4 files changed, 199 insertions, 25 deletions

diff --git a/src/WixToolset.Core.Native/Msi/Database.cs b/src/WixToolset.Core.Native/Msi/Database.cs
index a44e8cf9..b9c5c35b 100644
--- a/src/WixToolset.Core.Native/Msi/Database.cs
+++ b/src/WixToolset.Core.Native/Msi/Database.cs
@@ -3,7 +3,6 @@
 namespace WixToolset.Core.Native.Msi
 {
     using System;
-    using System.Globalization;
     using System.IO;
     using System.Threading;
 
@@ -44,10 +43,9 @@ namespace WixToolset.Core.Native.Msi
             var conditions = TransformErrorConditions.None;
             using (var summaryInfo = new SummaryInformation(transformFile))
             {
-                var value = summaryInfo.GetProperty((int)SummaryInformation.Transform.ValidationFlags);
                 try
                 {
-                    var validationFlags = Int32.Parse(value, CultureInfo.InvariantCulture);
+                    var validationFlags = summaryInfo.GetNumericProperty(SummaryInformation.Transform.ValidationFlags);
                     conditions = (TransformErrorConditions)(validationFlags & 0xffff);
                 }
                 catch (FormatException)
@@ -192,13 +190,20 @@ namespace WixToolset.Core.Native.Msi
         /// </summary>
         /// <param name="mergeDatabase">The database to merge into the base database.</param>
         /// <param name="tableName">The name of the table to receive merge conflict information.</param>
-        public void Merge(Database mergeDatabase, string tableName)
+        /// <returns>True if there were merge conflicts, otherwise false.</returns>
+        public bool Merge(Database mergeDatabase, string tableName)
         {
             var error = MsiInterop.MsiDatabaseMerge(this.Handle, mergeDatabase.Handle, tableName);
-            if (0 != error)
+            if (error == 1627)
+            {
+                return true;
+            }
+            else if (error != 0)
             {
                 throw new MsiException(error);
             }
+
+            return false;
         }
 
         /// <summary>
diff --git a/src/WixToolset.Core.Native/Msi/Installer.cs b/src/WixToolset.Core.Native/Msi/Installer.cs
index 2bb41078..8a45aaa8 100644
--- a/src/WixToolset.Core.Native/Msi/Installer.cs
+++ b/src/WixToolset.Core.Native/Msi/Installer.cs
@@ -24,6 +24,31 @@ namespace WixToolset.Core.Native.Msi
     public static class Installer
     {
         /// <summary>
+        /// Extacts the patch metadata as XML.
+        /// </summary>
+        /// <param name="path">Path to patch.</param>
+        /// <returns>String XML.</returns>
+        public static string ExtractPatchXml(string path)
+        {
+            var buffer = new StringBuilder(65535);
+            var size = buffer.Capacity;
+
+            var error = MsiInterop.MsiExtractPatchXMLData(path, 0, buffer, ref size);
+            if (234 == error)
+            {
+                buffer.EnsureCapacity(++size);
+                error = MsiInterop.MsiExtractPatchXMLData(path, 0, buffer, ref size);
+            }
+
+            if (error != 0)
+            {
+                throw new MsiException(error);
+            }
+
+            return buffer.ToString();
+        }
+
+        /// <summary>
         /// Takes the path to a file and returns a 128-bit hash of that file.
         /// </summary>
         /// <param name="filePath">Path to file that is to be hashed.</param>
diff --git a/src/WixToolset.Core.Native/Msi/MsiInterop.cs b/src/WixToolset.Core.Native/Msi/MsiInterop.cs
index 0d16fcb2..11ac4094 100644
--- a/src/WixToolset.Core.Native/Msi/MsiInterop.cs
+++ b/src/WixToolset.Core.Native/Msi/MsiInterop.cs
@@ -153,6 +153,17 @@ namespace WixToolset.Core.Native.Msi
         internal static extern int MsiDatabaseOpenView(uint database, string query, out uint view);
 
