20 files changed, 94 insertions, 108 deletions

diff --git a/src/api/burn/WixToolset.BootstrapperCore.Native/inc/BootstrapperApplication.h b/src/api/burn/WixToolset.BootstrapperCore.Native/inc/BootstrapperApplication.h
index c2641b5f..4fbfc890 100644
--- a/src/api/burn/WixToolset.BootstrapperCore.Native/inc/BootstrapperApplication.h
+++ b/src/api/burn/WixToolset.BootstrapperCore.Native/inc/BootstrapperApplication.h
@@ -725,7 +725,6 @@ struct BA_ONDETECTRELATEDBUNDLE_ARGS
     LPCWSTR wzBundleTag;
     BOOL fPerMachine;
     LPCWSTR wzVersion;
-    BOOTSTRAPPER_RELATED_OPERATION operation;
     BOOL fMissingFromCache;
 };
 
diff --git a/src/api/burn/WixToolset.Mba.Core/BootstrapperApplication.cs b/src/api/burn/WixToolset.Mba.Core/BootstrapperApplication.cs
index b1fcaea4..34b63a50 100644
--- a/src/api/burn/WixToolset.Mba.Core/BootstrapperApplication.cs
+++ b/src/api/burn/WixToolset.Mba.Core/BootstrapperApplication.cs
@@ -1345,9 +1345,9 @@ namespace WixToolset.Mba.Core
             return args.HResult;
         }
 
-        int IBootstrapperApplication.OnDetectRelatedBundle(string wzProductCode, RelationType relationType, string wzBundleTag, bool fPerMachine, string wzVersion, RelatedOperation operation, bool fMissingFromCache, ref bool fCancel)
+        int IBootstrapperApplication.OnDetectRelatedBundle(string wzProductCode, RelationType relationType, string wzBundleTag, bool fPerMachine, string wzVersion, bool fMissingFromCache, ref bool fCancel)
         {
-            DetectRelatedBundleEventArgs args = new DetectRelatedBundleEventArgs(wzProductCode, relationType, wzBundleTag, fPerMachine, wzVersion, operation, fMissingFromCache, fCancel);
+            DetectRelatedBundleEventArgs args = new DetectRelatedBundleEventArgs(wzProductCode, relationType, wzBundleTag, fPerMachine, wzVersion, fMissingFromCache, fCancel);
             this.OnDetectRelatedBundle(args);
 
             fCancel = args.Cancel;
diff --git a/src/api/burn/WixToolset.Mba.Core/EventArgs.cs b/src/api/burn/WixToolset.Mba.Core/EventArgs.cs
index 65169b25..93831be6 100644
--- a/src/api/burn/WixToolset.Mba.Core/EventArgs.cs
+++ b/src/api/burn/WixToolset.Mba.Core/EventArgs.cs
@@ -434,7 +434,7 @@ namespace WixToolset.Mba.Core
     public class DetectRelatedBundleEventArgs : CancellableHResultEventArgs
     {
         /// <summary />
-        public DetectRelatedBundleEventArgs(string productCode, RelationType relationType, string bundleTag, bool perMachine, string version, RelatedOperation operation, bool missingFromCache, bool cancelRecommendation)
+        public DetectRelatedBundleEventArgs(string productCode, RelationType relationType, string bundleTag, bool perMachine, string version, bool missingFromCache, bool cancelRecommendation)
             : base(cancelRecommendation)
         {
             this.ProductCode = productCode;
@@ -442,7 +442,6 @@ namespace WixToolset.Mba.Core
             this.BundleTag = bundleTag;
             this.PerMachine = perMachine;
             this.Version = version;
-            this.Operation = operation;
             this.MissingFromCache = missingFromCache;
         }
 
@@ -472,11 +471,6 @@ namespace WixToolset.Mba.Core
         public string Version { get; private set; }
 
         /// <summary>
-        /// Gets the operation that will be taken on the detected bundle.
-        /// </summary>
-        public RelatedOperation Operation { get; private set; }
-
-        /// <summary>
         /// Whether the related bundle is missing from the package cache.
         /// </summary>
         public bool MissingFromCache { get; set; }
diff --git a/src/api/burn/WixToolset.Mba.Core/IBootstrapperApplication.cs b/src/api/burn/WixToolset.Mba.Core/IBootstrapperApplication.cs
index 3df54bde..babd523a 100644
--- a/src/api/burn/WixToolset.Mba.Core/IBootstrapperApplication.cs
+++ b/src/api/burn/WixToolset.Mba.Core/IBootstrapperApplication.cs
@@ -156,15 +156,6 @@ namespace WixToolset.Mba.Core
         /// <summary>
         /// See <see cref="IDefaultBootstrapperApplication.DetectRelatedBundle"/>.
         /// </summary>
-        /// <param name="wzBundleId"></param>
-        /// <param name="relationType"></param>
-        /// <param name="wzBundleTag"></param>
-        /// <param name="fPerMachine"></param>
-        /// <param name="wzVersion"></param>
-        /// <param name="operation"></param>
-        /// <param name="fMissingFromCache"></param>
-        /// <param name="fCancel"></param>
-        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectRelatedBundle(
@@ -173,7 +164,6 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.LPWStr)] string wzBundleTag,
             [MarshalAs(UnmanagedType.Bool)] bool fPerMachine,
             [MarshalAs(UnmanagedType.LPWStr)] string wzVersion,
-            [MarshalAs(UnmanagedType.U4)] RelatedOperation operation,
             [MarshalAs(UnmanagedType.Bool)] bool fMissingFromCache,
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
@@ -289,11 +279,6 @@ namespace WixToolset.Mba.Core
         /// <summary>
         /// See <see cref="IDefaultBootstrapperApplication.PlanRelatedBundle"/>.
         /// </summary>
-        /// <param name="wzBundleId"></param>
-        /// <param name="recommendedState"></param>
-        /// <param name="pRequestedState"></param>
-        /// <param name="fCancel"></param>
-        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanRelatedBundle(
diff --git a/src/api/burn/balutil/inc/BalBaseBAFunctions.h b/src/api/burn/balutil/inc/BalBaseBAFunctions.h
index 7f52f76e..22e16f1b 100644
--- a/src/api/burn/balutil/inc/BalBaseBAFunctions.h
+++ b/src/api/burn/balutil/inc/BalBaseBAFunctions.h
@@ -167,7 +167,6 @@ public: // IBootstrapperApplication
         __in_z LPCWSTR /*wzBundleTag*/,
         __in BOOL /*fPerMachine*/,
         __in LPCWSTR /*wzVersion*/,
-        __in BOOTSTRAPPER_RELATED_OPERATION /*operation*/,
         __in BOOL /*fMissingFromCache*/,
         __inout BOOL* /*pfCancel*/
         )
diff --git a/src/api/burn/balutil/inc/BalBaseBootstrapperApplication.h b/src/api/burn/balutil/inc/BalBaseBootstrapperApplication.h
index 5665fee3..631d3c62 100644
--- a/src/api/burn/balutil/inc/BalBaseBootstrapperApplication.h
+++ b/src/api/burn/balutil/inc/BalBaseBootstrapperApplication.h
@@ -172,7 +172,6 @@ public: // IBootstrapperApplication
         __in_z LPCWSTR /*wzBundleTag*/,
         __in BOOL /*fPerMachine*/,
         __in LPCWSTR /*wzVersion*/,
-        __in BOOTSTRAPPER_RELATED_OPERATION /*operation*/,
         __in BOOL /*fMissingFromCache*/,
         __inout BOOL* pfCancel
         )
diff --git a/src/api/burn/balutil/inc/BalBaseBootstrapperApplicationProc.h b/src/api/burn/balutil/inc/BalBaseBootstrapperApplicationProc.h
index 2292cd64..b9866e4b 100644
--- a/src/api/burn/balutil/inc/BalBaseBootstrapperApplicationProc.h
+++ b/src/api/burn/balutil/inc/BalBaseBootstrapperApplicationProc.h
@@ -114,7 +114,7 @@ static HRESULT BalBaseBAProcOnDetectRelatedBundle(
     __inout BA_ONDETECTRELATEDBUNDLE_RESULTS* pResults
     )
 {
-    return pBA->OnDetectRelatedBundle(pArgs->wzBundleId, pArgs->relationType, pArgs->wzBundleTag, pArgs->fPerMachine, pArgs->wzVersion, pArgs->operation, pArgs->fMissingFromCache, &pResults->fCancel);
+    return pBA->OnDetectRelatedBundle(pArgs->wzBundleId, pArgs->relationType, pArgs->wzBundleTag, pArgs->fPerMachine, pArgs->wzVersion, pArgs->fMissingFromCache, &pResults->fCancel);
 }
 
