bug#9891: 24.0.90; Duplicated entry at the info directory

[Stefan Monnier]

> True, but this is what I see on GNU/Linux in "(dir) Top", at the top:

> * Info: (info).                 How to use the documentation browsing system.

> and in the "Texinfo documentation system" section:

> * Info: (info).                 How to use the documentation browsing system.

Info doesn't look at the context: it only sees those two lines, which
are identical and hence it would be a bug to behave differently on those
two lines.

> The former is from the Emacs source tree, and the latter duplicate
> is from /usr/share/info/.

Only *you* know that: Emacs has no clue whatsoever where those lines
come from.

> I think it's more wrong when clicking on the link in the
> "Texinfo documentation system" section visits the Info file
> from the Emacs source tree instead of the Texinfo installation
> in /usr/share/info/.

That happens to work for you because by chance the "Texinfo
documentation system" section only exists in one of the dir files, so
the entries in that section are "unambiguously" bound to that dir file
and hence to the directory where it was found.  But that's not the way
`dir' files and section headers usually behave, so there's no code in
info.el to try and special case such situations.


        Stefan