ignore empty IDs when retrieving multiple

This is for example useful for the template inputs. They should not be
sent due to the "disabled" attribute, but we never know what browsers
are doing, therefore we stay defensive. The test case already has to do
extra steps to prevent those from being sent.

1 files changed, 2 insertions, 0 deletions

diff --git a/fietsboek/util.py b/fietsboek/util.py
index d3a4064..f62a0d5 100644
--- a/fietsboek/util.py
+++ b/fietsboek/util.py
@@ -231,6 +231,8 @@ def retrieve_multiple(dbsession, model, params, name):
     """
     objects = []
     for obj_id in params.getall(name):
+        if not obj_id:
+            continue
         query = select(model).filter_by(id=obj_id)
         obj = dbsession.execute(query).scalar_one_or_none()
         if obj is None: