Groups

Automatic keyword group must offer subgroup for entries without value

req~groups.automatic-keyword.missing-value-subgroup~1

An automatic group based on a keyword field (for example, ranking) lists one subgroup per value. Entries that have no value in that field, or only delimiters, appear in an additional subgroup “No value”, so they can be found without a manual search. The subgroup is only shown when at least one entry has no value.

See https://github.com/JabRef/jabref/issues/10264.

Needs: impl, utest