The following description is copied from CXF-4910.

A following example results in incorrect behavior:

Namely:
WSDLGetUtils.updateSchemaImports() uses a map for caching processed schemata.
A service built from following path layout

Wsdl.wsdl
z/Types.xsd
z/z/Types.xsd

Where

- Wsdl.wsld imports z/Types.xsd(NS: http://example.com/NS1) using relative path
- z/Types.xsd imports z/Types.xsd(NS: http://example.com/NS2) using relative path (i.e. imports z/z/Types.xsd)

results in incorrect serving of service definition when querying the endpoint.

The link from wsdl to import points to "?xsd=z/Types.xsd".

<wsdl:definitions xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:tns="http://example.com/Service/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" name="Service" targetNamespace="http://example.com/Service/">
  <wsdl:types>
    <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:tns="http://example.com/Service/" xmlns:sty="http://example.com/StructTypes" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" targetNamespace="http://example.com/Service/">
      <xsd:import namespace="http://example.com/StructTypes" schemaLocation="http://localhost:8080/Service?xsd=z/Types.xsd"/>
    </xsd:schema>
    ...
  </wsdl:types>
  ...
</wsdl:definitions>

The link from z/Types.xsd points again to itself "?xsd=z/Types.xsd" (same content is served).
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
  xmlns:tns="http://example.com/StructTypes" 
  xmlns:bty="http://example.com/BaseTypes" 
  targetNamespace="http://example.com/StructTypes">
    <xsd:import namespace="http://example.com/BaseTypes" schemaLocation="http://localhost:8080/Service?xsd=z/Types.xsd"/>

This is because the WSDLGetUtils cuts of the schemata processing on the first import because relative path is used as key identifier in the schema map.

I suspect the same applies for the WSDL imports in WSDLGetUtils.updateDefinition() due to caching the definitions in the definition map.