IMCE integration doesn't work when Drupal is installed in a subdirectory

In imce.inc, the filefield_source_imce_value() function contains a hardcoded '/' instead of base_path() for $uri on line 135:
$uri = preg_replace('/^' . preg_quote('/' . $file_directory_prefix . '/', '/') . '/', $scheme . '://', $item['filefield_imce']['file_path']);

This should be:
$uri = preg_replace('/^' . preg_quote(base_path() . $file_directory_prefix . '/', '/') . '/', $scheme . '://', $item['filefield_imce']['file_path']);

As a result, when Drupal is installed in a subdirectory (i.e. '/drupal'), $uri ends up with a value of '/drupal/sites/default/files/example.png' instead of 'public://example.png' as expected, causing the fid lookup on line 138 to return no matching records and triggering an error.

Fix is attached.