1 files changed, 52 insertions, 0 deletions
diff --git a/tests/pending/run/t3984.scala b/tests/pending/run/t3984.scala
new file mode 100644
index 000000000..0747b0ee2
--- /dev/null
+++ b/tests/pending/run/t3984.scala
@@ -0,0 +1,52 @@
+object SetBug {
+  import scala.collection.immutable.{ Set => ImmutSet }
+  import scala.collection.mutable.{ Set => MutSet }
+
+  case class IH (i: Int, h: Int) {
+    override def hashCode: Int = h
+  }
+
+  def run() {
+    var is = ImmutSet.empty[IH]
+    var ms = MutSet.empty[IH]
+    for (ih <- List(IH(2,0),IH(0,0),IH(4,4),IH(6,4),IH(-8,1520786080))) {
+      is = is + ih
+      ms = ms + ih
+    }
+    assert(is == ms)
+    val x = IH(6,4)
+    is = is - x
+    ms = ms - x
+    assert(is == ms)
+  }
+}
+
+object MapBug {
+  import scala.collection.immutable.{ Map => ImmutMap }
+  import scala.collection.mutable.{ Map => MutMap }
+
+  case class IH (i: Int, h: Int) {
+    override def hashCode: Int = h
+  }
+
+  def run() {
+    var im = ImmutMap.empty[IH,IH]
+    var mm = MutMap.empty[IH,IH]
+    for (ih <- List(IH(2,0),IH(0,0),IH(4,4),IH(6,4),IH(-8,1520786080))) {
+      im = im + ((ih,ih))
+      mm = mm + ((ih,ih))
+    }
+    assert(im == mm)
+    val x = IH(6,4)
+    im = im - x
+    mm = mm - x
+    assert(im == mm)
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    SetBug.run()
+    MapBug.run()
+  }
+}