While troubleshooting an issue with test_distutils consistently failing on my XP buildbot, I narrowed it down to the test.bat change to use run_tests.py.  I don't yet know fully what's happening, but after replacing the new test.bat with the older version (that calls rt.bat) everything works fine.

Doing so also appears to clean up the stdin encoding problem (which was causing a consistent failure in test_capi).

As suggested by Zachary in msg222621, and given the status of XP going forward, I think it may be best, at least for now, to revert back to the traditional test.bat/rt.bat combination under XP, which has been stable for a long time.  At least until some further work can be done to discover what's happening with the new approach, assuming it's desired at some point under XP.

Attached is a simple test.bat update that reverts to the older rt.bat approach but only under XP.