1 files changed, 1197 insertions, 0 deletions

diff --git a/src/burn/engine/mspengine.cpp b/src/burn/engine/mspengine.cpp
new file mode 100644
index 00000000..6d58d324
--- /dev/null
+++ b/src/burn/engine/mspengine.cpp
@@ -0,0 +1,1197 @@
+// 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.
+
+#include "precomp.h"
+
+
+// constants
+
+
+// structs
+
+struct POSSIBLE_TARGETPRODUCT
+{
+    WCHAR wzProductCode[39];
+    LPWSTR pszLocalPackage;
+    MSIINSTALLCONTEXT context;
+};
+
+// internal function declarations
+
+static HRESULT GetPossibleTargetProductCodes(
+    __in BURN_PACKAGES*     pPackages,
+    __deref_inout_ecount_opt(*pcPossibleTargetProductCodes) POSSIBLE_TARGETPRODUCT** prgPossibleTargetProductCodes,
+    __inout DWORD* pcPossibleTargetProductCodes
+    );
+static HRESULT AddPossibleTargetProduct(
+    __in STRINGDICT_HANDLE sdUniquePossibleTargetProductCodes,
+    __in_z LPCWSTR wzPossibleTargetProductCode,
+    __in MSIINSTALLCONTEXT context,
+    __deref_inout_ecount_opt(*pcPossibleTargetProducts) POSSIBLE_TARGETPRODUCT** prgPossibleTargetProducts,
+    __inout DWORD* pcPossibleTargetProducts
+    );
+static HRESULT AddDetectedTargetProduct(
+    __in BURN_PACKAGE* pPackage,
+    __in DWORD dwOrder,
+    __in_z LPCWSTR wzProductCode,
+    __in MSIINSTALLCONTEXT context,
+    __out DWORD* pdwTargetProductIndex
+    );
+static HRESULT AddMsiChainedPatch(
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_PACKAGE* pMspPackage,
+    __in DWORD dwMspTargetProductIndex,
+    __out DWORD* pdwChainedPatchIndex
+    );
+static HRESULT DeterminePatchChainedTarget(
+    __in BURN_PACKAGES* pPackages,
+    __in BURN_PACKAGE* pMspPackage,
+    __in LPCWSTR wzTargetProductCode,
+    __in DWORD dwMspTargetProductIndex
+    );
+static HRESULT PlanTargetProduct(
+    __in BOOTSTRAPPER_DISPLAY display,
+    __in BURN_USER_EXPERIENCE* pUserExperience,
+    __in BOOL fRollback,
+    __in BURN_PLAN* pPlan,
+    __in BURN_LOGGING* pLog,
+    __in BURN_VARIABLES* pVariables,
+    __in BOOTSTRAPPER_ACTION_STATE actionState,
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_MSPTARGETPRODUCT* pTargetProduct,
+    __in_opt HANDLE hCacheEvent
+    );
+
+
+// function definitions
+
+extern "C" HRESULT MspEngineParsePackageFromXml(
+    __in IXMLDOMNode* pixnMspPackage,
+    __in BURN_PACKAGE* pPackage
+    )
+{
+    HRESULT hr = S_OK;
+
+    // @PatchCode
+    hr = XmlGetAttributeEx(pixnMspPackage, L"PatchCode", &pPackage->Msp.sczPatchCode);
+    ExitOnFailure(hr, "Failed to get @PatchCode.");
+
+    // @PatchXml
+    hr = XmlGetAttributeEx(pixnMspPackage, L"PatchXml", &pPackage->Msp.sczApplicabilityXml);
+    ExitOnFailure(hr, "Failed to get @PatchXml.");
+
+    // Read properties.
+    hr = MsiEngineParsePropertiesFromXml(pixnMspPackage, &pPackage->Msp.rgProperties, &pPackage->Msp.cProperties);
+    ExitOnFailure(hr, "Failed to parse properties from XML.");
+
+LExit:
+
+    return hr;
+}
+
+extern "C" void MspEnginePackageUninitialize(
+    __in BURN_PACKAGE* pPackage
+    )
+{
+    ReleaseStr(pPackage->Msp.sczPatchCode);
+    ReleaseStr(pPackage->Msp.sczApplicabilityXml);
+
+    // free properties
+    if (pPackage->Msp.rgProperties)
+    {
+        for (DWORD i = 0; i < pPackage->Msp.cProperties; ++i)
+        {
+            BURN_MSIPROPERTY* pProperty = &pPackage->Msp.rgProperties[i];
+
+            ReleaseStr(pProperty->sczId);
+            ReleaseStr(pProperty->sczValue);
+            ReleaseStr(pProperty->sczRollbackValue);
+        }
+        MemFree(pPackage->Msp.rgProperties);
+    }
+
+    // free target products
+    ReleaseMem(pPackage->Msp.rgTargetProducts);
+
+    // clear struct
+    memset(&pPackage->Msp, 0, sizeof(pPackage->Msp));
+}
+
+extern "C" HRESULT MspEngineDetectInitialize(
+    __in BURN_PACKAGES* pPackages
+    )
+{
+    AssertSz(pPackages->cPatchInfo, "MspEngineDetectInitialize() should only be called if there are MSP packages.");
+
+    HRESULT hr = S_OK;
+    POSSIBLE_TARGETPRODUCT* rgPossibleTargetProducts = NULL;
+    DWORD cPossibleTargetProducts = 0;
+
+#ifdef DEBUG
+    // All patch info should be initialized to zero.
+    for (DWORD i = 0; i < pPackages->cPatchInfo; ++i)
+    {
+        BURN_PACKAGE* pPackage = pPackages->rgPatchInfoToPackage[i];
+        Assert(!pPackage->Msp.cTargetProductCodes);
+        Assert(!pPackage->Msp.rgTargetProducts);
+    }
+#endif
+
+    // Figure out which product codes to target on the machine. In the worst case all products on the machine
+    // will be returned.
+    hr = GetPossibleTargetProductCodes(pPackages, &rgPossibleTargetProducts, &cPossibleTargetProducts);
+    ExitOnFailure(hr, "Failed to get possible target product codes.");
+
+    // Loop through possible target products, testing the collective patch applicability against each product in
+    // the appropriate context. Store the result with the appropriate patch package.
+    for (DWORD iSearch = 0; iSearch < cPossibleTargetProducts; ++iSearch)
+    {
+        const POSSIBLE_TARGETPRODUCT* pPossibleTargetProduct = rgPossibleTargetProducts + iSearch;
+
+        LogId(REPORT_STANDARD, MSG_DETECT_CALCULATE_PATCH_APPLICABILITY, pPossibleTargetProduct->wzProductCode, LoggingMsiInstallContext(pPossibleTargetProduct->context));
+
+        if (pPossibleTargetProduct->pszLocalPackage)
+        {
+            // Ignores current machine state to determine just patch applicability.
+            // Superseded and obsolesced patches will be planned separately.
+            hr = WiuDetermineApplicablePatches(pPossibleTargetProduct->pszLocalPackage, pPackages->rgPatchInfo, pPackages->cPatchInfo);
+        }
+        else
+        {
+            hr = WiuDeterminePatchSequence(pPossibleTargetProduct->wzProductCode, NULL, pPossibleTargetProduct->context, pPackages->rgPatchInfo, pPackages->cPatchInfo);
+        }
+
+        if (SUCCEEDED(hr))
+        {
+            for (DWORD iPatchInfo = 0; iPatchInfo < pPackages->cPatchInfo; ++iPatchInfo)
+            {
+                hr = HRESULT_FROM_WIN32(pPackages->rgPatchInfo[iPatchInfo].uStatus);
+                BURN_PACKAGE* pMspPackage = pPackages->rgPatchInfoToPackage[iPatchInfo];
+                Assert(BURN_PACKAGE_TYPE_MSP == pMspPackage->type);
+
+                if (S_OK == hr)
+                {
+                    // Note that we do add superseded and obsolete MSP packages. Package Detect and Plan will sort them out later.
+                    hr = MspEngineAddDetectedTargetProduct(pPackages, pMspPackage, pPackages->rgPatchInfo[iPatchInfo].dwOrder, pPossibleTargetProduct->wzProductCode, pPossibleTargetProduct->context);
+                    ExitOnFailure(hr, "Failed to add target product code to package: %ls", pMspPackage->sczId);
+                }
+                else
+                {
+                    LogStringLine(REPORT_DEBUG, "      0x%x: Patch applicability failed for package: %ls", hr, pMspPackage->sczId);
+                }
+            }
+        }
+        else
+        {
+            LogId(REPORT_STANDARD, MSG_DETECT_FAILED_CALCULATE_PATCH_APPLICABILITY, pPossibleTargetProduct->wzProductCode, LoggingMsiInstallContext(pPossibleTargetProduct->context), hr);
+        }
+
+        hr = S_OK; // always reset so we test all possible target products.
+    }
+
+LExit:
+    if (rgPossibleTargetProducts)
+    {
+        for (DWORD i = 0; i < cPossibleTargetProducts; ++i)
+        {
+            ReleaseStr(rgPossibleTargetProducts[i].pszLocalPackage);
+        }
+        MemFree(rgPossibleTargetProducts);
+    }
+
+    return hr;
+}
+
+extern "C" HRESULT MspEngineAddDetectedTargetProduct(
+    __in BURN_PACKAGES* pPackages,
+    __in BURN_PACKAGE* pPackage,
+    __in DWORD dwOrder,
+    __in_z LPCWSTR wzProductCode,
+    __in MSIINSTALLCONTEXT context
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD dwTargetProductIndex = 0;
+
+    hr = AddDetectedTargetProduct(pPackage, dwOrder, wzProductCode, context, &dwTargetProductIndex);
+    ExitOnFailure(hr, "Failed to add detected target product.");
+
+    hr = DeterminePatchChainedTarget(pPackages, pPackage, wzProductCode, dwTargetProductIndex);
+    ExitOnFailure(hr, "Failed to determine patch chained target.");
+
+LExit:
+    return hr;
+}
+
+extern "C" HRESULT MspEngineAddMissingSlipstreamTarget(
+    __in BURN_PACKAGE* pMsiPackage,
+    __in BURN_SLIPSTREAM_MSP* pSlipstreamMsp
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD dwTargetProductIndex = 0;
+    BURN_MSPTARGETPRODUCT* pTargetProduct = NULL;
+    DWORD dwChainedPatchIndex = 0;
+
+    hr = AddDetectedTargetProduct(pSlipstreamMsp->pMspPackage, 0, pMsiPackage->Msi.sczProductCode, pMsiPackage->fPerMachine ? MSIINSTALLCONTEXT_MACHINE : MSIINSTALLCONTEXT_USERUNMANAGED, &dwTargetProductIndex);
+    ExitOnFailure(hr, "Failed to add missing slipstream target.");
+
+    pTargetProduct = pSlipstreamMsp->pMspPackage->Msp.rgTargetProducts + dwTargetProductIndex;
+    pTargetProduct->fSlipstream = TRUE;
+    pTargetProduct->fSlipstreamRequired = TRUE;
+    pTargetProduct->pChainedTargetPackage = pMsiPackage;
+
+    hr = AddMsiChainedPatch(pMsiPackage, pSlipstreamMsp->pMspPackage, dwTargetProductIndex, &dwChainedPatchIndex);
+    ExitOnFailure(hr, "Failed to add chained patch.");
+
+    pSlipstreamMsp->dwMsiChainedPatchIndex = dwChainedPatchIndex;
+
+LExit:
+    return hr;
+}
+
+extern "C" HRESULT MspEngineDetectPackage(
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_USER_EXPERIENCE* pUserExperience
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR sczState = NULL;
+
+    if (pPackage->fCanAffectRegistration)
+    {
+        pPackage->installRegistrationState = BURN_PACKAGE_REGISTRATION_STATE_ABSENT;
+    }
+
+    if (0 == pPackage->Msp.cTargetProductCodes)
+    {
+        pPackage->currentState = BOOTSTRAPPER_PACKAGE_STATE_ABSENT;
+    }
+    else
+    {
+        // Start the package state at the highest state then loop through all the
+        // target product codes and end up setting the current state to the lowest
+        // package state applied to the target product codes.
+        pPackage->currentState = BOOTSTRAPPER_PACKAGE_STATE_SUPERSEDED;
+
+        for (DWORD i = 0; i < pPackage->Msp.cTargetProductCodes; ++i)
+        {
+            BURN_MSPTARGETPRODUCT* pTargetProduct = pPackage->Msp.rgTargetProducts + i;
+
+            hr = WiuGetPatchInfoEx(pPackage->Msp.sczPatchCode, pTargetProduct->wzTargetProductCode, NULL, pTargetProduct->context, INSTALLPROPERTY_PATCHSTATE, &sczState);
+            if (SUCCEEDED(hr))
+            {
+                switch (*sczState)
+                {
+                case '1':
+                    pTargetProduct->fInstalled = TRUE;
+                    pTargetProduct->patchPackageState = BOOTSTRAPPER_PACKAGE_STATE_PRESENT;
+                    break;
+
+                case '2':
+                    pTargetProduct->fInstalled = TRUE;
+                    pTargetProduct->patchPackageState = BOOTSTRAPPER_PACKAGE_STATE_SUPERSEDED;
+                    break;
+
+                case '4':
+                    pTargetProduct->fInstalled = TRUE;
+                    pTargetProduct->patchPackageState = BOOTSTRAPPER_PACKAGE_STATE_OBSOLETE;
+                    break;
+
+                default:
+                    pTargetProduct->patchPackageState = BOOTSTRAPPER_PACKAGE_STATE_ABSENT;
+                    break;
+                }
+            }
+            else if (HRESULT_FROM_WIN32(ERROR_UNKNOWN_PATCH) == hr || HRESULT_FROM_WIN32(ERROR_UNKNOWN_PRODUCT) == hr)
+            {
+                pTargetProduct->patchPackageState = BOOTSTRAPPER_PACKAGE_STATE_ABSENT;
+                hr = S_OK;
+            }
+            ExitOnFailure(hr, "Failed to get patch information for patch code: %ls, target product code: %ls", pPackage->Msp.sczPatchCode, pTargetProduct->wzTargetProductCode);
+
+            if (pPackage->currentState > pTargetProduct->patchPackageState)
+            {
+                pPackage->currentState = pTargetProduct->patchPackageState;
+            }
+
+            if (pPackage->fCanAffectRegistration)
+            {
+                pTargetProduct->registrationState = pTargetProduct->fInstalled ? BURN_PACKAGE_REGISTRATION_STATE_PRESENT : BURN_PACKAGE_REGISTRATION_STATE_ABSENT;
+
+                if (pTargetProduct->fInstalled)
+                {
+                    pPackage->installRegistrationState = BURN_PACKAGE_REGISTRATION_STATE_PRESENT;
+                }
+            }
+
+            hr = UserExperienceOnDetectPatchTarget(pUserExperience, pPackage->sczId, pTargetProduct->wzTargetProductCode, pTargetProduct->patchPackageState);
+            ExitOnRootFailure(hr, "BA aborted detect patch target.");
+        }
+    }
+
+LExit:
+    ReleaseStr(sczState);
+
+    return hr;
+}
+
+extern "C" HRESULT MspEnginePlanInitializePackage(
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_USER_EXPERIENCE* pUserExperience
+    )
+{
+    HRESULT hr = S_OK;
+
+    for (DWORD i = 0; i < pPackage->Msp.cTargetProductCodes; ++i)
+    {
+        BURN_MSPTARGETPRODUCT* pTargetProduct = pPackage->Msp.rgTargetProducts + i;
+
+        if (!pTargetProduct->fInstalled && pTargetProduct->fSlipstreamRequired && BOOTSTRAPPER_REQUEST_STATE_PRESENT > pTargetProduct->pChainedTargetPackage->requested)
+        {
+            // There's no way to apply the patch if the target isn't installed.
+            pTargetProduct->defaultRequested = pTargetProduct->requested = BOOTSTRAPPER_REQUEST_STATE_NONE;
+            continue;
+        }
+
+        pTargetProduct->defaultRequested = pTargetProduct->requested = pPackage->requested;
+
+        hr = UserExperienceOnPlanPatchTarget(pUserExperience, pPackage->sczId, pTargetProduct->wzTargetProductCode, &pTargetProduct->requested);
+        ExitOnRootFailure(hr, "BA aborted plan patch target.");
+    }
+
+LExit:
+    return hr;
+}
+
+//
+// PlanCalculate - calculates the execute and rollback state for the requested package state.
+//
+extern "C" HRESULT MspEnginePlanCalculatePackage(
+    __in BURN_PACKAGE* pPackage,
+    __in BOOL fInsideMsiTransaction
+    )
+{
+    HRESULT hr = S_OK;
+    BOOL fWillUninstallAll = TRUE;
+
+    for (DWORD i = 0; i < pPackage->Msp.cTargetProductCodes; ++i)
+    {
+        BURN_MSPTARGETPRODUCT* pTargetProduct = pPackage->Msp.rgTargetProducts + i;
+
+        BOOTSTRAPPER_ACTION_STATE execute = BOOTSTRAPPER_ACTION_STATE_NONE;
+        BOOTSTRAPPER_ACTION_STATE rollback = BOOTSTRAPPER_ACTION_STATE_NONE;
+
+        // Calculate the execute action.
+        switch (pTargetProduct->patchPackageState)
+        {
+        case BOOTSTRAPPER_PACKAGE_STATE_PRESENT:
+            switch (pTargetProduct->requested)
+            {
+            case BOOTSTRAPPER_REQUEST_STATE_REPAIR:
+                execute = BOOTSTRAPPER_ACTION_STATE_REPAIR;
+                fWillUninstallAll = FALSE;
+                break;
+
+            case BOOTSTRAPPER_REQUEST_STATE_ABSENT: __fallthrough;
+            case BOOTSTRAPPER_REQUEST_STATE_CACHE:
+                execute = pPackage->fUninstallable ? BOOTSTRAPPER_ACTION_STATE_UNINSTALL : BOOTSTRAPPER_ACTION_STATE_NONE;
+                break;
+
+            case BOOTSTRAPPER_REQUEST_STATE_FORCE_ABSENT:
+                execute = BOOTSTRAPPER_ACTION_STATE_UNINSTALL;
+                break;
+
+            default:
+                execute = BOOTSTRAPPER_ACTION_STATE_NONE;
+                fWillUninstallAll = FALSE;
+                break;
+            }
+            break;
+
+        case BOOTSTRAPPER_PACKAGE_STATE_ABSENT:
+            switch (pTargetProduct->requested)
+            {
+            case BOOTSTRAPPER_REQUEST_STATE_PRESENT: __fallthrough;
+            case BOOTSTRAPPER_REQUEST_STATE_REPAIR:
+                execute = BOOTSTRAPPER_ACTION_STATE_INSTALL;
+                fWillUninstallAll = FALSE;
+                break;
+
+            default:
+                execute = BOOTSTRAPPER_ACTION_STATE_NONE;
+                break;
+            }
+            break;
+
+        default:
+            if (pTargetProduct->fInstalled)
+            {
+                fWillUninstallAll = FALSE;
+            }
+            break;
+        }
+
+        // Calculate the rollback action if there is an execute action.
+        if (BOOTSTRAPPER_ACTION_STATE_NONE != execute && !fInsideMsiTransaction)
+        {
+            switch (pPackage->currentState)
+            {
+            case BOOTSTRAPPER_PACKAGE_STATE_PRESENT:
+                switch (pTargetProduct->requested)
+                {
+                case BOOTSTRAPPER_REQUEST_STATE_FORCE_ABSENT: __fallthrough;
+                case BOOTSTRAPPER_REQUEST_STATE_ABSENT:
+                    rollback = BOOTSTRAPPER_ACTION_STATE_INSTALL;
+                    break;
+
+                default:
+                    rollback = BOOTSTRAPPER_ACTION_STATE_NONE;
+                    break;
+                }
+                break;
+
+            case BOOTSTRAPPER_PACKAGE_STATE_ABSENT: __fallthrough;
+                switch (pTargetProduct->requested)
+                {
+                case BOOTSTRAPPER_REQUEST_STATE_PRESENT: __fallthrough;
+                case BOOTSTRAPPER_REQUEST_STATE_REPAIR:
+                    rollback = pPackage->fUninstallable ? BOOTSTRAPPER_ACTION_STATE_UNINSTALL : BOOTSTRAPPER_ACTION_STATE_NONE;
+                    break;
+
+                default:
+                    rollback = BOOTSTRAPPER_ACTION_STATE_NONE;
+                    break;
+                }
+                break;
+
+            default:
+                rollback = BOOTSTRAPPER_ACTION_STATE_NONE;
+                break;
+            }
+        }
+
+        pTargetProduct->execute = execute;
+        pTargetProduct->rollback = rollback;
+
+        // The highest aggregate action state found will be returned.
+        if (pPackage->execute < execute)
+        {
+            pPackage->execute = execute;
+        }
+
+        if (pPackage->rollback < rollback)
+        {
+            pPackage->rollback = rollback;
+        }
+    }
+
+    // The dependency manager will do the wrong thing if the package level action is UNINSTALL
+    // when the patch will still be applied to at least one product.
+    if (!fWillUninstallAll && BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pPackage->execute)
+    {
+        pPackage->execute = BOOTSTRAPPER_ACTION_STATE_NONE;
+    }
+
+    return hr;
+}
+
+//
+// PlanAdd - adds the calculated execute and rollback actions for the package.
+//
+extern "C" HRESULT MspEnginePlanAddPackage(
+    __in BOOTSTRAPPER_DISPLAY display,
+    __in BURN_USER_EXPERIENCE* pUserExperience,
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_PLAN* pPlan,
+    __in BURN_LOGGING* pLog,
+    __in BURN_VARIABLES* pVariables,
+    __in_opt HANDLE hCacheEvent
+    )
+{
+    HRESULT hr = S_OK;
+
+    // TODO: need to handle the case where this patch adds itself to an earlier patch's list of target products. That would
+    //       essentially bump this patch earlier in the plan and we need to make sure this patch is downloaded.
+    // add wait for cache
+    if (hCacheEvent)
+    {
+        hr = PlanExecuteCacheSyncAndRollback(pPlan, pPackage, hCacheEvent);
+        ExitOnFailure(hr, "Failed to plan package cache syncpoint");
+    }
+
+    hr = DependencyPlanPackage(NULL, pPackage, pPlan);
+    ExitOnFailure(hr, "Failed to plan package dependency actions.");
+
+    // Plan the actions for each target product code.
+    for (DWORD i = 0; i < pPackage->Msp.cTargetProductCodes; ++i)
+    {
+        BURN_MSPTARGETPRODUCT* pTargetProduct = pPackage->Msp.rgTargetProducts + i;
+
+        // If the dependency manager changed the action state for the patch, change the target product actions.
+        if (pPackage->fDependencyManagerWasHere)
+        {
+            pTargetProduct->execute = pPackage->execute;
+            pTargetProduct->rollback = pPackage->rollback;
+        }
+
+        if (BOOTSTRAPPER_ACTION_STATE_NONE != pTargetProduct->execute)
+        {
+            hr = PlanTargetProduct(display, pUserExperience, FALSE, pPlan, pLog, pVariables, pTargetProduct->execute, pPackage, pTargetProduct, hCacheEvent);
+            ExitOnFailure(hr, "Failed to plan target product.");
+        }
+
+        if (BOOTSTRAPPER_ACTION_STATE_NONE != pTargetProduct->rollback)
+        {
+            hr = PlanTargetProduct(display, pUserExperience, TRUE, pPlan, pLog, pVariables, pTargetProduct->rollback, pPackage, pTargetProduct, hCacheEvent);
+            ExitOnFailure(hr, "Failed to plan rollback target product.");
+        }
+    }
+
+LExit:
+
+    return hr;
+}
+
+extern "C" HRESULT MspEngineExecutePackage(
+    __in_opt HWND hwndParent,
+    __in BURN_EXECUTE_ACTION* pExecuteAction,
+    __in BURN_VARIABLES* pVariables,
+    __in BOOL fRollback,
+    __in PFN_MSIEXECUTEMESSAGEHANDLER pfnMessageHandler,
+    __in LPVOID pvContext,
+    __out BOOTSTRAPPER_APPLY_RESTART* pRestart
+    )
+{
+    HRESULT hr = S_OK;
+    WIU_MSI_EXECUTE_CONTEXT context = { };
+    WIU_RESTART restart = WIU_RESTART_NONE;
+
+    LPWSTR sczCachedDirectory = NULL;
+    LPWSTR sczMspPath = NULL;
+    LPWSTR sczPatches = NULL;
+    LPWSTR sczProperties = NULL;
+    LPWSTR sczObfuscatedProperties = NULL;
+
+    // default to "verbose" logging
+    DWORD dwLogMode = WIU_LOG_DEFAULT | INSTALLLOGMODE_VERBOSE;
+
+    // get cached MSP paths
+    for (DWORD i = 0; i < pExecuteAction->mspTarget.cOrderedPatches; ++i)
+    {
+        LPCWSTR wzAppend = NULL;
+        BURN_PACKAGE* pMspPackage = pExecuteAction->mspTarget.rgOrderedPatches[i].pPackage;
+        BURN_PAYLOAD* pMspPackagePayload = pMspPackage->payloads.rgItems[0].pPayload;
+        AssertSz(BURN_PACKAGE_TYPE_MSP == pMspPackage->type, "Invalid package type added to ordered patches.");
+
+        if (BOOTSTRAPPER_ACTION_STATE_INSTALL == pExecuteAction->mspTarget.action)
+        {
+            hr = CacheGetCompletedPath(pMspPackage->fPerMachine, pMspPackage->sczCacheId, &sczCachedDirectory);
+            ExitOnFailure(hr, "Failed to get cached path for MSP package: %ls", pMspPackage->sczId);
+
+            // TODO: Figure out if this makes sense -- the variable is set to the last patch's path only
+            // Best effort to set the execute package cache folder variable.
+            VariableSetString(pVariables, BURN_BUNDLE_EXECUTE_PACKAGE_CACHE_FOLDER, sczCachedDirectory, TRUE, FALSE);
+
+            hr = PathConcat(sczCachedDirectory, pMspPackagePayload->sczFilePath, &sczMspPath);
+            ExitOnFailure(hr, "Failed to build MSP path.");
+
+            wzAppend = sczMspPath;
+        }
+        else // uninstall
+        {
+            wzAppend = pMspPackage->Msp.sczPatchCode;
+        }
+
+        if (NULL != sczPatches)
+        {
+            hr = StrAllocConcat(&sczPatches, L";", 0);
+            ExitOnFailure(hr, "Failed to semi-colon delimit patches.");
+        }
+
+        hr = StrAllocConcat(&sczPatches, wzAppend, 0);
+        ExitOnFailure(hr, "Failed to append patch.");
+    }
+
+    // Best effort to set the execute package action variable.
+    VariableSetNumeric(pVariables, BURN_BUNDLE_EXECUTE_PACKAGE_ACTION, pExecuteAction->mspTarget.action, TRUE);
+
+    // Wire up the external UI handler and logging.
