df command not reporting correct directory when there are multiple mount points to the same device

[Jon Tollefson]

If I have for example,
/dev/sda1 mounted at /boot

then
mount /dev/sda1/ /mnt/test7/

this works fine
$ ./busybox df /boot
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1               495844    100853    369391  21% /boot

but
./busybox df /mnt/test7
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1               495844    100853    369391  21% /boot

shows /boot instead of /mnt/test7
It appears it is returning the first match with the same device id.


The non busybox df command shows the directory correctly.
$ df /mnt/test7
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/sda1         495844 100853    369391  22% /mnt/test7


$ ./busybox
BusyBox v1.23.0.git (2014-06-24 14:05:10 CDT) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2012.
Licensed under GPLv2. See source distribution for detailed
copyright notices.
....

Jon