From bf41fee58d931d732397a7d1f9878e14b89632fe Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 12 Dec 2019 11:59:27 -0700
Subject: [PATCH] fix argument check for `instantiate-linklet`

Closes #2962
---
 .../tests/racket/core-tests.rktl              |  1 +
 .../tests/racket/linklet.rktl                 | 26 +++++++++++++++++++
 racket/src/cs/linklet.sls                     | 10 +++++++
 racket/src/racket/src/linklet.c               |  2 +-
 4 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 pkgs/racket-test-core/tests/racket/linklet.rktl

diff --git a/pkgs/racket-test-core/tests/racket/core-tests.rktl b/pkgs/racket-test-core/tests/racket/core-tests.rktl
index ba61e0ff09..9af4f6e2b2 100644
--- a/pkgs/racket-test-core/tests/racket/core-tests.rktl
+++ b/pkgs/racket-test-core/tests/racket/core-tests.rktl
@@ -11,6 +11,7 @@
 (load-relative "letrec.rktl")
 (load-relative "procs.rktl")
 (load-relative "stx.rktl")
+(load-relative "linklet.rktl")
 (load-relative "module.rktl")
 (load-relative "submodule.rktl")
 (load-relative "stxparam.rktl")
diff --git a/pkgs/racket-test-core/tests/racket/linklet.rktl b/pkgs/racket-test-core/tests/racket/linklet.rktl
new file mode 100644
index 0000000000..96120be381
--- /dev/null
+++ b/pkgs/racket-test-core/tests/racket/linklet.rktl
@@ -0,0 +1,26 @@
+
+(load-relative "loadtest.rktl")
+
+(Section 'linklet)
+
+(require racket/linklet)
+
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(let ()
+  (define l (compile-linklet '(linklet
+                                  ()
+                                  ()
+                                4)))
+  (test #t linklet? l)
+  (test #t instance? (instantiate-linklet l '()))
+  (test 4 instantiate-linklet l '() (make-instance 'l))
+
+  (err/rt-test (instantiate-linklet l) exn:fail:contract:arity?)
+  (err/rt-test (instantiate-linklet l '#()))
+  (err/rt-test (instantiate-linklet l (list 5)))
+  (err/rt-test (instantiate-linklet l '() 5)))
+
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(report-errs)
diff --git a/racket/src/cs/linklet.sls b/racket/src/cs/linklet.sls
index 0bf648d271..5a5cc3f91d 100644
--- a/racket/src/cs/linklet.sls
+++ b/racket/src/cs/linklet.sls
@@ -697,8 +697,18 @@
      [(linklet import-instances target-instance)
       (instantiate-linklet linklet import-instances target-instance #f)]
      [(linklet import-instances target-instance use-prompt?)
+      (unless (linklet? linklet)
+        (raise-argument-error 'instantiate-linklet "linklet?" linklet))
+      (let loop ([l import-instances])
+        (unless (null? l)
+          (if (and (pair? l)
+                   (instance? (car l)))
+              (loop (cdr l))
+              (raise-argument-error 'instantiate-linklet "(listof instance?)" import-instances))))
       (cond
        [target-instance
+        (unless (instance? target-instance)
+          (raise-argument-error 'instantiate-linklet "(or/c instance? #f)" target-instance))
         ;; Instantiate into the given instance and return the
         ;; result of the linklet body:
         (with-continuation-mark
diff --git a/racket/src/racket/src/linklet.c b/racket/src/racket/src/linklet.c
index e5b3ae29d4..cb4c270d0a 100644
--- a/racket/src/racket/src/linklet.c
+++ b/racket/src/racket/src/linklet.c
@@ -593,7 +593,7 @@ static Scheme_Object *instantiate_linklet(int argc, Scheme_Object **argv)
     scheme_wrong_contract("instantiate-linklet", "linklet?", 0, argc, argv);
 
   l = argv[1];
-  while (!SCHEME_NULLP(l)) {
+  while (SCHEME_PAIRP(l)) {
     if (!SAME_TYPE(SCHEME_TYPE(SCHEME_CAR(l)), scheme_instance_type))
       break;
     l = SCHEME_CDR(l);