[sshfs] rename workaround don't work

[Donald J. <dj....@gm...>]

Hello there.
I have a simple question. Maybe it already answered.
I started using sshfs after samba and seen a small bug here: rename
system call against sshfs mount point fails when moving file in
different partitions on remote host. I found that this behaviour may
be workarounded with mount option "workaround=rename", but it did not
helps.
I looked at the sources and found that if an extension
"pos...@op..." appears, then workaround automatically
turned off (I checked sources quickly, without initial debugging).
I also straced an sshfs on client and seen that rename returns EPERM.
I straced sftp-server process on remote host and seen that the sftp
does nothing (tries to link(), then link() fails and it fall back to
rename(), it also fails with same reason as link - EXDEV) and gives
up. So may be sshfs should do the move itself after negative answer
from sftp? Or sftp must be patched to do the same as mv(1)? Last
thing: I have no access to patch sftp to do this.
Sorry for my bad English.

Cheers.