From a0378a2b02e6627909df943758182f869534d762 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sat, 12 Nov 2011 06:08:42 -0700
Subject: [PATCH] fix bug in prefab syntax marshaling

Closes PR 12352
---
 collects/tests/racket/macro.rktl | 9 +++++++++
 src/racket/src/syntax.c          | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/collects/tests/racket/macro.rktl b/collects/tests/racket/macro.rktl
index ebf8261244..073bf4e3a6 100644
--- a/collects/tests/racket/macro.rktl
+++ b/collects/tests/racket/macro.rktl
@@ -627,6 +627,15 @@
 
   (test 10 'ten (invoke compare)))
 
+;; ----------------------------------------
+;; Check zo marshaling of prefab in a list:
+
+(let ([s #'(quote-syntax (#s(foo bar)))])
+  (define-values (i o) (make-pipe))
+  (parameterize ([current-namespace (make-base-namespace)]
+                 [read-accept-compiled #t])
+    (write (compile s) o)
+    (test (syntax->datum (eval (read i))) values '(#s(foo bar)))))
 
 ;; ----------------------------------------
 
diff --git a/src/racket/src/syntax.c b/src/racket/src/syntax.c
index e367b7b01c..efc9354cdc 100644
--- a/src/racket/src/syntax.c
+++ b/src/racket/src/syntax.c
@@ -6338,7 +6338,7 @@ static Scheme_Object *extract_for_common_wrap(Scheme_Object *a, int get_mark, in
         else
           return SCHEME_CDR(v);
       }
-    } else if (!SCHEME_BOXP(v) && !SCHEME_VECTORP(v)) {
+    } else if (!SCHEME_BOXP(v) && !SCHEME_VECTORP(v) && !prefab_p(v)) {
       /* It's atomic. */
       if (get_mark)
         return SCHEME_CDR(a);