         /// <summary>
+        /// PInvoke of MsiExtractPatchXMLDataW.
+        /// </summary>
+        /// <param name="szPatchPath">Path to patch.</param>
+        /// <param name="dwReserved">Reserved for future use.</param>
+        /// <param name="szXMLData">Output XML data.</param>
+        /// <param name="pcchXMLData">Count of characters in XML.</param>
+        /// <returns></returns>
+        [DllImport("msi.dll", EntryPoint = "MsiExtractPatchXMLDataW", CharSet = CharSet.Unicode, ExactSpelling = true)]
+        internal static extern int MsiExtractPatchXMLData(string szPatchPath, int dwReserved, StringBuilder szXMLData, ref int pcchXMLData);
+
+        /// <summary>
         /// PInvoke of MsiGetFileHashW.
         /// </summary>
         /// <param name="filePath">File path.</param>
diff --git a/src/WixToolset.Core.Native/Msi/SummaryInformation.cs b/src/WixToolset.Core.Native/Msi/SummaryInformation.cs
index a7ba5717..da629df2 100644
--- a/src/WixToolset.Core.Native/Msi/SummaryInformation.cs
+++ b/src/WixToolset.Core.Native/Msi/SummaryInformation.cs
@@ -13,6 +13,63 @@ namespace WixToolset.Core.Native.Msi
     public sealed class SummaryInformation : MsiHandle
     {
         /// <summary>
+        /// Summary information properties for products.
+        /// </summary>
+        public enum Package
+        {
+            /// <summary>PID_CODEPAGE = code page of the summary information stream</summary>
+            CodePage = 1,
+
+            /// <summary>PID_TITLE = a brief description of the package type</summary>
+            Title = 2,
+
+            /// <summary>PID_SUBJECT = package name</summary>
+            PackageName = 3,
+
+            /// <summary>PID_AUTHOR = manufacturer of the patch package</summary>
+            Manufacturer = 4,
+
+            /// <summary>PID_KEYWORDS = list of keywords used by file browser</summary>
+            Keywords = 5,
+
+            /// <summary>PID_COMMENTS = general purpose of the package</summary>
+            Comments = 6,
+
+            /// <summary>PID_TEMPLATE = supported platforms and languages</summary>
+            PlatformsAndLanguages = 7,
+
+            /// <summary>PID_LASTAUTHOR should be null for packages</summary>
+            Reserved8 = 8,
+
+            /// <summary>PID_REVNUMBER = GUID package code</summary>
+            PackageCode = 9,
+
+            /// <summary>PID_LASTPRINTED should be null for packages</summary>
+            Reserved11 = 11,
+
+            /// <summary>PID_CREATED datetime when package was created</summary>
+            Created = 12,
+
+            /// <summary>PID_SAVED datetime when package was last modified</summary>
+            LastModified = 13,
+
+            /// <summary>PID_PAGECOUNT minimum required Windows Installer</summary>
+            InstallerRequirement = 14,
+
+            /// <summary>PID_WORDCOUNT elevation privileges of package</summary>
+            FileAndElevatedFlags = 15,
+
+            /// <summary>PID_CHARCOUNT should be null for patches</summary>
+            Reserved16 = 16,
+
+            /// <summary>PID_APPLICATION tool used to create package</summary>
+            BuildTool = 18,
+
+            /// <summary>PID_SECURITY = read-only attribute of the package</summary>
+            Security = 19,
+        }
+
+        /// <summary>
         /// Summary information properties for transforms.
         /// </summary>
         public enum Transform
@@ -140,7 +197,7 @@ namespace WixToolset.Core.Native.Msi
         {
             if (null == db)
             {
-                throw new ArgumentNullException("db");
+                throw new ArgumentNullException(nameof(db));
             }
 
             uint handle = 0;
@@ -160,7 +217,7 @@ namespace WixToolset.Core.Native.Msi
         {
             if (null == databaseFile)
             {
-                throw new ArgumentNullException("databaseFile");
+                throw new ArgumentNullException(nameof(databaseFile));
             }
 
             uint handle = 0;
@@ -173,50 +230,126 @@ namespace WixToolset.Core.Native.Msi
         }
 
         /// <summary>
-        /// Gets a summary information property.
+        /// Gets a summary information package property.
         /// </summary>
-        /// <param name="index">Index of the summary information property.</param>
+        /// <param name="property">The summary information package property.</param>
         /// <returns>The summary information property.</returns>
-        public string GetProperty(int index)
+        public string GetProperty(Package property)
         {
-            var bufSize = 64;
-            var stringValue = new StringBuilder(bufSize);
+            return this.GetProperty((int)property);
+        }
 
