n is always 'True', we can only stop the loop with the break statement

mercurial/localrepo.py

@@ -872,7 +872,7 b' class localrepository(object):'
         b = []
         for n in nodes:
             t = n
-            while n:
+            while 1:
                 p = self.changelog.parents(n)
                 if p[1] != nullid or p[0] == nullid:
                     b.append((t, n, p[0], p[1]))