backport TM.sortKey/setSortKey from Products.ZSQLMethod (previously on Zope 2.12)

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37151 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/patches/TM.py

@@ -29,3 +29,21 @@ def TM__register(self):
         #except: pass
 
 TM._register = TM__register
+
+if getattr(TM, 'setSortKey', None) is None:
+
+    # BACK: We're not yet on Zope 2.12, patch in the sort_key setting method
+    # remove this part when we drop support for earlier versions.
+    def setSortKey(self, sort_key):
+        self._sort_key = sort_key
+
+    def sortKey(self, *ignored):
+        """ The sortKey method is used by the transaction subsystem to have a
+            known commit order for lock acquisition.
+        """
+        return self._sort_key
+
+    TM._sort_key = 1
+    TM.setSortKey = setSortKey
+    TM.sortKey = sortKey
+