The C program does crash, but newwin() is returning NULL 
and the code should really be checking for this case.   When I try 
the Python script with 2.5-maint and 2.6-trunk, I get the error:
amk@amk:~/source/p/25$ ./python.exe ../python/curses-01.py
Traceback (most recent call last):
  File "../python/curses-01.py", line 8, in <module>
    curses.wrapper(foobar)
  File "/Users/amk/source/p/25/Lib/curses/wrapper.py", line 44, in wrapper
    return func(stdscr, *args, **kwds)
  File "../python/curses-01.py", line 4, in foobar
    winmain = curses.newwin(50,50,50,50)
_curses.error: curses function returned NULL

I removed the import of the 'readline' module 
because I don't have it on my Mac, but that seems unlikely to 
make a difference.