Prevent open SC terms.

Closes PR 15144.

typed-racket-lib/typed-racket/private/type-contract.rkt

@@ -284,7 +284,10 @@
                [else
                 (define sc (match type match-clause ...))
                 (define fvs (fv type))
-                (unless (or (ormap (λ (n) (member n fvs)) (bound-names))
+                ;; Only cache closed terms, otherwise open terms may show up
+                ;; out of context.
+                ;; TODO this used `bound-names`, get rid of it
+                (unless (or (not (null? fv))
                             ;; Don't cache types with applications of Name types because
                             ;; it does the wrong thing for recursive references
                             (has-name-app? type))

typed-racket-test/succeed/pr15144.rkt

@@ -0,0 +1,28 @@
+#lang typed/racket
+
+;; Caching in the type->sc translation was causing open sc terms to appear in
+;; the contract for `bar`.
+
+(define-type (Base-Shape R)
+  (U (foo-shape R)
+     (bar-shape R)))
+
+(define-syntax (def-base-shape stx)
+  (syntax-case stx ()
+    [(_ (R (func-name shape-name) [param-name : param-type] ...))
+     (syntax/loc stx
+       (begin
+         (struct (R) shape-name ([param-name : param-type] ...))
+         (define #:forall (R) (func-name [param-name : param-type] ...)
+           (shape-name param-name ...))))]))
+
+(def-base-shape (R (foo-func foo-shape) [s : (Base-Shape R)]))
+(def-base-shape (R (bar-func bar-shape) [s : R]))
+
+(provide foo)
+(define (foo [shapes : (Base-Shape String)])
+  (foo-func shapes))
+
+(provide bar)
+(define (bar [shapes : (Base-Shape String)])
+  (bar-func shapes))