Error on custom fields format when merging cases

[To-om]

Request Type

Bug

Work Environment

Question	Answer
OS version (server)	Ubuntu
OS version (client)	Any
TheHive version / git hash	2.13.x
Package Type	Any

Problem Description

When two cases is merged TheHive set common custom fields to "null" ; the value of one is not privileged over to the other. But the null value is not a valid for custom fields.

Steps to Reproduce

1. Create a case with a custom fields
2. Create another case and add a custom fields with the same name as the previous case
3. Merge the two cases

Possible Solutions

Remove custom fields present in both merged cases.