Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/PropertyCollection.cs

@@ -0,0 +1,39 @@
+//------------------------------------------------------------------------------
+// <copyright file="PropertyCollection.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+// <owner current="false" primary="false">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Data {
+    using System;
+    using System.Collections;
+    using System.Runtime.Serialization;
+
+    /// <devdoc>
+    /// <para>Represents a collection of properties that can be added to <see cref='System.Data.DataColumn'/>, 
+    /// <see cref='System.Data.DataSet'/>, 
+    ///    or <see cref='System.Data.DataTable'/>.</para>
+    /// </devdoc>
+    [Serializable]
+    public class PropertyCollection : Hashtable {
+        public PropertyCollection() : base() {
+        }
+        
+        protected PropertyCollection(SerializationInfo info, StreamingContext context) : base(info, context) {
+        }
+
+        public override object Clone() {
+            // override Clone so that returned object is an
+            // instance of PropertyCollection instead of Hashtable
+            PropertyCollection clone = new PropertyCollection();
+            foreach (DictionaryEntry pair in this) {
+                clone.Add(pair.Key, pair.Value);
+            }
+            return clone;
+        }
+    }
+    //3 NOTE: This should have been named PropertyDictionary, to avoid fxcop warnings about not having strongly typed IList and ICollection implementations, but it's too late now...
+}