issue with the $closing parameter.  It should be set to true when processing the final block of data.  Since PHP 7.2, it is always false.

It worked for PHP 5.5.21 -> 7.1.
It fails for PHP 7.2 and 7.3.
It fails for PHP <= 5.5.20

Test script:
---------------
<?php
class MyFilter extends php_user_filter {
    private $data = '';

    public function filter($in, $out, &$consumed, $closing) {
        $return = PSFS_FEED_ME;

        // While input data is available, continue to read it.
        while ($bucket_in = stream_bucket_make_writeable($in)) {
            $this->data .= $bucket_in->data;
            $consumed   += $bucket_in->datalen;

            // Process whole lines.
            while (preg_match('/(.*?)[\r\n]+(.*)/s', $this->data, $match) === 1) {
                list(, $data, $this->data) = $match;
                // Send this record output.
                $data       = strrev($data) . PHP_EOL;
                $bucket_out = stream_bucket_new($this->stream, $data);
                $return     = PSFS_PASS_ON;
                stream_bucket_append($out, $bucket_out);
            }
        }

        // Process the final line.
        if ($closing && $this->data !== '') {
            $data       = strrev($this->data) . PHP_EOL;
            $bucket_out = stream_bucket_new($this->stream, $data);
            $return     = PSFS_PASS_ON;
            stream_bucket_append($out, $bucket_out);
        }

        return $return;
    }
}

stream_filter_register('my-filter', 'MyFilter');

$input = "Line one\nLine two\nLine three";

$stream = fopen('data://text/plain,' . $input, 'r');
stream_filter_append($stream, 'my-filter');

$output = '';
while (!feof($stream)) {
    $output .= fread($stream, 16);
}
fclose($stream);

echo $output;


Expected result:
----------------
eno eniL
owt eniL
eerht eniL

Actual result:
--------------
eno eniL
owt eniL