Enhance bundle backend validation.

26 files changed, 926 insertions, 278 deletions

diff --git a/src/api/wix/WixToolset.Data/ErrorMessages.cs b/src/api/wix/WixToolset.Data/ErrorMessages.cs
index 80738f5e..a833452d 100644
--- a/src/api/wix/WixToolset.Data/ErrorMessages.cs
+++ b/src/api/wix/WixToolset.Data/ErrorMessages.cs
@@ -1184,6 +1184,11 @@ namespace WixToolset.Data
             return Message(null, Ids.InvalidCommandLineFileName, "Invalid file name specified on the command line: '{0}'. Error message: '{1}'", fileName, error);
         }
 
+        public static Message InvalidBundleCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition)
+        {
+            return Message(sourceLineNumbers, Ids.InvalidBundleCondition, "The {0}/@{1} attribute's value '{2}' is not a valid bundle condition.", elementName, attributeName, condition);
+        }
+
         public static Message InvalidDateTimeFormat(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string value)
         {
             return Message(sourceLineNumbers, Ids.InvalidDateTimeFormat, "The {0}/@{1} attribute's value '{2}' is not a valid date/time value. A date/time value should follow the format YYYY-MM-DDTHH:mm:ss.", elementName, attributeName, value);
@@ -2686,6 +2691,7 @@ namespace WixToolset.Data
             MultiplePackagePayloads3 = 406,
             MissingPackagePayload = 407,
             ExpectedAttributeWithoutOtherAttributes = 408,
+            InvalidBundleCondition = 409,
         }
     }
 }
diff --git a/src/api/wix/WixToolset.Data/WarningMessages.cs b/src/api/wix/WixToolset.Data/WarningMessages.cs
index b749bcf4..f555fd93 100644
--- a/src/api/wix/WixToolset.Data/WarningMessages.cs
+++ b/src/api/wix/WixToolset.Data/WarningMessages.cs
@@ -593,6 +593,11 @@ namespace WixToolset.Data
             return Message(null, Ids.UnableToResetAcls, "Unable to reset acls on destination files. Exception detail: {0}", error);
         }
 
+        public static Message UnavailableBundleConditionVariable(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string variable, string illegalValueList)
+        {
+            return Message(sourceLineNumbers, Ids.UnavailableBundleConditionVariable, "{0}/@{1} contains the built-in Variable '{2}', which is not available when it is evaluated. (Unavailable Variables are: {3}.). Rewrite the condition to avoid Variables that are never valid during its evaluation.", elementName, attributeName, variable, illegalValueList);
+        }
+
         public static Message UnclearShortcut(SourceLineNumber sourceLineNumbers, string shortcutId, string fileId, string componentId)
         {
             return Message(sourceLineNumbers, Ids.UnclearShortcut, "Because it is an advertised shortcut, the target of shortcut '{0}' will be the keypath of component '{2}' rather than parent file '{1}'. To eliminate this warning, you can (1) make the Shortcut element a child of the File element that is the keypath of component '{2}', (2) make file '{1}' the keypath of component '{2}', or (3) remove the @Advertise attribute so the shortcut is a non-advertised shortcut.", shortcutId, fileId, componentId);
@@ -804,6 +809,7 @@ namespace WixToolset.Data
             DetectConditionRecommended = 1153,
             CollidingModularizationTypes = 1156,
             InvalidEnvironmentVariable = 1157,
+            UnavailableBundleConditionVariable = 1159,
         }
     }
 }
diff --git a/src/api/wix/WixToolset.Extensibility/Data/BundleConditionPhase.cs b/src/api/wix/WixToolset.Extensibility/Data/BundleConditionPhase.cs
new file mode 100644
index 00000000..6d876bcc
--- /dev/null
+++ b/src/api/wix/WixToolset.Extensibility/Data/BundleConditionPhase.cs
@@ -0,0 +1,35 @@
+// 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.Extensibility.Data
+{
+    /// <summary>
+    /// The Burn execution phase during which a Condition will be evaluated.
+    /// </summary>
+    public enum BundleConditionPhase
+    {
+        /// <summary>
+        /// Condition is evaluated by the engine before loading the BootstrapperApplication (Bundle/@Condition).
+        /// </summary>
+        Startup,
+
+        /// <summary>
+        /// Condition is evaluated during Detect (ExePackage/@DetectCondition).
+        /// </summary>
+        Detect,
+
+        /// <summary>
+        /// Condition is evaluated during Plan (ExePackage/@InstallCondition).
+        /// </summary>
+        Plan,
+
+        /// <summary>
+        /// Condition is evaluated during Apply (MsiProperty/@Condition).
+        /// </summary>
+        Execute,
+
+        /// <summary>
+        /// Condition is evaluated after Apply.
+        /// </summary>
+        Shutdown,
+    }
+}
diff --git a/src/api/wix/WixToolset.Extensibility/Services/IBackendHelper.cs b/src/api/wix/WixToolset.Extensibility/Services/IBackendHelper.cs
index 29b8f8e6..23ad44f5 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IBackendHelper.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IBackendHelper.cs
@@ -74,17 +74,6 @@ namespace WixToolset.Extensibility.Services
         string GenerateIdentifier(string prefix, params string[] args);
 
