Before this change, if a file was created on a remote but deleted
externally from that remote then there was potential for the delete to
never be noticed.
The sequence of events was:
- Create file on VFS - creates virtual directory entry
- File deleted externally to remote before the directory refreshed
- Now the file has a virtual add but is not in the listings so will never disappear
This patch fixes it by removing all virtual directory entries except
the following when the directory is re-read.
- On remotes which can't have empty directories: virtual directory
adds are not flushed. These will remain virtual as long as the
directory is empty.
- For virtual file add: files that are in the process of being
uploaded are not flushed
This patch also adds the distinction between virtually added files and
directories.
It also refactors the virtual directory logic to make it easier to follow.
Fixes#4446
f980f230c5