catch bad request_id in request form GET

atst/domain/requests.py

@@ -1,4 +1,4 @@
-from sqlalchemy import exists, and_
+from sqlalchemy import exists, and_, exc
 from sqlalchemy.orm.exc import NoResultFound
 from sqlalchemy.orm.attributes import flag_modified
 
@@ -149,5 +149,5 @@ class Requests(object):
         try:
             db.session.query(Request).filter_by(id=request_id, creator=user_id).one()
             return True
-        except NoResultFound:
+        except (NoResultFound, exc.DataError):
             return False

tests/routes/test_request_new.py

@@ -62,3 +62,10 @@ def test_ccpo_can_view_request(client, user_session):
     response = client.get("/requests/new/1/{}".format(request.id), follow_redirects=True)
 
     assert response.status_code == 200
+
+
+def test_nonexistent_request(client, user_session):
+    user_session()
+    response = client.get("/requests/new/1/foo", follow_redirects=True)
+
+    assert response.status_code == 404