Add support using mergmod.dll and its interfaces

9 files changed, 539 insertions, 14 deletions

diff --git a/src/WixToolset.Core.Native/MsmInterop.cs b/src/WixToolset.Core.Native/MsmInterop.cs
new file mode 100644
index 00000000..6b1ad141
--- /dev/null
+++ b/src/WixToolset.Core.Native/MsmInterop.cs
@@ -0,0 +1,507 @@
+// 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 WixToolset.Core.Native
+{
+    using System;
+    using System.IO;
+    using System.Reflection;
+    using System.Runtime.InteropServices;
+
+    /// <summary>
+    /// Errors returned by merge operations.
+    /// </summary>
+    [Guid("0ADDA825-2C26-11D2-AD65-00A0C9AF11A6")]
+    public enum MsmErrorType
+    {
+        /// <summary>
+        /// A request was made to open a module with a language not supported by the module.
+        /// No more general language is supported by the module.
+        /// Adds msmErrorLanguageUnsupported to the Type property and the requested language
+        /// to the Language Property (Error Object).  All Error object properties are empty.
+        /// The OpenModule function returns ERROR_INSTALL_LANGUAGE_UNSUPPORTED (as HRESULT).
+        /// </summary>
+        msmErrorLanguageUnsupported = 1,
+
+        /// <summary>
+        /// A request was made to open a module with a supported language but the module has
+        /// an invalid language transform.  Adds msmErrorLanguageFailed to the Type property
+        /// and the applied transform's language to the Language Property of the Error object.
+        /// This may not be the requested language if a more general language was used.
+        /// All other properties of the Error object are empty.  The OpenModule function
+        /// returns ERROR_INSTALL_LANGUAGE_UNSUPPORTED (as HRESULT).
+        /// </summary>
+        msmErrorLanguageFailed = 2,
+
+        /// <summary>
+        /// The module cannot be merged because it excludes, or is excluded by, another module
+        /// in the database.  Adds msmErrorExclusion to the Type property of the Error object.
+        /// The ModuleKeys property or DatabaseKeys property contains the primary keys of the
+        /// excluded module's row in the ModuleExclusion table.  If an existing module excludes
+        /// the module being merged, the excluded module's ModuleSignature information is added
+        /// to ModuleKeys.  If the module being merged excludes an existing module, DatabaseKeys
+        /// contains the excluded module's ModuleSignature information.  All other properties
+        /// are empty (or -1).
+        /// </summary>
+        msmErrorExclusion = 3,
+
+        /// <summary>
+        /// Merge conflict during merge.  The value of the Type property is set to
+        /// msmErrorTableMerge.  The DatabaseTable property and DatabaseKeys property contain
+        /// the table name and primary keys of the conflicting row in the database.  The
+        /// ModuleTable property and ModuleKeys property contain the table name and primary keys
+        /// of the conflicting row in the module.  The ModuleTable and ModuleKeys entries may be
+        /// null if the row does not exist in the database.  For example, if the conflict is in a
+        /// generated FeatureComponents table entry.  On Windows Installer version 2.0, when
+        /// merging a configurable merge module, configuration may cause these properties to
+        /// refer to rows that do not exist in the module.
+        /// </summary>
+        msmErrorTableMerge = 4,
+
+        /// <summary>
+        /// There was a problem resequencing a sequence table to contain the necessary merged
+        /// actions.  The Type property is set to msmErrorResequenceMerge. The DatabaseTable
+        /// and DatabaseKeys properties contain the sequence table name and primary keys
+        /// (action name) of the conflicting row.  The ModuleTable and ModuleKeys properties
+        /// contain the sequence table name and primary key (action name) of the conflicting row.
+        /// On Windows Installer version 2.0, when merging a configurable merge module,
+        /// configuration may cause these properties to refer to rows that do not exist in the module.
+        /// </summary>
+        msmErrorResequenceMerge = 5,
+
+        /// <summary>
+        /// Not used.
+        /// </summary>
+        msmErrorFileCreate = 6,
+
+        /// <summary>
+        /// There was a problem creating a directory to extract a file to disk.  The Path property
+        /// contains the directory that could not be created.  All other properties are empty or -1.
