Custom field is rendered, even if its value is empty (for multiple)
Redmine checks, if the value is available for the custom field, as follows:
But for multiple custom fields (e.g., lists, that allow selecting multiple values), the original
nil value is replaced with
[nil] (not sure where exactly). So,
false and the custom field gets rendered.
This issue affects 3.0.x and 1.4.x versions of Redmine.
P.S. Can be solved by montkey-patching `CustomFieldValue` as follows:
alias_method_chain :value, :extended ... def value_with_extended value = value_without_extended if custom_field.multiple? && value.present? && value.size == 1 && value.first.nil? nil else value end end