Propagate attachment events for ARRAY

Fixed regression in :class:`.ARRAY` datatype caused by
:ticket:`3964`, which is essentially the same
issue as that of :ticket:`3832`, where column attachment events
for :class:`.ARRAY` would not be invoked.   This breaks the use case
of using declarative mixins that declare a :class:`.Column` which
makes use of :meth:`.MutableList.as_mutable`.

Change-Id: If8c57615860883837f6cf72661e46180a77778c1
Fixes: #4141

1 files changed, 9 insertions, 1 deletions

diff --git a/test/sql/test_metadata.py b/test/sql/test_metadata.py
index 7071782c4..45eb59453 100644
--- a/test/sql/test_metadata.py
+++ b/test/sql/test_metadata.py
@@ -7,7 +7,7 @@ from sqlalchemy import Integer, String, UniqueConstraint, \
     ForeignKeyConstraint, PrimaryKeyConstraint, ColumnDefault, Index, event,\
     events, Unicode, types as sqltypes, bindparam, \
     Table, Column, Boolean, Enum, func, text, TypeDecorator, \
-    BLANK_SCHEMA
+    BLANK_SCHEMA, ARRAY
 from sqlalchemy import schema, exc
 from sqlalchemy.engine import default
 from sqlalchemy.sql import elements, naming
@@ -1650,6 +1650,14 @@ class SchemaTypeTest(fixtures.TestBase):
         typ = MyType()
         self._test_before_parent_attach(typ, target_typ, double=True)
 
+    def test_before_parent_attach_array_enclosing_schematype(self):
+        # test for [ticket:4141] which is the same idea as [ticket:3832]
+        # for ARRAY
+
+        typ = ARRAY(String)
+
+        self._test_before_parent_attach(typ)
+
     def test_before_parent_attach_typedec_of_schematype(self):
         class MyType(TypeDecorator, sqltypes.SchemaType):
             impl = String