Fixes bug in intmap equality

Collision nodes were previously only testing for the equality
of keys and ignoring values.

pkgs/racket-test-core/tests/racket/hash.rktl

@@ -112,6 +112,10 @@
   ;; 5 bits for both keys:
   (define ht3 (hash (a 1 0) #t
                     (a 33 0) #t))
+  ;; A hash with the same (colliding) keys as h1 but
+  ;; different values:
+  (define ht4 (hash (a 1 0) #f
+                    (a 1 2) #f))
 
   ;; Subset must compare a collision node with a subtree node (that
   ;; contains a collision node):
@@ -125,7 +129,18 @@
   (test #f hash-keys-subset? ht2 ht1)
   (test #f hash-keys-subset? ht2 ht0)
   (test #f hash-keys-subset? ht1 ht0)
-  (test #f hash-keys-subset? ht1 ht3))
+  (test #f hash-keys-subset? ht1 ht3)
+
+  ;; Equality of collision nodes:
+  (test #f equal? ht1 ht4)
+  (let ([ht4a (hash-set ht4 (a 1 0) #t)]
+        [ht4b (hash-set ht4 (a 1 2) #t)]
+        [ht5 (hash-set* ht4
+                        (a 1 0) #t
+                        (a 1 2) #t)])
+    (test #f equal? ht1 ht4a)
+    (test #f equal? ht1 ht4b)
+    (test #t equal? ht1 ht5)))
 
 (let ()
   (define-syntax (define-hash-iterations-tester stx)

racket/src/cs/rumble/intmap.ss

@@ -206,12 +206,6 @@
           [(key=? et key (caar xs)) (loop (cdr xs))]
           [else (cons (car xs) (loop (cdr xs)))])))
 
-(define ($collision-has-key? et t key)
-  (let loop ([xs (Co-pairs t)])
-    (cond [(null? xs) #f]
-          [(key=? et key (caar xs)) #t]
-          [else (loop (cdr xs))])))
-
 ;; bit twiddling
 (define-syntax-rule (match-prefix? h p m)
   (fx= (mask h m) p))
@@ -390,9 +384,13 @@
           (let ([xs (Co-pairs a)])
             (and (fx= (length xs) (length (Co-pairs b)))
                  (let loop ([xs xs])
-                   (cond [(null? xs) #t]
-                         [($collision-has-key? et b (caar xs)) (loop (cdr xs))]
-                         [else #f])))))]
+                   (cond [(null? xs)
+                          #t]
+                         [else
+                          (let ([pair ($collision-ref et b (caar xs) values #f)])
+                            (and pair
+                                 (eql? (cdar xs) (cdr pair))
+                                 (loop (cdr xs))))])))))]
 
     [else (and (not a) (not b))])))