+        /// Not available with Windows Installer version 1.0.
+        /// </summary>
+        msmErrorDirCreate = 7,
+
+        /// <summary>
+        /// A feature name is required to complete the merge, but no feature name was provided.
+        /// The Type property is set to msmErrorFeatureRequired.  The DatabaseTable and DatabaseKeys
+        /// contain the table name and primary keys of the conflicting row.  The ModuleTable and
+        /// ModuleKeys properties contain the table name and primary keys of the row cannot be merged.
+        /// On Windows Installer version 2.0, when merging a configurable merge module, configuration
+        /// may cause these properties to refer to rows that do not exist in the module.
+        /// If the failure is in a generated FeatureComponents table, the DatabaseTable and
+        /// DatabaseKeys properties are empty and the ModuleTable and ModuleKeys properties refer to
+        /// the row in the Component table causing the failure.
+        /// </summary>
+        msmErrorFeatureRequired = 8,
+
+        /// <summary>
+        /// Available with Window Installer version 2.0. Substitution of a Null value into a
+        /// non-nullable column.  This enters msmErrorBadNullSubstitution in the Type property and
+        /// enters "ModuleSubstitution" and the keys from the ModuleSubstitution table for this row
+        /// into the ModuleTable property and ModuleKeys property.  All other properties of the Error
+        /// object are set to an empty string or -1.  This error causes the immediate failure of the
+        /// merge and the MergeEx function to return E_FAIL.
+        /// </summary>
+        msmErrorBadNullSubstitution = 9,
+
+        /// <summary>
+        /// Available with Window Installer version 2.0.  Substitution of Text Format Type or Integer
+        /// Format Type into a Binary Type data column.  This type of error returns
+        /// msmErrorBadSubstitutionType in the Type property and enters "ModuleSubstitution" and the
+        /// keys from the ModuleSubstitution table for this row into the ModuleTable property.
+        /// All other properties of the Error object are set to an empty string or -1.  This error
+        /// causes the immediate failure of the merge and the MergeEx function to return E_FAIL.
+        /// </summary>
+        msmErrorBadSubstitutionType = 10,
+
+        /// <summary>
+        /// Available with Window Installer Version 2.0.  A row in the ModuleSubstitution table
+        /// references a configuration item not defined in the ModuleConfiguration table.
+        /// This type of error returns msmErrorMissingConfigItem in the Type property and enters
+        /// "ModuleSubstitution" and the keys from the ModuleSubstitution table for this row into
+        /// the ModuleTable property. All other properties of the Error object are set to an empty
+        /// string or -1.  This error causes the immediate failure of the merge and the MergeEx
+        /// function to return E_FAIL.
+        /// </summary>
+        msmErrorMissingConfigItem = 11,
+
+        /// <summary>
+        /// Available with Window Installer version 2.0.  The authoring tool has returned a Null
+        /// value for an item marked with the msmConfigItemNonNullable attribute.  An error of this
+        /// type returns msmErrorBadNullResponse in the Type property and enters "ModuleSubstitution"
+        /// and the keys from the ModuleSubstitution table for for the item into the ModuleTable property.
+        /// All other properties of the Error object are set to an empty string or -1.  This error
+        /// causes the immediate failure of the merge and the MergeEx function to return E_FAIL.
+        /// </summary>
+        msmErrorBadNullResponse = 12,
+
+        /// <summary>
+        /// Available with Window Installer version 2.0.  The authoring tool returned a failure code
+        /// (not S_OK or S_FALSE) when asked for data. An error of this type will return
+        /// msmErrorDataRequestFailed in the Type property and enters "ModuleSubstitution"
+        /// and the keys from the ModuleSubstitution table for the item into the ModuleTable property.
+        /// All other properties of the Error object are set to an empty string or -1.  This error
+        /// causes the immediate failure of the merge and the MergeEx function to return E_FAIL.
