don't use a stack for InferenceContext.path

The stack failed to detect infinite recursions.
This also closes http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=568968

3 files changed, 12 insertions, 19 deletions

diff --git a/bases.py b/bases.py
index 66b621b..a6758f6 100644
--- a/bases.py
+++ b/bases.py
@@ -69,7 +69,7 @@ class InferenceContext(object):
 
     def __init__(self, path=None):
         if path is None:
-            self.path = []
+            self.path = set()
         else:
             self.path = path
         self.lookupname = None
@@ -80,10 +80,7 @@ class InferenceContext(object):
         name = self.lookupname
         if (node, name) in self.path:
             raise StopIteration()
-        self.path.append( (node, name) )
-
-    def pop(self):
-        return self.path.pop()
+        self.path.add( (node, name) )
 
     def clone(self):
         # XXX copy lookupname/callcontext ?
@@ -290,18 +287,15 @@ def path_wrapper(func):
             context = InferenceContext()
         context.push(node)
         yielded = set()
-        try:
-            for res in _func(node, context, **kwargs):
-                # unproxy only true instance, not const, tuple, dict...
-                if res.__class__ is Instance:
-                    ares = res._proxied
-                else:
-                    ares = res
-                if not ares in yielded:
-                    yield res
-                    yielded.add(ares)
-        finally:
-            context.pop()
+        for res in _func(node, context, **kwargs):
+            # unproxy only true instance, not const, tuple, dict...
+            if res.__class__ is Instance:
+                ares = res._proxied
+            else:
+                ares = res
+            if not ares in yielded:
+                yield res
+                yielded.add(ares)
     return wrapped
 
 def yes_if_nothing_infered(func):
diff --git a/manager.py b/manager.py
index 32194e9..75398d9 100644
--- a/manager.py
+++ b/manager.py
@@ -120,7 +120,6 @@ class ASTNGManager(OptionsProviderMixIn):
             source = False
         if modname is None:
             modname = '.'.join(modpath_from_file(filepath))
-        print >>sys.stderr, 'astng from file', filepath, modname
         try:
             return self._cache[modname]
         except KeyError:
diff --git a/test/unittest_inference.py b/test/unittest_inference.py
index 2516191..f3b962a 100644
--- a/test/unittest_inference.py
+++ b/test/unittest_inference.py
@@ -663,7 +663,7 @@ help()
         astng = builder.string_build(code, __name__, __file__)
         node = get_name_node(astng, 'help', -1)
         infered = list(node.infer())
-        self.failUnlessEqual(len(infered), 1)
+        self.failUnlessEqual(len(infered), 1, infered)
         self.assertIsInstance(infered[0], Instance)
         self.failUnlessEqual(str(infered[0]),
                              'Instance of site._Helper')