You need to include ant-sax2.jar in ant/lib, define a <path id='foo'> that includes
all the jars that you need ( junit.jar, etc ) and then use
 <systemPath pathRef='foo' /> to create the loader and reload all optional tasks.

After this step all optional tasks will work in the same way as if you have
included the jars from the <path> definition in ant/lib.

I did some basic tests and seems to work fine - note that <taskdef> will
work as before, i.e. if you explicitely define tasks that need optional
jars ( or redefine optional task ), you'll have the old behavior ( i.e.
require things in CLASSPATH ).

I'll try to find what changes are need for <import> and re-do the build
for ant-sax2, then do more testings.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273118 13f79535-47bb-0310-9956-ffa450edef68