Double slashes in the remote origin URL when setting stage_file_proxy_origin_dir to '/' or ''

Attached patch to prevent double slashes

Attached patch with correct filename to prevent double slashes

I think it would make sense to document an empty string as being the correct value. This falls inline with the current documentation that states the default value is 'sites/default/files', which has no leading or trailing slash.

It should already work with either '/' or '' as slashes get trimmed anyway.

It should already work if you have leading and trailing slashes as they are removed with this line:
$remote_file_dir = trim(variable_get('stage_file_proxy_origin_dir', $file_dir),'/');
So '/sites/default/files/' becomes 'sites/default/files' and '/' becomes ''

The problem was arising because the $remote_dir_path was being concatenated between 2 slashes even when it was empty:
$url = $server . '/' . $remote_dir_path . '/' . rawurlencode($filename);

The patch is a minor tweak to this:
$url = $server . '/' . ($remote_dir_path != '' ? $remote_dir_path . '/' : '') . rawurlencode($filename);

The patch could be changed to preg_replace // for / whenever a URL is constructed like this:
$url = $server . preg_replace('|//|', '/', '/' . $remote_dir_path . '/' . rawurlencode($filename));

It's an alternative way of achieving the same result, which do you prefer?