dcmqrscp: missing attributes in C-FIND responses

[gunterze]

If there is no value available for a requested attribute, no attribute is included into the C-FIND response.
Instead an empty attribute shall be included into the C-FIND response.

[wigun]

@gunterze Doesn't this violate the DICOM Conformance, since 'Type=1C attributes' like e.g. 'The Scheduled Protocol Code Sequence contains one or more Items.' (DICOM Standard, table K.6-1, PS 3.4) are added empty with this commit, if there is no respond for this?! I thought empty sequences like this have to be removed from the respond?!

[wigun]

@gunterze And isn't it required that unsupported query/return keys should always be removed?

[gunterze]

There are DICOM implementaions which claim on missing Type 2 attributes in C-FIND RSPs, if they were requested.
I am not aware of any DICOM implementation which claims against receive of empty Type 1C or Type 3 attributes.