Index: Python/getargs.c
===================================================================
--- Python/getargs.c	(revision 43246)
+++ Python/getargs.c	(working copy)
@@ -1041,7 +1041,7 @@
 			else {
 			char *buf;
 			Py_ssize_t count = convertbuffer(arg, p, &buf);
-			if (count < 0)
+			if (count < 0 || ((count % sizeof(Py_UNICODE)) != 0))
 				return converterr(buf, arg, msgbuf, bufsize);
 			STORE_SIZE(count/(sizeof(Py_UNICODE))); 
 			}
Index: Objects/unicodeobject.c
===================================================================
--- Objects/unicodeobject.c	(revision 43246)
+++ Objects/unicodeobject.c	(working copy)
@@ -321,7 +321,7 @@
 
 	/* Single character Unicode objects in the Latin-1 range are
 	   shared when using this constructor */
-	if (size == 1 && *u < 256) {
+	if (size == 1 && (unsigned) *u < 256) {
 	    unicode = unicode_latin1[*u];
 	    if (!unicode) {
 		unicode = _PyUnicode_New(1);