[XERCESJ-1726] Possible Bug: Xerces 2.12.1 for XML Validation with XSD 1.1 Schema under Java

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.12.1
• Fix Version/s: 2.12.2
• Component/s: XML Schema 1.1 Datatypes, XML Schema 1.1 Structures
• Labels: test
• Environment: Windows 7 ; Java 1.8.0_261 ; Xerces-J 2.12.1
• Flags: Important
• Assignee: Mukul Gandhi
• Reporter: J Morris
• Created: 26/Aug/20 17:46
• Updated: 19/Jan/22 11:13
• Resolved: 08/Jan/22 08:05

Description

I have recently been trying to validate the XML file test1.xml with a schema test.xsd containing assert/assertion constructs, using the sample program jaxp.SourceValidator.
Unexpectedly, the result was several reported errors in what appeared to be syntactically correct and valid XML lines (test1.xml: 9 errors).
After significant experimentation, it appeared that these errors were occurring at line numbers which the validation found troublesome. Inserting an extra line at one of the troublesome line numbers made the previously erroneous line (now not appearing at a troublesome line number) pass validation. On the other hand, the newly inserted line (occupying the troublesome line number) would fail validation.
I tentatively interpreted this as meaning that the validation errors were not real and began to try to develop a test-case, as similar as possible to test1.xml, but which passed validation. The result was test2.xml, which was generated from test1.xml by inserting XML comment lines at each of the troublesome line numbers, thereby displacing the previously erroneous lines to non-trooublesome line numbers. Since XML comment lines do not require validation, this file passed validation for me (test2.xml: 0 errors).
I then contacted Mukul Gandhi and he re-ran my validations but came to a different result. He saw errors in both XML files (test1.xml: 9 errors; test2.xml: 18 errors). Despite our joint efforts to achieve convergence between our respective validation runs, we have not so far succeeded.
Mukul did point out a couple of things:
1) The way that I was using the "matches" function in the assert constructs. His experience suggested that this was unreliable. However, I was not certain whether this would have led to the type of behaviour that I was seeing (apparent troublesome line numbers).
2) He found that certain characters (probably the two accented French characters) in my XML files were not supported in the default XML encoding scheme, UTF-8. However, for me, no errors were reported for those by the validation program jaxp.SourceValidator.

I would be very gratefull foe some help in getting to the bottom of this (both the original behaviour and the discrepancies with Mukul's validation runs).