Have list hashes depend on the order of the contents, as is the case for vectors. src/ChangeLog addition: 2008-01-16 Aidan Kehoe <kehoea@parhasard.net> * elhash.c (internal_hash): Make short lists with the same contents in a different order hash distinctly. Gives better performance for things like three-element lists describing colours. Thank you Sebastian Freundt! tests/ChangeLog addition: 2008-01-16 Aidan Kehoe <kehoea@parhasard.net> * automated/hash-table-tests.el: Assert that two short lists with the same contents in distinct orders hash differently.