Fabian Vogt authored Aug 12, 2020 and Alexander Saoutkin committed Dec 23, 2020

Absolute symlinks have a different meaning when accessed though the regular
filesystem, they don't anchor to the mounted URL anymore:
sftp://server/tmp/symlink -> /home/user/
/mnt/sftp/server/tmp/symlink -> /home/user/
Rewrite absolute symlinks when reading or writing them to keep the target
consistent:
/mnt/sftp/server/tmp/symlink -> /mnt/sftp/server/home/user/

It is necessary that KIOFuseVFS is aware of the mountpoint now, to be able to
deal with absolute paths. This is not ideal as it doesn't account for bind
mounts or symlinks.

Use readlink in fileopstest to get the raw link target instead of an absolute
path.

BUG: 422090