1 files changed, 36 insertions, 0 deletions
diff --git a/test/files/run/t5986.scala b/test/files/run/t5986.scala
new file mode 100644
index 0000000000..8cf7086f98
--- /dev/null
+++ b/test/files/run/t5986.scala
@@ -0,0 +1,36 @@
+
+
+
+import scala.collection._
+
+
+
+/** A sorted set should not replace elements when adding
+ *  and the element already exists in the set.
+ */
+object Test {
+  
+  class Foo(val name: String, val n: Int) {
+    override def equals(obj: Any): Boolean = obj match { case other: Foo => name == other.name; case _ => false }
+    override def hashCode = name.##
+    override def toString = "Foo(" + name + ", " + n + ")"
+  }
+  
+  implicit val ordering: Ordering[Foo] = Ordering.fromLessThan[Foo] { (a, b) => a.name.compareTo(b.name) < 0 }
+  
+  def check[S <: Set[Foo]](set: S) {
+    def output(s: Set[Foo]) = println(s.toList.sorted.mkString(","))
+    output(set + new Foo("bar", 2))
+    output(set ++ List(new Foo("bar", 2), new Foo("bar", 3), new Foo("bar", 4)))
+    output(set union Set(new Foo("bar", 2), new Foo("baz", 3), new Foo("bazz", 4)))
+  }
+  
+  def main(args: Array[String]) {
+    check(Set(new Foo("bar", 1)))
+    check(immutable.Set(new Foo("bar", 1)))
+    check(mutable.Set(new Foo("bar", 1)))
+    check(immutable.SortedSet(new Foo("bar", 1)))
+    check(mutable.SortedSet(new Foo("bar", 1)))
+  }
+  
+}