Re: Bug#793067: Bug#792328: info: can no longer find the Emacs manual

[Gavin Smith]

On 5 August 2015 at 16:06, Eli Zaretskii <address@hidden> wrote:
>> Date: Tue, 4 Aug 2015 21:20:47 +0100
>> From: Gavin Smith <address@hidden>
>> Cc: Rob Browning <address@hidden>, address@hidden,
>>       Texinfo <address@hidden>
>>
>> > A solution that supports inter-manual links, both in Info and in HTML
>> > formats.  To do this on a per-user basis, we would need some
>> > environment variable or/and user init file that would tell the Info
>> > reader what version of which manual it should look for, so that it
>> > could automagically substitute a reference to a "foo" manual with
>> > "foo-1.2.3".
>>
>> This could be done with a directory full of symlinks in the user's
>> home directory. For example, from ~/local/info/indirect/foo.info to
>> /usr/local/share/info/foo-1.2.3.info. ~/local/info/indirect would be
>> early in INFOPATH and references to the "foo" manual would be resolved
>> appropriately. Split Info files complicate the situation: either all
>> the subfiles would need to be symlinked, or the browser would have to
>> be able to find the containing directory of the target of the symlink.
>> (Avoiding split Info files in such circumstances would be the simplest
>> solution.)
>
> Yes, this is possible, but hardly convenient, for the reasons you
> point out.
>
> Which is why I think having a feature that would transparently replace
> "foo" in an Info file name with "foo-1.2.3" would be more convenient.
> Of course, such replacement should only take place where this kind of
> redirection is relevant.
>
> For the Info reader, this could done as part of the reader itself.
> For HTML, we could have a small application that would write
> appropriate redirection files.

The problem with split Info files isn't important: it's unlikely that
an Info reader will run out of memory reading a non-split file, so
simply avoid split files if it causes a problem. If it does become a
problem there would be ways to deal with it, for example teach
install-info how to rewrite a subfiles table.

A similar problem is with image files associated with Info files. I
can't think how that would be supported, but few Info files use images
anyway.

You suggest having some kind of configuration file defining aliases
for manuals. A subdirectory full of symbolic links is a kind of such a
file, and not harder to update than any other kind of file format you
could devise.

Anyway, however the resolution is done, some kind of renaming of the
installed Info file would have to be done. I plan on looking at how to
do this in coming days.