Issue #5249: time.strftime returned malformed string when format string

contained non ascii character on windows.

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 3.1 alpha 0
 Core and Builtins
 -----------------
 
+- Issue #5249: time.strftime returned malformed string when format string
+  contained non ascii character on windows.
+
 - Issue #5186: Reduce hash collisions for objects with no __hash__ method by
   rotating the object pointer by 4 bits to the right.
 

Modules/timemodule.c

@@ -508,9 +508,11 @@ time_strftime(PyObject *self, PyObject *args)
             return NULL;
         }
 
-    /* Convert the unicode string to an ascii one */
-    fmt = _PyUnicode_AsString(format);
-
+	/* Convert the unicode string to an ascii one */
+	format = PyUnicode_AsEncodedString(format, TZNAME_ENCODING, NULL);
+	if (format == NULL)
+		return NULL;
+	fmt = PyBytes_AS_STRING(format);
 	fmtlen = strlen(fmt);
 
 	/* I hate these functions that presume you know how big the output
@@ -519,6 +521,7 @@ time_strftime(PyObject *self, PyObject *args)
 	for (i = 1024; ; i += i) {
 		outbuf = (char *)PyMem_Malloc(i);
 		if (outbuf == NULL) {
+			Py_DECREF(format);
 			return PyErr_NoMemory();
 		}
 		buflen = strftime(outbuf, i, fmt, &buf);
@@ -532,6 +535,7 @@ time_strftime(PyObject *self, PyObject *args)
 			ret = PyUnicode_Decode(outbuf, buflen,
 					       TZNAME_ENCODING, NULL);
 			PyMem_Free(outbuf);
+			Py_DECREF(format);
 			return ret;
 		}
 		PyMem_Free(outbuf);
@@ -539,6 +543,7 @@ time_strftime(PyObject *self, PyObject *args)
 		/* VisualStudio .NET 2005 does this properly */
 		if (buflen == 0 && errno == EINVAL) {
 			PyErr_SetString(PyExc_ValueError, "Invalid format string");
+			Py_DECREF(format);
 			return 0;
 		}
 #endif