[xml] patches for xmlschemastypes.c

[Charles Bozeman <cbozeman hiwaay net>]

The function _xmlSchemaDateAdd alters the input parameter dt (by setting
the time-zone offset to 0) which alters the value in the context (when
validating with facets). The first patch fixes the problem by
duplicating the input value.
The second patch adds a test to date_0.xml in the test/schemas directory
to validate the patch.

These context diff patches are against current cvs and have been tested
with the regression tests and check-xsddata-test-suite.py.

Charlie Bozeman

Attachment: date_0.xml-pat
Description: Text Data

Attachment: xmlschemastypes.c-pat
Description: Text Data