Bugfix PersistentTreeSet lookup

src/cljs/cljs/core.cljs

@@ -5743,9 +5743,10 @@ reduces them without incurring seq initialization"
   (-lookup [coll v]
     (-lookup coll v nil))
   (-lookup [coll v not-found]
-    (if (-contains-key? tree-map v)
-      v
-      not-found))
+    (let [n (.entry-at tree-map v)]
+      (if-not (nil? n)
+        (.-key n)
+        not-found)))
 
   ISet
   (-disjoin [coll v]

test/cljs/cljs/core_test.cljs

@@ -1260,15 +1260,18 @@
   ;; PersistentTreeSet
   (let [s1 (sorted-set)
         c2 (comp - compare)
-        s2 (sorted-set-by c2)]
+        s2 (sorted-set-by c2)
+        c3 #(compare (quot %1 2) (quot %2 2))
+        s3 (sorted-set-by c3)]
     (assert (identical? cljs.core.PersistentTreeSet (type s1)))
     (assert (identical? cljs.core.PersistentTreeSet (type s2)))
     (assert (identical? compare (-comparator s1)))
     (assert (identical? c2 (-comparator s2)))
     (assert (zero? (count s1)))
     (assert (zero? (count s2)))
     (let [s1 (conj s1 1 2 3)
-          s2 (conj s2 1 2 3)]
+          s2 (conj s2 1 2 3)
+          s3 (conj s3 1 2 3)]
       (assert (= (hash s1) (hash s2)))
       (assert (= (hash s1) (hash #{1 2 3})))
       (assert (= (seq s1)  (list 1 2 3)))
@@ -1277,6 +1280,8 @@
       (assert (= (rseq s2) (list 1 2 3)))
       (assert (= (count s1) 3))
       (assert (= (count s2) 3))
+      (assert (= (count s3) 2))
+      (assert (= (get s3 0) 1))
       (let [s1 (disj s1 2)
             s2 (disj s2 2)]
         (assert (= (seq s1)  (list 1 3)))