         /// <summary>
-        /// Validates path is relative and canonicalizes it.
-        /// For example, "a\..\c\.\d.exe" => "c\d.exe".
-        /// </summary>
-        /// <param name="sourceLineNumbers"></param>
-        /// <param name="elementName"></param>
-        /// <param name="attributeName"></param>
-        /// <param name="relativePath"></param>
-        /// <returns>The original value if not relative, otherwise the canonicalized relative path.</returns>
-        string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath);
-
-        /// <summary>
         /// Gets a valid code page from the given web name or integer value.
         /// </summary>
         /// <param name="value">A code page web name or integer value as a string.</param>
diff --git a/src/api/wix/WixToolset.Extensibility/Services/IBundleValidator.cs b/src/api/wix/WixToolset.Extensibility/Services/IBundleValidator.cs
new file mode 100644
index 00000000..fc88a443
--- /dev/null
+++ b/src/api/wix/WixToolset.Extensibility/Services/IBundleValidator.cs
@@ -0,0 +1,56 @@
+// 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.Extensibility.Services
+{
+    using WixToolset.Data;
+    using WixToolset.Extensibility.Data;
+
+    /// <summary>
+    /// Interface provided to help with bundle validation.
+    /// </summary>
+    public interface IBundleValidator
+    {
+
+        /// <summary>
+        /// Validates path is relative and canonicalizes it.
+        /// For example, "a\..\c\.\d.exe" => "c\d.exe".
+        /// </summary>
+        /// <param name="sourceLineNumbers"></param>
+        /// <param name="elementName"></param>
+        /// <param name="attributeName"></param>
+        /// <param name="relativePath"></param>
+        /// <returns>The original value if not relative, otherwise the canonicalized relative path.</returns>
+        string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath);
+
+        /// <summary>
+        /// Validates an MsiProperty name value and displays an error for an illegal value.
+        /// </summary>
+        /// <param name="sourceLineNumbers"></param>
+        /// <param name="elementName"></param>
+        /// <param name="attributeName"></param>
+        /// <param name="propertyName"></param>
+        /// <returns>Whether the name is valid.</returns>
+        bool ValidateBundleMsiPropertyName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string propertyName);
+
+        /// <summary>
+        /// Validates a Bundle variable name and displays an error for an illegal value.
+        /// </summary>
+        /// <param name="sourceLineNumbers"></param>
+        /// <param name="elementName"></param>
+        /// <param name="attributeName"></param>
+        /// <param name="variableName"></param>
+        /// <returns>Whether the name is valid.</returns>
+        bool ValidateBundleVariableName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string variableName);
+
+        /// <summary>
+        /// Validates a bundle condition and displays an error for an illegal value.
+        /// </summary>
+        /// <param name="sourceLineNumbers"></param>
+        /// <param name="elementName"></param>
+        /// <param name="attributeName"></param>
+        /// <param name="condition"></param>
+        /// <param name="phase"></param>
+        /// <returns>Whether the condition is valid.</returns>
+        bool ValidateBundleCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition, BundleConditionPhase phase);
+    }
+}
diff --git a/src/api/wix/WixToolset.Extensibility/Services/IBurnBackendHelper.cs b/src/api/wix/WixToolset.Extensibility/Services/IBurnBackendHelper.cs
index ef5fcc65..1b6a2828 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IBurnBackendHelper.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IBurnBackendHelper.cs
@@ -7,7 +7,7 @@ namespace WixToolset.Extensibility.Services
     /// <summary>
     /// Interface provided to help Burn backend extensions.
     /// </summary>
-    public interface IBurnBackendHelper : IBackendHelper
+    public interface IBurnBackendHelper : IBackendHelper, IBundleValidator
     {
         /// <summary>
         /// Adds the given XML to the BootstrapperApplicationData manifest.
diff --git a/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs b/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
index fbe5aae4..de2c6f9f 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
@@ -13,7 +13,7 @@ namespace WixToolset.Extensibility.Services
     /// <summary>
     /// Interface provided to help compiler extensions parse.
     /// </summary>
-    public interface IParseHelper
+    public interface IParseHelper : IBundleValidator
     {
         /// <summary>
         /// Creates a version 3 name-based UUID.
@@ -323,17 +323,6 @@ namespace WixToolset.Extensibility.Services
         YesNoDefaultType GetAttributeYesNoDefaultValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
 