+    if (pExecuteAction->mspTarget.fDisableExternalUiHandler)
+    {
+        hr = WiuInitializeInternalUI(pExecuteAction->mspTarget.uiLevel, hwndParent, &context);
+        ExitOnFailure(hr, "Failed to initialize internal UI for MSP package.");
+    }
+    else
+    {
+        hr = WiuInitializeExternalUI(pfnMessageHandler, pExecuteAction->mspTarget.uiLevel, hwndParent, pvContext, fRollback, &context);
+        ExitOnFailure(hr, "Failed to initialize external UI handler.");
+    }
+
+    //if (BURN_LOGGING_LEVEL_DEBUG == logLevel)
+    //{
+    //    dwLogMode | INSTALLLOGMODE_EXTRADEBUG;
+    //}
+
+    if (pExecuteAction->mspTarget.sczLogPath && *pExecuteAction->mspTarget.sczLogPath)
+    {
+        hr = WiuEnableLog(dwLogMode, pExecuteAction->mspTarget.sczLogPath, 0);
+        ExitOnFailure(hr, "Failed to enable logging for package: %ls to: %ls", pExecuteAction->mspTarget.pPackage->sczId, pExecuteAction->mspTarget.sczLogPath);
+    }
+
+    // set up properties
+    hr = MsiEngineConcatProperties(pExecuteAction->mspTarget.pPackage->Msp.rgProperties, pExecuteAction->mspTarget.pPackage->Msp.cProperties, pVariables, fRollback, &sczProperties, FALSE);
+    ExitOnFailure(hr, "Failed to add properties to argument string.");
+
+    hr = MsiEngineConcatProperties(pExecuteAction->mspTarget.pPackage->Msp.rgProperties, pExecuteAction->mspTarget.pPackage->Msp.cProperties, pVariables, fRollback, &sczObfuscatedProperties, TRUE);
+    ExitOnFailure(hr, "Failed to add properties to obfuscated argument string.");
+
+    hr = MsiEngineConcatActionProperty(pExecuteAction->mspTarget.actionMsiProperty, &sczProperties);
+    ExitOnFailure(hr, "Failed to add action property to argument string.");
+
+    hr = MsiEngineConcatActionProperty(pExecuteAction->mspTarget.actionMsiProperty, &sczObfuscatedProperties);
+    ExitOnFailure(hr, "Failed to add action property to obfuscated argument string.");
+
+    LogId(REPORT_STANDARD, MSG_APPLYING_PATCH_PACKAGE, pExecuteAction->mspTarget.pPackage->sczId, LoggingActionStateToString(pExecuteAction->mspTarget.action), sczPatches, sczObfuscatedProperties, pExecuteAction->mspTarget.sczTargetProductCode);
+
+    //
+    // Do the actual action.
+    //
+    switch (pExecuteAction->mspTarget.action)
+    {
+    case BOOTSTRAPPER_ACTION_STATE_INSTALL: __fallthrough;
+    case BOOTSTRAPPER_ACTION_STATE_REPAIR:
+        hr = StrAllocConcatSecure(&sczProperties, L" PATCH=\"", 0);
+        ExitOnFailure(hr, "Failed to add PATCH property on install.");
+
+        hr = StrAllocConcatSecure(&sczProperties, sczPatches, 0);
+        ExitOnFailure(hr, "Failed to add patches to PATCH property on install.");
+
+        hr = StrAllocConcatSecure(&sczProperties, L"\" REBOOT=ReallySuppress", 0);
+        ExitOnFailure(hr, "Failed to add reboot suppression property on install.");
+
+        hr = WiuConfigureProductEx(pExecuteAction->mspTarget.sczTargetProductCode, INSTALLLEVEL_DEFAULT, INSTALLSTATE_DEFAULT, sczProperties, &restart);
+        ExitOnFailure(hr, "Failed to install MSP package.");
+        break;
+
+    case BOOTSTRAPPER_ACTION_STATE_UNINSTALL:
+        hr = StrAllocConcatSecure(&sczProperties, L" REBOOT=ReallySuppress", 0);
+        ExitOnFailure(hr, "Failed to add reboot suppression property on uninstall.");
+
+        // Ignore all dependencies, since the Burn engine already performed the check.
+        hr = StrAllocFormattedSecure(&sczProperties, L"%ls %ls=ALL", sczProperties, DEPENDENCY_IGNOREDEPENDENCIES);
+        ExitOnFailure(hr, "Failed to add the list of dependencies to ignore to the properties.");
+
+        hr = WiuRemovePatches(sczPatches, pExecuteAction->mspTarget.sczTargetProductCode, sczProperties, &restart);
+        ExitOnFailure(hr, "Failed to uninstall MSP package.");
+        break;
+    }
+
+LExit:
+    WiuUninitializeExternalUI(&context);
+
+    ReleaseStr(sczCachedDirectory);
+    ReleaseStr(sczMspPath);
+    StrSecureZeroFreeString(sczProperties);
+    ReleaseStr(sczObfuscatedProperties);
+    ReleaseStr(sczPatches);
+
+    switch (restart)
+    {
+        case WIU_RESTART_NONE:
+            *pRestart = BOOTSTRAPPER_APPLY_RESTART_NONE;
+            break;
+
+        case WIU_RESTART_REQUIRED:
+            *pRestart = BOOTSTRAPPER_APPLY_RESTART_REQUIRED;
+            break;
+
+        case WIU_RESTART_INITIATED:
+            *pRestart = BOOTSTRAPPER_APPLY_RESTART_INITIATED;
+            break;
+    }
+
+    // Best effort to clear the execute package cache folder and action variables.
