bin/59969: iostat(8) doesn't obey -H 0 option

["paul%whooppee.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         59969
>Category:       bin
>Synopsis:       iostat(8) doesn't obey -H 0 option
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Feb 07 16:30:00 +0000 2026
>Originator:     Paul Goyette
>Release:        NetBSD 11.99.5
>Organization:
+---------------------+--------------------------+----------------------+
| Paul Goyette (.sig) | PGP Key fingerprint:     | E-mail addresses:    |
| (Retired)           | 1B11 1849 721C 56C8 F63A | paul%whooppee.com@localhost    |
| Software Developer  | 6E2E 05FD 15CE 9F2D 5102 | pgoyette%netbsd.org@localhost  |
| & Network Engineer  |                          | pgoyette99%gmail.com@localhost |
+---------------------+--------------------------+----------------------+
>Environment:
	
	
System: NetBSD speedy.whooppee.com 11.99.5 NetBSD 11.99.5 (SPEEDY 2026-01-29 10:45:51 UTC) #0: Thu Jan 29 19:13:36 UTC 2026 paul%speedy.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY amd64
Architecture: x86_64
Machine: amd64
>Description:
iostat(8) man page says

 -H height ...  If explicitly set
         to zero, pages are considered to be infinitely long.  This
         parameter determines the frequency at which repeated headers
         are output.  If the value is greater than zero, but too small
         for the header, along with one output set, then a new header
         will be produced for each set of output.

With -H 0 one would expect than no repeated headers would be needed on
an infinitely long page.  Yet it actually repeats the header for every
set of output, just as though the value of height were "greater than 
zero, but too small ..."
	
>How-To-Repeat:
execute

	iostat -H 0 -c 2

and observe repeated headers.
	
>Fix:
	

>Unformatted: