1 files changed, 111 insertions, 0 deletions

diff --git a/src/WixToolset.Core.WindowsInstaller/MspBackend.cs b/src/WixToolset.Core.WindowsInstaller/MspBackend.cs
new file mode 100644
index 00000000..4b13258b
--- /dev/null
+++ b/src/WixToolset.Core.WindowsInstaller/MspBackend.cs
@@ -0,0 +1,111 @@
+// 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.WindowsInstaller
+{
+    using System;
+    using System.ComponentModel;
+    using System.IO;
+    using WixToolset.Core.Native;
+    using WixToolset.Core.WindowsInstaller.Unbind;
+    using WixToolset.Data;
+    using WixToolset.Data.Bind;
+    using WixToolset.Extensibility;
+    using WixToolset.Msi;
+    using WixToolset.Ole32;
+
+    internal class MspBackend : IBackend
+    {
+        public BindResult Bind(IBindContext context)
+        {
+            throw new NotImplementedException();
+        }
+
+        public bool Inscribe(IInscribeContext context)
+        {
+            throw new NotImplementedException();
+        }
+
+        public Output Unbind(IUnbindContext context)
+        {
+            Output patch;
+
+            // patch files are essentially database files (use a special flag to let the API know its a patch file)
+            try
+            {
+                using (Database database = new Database(context.InputFilePath, OpenDatabase.ReadOnly | OpenDatabase.OpenPatchFile))
+                {
+                    var unbindCommand = new UnbindDatabaseCommand(context.Messaging, database, context.InputFilePath, OutputType.Patch, context.ExportBasePath, context.IntermediateFolder, context.IsAdminImage, context.SuppressDemodularization, skipSummaryInfo: false);
+                    patch = unbindCommand.Execute();
+                }
+            }
+            catch (Win32Exception e)
+            {
+                if (0x6E == e.NativeErrorCode) // ERROR_OPEN_FAILED
+                {
+                    throw new WixException(WixErrors.OpenDatabaseFailed(context.InputFilePath));
+                }
+
+                throw;
+            }
+
+            // retrieve the transforms (they are in substorages)
+            using (Storage storage = Storage.Open(context.InputFilePath, StorageMode.Read | StorageMode.ShareDenyWrite))
+            {
+                Table summaryInformationTable = patch.Tables["_SummaryInformation"];
+                foreach (Row row in summaryInformationTable.Rows)
+                {
+                    if (8 == (int)row[0]) // PID_LASTAUTHOR
+                    {
+                        string value = (string)row[1];
+
+                        foreach (string decoratedSubStorageName in value.Split(';'))
+                        {
+                            string subStorageName = decoratedSubStorageName.Substring(1);
+                            string transformFile = Path.Combine(context.IntermediateFolder, String.Concat("Transform", Path.DirectorySeparatorChar, subStorageName, ".mst"));
+
+                            // ensure the parent directory exists
+                            System.IO.Directory.CreateDirectory(Path.GetDirectoryName(transformFile));
+
+                            // copy the substorage to a new storage for the transform file
+                            using (Storage subStorage = storage.OpenStorage(subStorageName))
+                            {
+                                using (Storage transformStorage = Storage.CreateDocFile(transformFile, StorageMode.ReadWrite | StorageMode.ShareExclusive | StorageMode.Create))
+                                {
+                                    subStorage.CopyTo(transformStorage);
+                                }
+                            }
+
+                            // unbind the transform
+                            var unbindCommand= new UnbindTransformCommand(context.Messaging, transformFile, (null == context.ExportBasePath ? null : Path.Combine(context.ExportBasePath, subStorageName)), context.IntermediateFolder);
+                            var transform = unbindCommand.Execute();
+
+                            patch.SubStorages.Add(new SubStorage(subStorageName, transform));
+                        }
+
+                        break;
+                    }
+                }
+            }
+
+            // extract the files from the cabinets
+            // TODO: use per-transform export paths for support of multi-product patches
+            if (null != context.ExportBasePath && !context.SuppressExtractCabinets)
+            {
+                using (Database database = new Database(context.InputFilePath, OpenDatabase.ReadOnly | OpenDatabase.OpenPatchFile))
+                {
+                    foreach (SubStorage subStorage in patch.SubStorages)
+                    {
+                        // only patch transforms should carry files
+                        if (subStorage.Name.StartsWith("#", StringComparison.Ordinal))
+                        {
+                            var extractCommand = new ExtractCabinetsCommand(subStorage.Data, database, context.InputFilePath, context.ExportBasePath, context.IntermediateFolder);
+                            extractCommand.Execute();
+                        }
+                    }
+                }
+            }
+
+            return patch;
+        }
+    }
+}
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