 static HRESULT BalBaseBAProcOnDetectPackageBegin(
diff --git a/src/api/burn/balutil/inc/IBootstrapperApplication.h b/src/api/burn/balutil/inc/IBootstrapperApplication.h
index 2ba1f503..577a705b 100644
--- a/src/api/burn/balutil/inc/IBootstrapperApplication.h
+++ b/src/api/burn/balutil/inc/IBootstrapperApplication.h
@@ -91,7 +91,6 @@ DECLARE_INTERFACE_IID_(IBootstrapperApplication, IUnknown, "53C31D56-49C0-426B-A
         __in_z LPCWSTR wzBundleTag,
         __in BOOL fPerMachine,
         __in_z LPCWSTR wzVersion,
-        __in BOOTSTRAPPER_RELATED_OPERATION operation,
         __in BOOL fMissingFromCache,
         __inout BOOL* pfCancel
         ) = 0;
diff --git a/src/burn/engine/core.cpp b/src/burn/engine/core.cpp
index 96845655..30c64b01 100644
--- a/src/burn/engine/core.cpp
+++ b/src/burn/engine/core.cpp
@@ -359,7 +359,7 @@ extern "C" HRESULT CoreDetect(
     ExitOnFailure(hr, "Failed to detect provider key bundle id.");
 
     // Report the related bundles.
-    hr = DetectReportRelatedBundles(&pEngineState->userExperience, &pEngineState->registration, pEngineState->command.relationType, pEngineState->command.action, &pEngineState->registration.fEligibleForCleanup);
+    hr = DetectReportRelatedBundles(&pEngineState->userExperience, &pEngineState->registration, pEngineState->command.relationType, &pEngineState->registration.fEligibleForCleanup);
     ExitOnFailure(hr, "Failed to report detected related bundles.");
 
     // Do update detection.
diff --git a/src/burn/engine/detect.cpp b/src/burn/engine/detect.cpp
index 4eda240e..be828366 100644
--- a/src/burn/engine/detect.cpp
+++ b/src/burn/engine/detect.cpp
@@ -154,68 +154,20 @@ extern "C" HRESULT DetectReportRelatedBundles(
     __in BURN_USER_EXPERIENCE* pUX,
     __in BURN_REGISTRATION* pRegistration,
     __in BOOTSTRAPPER_RELATION_TYPE relationType,
-    __in BOOTSTRAPPER_ACTION action,
     __out BOOL* pfEligibleForCleanup
     )
 {
     HRESULT hr = S_OK;
-    int nCompareResult = 0;
     BOOTSTRAPPER_REQUEST_STATE uninstallRequestState = BOOTSTRAPPER_REQUEST_STATE_NONE;
     *pfEligibleForCleanup = pRegistration->fInstalled || pRegistration->fCached;
 
