Fix list listener parsing

CHANGES.txt

@@ -116,3 +116,4 @@ Fixes
  * `TraitSetObject.copy` now returns a plain rather than an
    uninitialized `TraitSetObject` instance. (#97)
  * Fix cyclic garbage arising from dynamic trait change handlers. (#101)
+ * Fix error when trying to listen to traits using list bracket notation (#195)

traits/tests/test_regression.py

@@ -3,7 +3,7 @@
 import sys
 
 from ..has_traits import HasTraits, Property, on_trait_change
-from ..trait_types import Bool, DelegatesTo, Instance, Int
+from ..trait_types import Bool, DelegatesTo, Instance, Int, List
 from ..testing.unittest_tools import unittest
 
 
@@ -55,6 +55,16 @@ def _get_y(self):
         return self.obj.x
 
 
+class ListUpdatesTest(HasTraits):
+    a = List
+    b = List
+    events_received = Int(0)
+
+    @on_trait_change('a[], b[]')
+    def _receive_events(self):
+        self.events_received += 1
+
+
 class TestRegression(unittest.TestCase):
 
     def test_default_value_for_no_cache(self):
@@ -106,5 +116,17 @@ def test_no_leaking_notifiers(self):
         del presenter
         self.assertEqual(len(ctrait._notifiers(1)), 0)
 
+    def test_init_list_depends(self):
+        """ Using two lists with bracket notation in extended name notation
+        should not raise an error.
+        """
+        list_test = ListUpdatesTest()
+        # Updates to list items and the list trait itself should be counted.
+        list_test.a.append(0)
+        list_test.b = [1, 2, 3]
+        list_test.b[0] = 0
+        self.assertEqual(list_test.events_received, 3)
+
+
 if __name__ == '__main__':
     unittest.main()

traits/traits_listener.py

@@ -1255,7 +1255,10 @@ def parse_item ( self, terminator ):
             return result
 
         if c == '[':
-            if (self.skip_ws == ']') and (self.skip_ws == terminator):
+            is_closing_bracket = (self.skip_ws == ']')
+            next_char = self.skip_ws
+            item_complete = (next_char == terminator or next_char == ',')
+            if is_closing_bracket and item_complete:
                 self.backspace
                 result.is_list_handler = True
             else: