Created attachment 1306 [details]
a modified catalog.xsd file

The schema document for the SCDS test suite catalog has a number of errors. 

1 There are two top-level elements named paths; one is used as a child of 'test' in the catalog itself and the other is used in the paths files pointed to from the main catalog.  In the attached modification of catalog.xsd, I have made both 'schema' and 'paths' local to 'test'.

2 In the complex type for 'test', the attribute declarations had slipped down past the end-tag of the complexType, so they were its younger siblings instead of being its children.

3 The declarations of the types of canonical-section and selected-section lack groups around the single child element particles.  I've wrapped them in sequences.

4 The selected-section element appears to be have been caught in the middle of changing from a local declaration to a reference to a global declaration, or vice versa:  it has ref="this:selected-section", but it contains a type declaration, and there is no top-level declaration for the reference to point to.

5 The declarations for complex types canonicalPathType and selectedPathType use prefxed names in their 'name' attributes, instead of unprefixed names as required by the spec.

When these changes are made, Xerces J and Saxon accept the schema document and complain that the includes-builtins attribute is missing from each occurrence of  'test'.  (The catalog.xml file uses the name 'include-builtins'.  Since the name in the declaration seems more declarative, I have changed the attributes in the catalog instance, not the declaration.  When that is done, catalog.xml becomes schema-valid.)