+    VariableSetString(pVariables, BURN_BUNDLE_EXECUTE_PACKAGE_CACHE_FOLDER, NULL, TRUE, FALSE);
+    VariableSetString(pVariables, BURN_BUNDLE_EXECUTE_PACKAGE_ACTION, NULL, TRUE, FALSE);
+
+    return hr;
+}
+
+extern "C" void MspEngineUpdateInstallRegistrationState(
+    __in BURN_EXECUTE_ACTION* pAction,
+    __in HRESULT hrExecute,
+    __in BOOL fInsideMsiTransaction
+    )
+{
+    BURN_PACKAGE_REGISTRATION_STATE newState = BURN_PACKAGE_REGISTRATION_STATE_UNKNOWN;
+
+    if (FAILED(hrExecute))
+    {
+        ExitFunction();
+    }
+
+    if (BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pAction->mspTarget.action)
+    {
+        newState = BURN_PACKAGE_REGISTRATION_STATE_ABSENT;
+    }
+    else
+    {
+        newState = BURN_PACKAGE_REGISTRATION_STATE_PRESENT;
+    }
+
+    for (DWORD i = 0; i < pAction->mspTarget.cOrderedPatches; ++i)
+    {
+        BURN_ORDERED_PATCHES* pOrderedPatches = pAction->mspTarget.rgOrderedPatches + i;
+        BURN_PACKAGE* pPackage = pOrderedPatches->pPackage;
+        BURN_MSPTARGETPRODUCT* pTargetProduct = NULL;
+
+        Assert(BURN_PACKAGE_TYPE_MSP == pPackage->type);
+
+        if (!pPackage->fCanAffectRegistration)
+        {
+            continue;
+        }
+
+        for (DWORD j = 0; j < pPackage->Msp.cTargetProductCodes; ++j)
+        {
+            pTargetProduct = pPackage->Msp.rgTargetProducts + j;
+            if (pAction->mspTarget.fPerMachineTarget == (MSIINSTALLCONTEXT_MACHINE == pTargetProduct->context) &&
+                CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1))
+            {
+                break;
+            }
+
+            pTargetProduct = NULL;
+        }
+
+        if (!pTargetProduct)
+        {
+            AssertSz(pTargetProduct, "Ordered patch didn't have corresponding target product");
+            continue;
+        }
+
+        if (fInsideMsiTransaction)
+        {
+            pTargetProduct->transactionRegistrationState = newState;
+        }
+        else
+        {
+            pTargetProduct->registrationState = newState;
+        }
+    }
+
+LExit:
+    return;
+}
+
+extern "C" void MspEngineFinalizeInstallRegistrationState(
+    __in BURN_PACKAGE* pPackage
+    )
+{
+    if (!pPackage->fCanAffectRegistration)
+    {
+        ExitFunction();
+    }
+
+    if (!pPackage->Msp.cTargetProductCodes)
+    {
+        pPackage->installRegistrationState = BURN_PACKAGE_REGISTRATION_STATE_ABSENT;
+    }
+    else
+    {
+        pPackage->installRegistrationState = BURN_PACKAGE_REGISTRATION_STATE_UNKNOWN;
+
+        for (DWORD i = 0; i < pPackage->Msp.cTargetProductCodes; ++i)
+        {
+            BURN_MSPTARGETPRODUCT* pTargetProduct = pPackage->Msp.rgTargetProducts + i;
+
+            if (pPackage->installRegistrationState < pTargetProduct->registrationState)
+            {
+                pPackage->installRegistrationState = pTargetProduct->registrationState;
+            }
+        }
+    }
+
+LExit:
+    return;
+}
+
+
+// internal helper functions
+
+static HRESULT GetPossibleTargetProductCodes(
+    __in BURN_PACKAGES* pPackages,
+    __deref_inout_ecount_opt(*pcPossibleTargetProducts) POSSIBLE_TARGETPRODUCT** prgPossibleTargetProducts,
+    __inout DWORD* pcPossibleTargetProducts
+    )
+{
+    HRESULT hr = S_OK;
+    STRINGDICT_HANDLE sdUniquePossibleTargetProductCodes = NULL;
+    BOOL fCheckAll = FALSE;
+    WCHAR wzPossibleTargetProductCode[MAX_GUID_CHARS + 1];
+
+    // Use a dictionary to ensure we capture unique product codes. Otherwise, we could end up
+    // doing patch applicability for the same product code multiple times and that would confuse
+    // everything down stream.
+    hr = DictCreateStringList(&sdUniquePossibleTargetProductCodes, 5, DICT_FLAG_NONE);
+    ExitOnFailure(hr, "Failed to create unique target product codes.");
+
+    // If the patches target a specific set of product/upgrade codes, search only those. This
+    // should be much faster than searching all packages on the machine.
+    if (pPackages->rgPatchTargetCodes)
+    {
+        for (DWORD i = 0; i < pPackages->cPatchTargetCodes; ++i)
+        {
+            BURN_PATCH_TARGETCODE* pTargetCode = pPackages->rgPatchTargetCodes + i;
+
+            // If targeting a product, add the unique product code to the list.
+            if (BURN_PATCH_TARGETCODE_TYPE_PRODUCT == pTargetCode->type)
+            {
+                hr = AddPossibleTargetProduct(sdUniquePossibleTargetProductCodes, pTargetCode->sczTargetCode, MSIINSTALLCONTEXT_NONE, prgPossibleTargetProducts, pcPossibleTargetProducts);
+                ExitOnFailure(hr, "Failed to add product code to possible target product codes.");
+            }
+            else if (BURN_PATCH_TARGETCODE_TYPE_UPGRADE == pTargetCode->type)
+            {
+                // Enumerate all unique related products to the target upgrade code.
+                for (DWORD iProduct = 0; SUCCEEDED(hr); ++iProduct)
+                {
+                    hr = WiuEnumRelatedProducts(pTargetCode->sczTargetCode, iProduct, wzPossibleTargetProductCode);
+                    if (SUCCEEDED(hr))
+                    {
+                        hr = AddPossibleTargetProduct(sdUniquePossibleTargetProductCodes, wzPossibleTargetProductCode, MSIINSTALLCONTEXT_NONE, prgPossibleTargetProducts, pcPossibleTargetProducts);
+                        ExitOnFailure(hr, "Failed to add upgrade product code to possible target product codes.");
+                    }
+                    else if (E_BADCONFIGURATION == hr)
+                    {
+                        // Skip product's with bad configuration and continue.
+                        LogId(REPORT_STANDARD, MSG_DETECT_BAD_PRODUCT_CONFIGURATION, wzPossibleTargetProductCode);
+
+                        hr = S_OK;
+                    }
+                }
+
+                if (E_NOMOREITEMS == hr)
+                {
+                    hr = S_OK;
+                }
+                ExitOnFailure(hr, "Failed to enumerate all products to patch related to upgrade code: %ls", pTargetCode->sczTargetCode);
+            }
+            else
+            {
+                // The element does not target a specific product.
+                fCheckAll = TRUE;
+
+                break;
+            }
+        }
+    }
+    else
+    {
+        fCheckAll = TRUE;
+    }
+
+    // One or more of the patches do not target a specific product so search everything on the machine.
+    if (fCheckAll)
+    {
+        for (DWORD iProduct = 0; SUCCEEDED(hr); ++iProduct)
+        {
+            MSIINSTALLCONTEXT context = MSIINSTALLCONTEXT_NONE;
+
+            hr = WiuEnumProductsEx(NULL, NULL, MSIINSTALLCONTEXT_ALL, iProduct, wzPossibleTargetProductCode, &context, NULL, NULL);
+            if (SUCCEEDED(hr))
+            {
+                hr = AddPossibleTargetProduct(sdUniquePossibleTargetProductCodes, wzPossibleTargetProductCode, context, prgPossibleTargetProducts, pcPossibleTargetProducts);
+                ExitOnFailure(hr, "Failed to add product code to search product codes.");
+            }
+            else if (E_BADCONFIGURATION == hr)
+            {
+                // Skip products with bad configuration and continue.