+        /// </summary>
+        msmErrorDataRequestFailed = 13,
+
+        /// <summary>
+        /// Available with Windows Installer 2.0 and later versions.  Indicates that an attempt was
+        /// made to merge a 64-bit module into a package that was not a 64-bit package.  An error of
+        /// this type returns msmErrorPlatformMismatch in the Type property.  All other properties of
+        /// the error object are set to an empty string or -1. This error causes the immediate failure
+        /// of the merge and causes the Merge function or MergeEx function to return E_FAIL.
+        /// </summary>
+        msmErrorPlatformMismatch = 14,
+    }
+
+    /// <summary>
+    /// IMsmMerge2 interface.
+    /// </summary>
+    [ComImport, Guid("351A72AB-21CB-47ab-B7AA-C4D7B02EA305")]
+    public interface IMsmMerge2
+    {
+        /// <summary>
+        /// The OpenDatabase method of the Merge object opens a Windows Installer installation
+        /// database, located at a specified path, that is to be merged with a module.
+        /// </summary>
+        /// <param name="path">Path to the database being opened.</param>
+        void OpenDatabase(string path);
+
+        /// <summary>
+        /// The OpenModule method of the Merge object opens a Windows Installer merge module
+        /// in read-only mode. A module must be opened before it can be merged with an installation database.
+        /// </summary>
+        /// <param name="fileName">Fully qualified file name pointing to a merge module.</param>
+        /// <param name="language">A valid language identifier (LANGID).</param>
+        void OpenModule(string fileName, short language);
+
+        /// <summary>
+        /// The CloseDatabase method of the Merge object closes the currently open Windows Installer database.
+        /// </summary>
+        /// <param name="commit">true if changes should be saved, false otherwise.</param>
+        void CloseDatabase(bool commit);
+
+        /// <summary>
+        /// The CloseModule method of the Merge object closes the currently open Windows Installer merge module.
+        /// </summary>
+        void CloseModule();
+
+        /// <summary>
+        /// The OpenLog method of the Merge object opens a log file that receives progress and error messages.
+        /// If the log file already exists, the installer appends new messages. If the log file does not exist,
+        /// the installer creates a log file.
+        /// </summary>
+        /// <param name="fileName">Fully qualified filename pointing to a file to open or create.</param>
+        void OpenLog(string fileName);
+
+        /// <summary>
+        /// The CloseLog method of the Merge object closes the current log file.
+        /// </summary>
+        void CloseLog();
+
+        /// <summary>
+        /// The Log method of the Merge object writes a text string to the currently open log file.
+        /// </summary>
+        /// <param name="message">The text string to display.</param>
+        void Log(string message);
+
+        /// <summary>
+        /// Gets the errors from the last merge operation.
+        /// </summary>
+        /// <value>The errors from the last merge operation.</value>
+        IMsmErrors Errors
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets a collection of Dependency objects that enumerates a set of unsatisfied dependencies for the current database.
+        /// </summary>
+        /// <value>A  collection of Dependency objects that enumerates a set of unsatisfied dependencies for the current database.</value>
+        object Dependencies
+        {
+            get;
+        }
+
+        /// <summary>
+        /// The Merge method of the Merge object executes a merge of the current database and current
+        /// module. The merge attaches the components in the module to the feature identified by Feature.
+        /// The root of the module's directory tree is redirected to the location given by RedirectDir.
+        /// </summary>
+        /// <param name="feature">The name of a feature in the database.</param>
+        /// <param name="redirectDir">The key of an entry in the Directory table of the database.
+        /// This parameter may be NULL or an empty string.</param>
+        void Merge(string feature, string redirectDir);
+
+        /// <summary>
+        /// The Connect method of the Merge object connects a module to an additional feature.
+        /// The module must have already been merged into the database or will be merged into the database.
+        /// The feature must exist before calling this function.
+        /// </summary>
+        /// <param name="feature">The name of a feature already existing in the database.</param>
+        void Connect(string feature);
+
+        /// <summary>
+        /// The ExtractCAB method of the Merge object extracts the embedded .cab file from a module and
+        /// saves it as the specified file. The installer creates this file if it does not already exist
+        /// and overwritten if it does exist.
