do not execute more than 900 times uselessly this loop when

it is not needed, this makes unit test reporting infinite
activity loop much more faster

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@44365 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/tests/ProcessingNodeTestCase.py

@@ -169,7 +169,8 @@ class ProcessingNodeTestCase(backportUnittest.TestCase, ZopeTestCase.TestCase):
         message_count = len(message_list)
         # This prevents an infinite loop.
         count -= 1
-        if count == 0:
+        if count == 0 or (message_count and set([x.processing_node for x in 
+              message_list]).issubset(set([-2, -3]))):
           error_message = 'tic is looping forever. '
           try:
             self.assertNoPendingMessage()