`import` ignored, when importing second XSD into the same namespace

[jakubklimek]

I have this document and an XSD (linked from it from schemaLocation).

Now, the XSD imports 2 other XSDs with the same targetNamespace:

  <xs:import namespace="http://dia.gov.cz/ns/spolecne-casti-elektronickych-dokumentu/osoby" schemaLocation="https://ofn.gov.cz/společné-části-elektronických-dokumentů/2024-10-04/schémata/osoby/osoba-ve-vztahu-k-dokumentu.xsd"/>
  <xs:import namespace="http://dia.gov.cz/ns/spolecne-casti-elektronickych-dokumentu/osoby" schemaLocation="https://ofn.gov.cz/společné-části-elektronických-dokumentů/2024-10-04/schémata/osoby/fyzická-osoba-ve-vztahu-k-dokumentu.xsd"/>

The XSDs have both the same targetNamespace and contain no conflicting definitions. Nevertheless, the second import is ignored, resulting in an error:

because that type is defined in the second imported XSD. When I comment out the first import, the second starts working.

This should be legal in XML Schema, and other validators like Altova work fine with it.

[angelozerr]

This error comes from xerces so I dont know if it is possible to fix it without some hack or perhaps it is a configuration of xerces.

Any contribution are welcome !

[jakubklimek]

Just for the record, I investigated the XML Schema spec, and there is a note about this situation at the end of 4.2.6.2:

Given that the schemaLocation [attribute] is only a hint, it is open to applications to ignore all but the first for a given namespace, regardless of the ·actual value· of schemaLocation, but such a strategy risks missing useful information when new schemaLocations are offered.

Apparently, Xerces implementation indeed ignores all but the first import with a given namespace, resulting in exactly what the specification warns about - missing information, which then has to be provided by the user.