From d081586959eaeee1ebc8fb8b345b574e2dad10b4 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 14 Jul 2017 07:37:55 -0600
Subject: [PATCH] fix immutability of some `syntax-e` results

Internally, when scopes are propagated to nested syntax objects,
vectors and boxes were not reconstructed as immutable.

Closes #1745
---
 pkgs/racket-test-core/tests/racket/stx.rktl | 6 ++++++
 racket/src/racket/src/syntax.c              | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/pkgs/racket-test-core/tests/racket/stx.rktl b/pkgs/racket-test-core/tests/racket/stx.rktl
index 012284b855..9d461a82b5 100644
--- a/pkgs/racket-test-core/tests/racket/stx.rktl
+++ b/pkgs/racket-test-core/tests/racket/stx.rktl
@@ -228,6 +228,12 @@
 (define-define-stx stx-with-property)
 (test 'y syntax-property stx-with-property 'x)
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Check immutability
+
+(test #t immutable? (syntax-e #'#(1 2)))
+(test #t immutable? (syntax-e #'#&1))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Plain s, se derived from part of s
 
diff --git a/racket/src/racket/src/syntax.c b/racket/src/racket/src/syntax.c
index babc06a5fc..73ab62edbe 100644
--- a/racket/src/racket/src/syntax.c
+++ b/racket/src/racket/src/syntax.c
@@ -2196,6 +2196,7 @@ static Scheme_Object *raw_stx_content(Scheme_Object *o)
                          shifts,
                          add_taint, false_insp);
       v = scheme_box(result);
+      SCHEME_SET_BOX_IMMUTABLE(v);
     } else if (SCHEME_VECTORP(v)) {
       Scheme_Object *v2;
       int size = SCHEME_VEC_SIZE(v), i;
@@ -2209,6 +2210,8 @@ static Scheme_Object *raw_stx_content(Scheme_Object *o)
                            add_taint, false_insp);
       	SCHEME_VEC_ELS(v2)[i] = result;
       }
+
+      SCHEME_SET_VECTOR_IMMUTABLE(v2);
       
       v = v2;
     } else if (SCHEME_HASHTRP(v)) {