+        /// </summary>
+        /// <param name="fileName">The fully qualified destination file.</param>
+        void ExtractCAB(string fileName);
+
+        /// <summary>
+        /// The ExtractFiles method of the Merge object extracts the embedded .cab file from a module
+        /// and then writes those files to the destination directory.
+        /// </summary>
+        /// <param name="path">The fully qualified destination directory.</param>
+        void ExtractFiles(string path);
+
+        /// <summary>
+        /// The MergeEx method of the Merge object is equivalent to the Merge function, except that it
+        /// takes an extra argument.  The Merge method executes a merge of the current database and
+        /// current module. The merge attaches the components in the module to the feature identified
+        /// by Feature. The root of the module's directory tree is redirected to the location given by RedirectDir.
+        /// </summary>
+        /// <param name="feature">The name of a feature in the database.</param>
+        /// <param name="redirectDir">The key of an entry in the Directory table of the database. This parameter may
+        /// be NULL or an empty string.</param>
+        /// <param name="configuration">The pConfiguration argument is an interface implemented by the client. The argument may
+        /// be NULL. The presence of this argument indicates that the client is capable of supporting the configuration
+        /// functionality, but does not obligate the client to provide configuration data for any specific configurable item.</param>
+        void MergeEx(string feature, string redirectDir, IMsmConfigureModule configuration);
+
+        /// <summary>
+        /// The ExtractFilesEx method of the Merge object extracts the embedded .cab file from a module and
+        /// then writes those files to the destination directory.
+        /// </summary>
+        /// <param name="path">The fully qualified destination directory.</param>
+        /// <param name="longFileNames">Set to specify using long file names for path segments and final file names.</param>
+        /// <param name="filePaths">This is a list of fully-qualified paths for the files that were successfully extracted.
+        /// The list is empty if no files can be extracted.  This argument may be null.  No list is provided if pFilePaths is null.</param>
+        void ExtractFilesEx(string path, bool longFileNames, ref IntPtr filePaths);
+
+        /// <summary>
+        /// Gets a collection ConfigurableItem objects, each of which represents a single row from the ModuleConfiguration table.
+        /// </summary>
+        /// <value>A collection ConfigurableItem objects, each of which represents a single row from the ModuleConfiguration table.</value>
+        /// <remarks>Semantically, each interface in the enumerator represents an item that can be configured by the module consumer.
+        /// The collection is a read-only collection and implements the standard read-only collection interfaces of Item(), Count() and _NewEnum().
+        /// The IEnumMsmConfigItems enumerator implements Next(), Skip(), Reset(), and Clone() with the standard semantics.</remarks>
+        object ConfigurableItems
+        {
+            get;
+        }
+
+        /// <summary>
+        /// The CreateSourceImage method of the Merge object allows the client to extract the files from a module to
+        /// a source image on disk after a merge, taking into account changes to the module that might have been made
+        /// during module configuration. The list of files to be extracted is taken from the file table of the module
+        /// during the merge process. The list of files consists of every file successfully copied from the file table
+        /// of the module to the target database. File table entries that were not copied due to primary key conflicts
+        /// with existing rows in the database are not a part of this list. At image creation time, the directory for
+        /// each of these files comes from the open (post-merge) database. The path specified in the Path parameter is
+        /// the root of the source image for the install. fLongFileNames determines whether or not long file names are
+        /// used for both path segments and final file names. The function fails if no database is open, no module is
+        /// open, or no merge has been performed.
+        /// </summary>
+        /// <param name="path">The path of the root of the source image for the install.</param>
+        /// <param name="longFileNames">Determines whether or not long file names are used for both path segments and final file names. </param>
+        /// <param name="filePaths">This is a list of fully-qualified paths for the files that were successfully extracted.
+        /// The list is empty if no files can be extracted.  This argument may be null.  No list is provided if pFilePaths is null.</param>
+        void CreateSourceImage(string path, bool longFileNames, ref IntPtr filePaths);
+
+        /// <summary>
+        /// The get_ModuleFiles function implements the ModuleFiles property of the GetFiles object. This function
+        /// returns the primary keys in the File table of the currently open module. The primary keys are returned
+        /// as a collection of strings. The module must be opened by a call to the OpenModule function before calling get_ModuleFiles.
