Added safety checks

scheme/cyclone/cps-optimizations.sld

@@ -1959,8 +1959,14 @@
                     ))))))
 
 
+         (with-handler
+          (lambda (err)
+            (trace:error `(error transforming CC loop ,err))
+            result)
           (cond
-           (replace
+            ((and replace
+                  (tagged-list? '%closure (car result)) ;; TODO: see above, not always a closure, what to do then?
+             )
               (define (clo->lambda-body sexp)
                 (car (ast:lambda-body (cadr sexp))))
               
@@ -1973,7 +1979,7 @@
                 (set-cdr! outer-body `((cell ,set-clo))) ;; Relocate the closure
                 result
               ))
-           (else result))
+            (else result)))
 ))
          ((lambda? fn)   (error `(Unexpected lambda in closure-convert ,exp)))
          (else