From 9ac0abb554363136c332f3f3afa1fd8f61060234 Mon Sep 17 00:00:00 2001
From: Ben Adams <thundercat@illyriad.co.uk>
Date: Fri, 14 Feb 2020 17:41:30 +0000
Subject: [PATCH] Xml use strongly typed struct enumerators (#32296)

---
 .../src/System/Xml/Dom/XmlDocument.cs         | 15 +++++-----
 .../src/System/Xml/Dom/XmlLoader.cs           | 28 ++++++++-----------
 2 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlDocument.cs b/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlDocument.cs
index f0ac495afe06e..85cc8ab396ca5 100644
--- a/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlDocument.cs
+++ b/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlDocument.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Text;
@@ -673,19 +674,20 @@ internal void AddDefaultAttributes(XmlElement elem)
             SchemaElementDecl ed = GetSchemaElementDecl(elem);
             if (ed != null && ed.AttDefs != null)
             {
-                IDictionaryEnumerator attrDefs = ed.AttDefs.GetEnumerator();
-                while (attrDefs.MoveNext())
+                foreach (KeyValuePair<XmlQualifiedName, SchemaAttDef> attrDefs in ed.AttDefs)
                 {
-                    SchemaAttDef attdef = (SchemaAttDef)attrDefs.Value;
+                    SchemaAttDef attdef = attrDefs.Value;
                     if (attdef.Presence == SchemaDeclBase.Use.Default ||
                          attdef.Presence == SchemaDeclBase.Use.Fixed)
                     {
                         //build a default attribute and return
-                        string attrPrefix = string.Empty;
+                        string attrPrefix;
                         string attrLocalname = attdef.Name.Name;
                         string attrNamespaceURI = string.Empty;
                         if (schInfo.SchemaType == SchemaType.DTD)
+                        {
                             attrPrefix = attdef.Name.Namespace;
+                        }
                         else
                         {
                             attrPrefix = attdef.Prefix;
@@ -1687,10 +1689,9 @@ internal XmlAttribute GetDefaultAttribute(XmlElement elem, string attrPrefix, st
             SchemaElementDecl ed = GetSchemaElementDecl(elem);
             if (ed != null && ed.AttDefs != null)
             {
-                IDictionaryEnumerator attrDefs = ed.AttDefs.GetEnumerator();
-                while (attrDefs.MoveNext())
+                foreach (KeyValuePair<XmlQualifiedName, SchemaAttDef> attrDefs in ed.AttDefs)
                 {
-                    SchemaAttDef attdef = (SchemaAttDef)attrDefs.Value;
+                    SchemaAttDef attdef = attrDefs.Value;
                     if (attdef.Presence == SchemaDeclBase.Use.Default ||
                         attdef.Presence == SchemaDeclBase.Use.Fixed)
                     {
diff --git a/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlLoader.cs b/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlLoader.cs
index 1f292851869dc..b9ec9ae703ac3 100644
--- a/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlLoader.cs
+++ b/src/libraries/System.Private.Xml/src/System/Xml/Dom/XmlLoader.cs
@@ -655,27 +655,21 @@ private void LoadDocumentType(IDtdInfo dtdInfo, XmlDocumentType dtNode)
                 _doc.Entities = dtNode.Entities;
 
                 //extract the elements which has attribute defined as ID from the element declarations
-                IDictionaryEnumerator elementDecls = schInfo.ElementDecls.GetEnumerator();
-                if (elementDecls != null)
+                foreach (KeyValuePair<XmlQualifiedName, SchemaElementDecl> elementDecls in schInfo.ElementDecls)
                 {
-                    elementDecls.Reset();
-                    while (elementDecls.MoveNext())
+                    SchemaElementDecl elementDecl = elementDecls.Value;
+                    if (elementDecl.AttDefs != null)
                     {
-                        SchemaElementDecl elementDecl = (SchemaElementDecl)elementDecls.Value;
-                        if (elementDecl.AttDefs != null)
+                        foreach (KeyValuePair<XmlQualifiedName, SchemaAttDef> attDefs in elementDecl.AttDefs)
                         {
-                            IDictionaryEnumerator attDefs = elementDecl.AttDefs.GetEnumerator();
-                            while (attDefs.MoveNext())
+                            SchemaAttDef attdef = attDefs.Value;
+                            if (attdef.Datatype.TokenizedType == XmlTokenizedType.ID)
                             {
-                                SchemaAttDef attdef = (SchemaAttDef)attDefs.Value;
-                                if (attdef.Datatype.TokenizedType == XmlTokenizedType.ID)
-                                {
-                                    //we only register the XmlElement based on their Prefix/LocalName and skip the namespace
-                                    _doc.AddIdInfo(
-                                        _doc.AddXmlName(elementDecl.Prefix, elementDecl.Name.Name, string.Empty, null),
-                                        _doc.AddAttrXmlName(attdef.Prefix, attdef.Name.Name, string.Empty, null));
-                                    break;
-                                }
+                                //we only register the XmlElement based on their Prefix/LocalName and skip the namespace
+                                _doc.AddIdInfo(
+                                    _doc.AddXmlName(elementDecl.Prefix, elementDecl.Name.Name, string.Empty, null),
+                                    _doc.AddAttrXmlName(attdef.Prefix, attdef.Name.Name, string.Empty, null));
+                                break;
                             }
                         }
                     }