Due to a codegen error (see PR bin/7735) /sbin/dump in -current writes bad volumes.

To test run something like this:

toaster# ( cd /tmp && /sbin/dump 0f - /dev/rsd0a | restore ivf - )
Verify tape and initialize maps
  DUMP: Date of this level 0 dump: Tue Jun  8 12:05:11 1999
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rsd0a (/) to standard output
  DUMP: Label: none
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 158453 tape blocks.
  DUMP: Volume 1 started at: Tue Jun  8 12:05:13 1999
  DUMP: dumping (Pass III) [directories]
Tape is not a dump tape
toaster#   DUMP: Broken pipe
  DUMP: The ENTIRE dump is aborted.

Your /sbin/dump is buggy if the first tape block (1024 bytes) contains only 0's.

-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)