+                LogId(REPORT_STANDARD, MSG_DETECT_BAD_PRODUCT_CONFIGURATION, wzPossibleTargetProductCode);
+
+                hr = S_OK;
+            }
+        }
+
+        if (E_NOMOREITEMS == hr)
+        {
+            hr = S_OK;
+        }
+        ExitOnFailure(hr, "Failed to enumerate all products on the machine for patches applicability.");
+    }
+
+LExit:
+    ReleaseDict(sdUniquePossibleTargetProductCodes);
+
+    return hr;
+}
+
+static HRESULT AddPossibleTargetProduct(
+    __in STRINGDICT_HANDLE sdUniquePossibleTargetProductCodes,
+    __in_z LPCWSTR wzPossibleTargetProductCode,
+    __in MSIINSTALLCONTEXT context,
+    __deref_inout_ecount_opt(*pcPossibleTargetProducts) POSSIBLE_TARGETPRODUCT** prgPossibleTargetProducts,
+    __inout DWORD* pcPossibleTargetProducts
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR pszLocalPackage = NULL;
+
+    // Only add this possible target code if we haven't queried for it already.
+    if (E_NOTFOUND == DictKeyExists(sdUniquePossibleTargetProductCodes, wzPossibleTargetProductCode))
+    {
+        // If the install context is not known, ask the Windows Installer for it. If we can't get the context
+        // then bail.
+        if (MSIINSTALLCONTEXT_NONE == context)
+        {
+            hr = WiuEnumProductsEx(wzPossibleTargetProductCode, NULL, MSIINSTALLCONTEXT_ALL, 0, NULL, &context, NULL, NULL);
+            if (FAILED(hr))
+            {
+                ExitFunction1(hr = S_OK);
+            }
+        }
+
+        hr = DictAddKey(sdUniquePossibleTargetProductCodes, wzPossibleTargetProductCode);
+        ExitOnFailure(hr, "Failed to add possible target code to unique product codes.");
+
+        hr = MemEnsureArraySize(reinterpret_cast<LPVOID*>(prgPossibleTargetProducts), *pcPossibleTargetProducts + 1, sizeof(POSSIBLE_TARGETPRODUCT), 3);
+        ExitOnFailure(hr, "Failed to grow array of possible target products.");
+
+        POSSIBLE_TARGETPRODUCT *const pPossibleTargetProduct = *prgPossibleTargetProducts + *pcPossibleTargetProducts;
+
+        hr = ::StringCchCopyW(pPossibleTargetProduct->wzProductCode, countof(pPossibleTargetProduct->wzProductCode), wzPossibleTargetProductCode);
+        ExitOnFailure(hr, "Failed to copy possible target product code.");
+
+        // Attempt to get the local package path so we can more quickly determine patch applicability later.
+        hr = WiuGetProductInfoEx(wzPossibleTargetProductCode, NULL, context, INSTALLPROPERTY_LOCALPACKAGE, &pszLocalPackage);
+        if (SUCCEEDED(hr))
+        {
+            pPossibleTargetProduct->pszLocalPackage = pszLocalPackage;
+            pszLocalPackage = NULL;
+        }
+        else
+        {
+            // Will instead call MsiDeterminePatchSequence later.
+            hr = S_OK;
+        }
+
+        pPossibleTargetProduct->context = context;
+
+        ++(*pcPossibleTargetProducts);
+    }
+
+LExit:
+    ReleaseStr(pszLocalPackage);
+
+    return hr;
+}
+
+static HRESULT AddDetectedTargetProduct(
+    __in BURN_PACKAGE* pPackage,
+    __in DWORD dwOrder,
+    __in_z LPCWSTR wzProductCode,
+    __in MSIINSTALLCONTEXT context,
+    __out DWORD* pdwTargetProductIndex
+    )
+{
+    HRESULT hr = S_OK;
+    BURN_MSPTARGETPRODUCT* pTargetProduct = NULL;
+
+    *pdwTargetProductIndex = BURN_PACKAGE_INVALID_PATCH_INDEX;
+
+    hr = MemEnsureArraySize(reinterpret_cast<LPVOID*>(&pPackage->Msp.rgTargetProducts), pPackage->Msp.cTargetProductCodes + 1, sizeof(BURN_MSPTARGETPRODUCT), 5);
+    ExitOnFailure(hr, "Failed to ensure enough target product codes were allocated.");
+
+    pTargetProduct = pPackage->Msp.rgTargetProducts + pPackage->Msp.cTargetProductCodes;
+
+    hr = ::StringCchCopyW(pTargetProduct->wzTargetProductCode, countof(pTargetProduct->wzTargetProductCode), wzProductCode);
+    ExitOnFailure(hr, "Failed to copy target product code.");
+
+    pTargetProduct->context = context;
+    pTargetProduct->dwOrder = dwOrder;
+
+    *pdwTargetProductIndex = pPackage->Msp.cTargetProductCodes;
+    ++pPackage->Msp.cTargetProductCodes;
+
+LExit:
+    return hr;
+}
+
+static HRESULT AddMsiChainedPatch(
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_PACKAGE* pMspPackage,
+    __in DWORD dwMspTargetProductIndex,
+    __out DWORD* pdwChainedPatchIndex
+    )
+{
+    HRESULT hr = S_OK;
+
+    hr = MemEnsureArraySize(reinterpret_cast<LPVOID*>(&pPackage->Msi.rgChainedPatches), pPackage->Msi.cChainedPatches + 1, sizeof(BURN_CHAINED_PATCH), 5);
+    ExitOnFailure(hr, "Failed to ensure enough chained patches were allocated.");
+
+    BURN_CHAINED_PATCH* pChainedPatch = pPackage->Msi.rgChainedPatches + pPackage->Msi.cChainedPatches;
+    pChainedPatch->pMspPackage = pMspPackage;
+    pChainedPatch->dwMspTargetProductIndex = dwMspTargetProductIndex;
+
+    *pdwChainedPatchIndex = pPackage->Msi.cChainedPatches;
+    ++pPackage->Msi.cChainedPatches;
+LExit:
+    return hr;
+}
+
+static HRESULT DeterminePatchChainedTarget(
+    __in BURN_PACKAGES* pPackages,
+    __in BURN_PACKAGE* pMspPackage,
+    __in LPCWSTR wzTargetProductCode,
+    __in DWORD dwMspTargetProductIndex
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD dwChainedPatchIndex = 0;
+    BURN_MSPTARGETPRODUCT* pTargetProduct = pMspPackage->Msp.rgTargetProducts + dwMspTargetProductIndex;
+
+    for (DWORD iPackage = 0; iPackage < pPackages->cPackages; ++iPackage)
+    {
+        BURN_PACKAGE* pPackage = pPackages->rgPackages + iPackage;
+
+        if (BURN_PACKAGE_TYPE_MSI == pPackage->type && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, wzTargetProductCode, -1, pPackage->Msi.sczProductCode, -1))
+        {
+            pTargetProduct->pChainedTargetPackage = pPackage;
+
+            hr = AddMsiChainedPatch(pPackage, pMspPackage, dwMspTargetProductIndex, &dwChainedPatchIndex);
+            ExitOnFailure(hr, "Failed to add chained patch.");
+
+            for (DWORD j = 0; j < pPackage->Msi.cSlipstreamMspPackages; ++j)
+            {
+                BURN_SLIPSTREAM_MSP* pSlipstreamMsp = pPackage->Msi.rgSlipstreamMsps + j;
+                if (pSlipstreamMsp->pMspPackage == pMspPackage)
+                {
+                    AssertSz(BURN_PACKAGE_INVALID_PATCH_INDEX == pSlipstreamMsp->dwMsiChainedPatchIndex, "An MSP should only show up as a slipstreamed patch in an MSI once.");
+                    pTargetProduct->fSlipstream = TRUE;
+                    pSlipstreamMsp->dwMsiChainedPatchIndex = dwChainedPatchIndex;
+                    break;
+                }
+            }
+
+            break;
+        }
+    }
+
+LExit:
+    return hr;
+}
+
+static HRESULT PlanTargetProduct(
+    __in BOOTSTRAPPER_DISPLAY display,
+    __in BURN_USER_EXPERIENCE* pUserExperience,
+    __in BOOL fRollback,
+    __in BURN_PLAN* pPlan,
+    __in BURN_LOGGING* pLog,
+    __in BURN_VARIABLES* pVariables,
+    __in BOOTSTRAPPER_ACTION_STATE actionState,
+    __in BURN_PACKAGE* pPackage,
+    __in BURN_MSPTARGETPRODUCT* pTargetProduct,
+    __in_opt HANDLE hCacheEvent
+    )
+{
+    HRESULT hr = S_OK;
+    BURN_EXECUTE_ACTION* rgActions = fRollback ? pPlan->rgRollbackActions : pPlan->rgExecuteActions;
+    DWORD cActions = fRollback ? pPlan->cRollbackActions : pPlan->cExecuteActions;
+    BURN_EXECUTE_ACTION* pAction = NULL;
+    DWORD dwInsertSequence = 0;
+
+    // Try to find another MSP action with the exact same action (install or uninstall) targeting
+    // the same product in the same machine context (per-user or per-machine).
