Restrict the available functions in `DocumentTemplate.sequence` to public...

Restrict the available functions in `DocumentTemplate.sequence` to public API's of `zope.sequencesort`.

doc/CHANGES.rst

@@ -8,6 +8,9 @@ http://docs.zope.org/zope2/releases/.
 2.12.21 (unreleased)
 --------------------
 
+- Restrict the available functions in `DocumentTemplate.sequence` to public
+  API's of `zope.sequencesort`.
+
 - Turn `UndoSupport.get_request_var_or_attr` helper into a private API.
 
 - Provide security declarations for `BTreeFolder2Base` class, instead of only

src/DocumentTemplate/sequence/SortEx.py

@@ -11,4 +11,11 @@
 #
 ##############################################################################
 
-from zope.sequencesort.ssort import *
+from zope.sequencesort.ssort import nocase, make_sortfunctions
+from zope.sequencesort.ssort import sort, SortEx, SortBy
+
+# only if locale is already imported
+import sys
+if "locale" in sys.modules:
+    from zope.sequencesort.ssort import strcoll_nocase
+del sys