+        /// </summary>
+        IMsmStrings ModuleFiles
+        {
+            get;
+        }
+    }
+
+    /// <summary>
+    /// Collection of merge errors.
+    /// </summary>
+    [ComImport, Guid("0ADDA82A-2C26-11D2-AD65-00A0C9AF11A6")]
+    public interface IMsmErrors
+    {
+        /// <summary>
+        /// Gets the IMsmError at the specified index.
+        /// </summary>
+        /// <param name="index">The one-based index of the IMsmError to get.</param>
+        IMsmError this[int index]
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the count of IMsmErrors in this collection.
+        /// </summary>
+        /// <value>The count of IMsmErrors in this collection.</value>
+        int Count
+        {
+            get;
+        }
+    }
+
+    /// <summary>
+    /// A merge error.
+    /// </summary>
+    [ComImport, Guid("0ADDA828-2C26-11D2-AD65-00A0C9AF11A6")]
+    public interface IMsmError
+    {
+        /// <summary>
+        /// Gets the type of merge error.
+        /// </summary>
+        /// <value>The type of merge error.</value>
+        MsmErrorType Type
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the path information from the merge error.
+        /// </summary>
+        /// <value>The path information from the merge error.</value>
+        string Path
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the language information from the merge error.
+        /// </summary>
+        /// <value>The language information from the merge error.</value>
+        short Language
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the database table from the merge error.
+        /// </summary>
+        /// <value>The database table from the merge error.</value>
+        string DatabaseTable
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the collection of database keys from the merge error.
+        /// </summary>
+        /// <value>The collection of database keys from the merge error.</value>
+        IMsmStrings DatabaseKeys
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the module table from the merge error.
+        /// </summary>
+        /// <value>The module table from the merge error.</value>
+        string ModuleTable
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the collection of module keys from the merge error.
+        /// </summary>
+        /// <value>The collection of module keys from the merge error.</value>
+        IMsmStrings ModuleKeys
+        {
+            get;
+        }
+    }
+
+    /// <summary>
+    /// A collection of strings.
+    /// </summary>
+    [ComImport, Guid("0ADDA827-2C26-11D2-AD65-00A0C9AF11A6")]
+    public interface IMsmStrings
+    {
+        /// <summary>
+        /// Gets the string at the specified index.
+        /// </summary>
+        /// <param name="index">The one-based index of the string to get.</param>
+        string this[int index]
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the count of strings in this collection.
+        /// </summary>
+        /// <value>The count of strings in this collection.</value>
+        int Count
+        {
+            get;
+        }
+    }
+
+    /// <summary>
+    /// Callback for configurable merge modules.
+    /// </summary>
+    [ComImport, Guid("AC013209-18A7-4851-8A21-2353443D70A0"), InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
+    public interface IMsmConfigureModule
+    {
+        /// <summary>
+        /// Callback to retrieve text data for configurable merge modules.
+        /// </summary>
+        /// <param name="name">Name of the data to be retrieved.</param>
+        /// <param name="configData">The data corresponding to the name.</param>
+        /// <returns>The error code (HRESULT).</returns>
+        [PreserveSig]
+        int ProvideTextData([In, MarshalAs(UnmanagedType.BStr)] string name, [MarshalAs(UnmanagedType.BStr)] out string configData);
+
+        /// <summary>
+        /// Callback to retrieve integer data for configurable merge modules.
+        /// </summary>
+        /// <param name="name">Name of the data to be retrieved.</param>
+        /// <param name="configData">The data corresponding to the name.</param>
+        /// <returns>The error code (HRESULT).</returns>
+        [PreserveSig]
+        int ProvideIntegerData([In, MarshalAs(UnmanagedType.BStr)] string name, out int configData);
+    }
+
+    /// <summary>
+    /// Merge merge modules into an MSI file.
