Use XmlDOMTextWriter instead of XmlWriter.Create

src/DocumentFormat.OpenXml.Framework/OpenXmlPartRootElement.cs

@@ -216,7 +216,7 @@ public void Save(Stream stream)
             var events = Features.Get<IPartRootEventsFeature>();
             events?.OnChange(EventType.Saving, OpenXmlPart);
 
-            using (var xmlWriter = XmlWriter.Create(stream, settings))
+            using (var xmlWriter = new XmlDOMTextWriter(stream, settings))
             {
                 if (_standaloneDeclaration is not null)
                 {

src/DocumentFormat.OpenXml.Framework/Packaging/FlatOpcExtensions.cs

@@ -206,7 +206,7 @@ private static void AddXmlPackagePart(XElement flatOpcPart, IPackage package)
         var part = CreatePackagePart(flatOpcPart, package);
 
         using var stream = part.GetStream(FileMode.Create);
-        using var xmlWriter = XmlWriter.Create(stream);
+        using var xmlWriter = new XmlDOMTextWriter(stream);
 
         XElement rootElement = flatOpcPart.Elements(Pkg + "xmlData").Elements().First();
         rootElement.WriteTo(xmlWriter);

src/DocumentFormat.OpenXml.Framework/Properties/Properties.cs

@@ -6,6 +6,7 @@
 using System.Runtime.CompilerServices;
 
 [assembly: InternalsVisibleTo("DocumentFormat.OpenXml, Publickey=002400000480000094000000060200000024000052534131000400000100010061d8931836c82bf25ca6b773dfd6e7b3ab4e43fba60cf4a86347170373415a165ccc40da3da4a52163822db9fa91f15828236d32d6a9fe754859f10d1f8262646c1f3fb6b4348123f14d733db0ff11c3198b7cf56caaebbf14563990446a6c32aff36d5a7097194294c127fe3cdf9f2609daae5f4daf26f8b6227f203d2a8bbf")]
+[assembly: InternalsVisibleTo("DocumentFormat.OpenXml.Linq, Publickey=002400000480000094000000060200000024000052534131000400000100010061d8931836c82bf25ca6b773dfd6e7b3ab4e43fba60cf4a86347170373415a165ccc40da3da4a52163822db9fa91f15828236d32d6a9fe754859f10d1f8262646c1f3fb6b4348123f14d733db0ff11c3198b7cf56caaebbf14563990446a6c32aff36d5a7097194294c127fe3cdf9f2609daae5f4daf26f8b6227f203d2a8bbf")]
 
 // For testing
 [assembly: InternalsVisibleTo("DocumentFormat.OpenXml.Tests, Publickey=002400000480000094000000060200000024000052534131000400000100010061d8931836c82bf25ca6b773dfd6e7b3ab4e43fba60cf4a86347170373415a165ccc40da3da4a52163822db9fa91f15828236d32d6a9fe754859f10d1f8262646c1f3fb6b4348123f14d733db0ff11c3198b7cf56caaebbf14563990446a6c32aff36d5a7097194294c127fe3cdf9f2609daae5f4daf26f8b6227f203d2a8bbf")]

src/DocumentFormat.OpenXml.Framework/XmlDOMTextWriter.cs

@@ -11,6 +11,16 @@ internal class XmlDOMTextWriter : XmlWriter
     {
         private readonly XmlWriter _writer;
 
+        public XmlDOMTextWriter(Stream stream)
+        {
+            _writer = Create(stream);
+        }
+
+        public XmlDOMTextWriter(Stream stream, XmlWriterSettings settings)
+        {
+            _writer = Create(stream, settings);
+        }
+
         public XmlDOMTextWriter(TextWriter w)
         {
             var xwSettings = new XmlWriterSettings

src/DocumentFormat.OpenXml.Linq/Feature/OpenXmlPartRootXElementFeature.cs

@@ -138,7 +138,7 @@ public bool Save()
             }
 
             using (var stream = _part.GetStream(FileMode.Create, FileAccess.Write))
-            using (var xmlWriter = XmlWriter.Create(stream))
+            using (var xmlWriter = new XmlDOMTextWriter(stream))
             {
                 _partXDocument.Save(xmlWriter);
             }