Description:
------------
If the input stream is filtered then fgets($stdin) does not return when newline is typed.

Reproduce code:
---------------
<?php
class test_filter extends php_user_filter {
  public function filter($in, $out, &$consumed, $closing) {
    while ($bucket = stream_bucket_make_writeable($in)) {
      $bucket->data = strtoupper($bucket->data);
      $consumed += $bucket->datalen;
      stream_bucket_append($out, $bucket);
    }

    return PSFS_PASS_ON;
  }
}

$stdin = fopen("php://stdin", "r");
stream_filter_register("test.23", "test_filter");
stream_filter_append($stdin, "test.23");
fgets($stdin);
?>

Expected result:
----------------
Should return after newline. It does return if you comment the 2 stream... lines.

Actual result:
--------------
It hangs, probably waiting for more input.