[AXIOM-497] Removal of namespace declaration breaks type attribute

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Cannot Reproduce
• Affects Version/s: 1.2.13
• Component/s: Core Model, OM Mixins
• Environment: Weblogic 12.2.1.3 version application server
• Flags: Patch, Important
• Docs Text: This issue is impacting our customers' business operations critically.
• Assignee: Unassigned
• Reporter: Unifiers Pega
• Created: 09/May/19 08:37
• Updated: 11/May/19 10:44
• Resolved: 11/May/19 10:35

Description

When the following XML is converted to an OMElement, then written back out, the namespace prefix used by the xsi:type attribute refers to the incorrect namespace URI. That is because the local prefix mapping used in the type name reference is removed from the element that contains the type attribute during parsing.

It appears to be caused by a null return value from the getNsBuilder method of AttributeCollector when it thinks the namespace declaration is redundant.

Original XML:
<ns1:A xmlns:ns1="urn:foo">
<ns1:B xmlns:ns1="urn:bar">
<ns2:C xmlns:ns1="urn:foo" xmlns:ns2="urn:bar" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns1:TypeA"/>
</ns1:B>
</ns1:A>

After conversion to OMElement, xsi:type name cannot be resolved because it is mapped to the wrong namespace URI:
<ns1:A xmlns:ns1="urn:foo">
<ns1:B xmlns:ns1="urn:bar">
<ns2:C xmlns:ns2="urn:bar" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns1:TypeA"/>
</ns1:B>
</ns1:A>

 

Here's some sample code to reproduce the issue:

```

System.out.println("Before StAX parsing:\n"+xmlString);

try

{ java.io.StringReader stringReader = new java.io.StringReader(xmlString); javax.xml.stream.XMLInputFactory inputFactory = javax.xml.stream.XMLInputFactory.newInstance(); javax.xml.stream.XMLStreamReader streamReader = inputFactory.createXMLStreamReader(stringReader); org.apache.axiom.om.impl.builder.StAXOMBuilder builder = new org.apache.axiom.om.impl.builder.StAXOMBuilder(streamReader); xmlString = builder.getDocumentElement().toString(); }

catch (Exception e)

{ System.out.println("Caught exception " + e); }

System.out.println("After StAX parsing:\n"+xmlString);

```