[xml] Why some XHTML related tests fail with HTTP support disabled?

["Leonid Romanov" <agent couper gmail com>]

Hi,
All below is for libxm2-2.6.31 compiled on Ubuntu 7.10. 

I've noticed that disabling HTTP support (--without-html) makes some XHTML-related tests to fail. 
Here are failure messages (I've removed all other non-failure messages):

leonid tihiro:~/src/libxml2-2.6.31$ ./runtest 
## XML regression tests
File ./test/xhtml1 generated an error
File ./test/xhtmlcomp generated an error
## XML regression tests on memory
Result for ./test/xhtml1 failed
File ./test/xhtml1 generated an error
Result for ./test/xhtmlcomp failed
File ./test/xhtmlcomp generated an error
## XML entity subst regression tests
File ./test/xhtml1 generated an error
File ./test/xhtmlcomp generated an error
## XML push regression tests
Result for ./test/xhtml1 failed
File ./test/xhtml1 generated an error
Result for ./test/xhtmlcomp failed
File ./test/xhtmlcomp generated an error
## General documents valid regression tests
Result for ./test/valid/xhtml1.xhtml failed
File ./test/valid/xhtml1.xhtml generated an error

I wonder why did they fail? My assumptions are following:

- "--with-html" option enables HTML4 tag soup parser.
- XHTML is just an XML vocabulary for HTML, so parsing it only requires XML parser.

Under these assumptions, enabling/disabling HTTP support should have no effect on 
XHTML tests. However, its not the case. Could anyone explain, please, whats going on here: 
are my assumptions wrong or there is some other reason why they fail?

Thanks in advance,
Leonid.