3 files changed, 69 insertions, 11 deletions

diff --git a/src/WixToolset.Converters/WixConverter.cs b/src/WixToolset.Converters/WixConverter.cs
index 89d33598..7ac64710 100644
--- a/src/WixToolset.Converters/WixConverter.cs
+++ b/src/WixToolset.Converters/WixConverter.cs
@@ -24,6 +24,7 @@ namespace WixToolset.Converters
 
         private const char XDocumentNewLine = '\n'; // XDocument normalizes "\r\n" to just "\n".
         private static readonly XNamespace WixNamespace = "http://wixtoolset.org/schemas/v4/wxs";
+        private static readonly XNamespace Wix3Namespace = "http://schemas.microsoft.com/wix/2006/wi";
         private static readonly XNamespace WixUtilNamespace = "http://wixtoolset.org/schemas/v4/wxs/util";
 
         private static readonly XName AdminExecuteSequenceElementName = WixNamespace + "AdminExecuteSequence";
@@ -68,7 +69,11 @@ namespace WixToolset.Converters
         private static readonly XName UtilXmlConfigElementName = WixUtilNamespace + "XmlConfig";
         private static readonly XName CustomActionElementName = WixNamespace + "CustomAction";
         private static readonly XName PropertyElementName = WixNamespace + "Property";
+        private static readonly XName Wix4ElementName = WixNamespace + "Wix";
+        private static readonly XName Wix3ElementName = Wix3Namespace + "Wix";
         private static readonly XName WixElementWithoutNamespaceName = XNamespace.None + "Wix";
+        private static readonly XName Include4ElementName = WixNamespace + "Include";
+        private static readonly XName Include3ElementName = Wix3Namespace + "Include";
         private static readonly XName IncludeElementWithoutNamespaceName = XNamespace.None + "Include";
 
         private static readonly Dictionary<string, XNamespace> OldToNewNamespaceMapping = new Dictionary<string, XNamespace>()
@@ -343,17 +348,17 @@ namespace WixToolset.Converters
 
             foreach (var declaration in element.Attributes().Where(a => a.IsNamespaceDeclaration))
             {
-                if (WixConverter.OldToNewNamespaceMapping.TryGetValue(declaration.Value, out var ns))
+                if (element.Name == Wix3ElementName || element.Name == Include3ElementName)
                 {
-                    if (Wix3Namespaces.Contains(declaration.Value))
-                    {
-                        this.SourceVersion = 3;
-                    }
-                    else if (Wix4Namespaces.Contains(declaration.Value))
-                    {
-                        this.SourceVersion = 4;
-                    }
+                    this.SourceVersion = 3;
+                }
+                else if (element.Name == Wix4ElementName || element.Name == Include4ElementName)
+                {
+                    this.SourceVersion = 4;
+                }
 
+                if (WixConverter.OldToNewNamespaceMapping.TryGetValue(declaration.Value, out var ns))
+                {
                     if (this.OnError(ConverterTestType.XmlnsValueWrong, declaration, "The namespace '{0}' is out of date.  It must be '{1}'.", declaration.Value, ns.NamespaceName))
                     {
                         deprecatedToUpdatedNamespaces.Add(declaration.Value, ns);
diff --git a/src/test/WixToolsetTest.Converters/ConverterFixture.cs b/src/test/WixToolsetTest.Converters/ConverterFixture.cs
index c205df39..6e2ad2c5 100644
--- a/src/test/WixToolsetTest.Converters/ConverterFixture.cs
+++ b/src/test/WixToolsetTest.Converters/ConverterFixture.cs
@@ -331,7 +331,7 @@ namespace WixToolsetTest.Converters
         {
             var parse = String.Join(Environment.NewLine,
                 "<?xml version='1.0' encoding='utf-8'?>",
-                "<Wix xmlns='http://wixtoolset.org/schemas/v4/wxs'>",
+                "<Wix xmlns='http://schemas.microsoft.com/wix/2006/wi'>",
                 "  <File Source='path\\to\\foo.txt' />",
                 "</Wix>");
 
@@ -349,7 +349,7 @@ namespace WixToolsetTest.Converters
 
             var actual = UnformattedDocumentString(document);
 
-            Assert.Equal(2, errors);
+            Assert.Equal(3, errors);
             Assert.Equal(expected, actual);
         }
 
diff --git a/src/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs b/src/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs
new file mode 100644
index 00000000..a3f2adc8
--- /dev/null
+++ b/src/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs
@@ -0,0 +1,53 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolsetTest.Converters
+{
+    using System;
+    using System.Xml.Linq;
+    using WixToolset.Converters;
+    using WixToolsetTest.Converters.Mocks;
+    using Xunit;
+
+    public class Wix4ConversionFixture : BaseConverterFixture
+    {
+        [Fact]
+        public void DoesNotAddFileId()
+        {
+            var parse = String.Join(Environment.NewLine,
+                "<?xml version=\"1.0\" encoding=\"utf-16\"?>",
+                "<Wix xmlns='http://wixtoolset.org/schemas/v4/wxs'>",
+                "  <Fragment>",
+                "    <ComponentGroup Id='ProductComponents' Directory='INSTALLFOLDER'>",
+                "      <Component>",
+                "        <File Source='example.txt' />",
+                "      </Component>",
+                "    </ComponentGroup>",
+                "  </Fragment>",
+                "</Wix>");
+
+            var expected = new[]
+            {
+                "<Wix xmlns=\"http://wixtoolset.org/schemas/v4/wxs\">",
+                "  <Fragment>",
+                "    <ComponentGroup Id=\"ProductComponents\" Directory=\"INSTALLFOLDER\">",
+                "      <Component>",
+                "        <File Source=\"example.txt\" />",
+                "      </Component>",
+                "    </ComponentGroup>",
+                "  </Fragment>",
+                "</Wix>"
+            };
+
+            var document = XDocument.Parse(parse, LoadOptions.PreserveWhitespace | LoadOptions.SetLineInfo);
+
+            var messaging = new MockMessaging();
+            var converter = new WixConverter(messaging, 2, null, null);
+
+            var errors = converter.ConvertDocument(document);
+            Assert.Equal(1, errors);
+
+            var actualLines = UnformattedDocumentLines(document);
+            CompareLineByLine(expected, actualLines);
+        }
+    }
+}