Drupal public and private file schemes are not supported junctions (symlinks) of Windows NTFS!

Steps to reproduce error:

1. We will use Windows 7 (or any Windows Server). Create junction folder in drupal public or private files folder. Junction folder can be created by junction utility (http://technet.microsoft.com/en-us/sysinternals/bb896768) or by mklink command in cmd.exe (Windows 7 only).
Example:
junction "C:/Net/Web/root/sites/default/files/priv/images/DWall" "D:/PictersHugeLibrary"

where "C:/Net/Web/root/sites/default/files/priv" - private files Drupal folder, "C:/Net/Web/root" - Drupal installation folder, "D:/PictersHugeLibrary" - mounted volume with pictures library, "C:/Net/Web/root/sites/default/files/priv/images/DWall" - junction (symlink) folder which reflects content of "D:/PictersHugeLibrary".

2. Create php block with code:

echo var_export( is_dir("C:/Net/Web/root/sites/default/files/priv/images/DWall") );
echo var_export( is_dir("private://images/DWall") );

3. First echo return "true" (because junction is real folder in terms of Windows NTFS system). But second echo returns "false", may error exists in classes DrupalLocalStreamWrapper, DrupalStreamWrapperInterface, DrupalPublicStreamWrapper, DrupalPrivateStreamWrapper (see stream_wrappers.inc).

This Bug in method DrupalLocalStreamWrapper::getLocalPath().

Looking at method DrupalLocalStreamWrapper::getLocalPath().

  /**
   * Return the local filesystem path.
   *
   * @param $uri
   *   Optional URI, supplied when doing a move or rename.
   */
  protected function getLocalPath($uri = NULL) {
    if (!isset($uri)) {
      $uri = $this->uri;
    }
    $path = $this->getDirectoryPath() . '/' . $this->getTarget($uri);
    $realpath = realpath($path);
    if (!$realpath) {
      // This file does not yet exist.
      $realpath = realpath(dirname($path)) . '/' . basename($path);
    }
    $directory = realpath($this->getDirectoryPath());
    if (!$realpath || !$directory || strpos($realpath, $directory) !== 0) {       // <== strpos() is error approach
      return FALSE;
    }
    return $realpath;
  }

As we can see, path to file/folder after concatenations with base folder is passed throw realpath() method. It's ok while $path is real file or folder, but if $path is symlink (junction point) than method realpath() returns not fixed $path, but REAL PATH on which symlink is refers! So, strpos() method, that checks base folder overruning validation, returns FALSE. But this FALSE is mistaken, because $realpath is really stands in drupal folder (by means of his symlink).

This is a fixed method DrupalLocalStreamWrapper::getLocalPath() ( file stream_wrappers.inc ).

  /**
   * Return the local filesystem path.
   *
   * @param $uri
   *   Optional URI, supplied when doing a move or rename.
   */
  protected function getLocalPath($uri = NULL) {
    if (!isset($uri)) {
      $uri = $this->uri;
    }
    $path = $this->getDirectoryPath() . '/' . $this->getTarget($uri);
    $realpath = realpath($path);
    if (!$realpath) {
      // This file does not yet exist.
      $realpath = realpath(dirname($path)) . '/' . basename($path);
    }
    $directory = realpath($this->getDirectoryPath());
    if (!$realpath || !$directory) {       // <== whithout strpos() 
      return FALSE;
    }
    return $realpath;
  }

Does anybody can apply this patch to current drupal7 code ?