[runtime] Fix Empty generic enumerator equality

[mono.git] / mcs / class / corlib / System / Array.cs

diff --git a/mcs/class/corlib/System/Array.cs b/mcs/class/corlib/System/Array.cs
index 00e0430d3de27dc3b5019a4a2cb84604d1934cc4..91424bc6f8f6dfbf4d2c5457e453f4db01add388 100644 (file)
--- a/mcs/class/corlib/System/Array.cs
+++ b/mcs/class/corlib/System/Array.cs
@@ -68,7 +68,10 @@ namespace System
 
                internal IEnumerator<T> InternalArray__IEnumerable_GetEnumerator<T> ()
                {
-                       return new InternalEnumerator<T> (this);
+                       if (Length == 0)
+                               return EmptyInternalEnumerator<T>.Value;
+                       else
+                               return new InternalEnumerator<T> (this);
                }
 
                internal void InternalArray__ICollection_Clear ()
@@ -207,7 +210,7 @@ namespace System
                        // we just decr the size, so, 0 - 1 == FINISHED
                        const int FINISHED = -1;
                        
-                       Array array;
+                       readonly Array array;
                        int idx;
 
                        internal InternalEnumerator (Array array)
@@ -218,7 +221,6 @@ namespace System
 
                        public void Dispose ()
                        {
-                               idx = NOT_STARTED;
                        }
 
                        public bool MoveNext ()
@@ -272,6 +274,38 @@ namespace System
                        }
                }
 
+               internal class EmptyInternalEnumerator<T> : IEnumerator<T>
+               {
+                       public static readonly EmptyInternalEnumerator<T> Value = new EmptyInternalEnumerator<T> ();
+
+                       public void Dispose ()
+                       {
+                               return;
+                       }
+
+                       public bool MoveNext ()
+                       {
+                               return false;
+                       }
+
+                       public T Current {
+                               get {
+                                       throw new InvalidOperationException ("Enumeration has not started. Call MoveNext");
+                               }
+                       }
+
+                       object IEnumerator.Current {
+                               get {
+                                       return Current;
+                               }
+                       }
+
+                       void IEnumerator.Reset ()
+                       {
+                               return;
+                       }
+               }
+
                // InternalCall Methods
                [MethodImplAttribute (MethodImplOptions.InternalCall)]
                extern int GetRank ();