Listeneres should be removed even in exception cases. Do a 'finally' cleanup.

jedi/evaluate/dynamic.py

@@ -145,14 +145,15 @@ def search_params(evaluator, param):
     listener = ParamListener()
     func.listeners.add(listener)
 
-    result = []
+    try:
-    # This is like backtracking: Get the first possible result.
+        result = []
-    for mod in imports.get_modules_containing_name([current_module], func_name):
+        # This is like backtracking: Get the first possible result.
-        result = get_params_for_module(mod)
+        for mod in imports.get_modules_containing_name([current_module], func_name):
-        if result:
+            result = get_params_for_module(mod)
-            break
+            if result:
-
+                break
-    # cleanup: remove the listener; important: should not stick.
+    finally:
-    func.listeners.remove(listener)
+        # cleanup: remove the listener; important: should not stick.
+        func.listeners.remove(listener)
 
     return result