+    /// </summary>
+    [ComImport, Guid("F94985D5-29F9-4743-9805-99BC3F35B678")]
+    public class MsmMerge2
+    {
+    }
+
+    /// <summary>
+    /// Defines the standard COM IClassFactory interface.
+    /// </summary>
+    [ComImport, Guid("00000001-0000-0000-C000-000000000046")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    public interface IClassFactory
+    {
+        [return: MarshalAs(UnmanagedType.IUnknown)]
+        object CreateInstance(IntPtr unkOuter, [MarshalAs(UnmanagedType.LPStruct)] Guid iid);
+    }
+
+    /// <summary>
+    /// Contains native methods for merge operations.
+    /// </summary>
+    public class MsmInterop
+    {
+        [DllImport("mergemod.dll", EntryPoint = "DllGetClassObject", PreserveSig = false)]
+        [return: MarshalAs(UnmanagedType.IUnknown)]
+        private static extern object MergeModGetClassObject([MarshalAs(UnmanagedType.LPStruct)] Guid clsid, [MarshalAs(UnmanagedType.LPStruct)] Guid iid);
+
+        /// <summary>
+        /// Load the merge object directly from a local mergemod.dll without going through COM registration.
+        /// </summary>
+        /// <returns>Merge interface.</returns>
+        public IMsmMerge2 GetMsmMerge()
+        {
+            var classFactory = (IClassFactory)MergeModGetClassObject(typeof(MsmMerge2).GUID, typeof(IClassFactory).GUID);
+            return (IMsmMerge2)classFactory.CreateInstance(IntPtr.Zero, typeof(IMsmMerge2).GUID);
+        }
+    }
+}
diff --git a/src/WixToolset.Core.Native/WixToolset.Core.Native.csproj b/src/WixToolset.Core.Native/WixToolset.Core.Native.csproj
index ee5cbc8e..ca8797a9 100644
--- a/src/WixToolset.Core.Native/WixToolset.Core.Native.csproj
+++ b/src/WixToolset.Core.Native/WixToolset.Core.Native.csproj
@@ -23,13 +23,13 @@
   </PropertyGroup>
 
   <Target Name="BuildWixNative" BeforeTargets="GetCopyToOutputDirectoryItems" Condition=" '$(NCrunch)'=='' ">
-    <MSBuild Projects="..\wixnative\wixnative.vcxproj" Properties="Platform=Win32" Targets="Build;BuiltProjectOutputGroup;DebugSymbolsProjectOutputGroup">
+    <MSBuild Projects="..\wixnative\wixnative.vcxproj" Properties="Platform=Win32" Targets="Build;BuiltProjectOutputGroup;ContentFilesProjectOutputGroup;DebugSymbolsProjectOutputGroup">
       <Output TaskParameter="TargetOutputs" ItemName="_NativeProjectOutput" />
     </MSBuild>
-    <MSBuild Projects="..\wixnative\wixnative.vcxproj" Properties="Platform=x64" Targets="Build;BuiltProjectOutputGroup;DebugSymbolsProjectOutputGroup">
+    <MSBuild Projects="..\wixnative\wixnative.vcxproj" Properties="Platform=x64" Targets="Build;BuiltProjectOutputGroup;ContentFilesProjectOutputGroup;DebugSymbolsProjectOutputGroup">
       <Output TaskParameter="TargetOutputs" ItemName="_NativeProjectOutput" />
     </MSBuild>
-
+      
     <WriteLinesToFile File="$(NativeFileListPath)" Lines="@(_NativeProjectOutput)" Overwrite="true" />
 
     <ItemGroup>
diff --git a/src/WixToolset.Core.Native/WixToolset.Core.Native.v3.ncrunchproject b/src/WixToolset.Core.Native/WixToolset.Core.Native.v3.ncrunchproject
deleted file mode 100644
index 0da1f42d..00000000
--- a/src/WixToolset.Core.Native/WixToolset.Core.Native.v3.ncrunchproject
+++ /dev/null
@@ -1,10 +0,0 @@
-<ProjectConfiguration>
-  <Settings>
-    <AdditionalFilesToIncludeForProject>
-      <Value>..\..\build\Debug\Win32\wixnative.x86.exe</Value>
