Issue #3187: Add sys.setfilesystemencoding.
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index f4118d6..89f50b5 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -216,7 +216,24 @@
 operating system filenames."
 );
 
+static PyObject *
+sys_setfilesystemencoding(PyObject *self, PyObject *args)
+{
+	PyObject *new_encoding;
+	if (!PyArg_ParseTuple(args, "U:setfilesystemencoding", &new_encoding))
+		return NULL;
+	if (_Py_SetFileSystemEncoding(new_encoding))
+		return NULL;
+	Py_INCREF(Py_None);
+	return Py_None;
+}
 
+PyDoc_STRVAR(setfilesystemencoding_doc,
+"setfilesystemencoding(string) -> None\n\
+\n\
+Set the encoding used to convert Unicode filenames in\n\
+operating system filenames."
+);
 
 static PyObject *
 sys_intern(PyObject *self, PyObject *args)
@@ -872,6 +889,8 @@
 #endif
 	{"setdefaultencoding", sys_setdefaultencoding, METH_VARARGS,
 	 setdefaultencoding_doc},
+	{"setfilesystemencoding", sys_setfilesystemencoding, METH_VARARGS,
+	 setfilesystemencoding_doc},
 	{"setcheckinterval",	sys_setcheckinterval, METH_VARARGS,
 	 setcheckinterval_doc},
 	{"getcheckinterval",	sys_getcheckinterval, METH_NOARGS,