Fix impersonate-mvar (and mvar/c as an impersonator contract)

Author: lexi-lambda

mvar-lib/data/mvar.rkt

@@ -296,7 +296,7 @@
     (apply wrap-proc mv struct:mvar props)))
 
 (define (impersonate-mvar mv #:get [get-proc #f] #:put [put-proc #f] . props)
-  (wrap-mvar impersonate-struct mv get-proc put-proc props))
+  (wrap-mvar impersonate-struct mv props #:get get-proc #:put put-proc))
 (define (chaperone-mvar mv #:get [get-proc #f] #:put [put-proc #f] . props)
   (define ((make-checked-chaperone-proc proc) a)
     (define b (proc a))

mvar-test/tests/data/mvar.rkt

@@ -127,3 +127,26 @@
  (check-exn (exn?-blaming 'pos) (λ () (mvar-peek mv+c)))
  (check-exn (exn?-blaming 'pos) (λ () (mvar-take! mv+c)))
  (check-equal? (mvar-empty? mv+c) #t))
+
+(test-case
+ "mvar/c impersonator contract"
+
+ (define coerce-to-bool/c
+   (make-contract
+    #:late-neg-projection
+    (λ (blame)
+      (λ (val neg-party)
+        (and val #t)))))
+
+ (define mv (contract (mvar/c coerce-to-bool/c boolean?)
+                      (make-mvar)
+                      'pos
+                      'neg))
+
+ (check-equal? (mvar-put! mv 'ok) (void))
+ (check-equal? (mvar-peek mv) #t)
+ (check-equal? (mvar-take! mv) #t)
+
+ (check-equal? (mvar-put! mv #f) (void))
+ (check-equal? (mvar-peek mv) #f)
+ (check-equal? (mvar-take! mv) #f))