`whereis` doesn't honor $MANPATH or command line argument -M as expected

`whereis` doesn't honor $MANPATH or command line argument -M as expected

[Reuti]

Hi,

The `whereis` command is supposed to look also in $PATH and $MANPATH. While the $PATH lookup works as expected, I observe a glitch how $MANPATH or -M is handled:

The builtin man pages e.g. /usr/share/man will be expanded inside `whereis` as /usr/share/man/* to look into the individual sections man1, man2, ... This seems not to happen neither for the paths given in $MANPATH, nor the command line argument -M. While for the command line argument it might be a matter of discussion whether one prefers that it's necessary to specify /opt/chemsoft/man/man1 instead of just /opt/chemsoft/man, it's mandatory to have a setting of /opt/chemsoft/man in $MANPATH to get access to different sections of the man pages with the usual `man 1 mycommand` resp. `man 3 mycommand` from the individual subdirectories man1 and man3.

I would prefer that `whereis` looks in all the subdircetories of all the paths set in $MANPATH too.

(observed in the actual version util-linux-2.28)

-- Reuti