SI-10113 mutable.TreeMap.range does not work

added missing overrides for TreeMapView

src/library/scala/collection/mutable/TreeMap.scala

@@ -180,6 +180,9 @@ sealed class TreeMap[A, B] private (tree: RB.Tree[A, B])(implicit val ordering:
       this
     }
 
+    override def valuesIterator: Iterator[B] = RB.valuesIterator(tree, from, until)
+    override def keysIterator: Iterator[A] = RB.keysIterator(tree, from, until)
+
     override def clone() = super.clone().rangeImpl(from, until)
   }
 }

test/junit/scala/collection/mutable/TreeMapTest.scala

@@ -0,0 +1,34 @@
+package scala.collection.mutable
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+import scala.collection.mutable
+
+@RunWith(classOf[JUnit4])
+class TreeMapTest {
+
+  @Test
+  def rangeMkString() {
+
+    val map = mutable.TreeMap[String, String]()
+
+    List("a", "b", "c", "d").foreach(v => map.put(v, v))
+
+    val range = map.range("b", "c")
+
+    val valuesRange = range.values
+    val keysRange = range.keys
+
+    assertEquals(1, valuesRange.size)
+    assertEquals(1, keysRange.size)
+
+    assertEquals("b", valuesRange.mkString(","))
+    assertEquals("b", keysRange.mkString(","))
+    assertEquals("b -> b", range.mkString(","))
+
+  }
+
+}

test/junit/scala/collection/mutable/TreeSetTest.scala

@@ -0,0 +1,20 @@
+package scala.collection.mutable
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+import scala.collection.mutable
+
+
+@RunWith(classOf[JUnit4])
+class TreeSetTest {
+
+  @Test
+  def rangeMkString() {
+
+    val set = mutable.TreeSet("a", "b", "c", "d")
+    assertEquals("b", set.range("b", "c").mkString(","))
+  }
+}