(use srfi-1)
#>
void FOO1(C_word cb)
{
 C_callback (cb, 0);
}
// Foo2 randomly produces:
//; Error: call of non-procedure: #<invalid forwarded object>
//; or segfaults,
void FOO2(C_word cb)
{
 C_callback (cb, 0);
 C_callback (cb, 0);
}
<#

(define FOO1 (foreign-safe-lambda void "FOO1" scheme-object))
(define FOO2 (foreign-safe-lambda void "FOO2" scheme-object))

;; called with C_callback
(define check-proc-callback (lambda args (if (null? args) #f #t)))

;; works fine:
(define (run-test1) 
  (for-each (lambda _ (FOO1 check-proc-callback))
            (iota 100000)))
(define (run-test2) 
  (for-each (lambda _ (FOO2 check-proc-callback))
            (iota 100000)))


(print "test 1")
(run-test1)
(print "test 2-bad")
(run-test2)

(print "compiled tests ok (not!)")



/tmp $ csc bad.scm && ./bad
test 1
test 2-bad
segmentation fault