Describe the current behavior

When the user uses Table.lookupRecords(key=value).ReferencedColumn in a situation where there is no match, the formula returns a list instead ot a RecordSet. This can introduce edge cases that make the python formula fail.

Steps to reproduce

1. Create a "Rooms" table
2. Add a column "Name" and add "Room A" and "Room B" items
3. Create a "Objects" table
4. Add a column "Name" and a column "Room" that references the first table
5. Add a single item: a needle in "Room A"
6. Go back to the "Rooms" table and add a formula column with this content: type(Objects.lookupRecords(Room=$id).Room)
7. Observe that it is equal to RecordSet for "Room A" and list for "Room B"

Here is the code view:

import grist
from functions import *       # global uppercase functions
import datetime, math, re     # modules commonly needed in formulas


@grist.UserTable
class Objects:
  Name = grist.Text()
  Where = grist.Reference('Rooms')


@grist.UserTable
class Rooms:
  Name = grist.Text()

  def Items(rec, table):
    return None

Describe the expected behavior

The engine should return the same type for both, probably a RecordSet

Where have you encountered this bug?

• On docs.getgrist.com
• On a self-hosted instance

Instance information (when self-hosting only)

N/A