-      <Value>..\..\build\Debug\Win32\wixnative.x86.pdb</Value>
-      <Value>..\..\build\Debug\x64\wixnative.amd64.exe</Value>
-      <Value>..\..\build\Debug\x64\wixnative.amd64.pdb</Value>
-    </AdditionalFilesToIncludeForProject>
-  </Settings>
-</ProjectConfiguration>
\ No newline at end of file
diff --git a/src/test/WixToolsetTest.Core.Native/MsmFixture.cs b/src/test/WixToolsetTest.Core.Native/MsmFixture.cs
new file mode 100644
index 00000000..a1e42d94
--- /dev/null
+++ b/src/test/WixToolsetTest.Core.Native/MsmFixture.cs
@@ -0,0 +1,18 @@
+// 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.CoreNative
+{
+    using WixToolset.Core.Native;
+    using Xunit;
+
+    public class MsmFixture
+    {
+        [Fact]
+        public void CanCreateMsmInterface()
+        {
+            var msm = new MsmInterop();
+            var merge = msm.GetMsmMerge();
+            Assert.NotNull(merge);
+        }
+    }
+}
diff --git a/src/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj b/src/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
index 263712bb..14928112 100644
--- a/src/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
+++ b/src/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
@@ -3,7 +3,7 @@
 
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
diff --git a/src/wixnative/Win32/mergemod.dll b/src/wixnative/Win32/mergemod.dll
new file mode 100644
index 00000000..2bf647b2
--- /dev/null
+++ b/src/wixnative/Win32/mergemod.dll
diff --git a/src/wixnative/runtime.win.WixToolset.Core.Native.nuspec b/src/wixnative/runtime.win.WixToolset.Core.Native.nuspec
index 59eff4e6..a775b570 100644
--- a/src/wixnative/runtime.win.WixToolset.Core.Native.nuspec
+++ b/src/wixnative/runtime.win.WixToolset.Core.Native.nuspec
@@ -14,8 +14,10 @@
   </metadata>
 
   <files>
+    <file src="Win32\mergemod.dll" target="runtimes\win-x86\native" />
     <file src="Win32\wixnative.exe" target="runtimes\win-x86\native" />
     <file src="Win32\wixnative.pdb" target="runtimes\win-x86\native" />
+    <file src="x64\mergemod.dll" target="runtimes\win-x64\native" />
     <file src="x64\wixnative.exe" target="runtimes\win-x64\native" />
     <file src="x64\wixnative.pdb" target="runtimes\win-x64\native" />
   </files>
diff --git a/src/wixnative/wixnative.vcxproj b/src/wixnative/wixnative.vcxproj
index 57afcc0b..80e0aae5 100644
--- a/src/wixnative/wixnative.vcxproj
+++ b/src/wixnative/wixnative.vcxproj
@@ -69,6 +69,14 @@
     <None Include="packages.config" />
   </ItemGroup>
 
+  <ItemGroup>
+    <None Include="$(Platform)\mergemod.dll">
+      <DeploymentContent>true</DeploymentContent>
+      <Link>%(Filename)%(Extension)</Link>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
   <Target Name="Pack" DependsOnTargets="GetBuildVersion">
     <Exec Command='nuget pack runtime.win.WixToolset.Core.Native.nuspec -BasePath "$(BaseOutputPath)$(Configuration)" -OutputDirectory "$(BaseOutputPath)$(Configuration)" -NoPackageAnalysis -Properties Configuration=$(Configuration);Id=runtime.win.WixToolset.Core.Native;Version="$(BuildVersionSimple)";Platform=$(PlatformTarget);Authors="$(Authors)";Copyright="$(Copyright)";Description="$(Description)";Title="$(Title)"' />
   </Target>
diff --git a/src/wixnative/x64/mergemod.dll b/src/wixnative/x64/mergemod.dll
new file mode 100644
index 00000000..2f4cdc7c
--- /dev/null
+++ b/src/wixnative/x64/mergemod.dll