-            FILETIME timeValue;
-            timeValue.dwHighDateTime = 0;
-            timeValue.dwLowDateTime = 0;
+        /// <summary>
+        /// Gets a summary information package property as a number.
+        /// </summary>
+        /// <param name="property">The summary information package property.</param>
+        /// <returns>The summary information property.</returns>
+        public long GetNumericProperty(Package property)
+        {
+            return this.GetNumericProperty((int)property);
+        }
 
-            var error = MsiInterop.MsiSummaryInfoGetProperty(this.Handle, index, out var dataType, out var intValue, ref timeValue, stringValue, ref bufSize);
-            if (234 == error)
-            {
-                stringValue.EnsureCapacity(++bufSize);
-                error = MsiInterop.MsiSummaryInfoGetProperty(this.Handle, index, out dataType, out intValue, ref timeValue, stringValue, ref bufSize);
-            }
+        /// <summary>
+        /// Gets a summary information patch property.
+        /// </summary>
+        /// <param name="property">The summary information patch property.</param>
+        /// <returns>The summary information property.</returns>
+        public string GetProperty(Patch property)
+        {
+            return this.GetProperty((int)property);
+        }
 
-            if (0 != error)
-            {
-                throw new MsiException(error);
-            }
+        /// <summary>
+        /// Gets a summary information transform property.
+        /// </summary>
+        /// <param name="property">The summary information transform property.</param>
+        /// <returns>The summary information property.</returns>
+        public long GetNumericProperty(Transform property)
+        {
+            return this.GetNumericProperty((int)property);
+        }
+
+        /// <summary>
+        /// Gets a summary information property.
+        /// </summary>
+        /// <param name="index">Index of the summary information property.</param>
+        /// <returns>The summary information property.</returns>
+        public string GetProperty(int index)
+        {
+            this.GetSummaryInformationValue(index, out var dataType, out var intValue, out var stringValue, out var timeValue);
 
             switch ((VT)dataType)
             {
                 case VT.EMPTY:
                     return String.Empty;
+
                 case VT.LPSTR:
                     return stringValue.ToString();
+
                 case VT.I2:
                 case VT.I4:
                     return Convert.ToString(intValue, CultureInfo.InvariantCulture);
+
                 case VT.FILETIME:
                     var longFileTime = (((long)timeValue.dwHighDateTime) << 32) | unchecked((uint)timeValue.dwLowDateTime);
                     var dateTime = DateTime.FromFileTime(longFileTime);
                     return dateTime.ToString("yyyy/MM/dd HH:mm:ss", CultureInfo.InvariantCulture);
+
                 default:
                     throw new InvalidOperationException();
             }
         }
 
         /// <summary>
+        /// Gets a summary information property as a number.
+        /// </summary>
+        /// <param name="index">Index of the summary information property.</param>
+        /// <returns>The summary information property.</returns>
+        public long GetNumericProperty(int index)
+        {
+            this.GetSummaryInformationValue(index, out var dataType, out var intValue, out var stringValue, out var timeValue);
+
+            switch ((VT)dataType)
+            {
+                case VT.EMPTY:
+                    return 0;
+
+                case VT.LPSTR:
+                    return Int64.Parse(stringValue.ToString(), CultureInfo.InvariantCulture);
+
+                case VT.I2:
+                case VT.I4:
+                    return intValue;
+
+                case VT.FILETIME:
+                    return (((long)timeValue.dwHighDateTime) << 32) | unchecked((uint)timeValue.dwLowDateTime);
+
+                default:
+                    throw new InvalidOperationException();
+            }
+        }
+
+        private void GetSummaryInformationValue(int index, out uint dataType, out int intValue, out StringBuilder stringValue, out FILETIME timeValue)
+        {
+            var bufSize = 64;
+            stringValue = new StringBuilder(bufSize);
+            timeValue.dwHighDateTime = 0;
+            timeValue.dwLowDateTime = 0;
+
+            var error = MsiInterop.MsiSummaryInfoGetProperty(this.Handle, index, out dataType, out intValue, ref timeValue, stringValue, ref bufSize);
+            if (234 == error)
+            {
+                stringValue.EnsureCapacity(++bufSize);
+                error = MsiInterop.MsiSummaryInfoGetProperty(this.Handle, index, out dataType, out intValue, ref timeValue, stringValue, ref bufSize);
+            }
+
+            if (0 != error)
+            {
+                throw new MsiException(error);
+            }
+        }
+
+        /// <summary>
         /// Variant types in the summary information table.
         /// </summary>
         private enum VT : uint