bug in "df -h"

gistfile1.txt

steps to reproduce:

1. make a cifs share on another host
2. mount it with smbfs
3. unshare the cifs share on that other host
4. df -h

problem:

dumps core with arithmetic exception here:

08047a98 libc_hwcap2.so.1`UDiv+0x2a(8047c00, 0, 0, 0, 400, 8047af8)
08047ca8 k_output+0x3ab(806aaa0, 8047ce0, 8047db8, 8055422)
08047db8 do_df+0x11e(0, 8047df4, 8047df8, feffbafc)
08047de0 _start+0x7d(2, 8047ea0, 8047ea3, 0, 8047ea6, 8047eb1)

the call prior to 0x3ab was:

k_output+0x3a6:                 call   -0xe43   <number_to_scaled_string>

doing this:

dtrace -q -n 'pid$target::k_output:entry { self->k_output = 1; } pid$target::k_output:return { self->k_output = 0; } pid$target::number_to_scaled_string:entry /self->k_output/ { printf("num: %llu\tunit_from: %d\tscale: %d\n", (unsigned long long) arg1, arg2, arg3); }' -c 'df -h'

the last line of output is:

num: 0  unit_from: 0    scale: 0