Improve the scope_lookup method for Classes.

This patch improves the scope lookup for Classes, regarding qualified
objects, with an attribute name exactly as one provided in the
class itself.
For example, a class containing an attribute 'first',
which was also an import and which had, as a base, a qualified name
or a Gettattr node, in the form 'module.first', then Pylint would
have inferred the `first` name as the function from the Class,
not the import. Closes Pylint issue #466.

3 files changed, 41 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 54ecc08..5adc6a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,16 @@ Change log for the astroid package (used to be astng)
 
     * Fix a crash which occurred when a class was the ancestor
       of itself. Closes issue #78.
+
+    * Improve the scope_lookup method for Classes regarding qualified
+      objects, with an attribute name exactly as one provided in the
+      class itself.
+
+      For example, a class containing an attribute 'first',
+      which was also an import and which had, as a base, a qualified name
+      or a Gettattr node, in the form 'module.first', then Pylint would
+      have inferred the `first` name as the function from the Class,
+      not the import. Closes Pylint issue #466. 
            
 
 2015-01-17 -- 1.3.4
diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index 88e4fe1..2bbd2c2 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -1036,7 +1036,21 @@ class Class(Statement, LocalsDictNodeNG, FilterStmtsMixin):
             yield Instance(self)
 
     def scope_lookup(self, node, name, offset=0):
-        if node in self.bases:
+        if any(node == base or base.parent_of(node)
+               for base in self.bases):
+            # Handle the case where we have either a name
+            # in the bases of a class, which exists before
+            # the actual definition or the case where we have
+            # a Getattr node, with that name.
+            #
+            # name = ...
+            # class A(name):
+            #     def name(self): ...
+            #
+            # import name
+            # class A(name.Name):
+            #     def name(self): ...
+
             frame = self.parent.frame()
             # line offset to avoid that class A(A) resolve the ancestor to
             # the defined class
diff --git a/astroid/tests/unittest_inference.py b/astroid/tests/unittest_inference.py
index 84d0414..1a53b05 100644
--- a/astroid/tests/unittest_inference.py
+++ b/astroid/tests/unittest_inference.py
@@ -1624,5 +1624,21 @@ class InferenceTest(resources.SysPathSetup, unittest.TestCase):
          for i in range(16, 19):
              self.assertInferConst(ast[i], 0)
 
+    def test_scope_lookup_same_attributes(self):
+        code = '''
+        import collections
+        class Second(collections.Counter):
+            def collections(self):
+                return "second"
+
+        '''
+        ast = test_utils.build_module(code, __name__)
+        bases = ast['Second'].bases[0]
+        inferred = next(bases.infer())
+        self.assertTrue(inferred)
+        self.assertIsInstance(inferred, nodes.Class)
+        self.assertEqual(inferred.qname(), 'collections.Counter')
+
+
 if __name__ == '__main__':
     unittest.main()