Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/Common/HandlerBase.cs

@@ -0,0 +1,72 @@
+//------------------------------------------------------------------------------
+// <copyright file="HandlerBase.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Data.Common {
+
+    using System;
+    using System.Collections;
+    using System.Configuration;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Xml;
+
+    internal static class HandlerBase {
+
+        static internal void CheckForChildNodes(XmlNode node) {
+            if (node.HasChildNodes) {
+                throw ADP.ConfigBaseNoChildNodes(node.FirstChild);
+            }
+        }
+        static private void CheckForNonElement(XmlNode node) {
+            if (XmlNodeType.Element != node.NodeType) {
+                throw ADP.ConfigBaseElementsOnly(node);
+            }
+        }
+        static internal void CheckForUnrecognizedAttributes(XmlNode node) {
+            if (0 != node.Attributes.Count) {
+                throw ADP.ConfigUnrecognizedAttributes(node);
+            }
+        }
+        
+        // skip whitespace and comments, throws if non-element
+        static internal bool IsIgnorableAlsoCheckForNonElement(XmlNode node) {
+            if ((XmlNodeType.Comment == node.NodeType) || (XmlNodeType.Whitespace == node.NodeType)) {
+                return true;
+            }
+            CheckForNonElement(node);
+            return false;
+        }
+
+        static internal string RemoveAttribute(XmlNode node, string name, bool required, bool allowEmpty) {
+            XmlNode attribute = node.Attributes.RemoveNamedItem(name);
+            if (null == attribute) {
+                if (required) {
+                    throw ADP.ConfigRequiredAttributeMissing(name, node);
+                }
+                return null;
+            }
+            string value = attribute.Value;
+            if (!allowEmpty && (0 == value.Length)) {
+                throw ADP.ConfigRequiredAttributeEmpty(name, node);
+            }
+            return value;
+        }
+
+        static internal DataSet CloneParent(DataSet parentConfig, bool insenstive) {
+            if (null == parentConfig) {
+                parentConfig = new DataSet(DbProviderFactoriesConfigurationHandler.sectionName);
+                parentConfig.CaseSensitive = !insenstive;
+                parentConfig.Locale = CultureInfo.InvariantCulture;
+            }
+            else {
+                parentConfig = parentConfig.Copy();
+            }
+            return parentConfig;
+        }
+    }
+}