--- a/tests/run-tests.py	Mon Nov 22 20:44:36 2010 +0100
+++ b/tests/run-tests.py	Thu Dec 02 09:41:56 2010 +0100
@@ -594,7 +594,7 @@
         tochild.close()
         output = fromchild.read()
         ret = fromchild.close()
-        if ret == None:
+        if ret is None:
             ret = 0
     else:
         proc = Popen4(cmd)
@@ -714,7 +714,7 @@
     # If we're not in --debug mode and reference output file exists,
     # check test output against it.
     if options.debug:
-        refout = None                   # to match out == None
+        refout = None                   # to match "out is None"
     elif os.path.exists(ref):
         f = open(ref, "r")
         refout = splitnewlines(f.read())