bug#11631: Head command does not position file pointer correctly for negative line count

[Voelker, Bernhard]

Anoop Sharma wrote:

> Head command does not position file pointer correctly for negative line
> count. Here is a demonstration of the problem.

The problem doesn't seem to be limited to negative
line counts. I replaced the 10 ABC lines by a number
sequence to demonstrate this issue clearer.

  $ seq 10 | ( head -n -2 ; echo xxx ; cat )
  1
  2
  3
  4
  5
  6
  7
  8
  xxx
  $ seq 10 | ( head -n 2 ; echo xxx ; cat )
  1
  2
  xxx

So head eats all of the input. The info page is silent
about this.

Have a nice day,
Berny