On Wed, Apr 9, 2008 at 1:16 PM, Justin Ferguson <report@bugs.python.org> wrote:
..
>  That said, theres plenty of other implementations that manage this
>  without the potential of underflowing a buffer
>

Do you have in mind something like the following?

===================================================================
--- Python/mysnprintf.c (revision 62211)
+++ Python/mysnprintf.c (working copy)
@@ -88,6 +88,7 @@
        PyMem_FREE(buffer);
 Done:
 #endif
-       str[size-1] = '\0';
+       if (size > 0)
+               str[size-1] = '\0';
        return len;
 }

I would be +0 on such change.