Dealing with cyclic hashes

original commit: 4088448317

collects/compiler/zo-marshal.rkt

@@ -228,6 +228,11 @@
      (traverse-stx expr visit)]
     [(wrapped? expr)
      (traverse-wrapped expr visit)]
+    [(hash? expr)
+     (when (visit expr)
+       (for ([(k v) (in-hash expr)])
+         (traverse-data k visit)
+         (traverse-data v visit)))]
     [else
      (void)]))
 
@@ -987,6 +992,8 @@
      (for ([v (in-vector expr)])
        (out-data v out))]
     [(hash? expr)
+     (out-shared expr out
+                 (lambda ()
                    (out-byte CPT_HASH_TABLE out)
                    (out-number (cond
                                  [(hash-eqv? expr) 2]
@@ -996,7 +1003,7 @@
                    (out-number (hash-count expr) out)
                    (for ([(k v) (in-hash expr)])
                      (out-data k out)
-       (out-data v out))]
+                     (out-data v out))))]
     [(svector? expr)
      (let* ([vec (svector-vec expr)]
             [len (vector-length vec)])