+    for (DWORD i = 0; i < cActions; ++i)
+    {
+        pAction = rgActions + i;
+
+        if (BURN_EXECUTE_ACTION_TYPE_MSP_TARGET == pAction->type &&
+            pAction->mspTarget.action == actionState &&
+            pAction->mspTarget.fPerMachineTarget == (MSIINSTALLCONTEXT_MACHINE == pTargetProduct->context) &&
+            CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1))
+        {
+            dwInsertSequence = i;
+            break;
+        }
+
+        pAction = NULL;
+    }
+
+    // If we didn't find an MSP target action already updating the product, create a new action.
+    if (!pAction)
+    {
+        if (fRollback)
+        {
+            hr = PlanAppendRollbackAction(pPlan, &pAction);
+        }
+        else
+        {
+            hr = PlanAppendExecuteAction(pPlan, &pAction);
+        }
+        ExitOnFailure(hr, "Failed to plan action for target product.");
+
+        pAction->type = BURN_EXECUTE_ACTION_TYPE_MSP_TARGET;
+        pAction->mspTarget.action = actionState;
+        pAction->mspTarget.pPackage = pPackage;
+        pAction->mspTarget.fPerMachineTarget = (MSIINSTALLCONTEXT_MACHINE == pTargetProduct->context);
+        pAction->mspTarget.pChainedTargetPackage = pTargetProduct->pChainedTargetPackage;
+        pAction->mspTarget.fSlipstream = pTargetProduct->fSlipstream;
+        hr = StrAllocString(&pAction->mspTarget.sczTargetProductCode, pTargetProduct->wzTargetProductCode, 0);
+        ExitOnFailure(hr, "Failed to copy target product code.");
+
+        hr = MsiEngineCalculateInstallUiLevel(display, pUserExperience, pPackage->sczId, !fRollback, pAction->mspTarget.action,
+            &pAction->mspTarget.actionMsiProperty, &pAction->mspTarget.uiLevel, &pAction->mspTarget.fDisableExternalUiHandler);
+        ExitOnFailure(hr, "Failed to get msp ui options.");
+
+        // If this is a per-machine target product, then the plan needs to be per-machine as well.
+        if (pAction->mspTarget.fPerMachineTarget)
+        {
+            pPlan->fPerMachine = TRUE;
+        }
+
+        LoggingSetPackageVariable(pPackage, pAction->mspTarget.sczTargetProductCode, fRollback, pLog, pVariables, &pAction->mspTarget.sczLogPath); // ignore errors.
+    }
+    else
+    {
+        if (!fRollback && hCacheEvent)
+        {
+            // Since a previouse MSP target action is being updated with the new MSP, 
+            // insert a wait syncpoint to before this action since we need to cache the current MSI before using it.
+            BURN_EXECUTE_ACTION* pWaitSyncPointAction = NULL;
+            hr = PlanInsertExecuteAction(dwInsertSequence, pPlan, &pWaitSyncPointAction);
+            ExitOnFailure(hr, "Failed to insert execute action.");
+
+            pWaitSyncPointAction->type = BURN_EXECUTE_ACTION_TYPE_WAIT_SYNCPOINT;
+            pWaitSyncPointAction->syncpoint.hEvent = hCacheEvent;
+
+            // Since we inserted an action before the MSP target action that we will be updating, need to update the pointer.
+            pAction = pPlan->rgExecuteActions + (dwInsertSequence + 1);
+        }
+    }
+
+    // Add our target product to the array and sort based on their order determined during detection.
+    hr = MemEnsureArraySize(reinterpret_cast<LPVOID*>(&pAction->mspTarget.rgOrderedPatches), pAction->mspTarget.cOrderedPatches + 1, sizeof(BURN_ORDERED_PATCHES), 2);
+    ExitOnFailure(hr, "Failed grow array of ordered patches.");
+
+    pAction->mspTarget.rgOrderedPatches[pAction->mspTarget.cOrderedPatches].pTargetProduct = pTargetProduct;
+    pAction->mspTarget.rgOrderedPatches[pAction->mspTarget.cOrderedPatches].pPackage = pPackage;
+    ++pAction->mspTarget.cOrderedPatches;
+
+    // Insertion sort to keep the patches ordered.
+    for (DWORD i = pAction->mspTarget.cOrderedPatches - 1; i > 0; --i)
+    {
+        if (pAction->mspTarget.rgOrderedPatches[i].pTargetProduct->dwOrder < pAction->mspTarget.rgOrderedPatches[i - 1].pTargetProduct->dwOrder)
+        {
+            BURN_ORDERED_PATCHES temp = pAction->mspTarget.rgOrderedPatches[i - 1];
+            pAction->mspTarget.rgOrderedPatches[i - 1] = pAction->mspTarget.rgOrderedPatches[i];
+            pAction->mspTarget.rgOrderedPatches[i] = temp;
+        }
+        else // no swap necessary, we're done.
+        {
+            break;
+        }
+    }
+
+LExit:
+    return hr;
+}