     for (DWORD iRelatedBundle = 0; iRelatedBundle < pRegistration->relatedBundles.cRelatedBundles; ++iRelatedBundle)
     {
         const BURN_RELATED_BUNDLE* pRelatedBundle = pRegistration->relatedBundles.rgRelatedBundles + iRelatedBundle;
-        BOOTSTRAPPER_RELATED_OPERATION operation = BOOTSTRAPPER_RELATED_OPERATION_NONE;
-
-        switch (pRelatedBundle->relationType)
-        {
-        case BOOTSTRAPPER_RELATION_UPGRADE:
-            if (BOOTSTRAPPER_RELATION_UPGRADE != relationType && BOOTSTRAPPER_ACTION_UNINSTALL < action)
-            {
-                hr = VerCompareParsedVersions(pRegistration->pVersion, pRelatedBundle->pVersion, &nCompareResult);
-                ExitOnFailure(hr, "Failed to compare bundle version '%ls' to related bundle version '%ls'", pRegistration->pVersion->sczVersion, pRelatedBundle->pVersion->sczVersion);
-
-                if (nCompareResult < 0)
-                {
-                    operation = BOOTSTRAPPER_RELATED_OPERATION_DOWNGRADE;
-                }
-                else
-                {
-                    operation = BOOTSTRAPPER_RELATED_OPERATION_MAJOR_UPGRADE;
-                }
-            }
-            break;
-
-        case BOOTSTRAPPER_RELATION_PATCH: __fallthrough;
-        case BOOTSTRAPPER_RELATION_ADDON:
-            if (BOOTSTRAPPER_ACTION_UNINSTALL == action)
-            {
-                operation = BOOTSTRAPPER_RELATED_OPERATION_REMOVE;
-            }
-            else if (BOOTSTRAPPER_ACTION_INSTALL == action || BOOTSTRAPPER_ACTION_MODIFY == action)
-            {
-                operation = BOOTSTRAPPER_RELATED_OPERATION_INSTALL;
-            }
-            else if (BOOTSTRAPPER_ACTION_REPAIR == action)
-            {
-                operation = BOOTSTRAPPER_RELATED_OPERATION_REPAIR;
-            }
-            break;
-
-        case BOOTSTRAPPER_RELATION_DETECT: __fallthrough;
-        case BOOTSTRAPPER_RELATION_DEPENDENT:
-            break;
-
-        default:
-            hr = E_FAIL;
-            ExitOnRootFailure(hr, "Unexpected relation type encountered: %d", pRelatedBundle->relationType);
-            break;
-        }
 
-        LogId(REPORT_STANDARD, MSG_DETECTED_RELATED_BUNDLE, pRelatedBundle->package.sczId, LoggingRelationTypeToString(pRelatedBundle->relationType), LoggingPerMachineToString(pRelatedBundle->package.fPerMachine), pRelatedBundle->pVersion->sczVersion, LoggingRelatedOperationToString(operation), LoggingBoolToString(pRelatedBundle->package.fCached));
+        LogId(REPORT_STANDARD, MSG_DETECTED_RELATED_BUNDLE, pRelatedBundle->package.sczId, LoggingRelationTypeToString(pRelatedBundle->relationType), LoggingPerMachineToString(pRelatedBundle->package.fPerMachine), pRelatedBundle->pVersion->sczVersion, LoggingBoolToString(pRelatedBundle->package.fCached));
 
-        hr = UserExperienceOnDetectRelatedBundle(pUX, pRelatedBundle->package.sczId, pRelatedBundle->relationType, pRelatedBundle->sczTag, pRelatedBundle->package.fPerMachine, pRelatedBundle->pVersion, operation, !pRelatedBundle->package.fCached);
+        hr = UserExperienceOnDetectRelatedBundle(pUX, pRelatedBundle->package.sczId, pRelatedBundle->relationType, pRelatedBundle->sczTag, pRelatedBundle->package.fPerMachine, pRelatedBundle->pVersion, !pRelatedBundle->package.fCached);
         ExitOnRootFailure(hr, "BA aborted detect related bundle.");
 
