bug#25033: [PATCH] Add a missing index for `man'.

[Eli Zaretskii]

> From: Hong Xu <hong@topbug.net>
> Cc: 25033@debbugs.gnu.org
> Date: Sat, 26 Nov 2016 02:06:02 -0800
> 
> >> +@findex man
> >>  @findex manual-entry
> >>    You can read the man page for an operating system command, library
> >>  function, or system call, with the @kbd{M-x man} command.  This
> >
> > If I type "i man RET" in the current Emacs manual, I land in that
> > node, and "i man TAB" produces a list of completions one of which is
> > "man pages", which leads to the same node.  So why did you see the
> > need for adding this index entry?
> 
> The missing index actually confused me when I searched the manual for
> it, as it was hidden in my completion list.

Please describe in more detail how it happened that it was hidden,
perhaps there's something I'm missing.

> The main reason is though for the completeness of the documentation --
> "man" should be an indexed function name just like "manual-entry". I
> don't see how it could be harmful to add this index, although the
> benefit may also not be significant.

The harm is in having two or more index entries that begin with the
same text and point to the same page.  That's not useful, and its only
effect is bloating the index, including in the printed version of the
manual (which increases the page count).  So we try to avoid that.

Thanks.