Imported Upstream version 5.10.0.47

Former-commit-id: d0813289fa2d35e1f8ed77530acb4fb1df441bc0

mcs/class/corlib/Test/System/ArrayTest.cs

@@ -3385,6 +3385,30 @@ public class ArrayTest
 		}
 	}
 
+	[Test]
+	public void IEnumerator_Dispose ()
+	{
+		IEnumerable<int> e = new int[] { 1 };
+		var en = e.GetEnumerator ();
+		Assert.IsTrue (en.MoveNext (), "#1");
+		Assert.IsFalse (en.MoveNext (), "#2");
+		en.Dispose ();
+		Assert.IsFalse (en.MoveNext (), "#3");
+	}
+
+	[Test]
+	public void IEnumerator_ZeroSize ()
+	{
+		IEnumerable<int> e = Array.Empty<int> ();
+		var en = e.GetEnumerator ();
+		Assert.IsFalse (en.MoveNext (), "#1");
+
+		e = Array.Empty<int> ();
+		en = e.GetEnumerator ();
+		Assert.IsFalse (en.MoveNext (), "#2");
+	}
+
+	[Test]
 	public void ICollection_IsReadOnly() {
 		ICollection<string> arr = new string [10];
 
@@ -3669,6 +3693,20 @@ public class ArrayTest
 		Assert.AreEqual (3, c.Counter);		
 	}
 
+	[Test]
+	public void EnumeratorsEquality ()
+	{
+		int [] normalBase = new int [0];
+		IEnumerable<int> specialBase = new int [0];
+
+		var firstSpecial = specialBase.GetEnumerator ();
+		var secondSpecial = specialBase.GetEnumerator ();
+		var firstNormal = normalBase.GetEnumerator ();
+		var secondNormal = normalBase.GetEnumerator ();
+
+		Assert.IsFalse (object.ReferenceEquals (firstNormal, secondNormal));
+		Assert.IsTrue (object.ReferenceEquals (firstSpecial, secondSpecial));
+	}
 
 	[Test]
 	public void JaggedArrayCtor ()