From aa42163b705d96b76d37fcf0206ea85591ff8935 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Mon, 25 Feb 2019 10:41:30 -0700
Subject: [PATCH] fix place-channel handling of hash tables that contain
 impersonators

Closes #2504
---
 .../tests/racket/place-channel-chaperone.rkt  | 44 +++++++++++++++++++
 racket/src/racket/src/list.c                  |  5 ++-
 2 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 pkgs/racket-test/tests/racket/place-channel-chaperone.rkt

diff --git a/pkgs/racket-test/tests/racket/place-channel-chaperone.rkt b/pkgs/racket-test/tests/racket/place-channel-chaperone.rkt
new file mode 100644
index 0000000000..82aae4f545
--- /dev/null
+++ b/pkgs/racket-test/tests/racket/place-channel-chaperone.rkt
@@ -0,0 +1,44 @@
+#lang racket/base
+(require racket/place)
+
+(define-values (i o) (place-channel))
+
+(define (bounce v)
+  (place-channel-put o v)
+  (place-channel-get i))
+
+(define (check a b)
+  (unless (equal? a b)
+    (error 'fail "different ~s ~s" a b)))
+
+(check (vector 1 2 3)
+       (bounce (chaperone-vector (vector 1 2 3)
+                                 (lambda (v i val) val)
+                                 (lambda (v i val) val))))
+
+(check (hash 1 (vector 1 2 3))
+       (bounce (hash 1
+                     (chaperone-vector (vector 1 2 3)
+                                       (lambda (v i val) val)
+                                       (lambda (v i val) val)))))
+
+(struct posn (x y) #:prefab)
+
+(check (posn (vector 1 2 3) 4)
+       (bounce (chaperone-struct (posn (vector 1 2 3) 4)
+                                 posn-x (lambda (s val)
+                                          (chaperone-vector val
+                                                            (lambda (v i val) val)
+                                                            (lambda (v i val) val))))))
+
+(check (hash 'a (vector 1 2 3))
+       (bounce (chaperone-hash (hash 'a (vector 1 2 3))
+                               (lambda (ht k)
+                                 (values k
+                                         (lambda (ht k val)
+                                           (chaperone-vector val
+                                                             (lambda (v i val) val)
+                                                             (lambda (v i val) val)))))
+                               (lambda (ht k val) val)
+                               (lambda (ht k) k)
+                               (lambda (ht k) k))))
diff --git a/racket/src/racket/src/list.c b/racket/src/racket/src/list.c
index 94f9d7a8eb..265bae00d6 100644
--- a/racket/src/racket/src/list.c
+++ b/racket/src/racket/src/list.c
@@ -3625,7 +3625,10 @@ Scheme_Object *scheme_chaperone_hash_table_filtered_copy(Scheme_Object *obj,
   Scheme_Object *a[3], *v, *v2, *idx, *key, *val;
   int is_eq, is_eqv;
 
-  v = SCHEME_CHAPERONE_VAL(obj);
+  if (SCHEME_CHAPERONEP(obj))
+    v = SCHEME_CHAPERONE_VAL(obj);
+  else
+    v = obj;
 
   a[0] = obj;
   is_eq = SCHEME_TRUEP(scheme_hash_eq_p(1, a));