dav: Be sure that enumeration is possible when looking for a root
The DAV backend tries to find the top-most directory when mounting.
Unfortunatelly, for example with nextcloud.com, the enumeration job
fails with Method not allowed
error for the root directory found
by this logic:
<?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns">
<s:exception>Sabre\DAV\Exception\MethodNotAllowed</s:exception>
<s:message>Listing members of this collection is disabled</s:message>
</d:error>
This is because nextcloud.com prevents listing of its users. Let's change the mount logic and always require info about children to be sure that enumeration won't fail later.
Fixes: #468 (closed)
Edited by Ondrej Holy