         // For now, if any related bundles will be executed during uninstall by default then never automatically clean up the bundle.
diff --git a/src/burn/engine/detect.h b/src/burn/engine/detect.h
index 9bc34882..cdca2777 100644
--- a/src/burn/engine/detect.h
+++ b/src/burn/engine/detect.h
@@ -29,7 +29,6 @@ HRESULT DetectReportRelatedBundles(
     __in BURN_USER_EXPERIENCE* pUX,
     __in BURN_REGISTRATION* pRegistration,
     __in BOOTSTRAPPER_RELATION_TYPE relationType,
-    __in BOOTSTRAPPER_ACTION action,
     __out BOOL* pfEligibleForCleanup
     );
 
diff --git a/src/burn/engine/engine.mc b/src/burn/engine/engine.mc
index dde4d40b..5c1b0b69 100644
--- a/src/burn/engine/engine.mc
+++ b/src/burn/engine/engine.mc
@@ -223,7 +223,7 @@ MessageId=102
 Severity=Success
 SymbolicName=MSG_DETECTED_RELATED_BUNDLE
 Language=English
-Detected related bundle: %1!ls!, type: %2!hs!, scope: %3!hs!, version: %4!ls!, operation: %5!hs!, cached: %6!hs!
+Detected related bundle: %1!ls!, type: %2!hs!, scope: %3!hs!, version: %4!ls!, cached: %5!hs!
 .
 
 MessageId=103
diff --git a/src/burn/engine/userexperience.cpp b/src/burn/engine/userexperience.cpp
index ee22a318..6ea16905 100644
--- a/src/burn/engine/userexperience.cpp
+++ b/src/burn/engine/userexperience.cpp
@@ -104,7 +104,7 @@ extern "C" HRESULT UserExperienceLoad(
     args.pCommand = pCommand;
     args.pfnBootstrapperEngineProc = EngineForApplicationProc;
     args.pvBootstrapperEngineProcContext = pEngineContext;
-    args.qwEngineAPIVersion = MAKEQWORDVERSION(2021, 12, 7, 0);
+    args.qwEngineAPIVersion = MAKEQWORDVERSION(2021, 12, 30, 0);
 
     results.cbSize = sizeof(BOOTSTRAPPER_CREATE_RESULTS);
 
@@ -1164,7 +1164,6 @@ EXTERN_C BAAPI UserExperienceOnDetectRelatedBundle(
     __in_z LPCWSTR wzBundleTag,
     __in BOOL fPerMachine,
     __in VERUTIL_VERSION* pVersion,
-    __in BOOTSTRAPPER_RELATED_OPERATION operation,
     __in BOOL fMissingFromCache
     )
 {
@@ -1178,7 +1177,6 @@ EXTERN_C BAAPI UserExperienceOnDetectRelatedBundle(
     args.wzBundleTag = wzBundleTag;
     args.fPerMachine = fPerMachine;
     args.wzVersion = pVersion->sczVersion;
-    args.operation = operation;
     args.fMissingFromCache = fMissingFromCache;
 
     results.cbSize = sizeof(results);
diff --git a/src/burn/engine/userexperience.h b/src/burn/engine/userexperience.h
index 27d0a1e3..e4c5d3ee 100644
--- a/src/burn/engine/userexperience.h
+++ b/src/burn/engine/userexperience.h
@@ -286,7 +286,6 @@ BAAPI UserExperienceOnDetectRelatedBundle(
     __in_z LPCWSTR wzBundleTag,
     __in BOOL fPerMachine,
     __in VERUTIL_VERSION* pVersion,
-    __in BOOTSTRAPPER_RELATED_OPERATION operation,
     __in BOOL fMissingFromCache
     );
 BAAPI UserExperienceOnDetectRelatedMsiPackage(
diff --git a/src/ext/Bal/wixstdba/WixStandardBootstrapperApplication.cpp b/src/ext/Bal/wixstdba/WixStandardBootstrapperApplication.cpp
index ec3c268a..7b70d772 100644
--- a/src/ext/Bal/wixstdba/WixStandardBootstrapperApplication.cpp
+++ b/src/ext/Bal/wixstdba/WixStandardBootstrapperApplication.cpp
@@ -246,12 +246,12 @@ public: // IBootstrapperApplication
         __in LPCWSTR wzBundleTag,
         __in BOOL fPerMachine,
         __in LPCWSTR wzVersion,
-        __in BOOTSTRAPPER_RELATED_OPERATION operation,
         __in BOOL fMissingFromCache,
         __inout BOOL* pfCancel
         )
     {
         BAL_INFO_PACKAGE* pPackage = NULL;
+        int nCompare = 0;
 
         if (!fMissingFromCache)
         {
@@ -261,14 +261,15 @@ public: // IBootstrapperApplication
             }
 
             // If we're not doing a prerequisite install, remember when our bundle would cause a downgrade.
-            if (!m_fPrereq && BOOTSTRAPPER_RELATED_OPERATION_DOWNGRADE == operation)
+            if (!m_fPrereq && BOOTSTRAPPER_RELATION_UPGRADE == relationType &&
+                SUCCEEDED(m_pEngine->CompareVersions(m_sczBundleVersion, wzVersion, &nCompare)) && 0 > nCompare)
             {
                 BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "A newer version (v%ls) of this product is installed.", wzVersion);
                 m_fDowngrading = TRUE;
             }
         }
 
-        return CBalBaseBootstrapperApplication::OnDetectRelatedBundle(wzBundleId, relationType, wzBundleTag, fPerMachine, wzVersion, operation, fMissingFromCache, pfCancel);
+        return CBalBaseBootstrapperApplication::OnDetectRelatedBundle(wzBundleId, relationType, wzBundleTag, fPerMachine, wzVersion, fMissingFromCache, pfCancel);
     }
 
 
@@ -2091,7 +2092,8 @@ public: //CBalBaseBootstrapperApplication
             }
         }
 
-        hr = S_OK;
+        hr = BalGetStringVariable(L"WixBundleVersion", &m_sczBundleVersion);
+        BalExitOnFailure(hr, "CWixStandardBootstrapperApplication initialization failed.");
 
     LExit:
         return hr;
@@ -4129,6 +4131,7 @@ public:
         m_plannedAction = BOOTSTRAPPER_ACTION_UNKNOWN;
 
         m_sczAfterForcedRestartPackage = NULL;
+        m_sczBundleVersion = NULL;
 
         m_pWixLoc = NULL;
         m_Bundle = { };
@@ -4367,6 +4370,7 @@ public:
         ReleaseStr(m_sczLanguage);
         ReleaseStr(m_sczLicenseFile);
         ReleaseStr(m_sczLicenseUrl);
+        ReleaseStr(m_sczBundleVersion);
         ReleaseStr(m_sczAfterForcedRestartPackage);
         ReleaseNullObject(m_pEngine);
 
@@ -4391,6 +4395,7 @@ private:
     BOOTSTRAPPER_ACTION m_plannedAction;
 
     LPWSTR m_sczAfterForcedRestartPackage;
+    LPWSTR m_sczBundleVersion;
 
     WIX_LOCALIZATION* m_pWixLoc;
     BAL_INFO_BUNDLE m_Bundle;
diff --git a/src/test/burn/TestData/WixStdBaTests/BundleA_v10/BundleA_v10.wixproj b/src/test/burn/TestData/WixStdBaTests/BundleA_v10/BundleA_v10.wixproj
new file mode 100644
index 00000000..602dc4bc
--- /dev/null
+++ b/src/test/burn/TestData/WixStdBaTests/BundleA_v10/BundleA_v10.wixproj
@@ -0,0 +1,20 @@
+<!-- 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. -->
+<Project Sdk="WixToolset.Sdk">
+  <PropertyGroup>
+    <OutputType>Bundle</OutputType>
+    <BA>hyperlinkLicense</BA>
+    <UpgradeCode>{7D977157-06C9-4176-A931-AC16E18AAB51}</UpgradeCode>
+    <DefineConstants>$(DefineConstants);Version=1.0</DefineConstants>
+    <OutputName>WixStdBaTest1_v10</OutputName>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="..\..\Templates\Bundle.wxs" Link="Bundle.wxs" />
+    <Compile Include="..\BundleA\BundleA.wxs" Link="BundleA.wxs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\PackageA\PackageA.wixproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="WixToolset.Bal.wixext" />
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/src/test/burn/WixToolset.WixBA/InstallationViewModel.cs b/src/test/burn/WixToolset.WixBA/InstallationViewModel.cs
index 1846d51b..e056b943 100644
--- a/src/test/burn/WixToolset.WixBA/InstallationViewModel.cs
+++ b/src/test/burn/WixToolset.WixBA/InstallationViewModel.cs
@@ -19,6 +19,18 @@ namespace WixToolset.WixBA
     {
         Absent,
         Present,
+    }
+
+    /// <summary>
+    /// The states of upgrade detection.
+    /// </summary>
+    public enum UpgradeDetectionState
+    {
+        // There are no Upgrade related bundles installed.
+        None,
+        // All Upgrade related bundles that are installed are older than or the same version as this bundle.
+        Older,
+        // At least one Upgrade related bundle is installed that is newer than this bundle.
         Newer,
     }
 
@@ -90,7 +102,7 @@ namespace WixToolset.WixBA
 
         void RootPropertyChanged(object sender, PropertyChangedEventArgs e)
         {
-            if (("DetectState" == e.PropertyName) || ("InstallState" == e.PropertyName))
+            if (("DetectState" == e.PropertyName) || ("UpgradeDetectState" == e.PropertyName) || ("InstallState" == e.PropertyName))
             {
                 base.OnPropertyChanged("RepairEnabled");
                 base.OnPropertyChanged("InstallEnabled");
@@ -276,7 +288,9 @@ namespace WixToolset.WixBA
             {
                 if (this.installCommand == null)
                 {
-                    this.installCommand = new RelayCommand(param => WixBA.Plan(LaunchAction.Install), param => this.root.DetectState == DetectionState.Absent && this.root.InstallState == InstallationState.Waiting);
+                    this.installCommand = new RelayCommand(
+                        param => WixBA.Plan(LaunchAction.Install),
+                        param => this.root.DetectState == DetectionState.Absent && this.root.UpgradeDetectState != UpgradeDetectionState.Newer && this.root.InstallState == InstallationState.Waiting);
                 }
 
                 return this.installCommand;
@@ -399,9 +413,19 @@ namespace WixToolset.WixBA
 
         private void DetectedRelatedBundle(object sender, DetectRelatedBundleEventArgs e)
         {
-            if (e.Operation == RelatedOperation.Downgrade)
+            if (e.RelationType == RelationType.Upgrade)
             {
-                this.Downgrade = true;
+                if (WixBA.Model.Engine.CompareVersions(this.Version, e.Version) > 0)
+                {
+                    if (this.root.UpgradeDetectState == UpgradeDetectionState.None)
+                    {
+                        this.root.UpgradeDetectState = UpgradeDetectionState.Older;
+                    }
+                }
+                else
+                {
+                    this.root.UpgradeDetectState = UpgradeDetectionState.Newer;
+                }
             }
 
             if (!WixBA.Model.BAManifest.Bundle.Packages.ContainsKey(e.ProductCode))
@@ -432,19 +456,10 @@ namespace WixToolset.WixBA
             }
             else if (Hresult.Succeeded(e.Status))
             {
-                if (this.Downgrade)
+                if (this.root.UpgradeDetectState == UpgradeDetectionState.Newer)
                 {
-                    this.root.DetectState = DetectionState.Newer;
-                    var relatedPackages = WixBA.Model.BAManifest.Bundle.Packages.Values.Where(p => p.Type == PackageType.UpgradeBundle);
-                    var installedVersion = relatedPackages.Any() ? new Version(relatedPackages.Max(p => p.Version)) : null;
-                    if (installedVersion != null && installedVersion < new Version(4, 1) && installedVersion.Build > 10)
-                    {
-                        this.DowngradeMessage = "You must uninstall WiX v" + installedVersion + " before you can install this.";
-                    }
-                    else
-                    {
-                        this.DowngradeMessage = "There is already a newer version of WiX installed on this machine.";
-                    }
+                    this.Downgrade = true;
+                    this.DowngradeMessage = "There is already a newer version of WiX installed on this machine.";
                 }
 
                 if (LaunchAction.Layout == WixBA.Model.Command.Action)
diff --git a/src/test/burn/WixToolset.WixBA/RootViewModel.cs b/src/test/burn/WixToolset.WixBA/RootViewModel.cs
index 8cff7274..2dfd214e 100644
--- a/src/test/burn/WixToolset.WixBA/RootViewModel.cs
+++ b/src/test/burn/WixToolset.WixBA/RootViewModel.cs
@@ -27,6 +27,7 @@ namespace WixToolset.WixBA
         private bool canceled;
         private InstallationState installState;
         private DetectionState detectState;
+        private UpgradeDetectionState upgradeDetectState;
 
         /// <summary>
         /// Creates a new model of the root view.
@@ -120,6 +121,28 @@ namespace WixToolset.WixBA
         }
 
         /// <summary>
+        /// Gets and sets the upgrade detect state of the view's model.
+        /// </summary>
+        public UpgradeDetectionState UpgradeDetectState
+        {
+            get
+            {
+                return this.upgradeDetectState;
+            }
+
+            set
+            {
+                if (this.upgradeDetectState != value)
+                {
+                    this.upgradeDetectState = value;
+
+                    // Notify all the properties derived from the state that the state changed.
+                    base.OnPropertyChanged("UpgradeDetectState");
+                }
+            }
+        }
+
+        /// <summary>
         /// Gets and sets the installation state of the view's model.
         /// </summary>
         public InstallationState InstallState
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/DependencyTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/DependencyTests.cs
index e2975fc9..309241d9 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/DependencyTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/DependencyTests.cs
@@ -596,7 +596,7 @@ namespace WixToolsetTest.BurnE2E
             packageDv2.VerifyInstalled(true);
 
             Assert.True(LogVerifier.MessageInLogFileRegex(bundleHv2InstallLogFilePath, @"Skipping cross-scope dependency registration on package: PackageA, bundle scope: PerUser, package scope: PerMachine"));
-            Assert.True(LogVerifier.MessageInLogFileRegex(bundleHv2InstallLogFilePath, @"Detected related bundle: \{[0-9A-Za-z\-]{36}\}, type: Upgrade, scope: PerUser, version: 1\.0\.0\.0, operation: MajorUpgrade, cached: Yes"));
+            Assert.True(LogVerifier.MessageInLogFileRegex(bundleHv2InstallLogFilePath, @"Detected related bundle: \{[0-9A-Za-z\-]{36}\}, type: Upgrade, scope: PerUser, version: 1\.0\.0\.0, cached: Yes"));
 
             bundleHv2.Uninstall();
             bundleHv2.VerifyUnregisteredAndRemovedFromPackageCache();
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/UpgradeRelatedBundleTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/UpgradeRelatedBundleTests.cs
index 70c0c474..35cc64f0 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/UpgradeRelatedBundleTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/UpgradeRelatedBundleTests.cs
@@ -30,7 +30,7 @@ namespace WixToolsetTest.BurnE2E
             bundleAv2.VerifyRegisteredAndInPackageCache();
 
             Assert.True(LogVerifier.MessageInLogFileRegex(bundleAv2InstallLogFilePath, @"OnDetectRelatedBundle\(\) - id: \{[0-9A-Za-z\-]{36}\}, missing from cache: True"));
-            Assert.True(LogVerifier.MessageInLogFileRegex(bundleAv2InstallLogFilePath, @"Detected related bundle: \{[0-9A-Za-z\-]{36}\}, type: Upgrade, scope: PerMachine, version: 1\.0\.0\.0, operation: MajorUpgrade, cached: No"));
+            Assert.True(LogVerifier.MessageInLogFileRegex(bundleAv2InstallLogFilePath, @"Detected related bundle: \{[0-9A-Za-z\-]{36}\}, type: Upgrade, scope: PerMachine, version: 1\.0\.0\.0, cached: No"));
         }
     }
 }