makeinfo --docbook versus @documentencoding

[Kevin Ryde]

In the debian packaged makeinfo 4.5, or with my own build of the
latest cvs, the file foo.texi below processed with

        makeinfo --docbook foo.texi

gives

        foo.texi:5: warning: unrecognized encoding name `'.

It seems to be the @documentencoding which upsets it, and only in
docbook mode since without the --docbook option it's fine.

(I don't know if latin1 makes sense for docbook, I wasn't trying to
actually use it, just seeing that my document passed all makeinfo
modes.)

foo.texi
Description: TeXInfo document