         /// <summary>
-        /// Validates path is relative and canonicalizes it.
-        /// For example, "a\..\c\.\d.exe" => "c\d.exe".
-        /// </summary>
-        /// <param name="sourceLineNumbers"></param>
-        /// <param name="elementName"></param>
-        /// <param name="attributeName"></param>
-        /// <param name="relativePath"></param>
-        /// <returns>The original value if not relative, otherwise the canonicalized relative path.</returns>
-        string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath);
-
-        /// <summary>
         /// Gets a source line number for an element.
         /// </summary>
         /// <param name="element">Element to get source line number.</param>
diff --git a/src/burn/test/BurnUnitTest/VariableTest.cpp b/src/burn/test/BurnUnitTest/VariableTest.cpp
index 53105e69..d0361c0e 100644
--- a/src/burn/test/BurnUnitTest/VariableTest.cpp
+++ b/src/burn/test/BurnUnitTest/VariableTest.cpp
@@ -381,6 +381,7 @@ namespace Bootstrapper
                 Assert::True(EvaluateConditionHelper(&variables, L"(PROP3 = \"NOT\" OR PROP1 = \"VAL1\") AND PROP2 = \"VAL2\""));
                 Assert::True(EvaluateConditionHelper(&variables, L"PROP3 = \"NOT\" OR (PROP1 = \"VAL1\" AND PROP2 = \"VAL2\")"));
 
+                Assert::True(EvaluateFailureConditionHelper(&variables, L""));
                 Assert::True(EvaluateFailureConditionHelper(&variables, L"="));
                 Assert::True(EvaluateFailureConditionHelper(&variables, L"(PROP1"));
                 Assert::True(EvaluateFailureConditionHelper(&variables, L"(PROP1 = \""));
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs b/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
index ef4ee49a..9aea8c1d 100644
--- a/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
@@ -2,6 +2,7 @@
 
 namespace WixToolsetTest.Bal
 {
+    using System;
     using System.IO;
     using System.Linq;
     using System.Xml;
@@ -138,20 +139,33 @@ namespace WixToolsetTest.Bal
             {
                 var baseFolder = fs.GetFolder();
                 var bundleFile = Path.Combine(baseFolder, "bin", "test.exe");
-                var bundleSourceFolder = TestData.Get(@"TestData\Overridable");
+                var bundleSourceFolder = TestData.Get(@"TestData");
                 var intermediateFolder = Path.Combine(baseFolder, "obj");
                 var baFolderPath = Path.Combine(baseFolder, "ba");
                 var extractFolderPath = Path.Combine(baseFolder, "extract");
 
