#21406 [NEW]: Appending same filter twice causes segfault

[pollita]

From:             [EMAIL PROTECTED]
Operating system: linux
PHP version:      4CVS-2003-01-03 (dev)
PHP Bug Type:     Filesystem function related
Bug description:  Appending same filter twice causes segfault

The following code works fine when "stream_filter_append()" is called only
once.  Adding the second call causes a segfault when fclose() is called.


<?php

class rot13_filter extends php_user_filter {
  function read($length) {
    $tempstr = parent::read($length);
    for($i = 0; $i < strlen($tempstr); $i++)
      if (($tempstr[$i] >= 'A' AND $tempstr[$i] <= 'M') OR
          ($tempstr[$i] >= 'a' AND $tempstr[$i] <= 'm')) $tempstr[$i] =
chr(ord($tempstr[$i]) + 13);
      else if (($tempstr[$i] >= 'N' AND $tempstr[$i] <= 'Z') OR
               ($tempstr[$i] >= 'n' AND $tempstr[$i] <= 'z')) $tempstr[$i]
= chr(ord($tempstr[$i]) - 13);
    return $tempstr;
  }

  function write($data) {
    for($i = 0; $i < strlen($data); $i++)
      if (($data[$i] >= 'A' AND $data[$i] <= 'M') OR
          ($data[$i] >= 'a' AND $data[$i] <= 'm')) $data[$i] =
chr(ord($data[$i]) + 13);
      else if (($data[$i] >= 'N' AND $data[$i] <= 'Z') OR
               ($data[$i] >= 'n' AND $data[$i] <= 'z')) $data[$i] =
chr(ord($data[$i]) - 13);
    return parent::write($data);
  }
}

stream_register_filter("rot13", "rot13_filter")
    or die("Failed to register filter");

$fp = fopen("foo-bar.txt", "r");

stream_filter_append($fp, "rot13");
stream_filter_append($fp, "rot13");

fwrite($fp, "Line1\n");
fwrite($fp, "Word - 2\n");
fwrite($fp, "Easy As 123\n");

fclose($fp);

?>

-- 
Edit bug report at http://bugs.php.net/?id=21406&edit=1
-- 
Try a CVS snapshot:         http://bugs.php.net/fix.php?id=21406&r=trysnapshot
Fixed in CVS:               http://bugs.php.net/fix.php?id=21406&r=fixedcvs
Fixed in release:           http://bugs.php.net/fix.php?id=21406&r=alreadyfixed
Need backtrace:             http://bugs.php.net/fix.php?id=21406&r=needtrace
Try newer version:          http://bugs.php.net/fix.php?id=21406&r=oldversion
Not developer issue:        http://bugs.php.net/fix.php?id=21406&r=support
Expected behavior:          http://bugs.php.net/fix.php?id=21406&r=notwrong
Not enough info:            http://bugs.php.net/fix.php?id=21406&r=notenoughinfo
Submitted twice:            http://bugs.php.net/fix.php?id=21406&r=submittedtwice
register_globals:           http://bugs.php.net/fix.php?id=21406&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=21406&r=php3
Daylight Savings:           http://bugs.php.net/fix.php?id=21406&r=dst
IIS Stability:              http://bugs.php.net/fix.php?id=21406&r=isapi
Install GNU Sed:            http://bugs.php.net/fix.php?id=21406&r=gnused