[Unionfs] Stacking semantics with multiple rw branches changed ?

[pascal at pabr.org]

With unionfs-2.1.7 for 2.6.23.1:

+ mkdir /b0 /b1 /b1/foo /union
+ mount -t unionfs -o dirs=/b0:/b1 none /union
+ mkdir /union/foo/bar1
+ touch /union/foo/z
+ mkdir /union/foo/bar2
+ tree /b0 /b1
/b0
`-- foo
     |-- bar2
     `-- z
/b1
`-- foo
     `-- bar1

4 directories, 1 file
+ umount /union
+ rm -r /b0 /b1 /union


Is this normal ?  I would have expected "bar1",
"z" and "bar2" to be all created in /b1/foo,
and IIRC this is how unionfs used to behave when
I started testing it (around 2.1.1).
Has the stacking semantics been changed recently ?


Regards,

Pascal