Various minor problems in VO-DML repo

[Markus Demleitner]

Dear DM,

I didn't look for them -- but while giving in to the fact that I'll
have to shallow-parse the VO-DML in order to come up with the
<mild expletive deleted> VO-DML ids in MIVOT I stepped into a few
problems related to obtaining VO-DML files that, I think, nicely
illustrate my point that whatever isn't validated (or at least used)
by a machine is broken.

(1) The IVOA types DM (sigh!) ivoa.vo-dml.xml
(https://ivoa.net/xml/VODML/IVOA-v1.vo-dml.xml) is schema-invalid:

  <string>:7:0:ERROR:SCHEMASV:SCHEMAV_ELEMENT_CONTENT: Element 'title': This element is not expected. Expected is one of ( identifier, uri ).

This is because the model element in VO-DML has a mandatory uri
element, which is described as:

  Each model has an associated model URI that MUST be used to
  reference it, for example in ModelImports or in VOTable
  annotations. Dereferencing the model URI and following redirects
  yields the latest VO-DML for the data model

Inserting <uri>http://www.ivoa.net/xml/VODML/v1</uri> in front of the
title element fixes this.

(2) While I was figuring this out, I noticed that in coords, meas,
and phot (didn't check the others), the uri element is present but
empty.  I'm pretty sure we should fix that, and I guess as an
editorial oversight I'd even do it without an erratum process.
Who'll push it along?

[but at least these other vo-dmls are schema-valid]

(3) Requesting the coords model at

https://ivoa.net/xml/VODML/Coords-v1.vo-dml.xml

results in a 300 Multiple Choices response from our web server.
That's because the underlying file is called Coords-v1.0.vo-dml.xml
(note the extra ".0").  I think I've always argued that -v1 should
redirect to -v1.0.  But I'm open to any alternative, as long as
people get a plain 200 or redirect when they access the DM URI.
Who'll tackle this?


I give you all of these are minor annoyances, but, really, I again
take them as indications we've not done a good job providing
reference implementations of MIVOT yet.

        -- Markus