-                var compileResult = WixRunner.Execute(new[]
+                var result = WixRunner.Execute(new[]
                 {
                     "build",
-                    Path.Combine(bundleSourceFolder, "WrongCaseBundle.wxs"),
+                    Path.Combine(bundleSourceFolder, "Overridable", "WrongCaseBundle.wxs"),
+                    "-loc", Path.Combine(bundleSourceFolder, "Overridable", "WrongCaseBundle.wxl"),
+                    "-bindpath", Path.Combine(bundleSourceFolder, "WixStdBa", "Data"),
                     "-ext", TestData.Get(@"WixToolset.Bal.wixext.dll"),
                     "-intermediateFolder", intermediateFolder,
                     "-o", bundleFile,
                 });
-                Assert.Equal((int)BalErrors.Ids.NonUpperCaseOverridableVariable, compileResult.ExitCode);
+
+                Assert.InRange(result.ExitCode, 2, Int32.MaxValue);
+
+                var messages = result.Messages.Select(m => m.ToString()).ToList();
+                messages.Sort();
+
+                WixAssert.CompareLineByLine(new[]
+                {
+                    "bal:Condition/@Condition contains the built-in Variable 'WixBundleAction', which is not available when it is evaluated. (Unavailable Variables are: 'WixBundleAction'.). Rewrite the condition to avoid Variables that are never valid during its evaluation.",
+                    "Overridable variable 'Test1' must be 'TEST1' with Bundle/@CommandLineVariables value 'upperCase'.",
+                    "The *Package/@bal:DisplayInternalUICondition attribute's value '=' is not a valid bundle condition.",
+                }, messages.ToArray());
             }
         }
     }
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxl b/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxl
new file mode 100644
index 00000000..223a7874
--- /dev/null
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxl
@@ -0,0 +1,4 @@
+<WixLocalization xmlns="http://wixtoolset.org/schemas/v4/wxl" Culture="en-US">
+  <String Id="NonsenseDetectCondition">WixBundleAction = 4</String>
+  <String Id="NonsensePlanCondition">=</String>
+</WixLocalization>
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxs b/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxs
index 91380c69..547af644 100644
--- a/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxs
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/TestData/Overridable/WrongCaseBundle.wxs
@@ -8,6 +8,8 @@
         <Variable Name="Test1" bal:Overridable="yes" />
         <Chain>
             <ExePackage Permanent="yes" DetectCondition="none" SourceFile="runtimes\win-x86\native\wixnative.exe" />
+            <MsiPackage SourceFile="test.msi" bal:DisplayInternalUICondition="!(loc.NonsensePlanCondition)" />
         </Chain>
+        <bal:Condition Condition="!(loc.NonsenseDetectCondition)" Message="Unsupported" />
     </Bundle>
 </Wix>
diff --git a/src/ext/Bal/wixext/BalBurnBackendExtension.cs b/src/ext/Bal/wixext/BalBurnBackendExtension.cs
index 854b8b35..3b19ae78 100644
--- a/src/ext/Bal/wixext/BalBurnBackendExtension.cs
+++ b/src/ext/Bal/wixext/BalBurnBackendExtension.cs
@@ -10,6 +10,7 @@ namespace WixToolset.Bal
     using WixToolset.Data.Burn;
     using WixToolset.Data.Symbols;
     using WixToolset.Extensibility;
+    using WixToolset.Extensibility.Data;
 
     public class BalBurnBackendExtension : BaseBurnBackendBinderExtension
     {
@@ -31,6 +32,8 @@ namespace WixToolset.Bal
         {
             base.SymbolsFinalized(section);
 
+            this.VerifyBalConditions(section);
+            this.VerifyBalPackageInfos(section);
             this.VerifyOverridableVariables(section);
 
             var baSymbol = section.Symbols.OfType<WixBootstrapperApplicationDllSymbol>().SingleOrDefault();
@@ -100,7 +103,7 @@ namespace WixToolset.Bal
             {
                 foreach (var payloadPropertiesSymbol in payloadPropertiesSymbols)
                 {
-                    if (string.Equals(payloadPropertiesSymbol.Name, "bafunctions.dll", StringComparison.OrdinalIgnoreCase) &&
+                    if (String.Equals(payloadPropertiesSymbol.Name, "bafunctions.dll", StringComparison.OrdinalIgnoreCase) &&
                         BurnConstants.BurnUXContainerName == payloadPropertiesSymbol.ContainerRef)
                     {
                         this.Messaging.Write(BalWarnings.UnmarkedBAFunctionsDLL(payloadPropertiesSymbol.SourceLineNumbers));
@@ -120,6 +123,24 @@ namespace WixToolset.Bal
             }
         }
 
+        private void VerifyBalConditions(IntermediateSection section)
+        {
+            var balConditionSymbols = section.Symbols.OfType<WixBalConditionSymbol>().ToList();
+            foreach (var balConditionSymbol in balConditionSymbols)
+            {
+                this.BackendHelper.ValidateBundleCondition(balConditionSymbol.SourceLineNumbers, "bal:Condition", "Condition", balConditionSymbol.Condition, BundleConditionPhase.Detect);
+            }
+        }
+
+        private void VerifyBalPackageInfos(IntermediateSection section)
+        {
+            var balPackageInfoSymbols = section.Symbols.OfType<WixBalPackageInfoSymbol>().ToList();
+            foreach (var balPackageInfoSymbol in balPackageInfoSymbols)
+            {
+                this.BackendHelper.ValidateBundleCondition(balPackageInfoSymbol.SourceLineNumbers, "*Package", "bal:DisplayInternalUICondition", balPackageInfoSymbol.DisplayInternalUICondition, BundleConditionPhase.Plan);
+            }
+        }
+
         private void VerifyOverridableVariables(IntermediateSection section)
         {
             var bundleSymbol = section.Symbols.OfType<WixBundleSymbol>().Single();
diff --git a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
index 16e63492..a73992da 100644
--- a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
@@ -150,7 +150,7 @@ namespace WixToolset.Core.Burn
             // Process the explicitly authored payloads.
             ISet<string> processedPayloads;
             {
-                var command = new ProcessPayloadsCommand(this.BackendHelper, this.PayloadHarvester, payloadSymbols.Values, bundleSymbol.DefaultPackagingType, layoutDirectory);
+                var command = new ProcessPayloadsCommand(this.InternalBurnBackendHelper, this.PayloadHarvester, payloadSymbols.Values, bundleSymbol.DefaultPackagingType, layoutDirectory);
                 command.Execute();
 
