Ticket #940: set-read-syntax-unset-with-false.patch

library.scm

@@ -3067 +3067 @@
              (##sys#check-char chr loc)
              (let ([i (char->integer chr)])
                (##sys#check-range i 0 256 loc)
-               (##sys#setslot (##sys#slot crt slot) i (wrap proc)) ) ) ) ) )
+               (cond 
+                ((procedure? proc)
+                 (##sys#setslot (##sys#slot crt slot) i (wrap proc)))
+                ((not proc)
+                   (##sys#setslot (##sys#slot crt slot) i #f))
+                (else (##sys#error "not a procedure" proc))) ) ) ) ))
  
   (set! set-read-syntax!
     (syntax-setter