Use last previous assignment for comprehension-escape (#2131)

2 files changed, 13 insertions, 3 deletions

diff --git a/pylint/checkers/python3.py b/pylint/checkers/python3.py
index 1e988f63b..f2efa18d1 100644
--- a/pylint/checkers/python3.py
+++ b/pylint/checkers/python3.py
@@ -638,9 +638,10 @@ class Python3Checker(checkers.BaseChecker):
         # On Python 3 we don't find the leaked objects as
         # they are already deleted, so instead look for them manually.
         scope = node.scope()
-        assign_names = (node_ for node_ in scope.nodes_of_class(astroid.AssignName)
-                        if node_.name == node.name and node_.lineno < node.lineno)
-        assigned = next(assign_names, None)
+        assigned = None
+        for node_ in scope.nodes_of_class(astroid.AssignName):
+            if node_.name == node.name and node_.lineno < node.lineno:
+                assigned = node_
         if not assigned:
             return
 
diff --git a/pylint/test/unittest_checker_python3.py b/pylint/test/unittest_checker_python3.py
index b6f98ad70..8e1bce493 100644
--- a/pylint/test/unittest_checker_python3.py
+++ b/pylint/test/unittest_checker_python3.py
@@ -735,6 +735,15 @@ class TestPython3Checker(testutils.CheckerTestCase):
             with self.assertNoMessages():
                 self.checker.visit_name(node)
 
+    def test_comprehension_escape_newly_introduced(self):
+        node = astroid.extract_node('''
+        [i for i in range(3)]
+        for i in range(3):
+            i
+        ''')
+        with self.assertNoMessages():
+            self.walk(node)
+
     def test_exception_escape(self):
         bad, good = astroid.extract_node('''
         try: 1/0