Author: mhenoch Date: Sat Jul 8 10:03:30 2006 New Revision: 17 Modified: cl-darcs/trunk/unwind.lisp Log: In put-before, handle case of empty patch list correctly. Modified: cl-darcs/trunk/unwind.lisp ============================================================================== --- cl-darcs/trunk/unwind.lisp (original) +++ cl-darcs/trunk/unwind.lisp Sat Jul 8 10:03:30 2006 @@ -73,11 +73,12 @@ and commuted through PATCHES, to finally give a list of patches whose context consists of P1. If any commutation fails, this operation fails as well." - (destructuring-bind (&optional p2-c p1-c) (commute (invert-patch p1) (car patches)) - (and p2-c p1-c - (commute p1 p2-c) - (let ((rest (put-before p1-c (cdr patches)))) - (and rest (cons p2-c rest)))))) + (when patches + (destructuring-bind (&optional p2-c p1-c) (commute (invert-patch p1) (car patches)) + (and p2-c p1-c + (commute p1 p2-c) + (let ((rest (put-before p1-c (cdr patches)))) + (and rest (cons p2-c rest))))))) (defun all-head-permutations (ps) "Return all possible permutations of PS.