[xml] Regression failures with libxml2-2.4.26

[Chris Rankin <rankincj yahoo com>]

Hi,
I have just tried compiling libxml2-2.4.26, and have found the following 
regression test failures:

##
## Valid documents regression tests
##
Testing 21.xml
Testing v1.xml
Testing v10.xml
Testing v11.xml
Testing v12.xml
Testing v13.xml
Testing v14.xml
Testing v15.xml
Testing v16.xml
Testing v17.xml
Testing v18.xml
Testing v19.xml
Testing v2.xml
Testing v20.xml
not determinist
./test/VCM/v20.xml:10: validity error: Content model of doc is not 
determinist: ((a | b)* , a , b)
</doc>
     ^
...

##
## Validity checking regression tests
##
Testing AttributeDefaultLegal
Testing DuplicateType
Testing ElementValid
Testing ElementValid2
Testing ElementValid3
Testing ElementValid4
Testing ElementValid5
Testing ElementValid6
Testing ElementValid7
Testing ElementValid8
not determinist
1c1
< ./test/VC/ElementValid8:7: validity warning: Content model for Element 
doc is ambiguous
---
> ./test/VC/ElementValid8:7: validity error: Content model of doc is 
not determinist: ((a , b) | (a , c))
...

##
## Automata regression tests
##
Testing a
Testing aba
Testing abaa
0a1
> not determinist
...

Should I be concerned?
Cheers,
Chris