Note up front: there is a win32 function wsprintf() and an ISO C
function swprintf(), these are different things in case you wonder.

In _winreg.c, there are two functions that use wsprintf on a char
buffer, while the function takes a TCHAR buffer instead. This leads to
compile warning and runtime errors when _UNICODE is defined, like e.g.
under MS Windows CE. The attached patch replaces the two calls to that
function with calls to fprintf() and PyString_FromFormat().

The patch seems good.
This only applies to trunk: py3k already uses PyUnicode_FromFormat.

fprintf() is much better than wsprintf() + fputs() with a fixed size 
buffer (with no size/error check!). Same remark for 
PyString_FromFormat() instead of wsprintf()+PyString_FromString().

Fixed in r68592.