"dd conv=unblock" always add a new line in Red Hat Enterprise Linux 7

Issue

• The behavior of dd conv=unblock is different between RHEL5 and 7.

• "dd conv=unblock" always add a new line in Red Hat Enterprise Linux 7

  (RHEL5)

  $ dd --version
  dd (coreutils) 5.97
  ...
  
  $ echo -n a | dd cbs=600 conv=unblock
  a0+1 record in
  0+1 record out
  1 bytes (1 B) copied, 0.00137652 s, 0.7kB/s
  
  $ echo -n a | dd cbs=600 conv=unblock 2> /dev/null | hexdump -C
  00000000  61                                                |a|
  00000001
  

  (RHEL7)

  $ dd --version
  dd (coreutils) 8.22
  ...
  
  $ echo -n a | dd cbs=600 conv=unblock
  a
  0+1 record in
  0+1 record out
  2 bytes (2 B) copied, 0.0013602 s, 1.5kB/s
  
  $ echo -n a | dd cbs=600 conv=unblock 2> /dev/null | hexdump -C
  00000000  61 0a                                             |a.|
  00000002