Bug: bfconvert writes invalid OME-XML containing MetadataOnly

[rleigh]

Reproducible with 5.0.8:

tools/bfconvert Beta\ Catenin.lif BetaCatenin.ome.tiff
./tools/tiffcomment BetaCatenin.ome.tiff > xml
./tools/xmlvalid xml 
Parsing schema path
http://www.openmicroscopy.org/Schemas/OME/2013-06/ome.xsd
Validating xml
cvc-complex-type.2.4.a: Invalid content was found starting with element 'MetadataOnly'. One of '{"http://www.openmicroscopy.org/Schemas/OME/2013-06":TiffData, "http://www.openmicroscopy.org/Schemas/OME/2013-06":Plane, "http://www.openmicroscopy.org/Schemas/SA/2013-06":AnnotationRef}' is expected.
cvc-complex-type.2.4.a: Invalid content was found starting with element 'MetadataOnly'. One of '{"http://www.openmicroscopy.org/Schemas/OME/2013-06":TiffData, "http://www.openmicroscopy.org/Schemas/OME/2013-06":Plane, "http://www.openmicroscopy.org/Schemas/SA/2013-06":AnnotationRef}' is expected.
cvc-complex-type.2.4.a: Invalid content was found starting with element 'MetadataOnly'. One of '{"http://www.openmicroscopy.org/Schemas/OME/2013-06":TiffData, "http://www.openmicroscopy.org/Schemas/OME/2013-06":Plane, "http://www.openmicroscopy.org/Schemas/SA/2013-06":AnnotationRef}' is expected.
cvc-complex-type.2.4.a: Invalid content was found starting with element 'MetadataOnly'. One of '{"http://www.openmicroscopy.org/Schemas/OME/2013-06":TiffData, "http://www.openmicroscopy.org/Schemas/OME/2013-06":Plane, "http://www.openmicroscopy.org/Schemas/SA/2013-06":AnnotationRef}' is expected.
cvc-complex-type.2.4.a: Invalid content was found starting with element 'MetadataOnly'. One of '{"http://www.openmicroscopy.org/Schemas/OME/2013-06":TiffData, "http://www.openmicroscopy.org/Schemas/OME/2013-06":Plane, "http://www.openmicroscopy.org/Schemas/SA/2013-06":AnnotationRef}' is expected.

Note that the showinf -omexml does validate, but it's validating the OME-XML after we've converted it and mangled it; it's not validating the original OME-XML which it silently accepts without warning.

[mlinkert]

I can reproduce as well with the v5.0.8 tag, but the same test on develop results in valid XML with no MetadataOnly?.

[rleigh]

Is this something we want to backport? Should we treat the creation of invalid OME-XML as a serious problem given the interoperability issues it could cause?

[mlinkert]

Likely not worth backporting unless a 5.0.9 is planned imminently. I don't think this is a particularly serious problem, as actually reading the exported files should be unaffected.

[rleigh]

It's certainly not an issue with the Java OME-TIFF reader, since it silently ignores the problem when processing the data. But from the POV of an external consumer of OME-XML, we're writing out invalid nonconforming data.