From 164442ab268e2aa94f26a693f7666dc9f84603ad Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 30 Apr 2019 17:02:07 -0600
Subject: [PATCH] fix `place-message-allowed?` on an empty vector

---
 pkgs/racket-test-core/tests/racket/place.rktl | 1 +
 racket/src/racket/src/place.c                 | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/racket-test-core/tests/racket/place.rktl b/pkgs/racket-test-core/tests/racket/place.rktl
index a8e135c589..1816605e57 100644
--- a/pkgs/racket-test-core/tests/racket/place.rktl
+++ b/pkgs/racket-test-core/tests/racket/place.rktl
@@ -100,6 +100,7 @@
   (test #t place-message-allowed? v)
   (test #t place-message-allowed? (list v))
   (test #t place-message-allowed? (vector v)))
+(test #t place-message-allowed? (vector))
 
 (for ([v (list (lambda () 10)
                add1)])
diff --git a/racket/src/racket/src/place.c b/racket/src/racket/src/place.c
index 76b9ba27fc..3956e9fdf1 100644
--- a/racket/src/racket/src/place.c
+++ b/racket/src/racket/src/place.c
@@ -1655,7 +1655,8 @@ DEEP_VEC2:
       if (set_mode) {
         SCHEME_SET_IMMUTABLE(vec);
         new_so = vec;
-      }
+      } else
+        new_so = vec;
       RETURN;
       break;