bin/46255: apropos(1) sometimes report unrelated responses

[njoly%pasteur.fr@localhost]

>Number:         46255
>Category:       bin
>Synopsis:       apropos(1) sometimes report unrelated results
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 24 23:00:00 +0000 2012
>Originator:     Nicolas Joly
>Release:        NetBSD 6.99.4
>Organization:
Institut Pasteur
>Environment:
System: NetBSD lanfeust.sis.pasteur.fr 6.99.4 NetBSD 6.99.4 (LANFEUST) #5: Sat 
Mar 24 14:34:56 CET 2012 
njoly%lanfeust.sis.pasteur.fr@localhost:/local/src/NetBSD/obj.amd64/sys/arch/amd64/compile/LANFEUST
 amd64
Architecture: x86_64
Machine: amd64
>Description:
Sometimes, apropos(1) return un-related results. By example, the `apropos lfs'
command report correct entries that include the searched word but some
un-related ones for the LF word .

newfs_lfs(8)    construct a new LFS file system
rump_lfs(8)     mount a lfs image with a userspace server
scan_ffs(8)     find FFSv1/FFSv2/LFS partitions on a disk or file
lfs_segclean(2) mark a segment clean
mvme68k/lpt(4)  parallel port driver
lfs_segwait(2)  wait until a segment is written
x86/lpt(4)      Parallel port driver
installboot(8)  install disk bootstrap software
PCRE(3) - Perl-compatible regular expressions
PCRE(3) - Perl-compatible regular expressions

For the 10 results reported, 6 are correct and 4 are wrong (2 lpt and 2 PCRE).

Things are worse for `apropos crs' which only report pages with "cr" word,
not even a single "crs" result is found.

njoly@lanfeust [~]> apropos -n 1000 crs | head        
mvme68k/lpt(4)  parallel port driver
...the driver. Minor Bit Function 128 Use the interruptless driver. (polling) 
64 Do not initialize the device on the port. 32 Automatic LF on CR. 16 Select 
1.6uS strobe pulse width (default is 6.4uS) pcc(4) , pcctwo(4)
[...]
njoly@lanfeust [~]> apropos -n 1000 crs | grep -ic crs
0

>How-To-Repeat:
Check results from `apropos lfs' or `apropos crs' commands.
>Fix: