Don't share a counter when checking for circularity, list_merge(). src/ChangeLog addition: 2010-10-12 Aidan Kehoe <kehoea@parhasard.net> * fns.c (list_merge): Circularity checking here needs to be done independently for each list, they can't share a loop counter. Thank you for the bug report, Robert Pluim! tests/ChangeLog addition: 2010-10-12 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-tests.el: Make sure circularity checking with #'merge is sane.