                 fileTransfers.AddRange(command.FileTransfers);
@@ -228,7 +228,7 @@ namespace WixToolset.Core.Burn
             {
                 var toProcess = payloadSymbols.Values.Where(r => !processedPayloads.Contains(r.Id.Id)).ToList();
 
-                var command = new ProcessPayloadsCommand(this.BackendHelper, this.PayloadHarvester, toProcess, bundleSymbol.DefaultPackagingType, layoutDirectory);
+                var command = new ProcessPayloadsCommand(this.InternalBurnBackendHelper, this.PayloadHarvester, toProcess, bundleSymbol.DefaultPackagingType, layoutDirectory);
                 command.Execute();
 
                 fileTransfers.AddRange(command.FileTransfers);
@@ -381,6 +381,17 @@ namespace WixToolset.Core.Burn
                 return;
             }
 
+            // Now that extensions can't change anything else, verify everything is still valid.
+            {
+                var command = new PerformBundleBackendValidationCommand(this.Messaging, this.InternalBurnBackendHelper, section, facades);
+                command.Execute();
+            }
+
+            if (this.Messaging.EncounteredError)
+            {
+                return;
+            }
+
             // Generate data for all manifests.
             {
                 var command = new GenerateManifestDataFromIRCommand(this.Messaging, section, this.BackendExtensions, this.InternalBurnBackendHelper, extensionSearchSymbolsById);
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/PerformBundleBackendValidationCommand.cs b/src/wix/WixToolset.Core.Burn/Bundles/PerformBundleBackendValidationCommand.cs
new file mode 100644
index 00000000..ee18ff2c
--- /dev/null
+++ b/src/wix/WixToolset.Core.Burn/Bundles/PerformBundleBackendValidationCommand.cs
@@ -0,0 +1,156 @@
+// 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.Burn.Bundles
+{
+    using System;
+    using System.Collections.Generic;
+    using WixToolset.Data;
+    using WixToolset.Data.Symbols;
+    using WixToolset.Extensibility.Data;
+    using WixToolset.Extensibility.Services;
+
+    internal class PerformBundleBackendValidationCommand
+    {
+        public PerformBundleBackendValidationCommand(IMessaging messaging, IBurnBackendHelper burnBackendHelper, IntermediateSection section, IDictionary<string, PackageFacade> packageFacadesById)
+        {
+            this.Messaging = messaging;
+            this.BackendHelper = burnBackendHelper;
+            this.Section = section;
+            this.PackageFacadesById = packageFacadesById;
+        }
+
+        public IMessaging Messaging { get; }
+
+        public IBurnBackendHelper BackendHelper { get; }
+
+        public IntermediateSection Section { get; }
+
+        public IDictionary<string, PackageFacade> PackageFacadesById { get; }
+
+        public void Execute()
+        {
+            foreach (var symbol in this.Section.Symbols)
+            {
+                if (symbol is WixBundleSymbol wixBundleSymbol)
+                {
+                    this.ValidateBundle(wixBundleSymbol);
+                }
+                else if (symbol is WixBundleMsiPropertySymbol wixBundleMsiPropertySymbol)
+                {
+                    this.ValidateMsiProperty(wixBundleMsiPropertySymbol);
+                }
+                else if (symbol is WixBundleVariableSymbol wixBundleVariableSymbol)
+                {
+                    this.ValidateVariable(wixBundleVariableSymbol);
+                }
+                else if (symbol is WixBundlePackageCommandLineSymbol wixBundlePackageCommandLineSymbol)
+                {
+                    this.ValidatePackageCommandLine(wixBundlePackageCommandLineSymbol);
+                }
+                else if (symbol is WixSearchSymbol wixSearchSymbol)
+                {
+                    this.ValidateSearch(wixSearchSymbol);
+                }
+            }
+
+            foreach (var packageFacade in this.PackageFacadesById.Values)
+            {
+                if (packageFacade.SpecificPackageSymbol is WixBundleExePackageSymbol wixBundleExePackageSymbol)
+                {
+                    this.ValidateExePackage(wixBundleExePackageSymbol, packageFacade.PackageSymbol);
+                }
+                else if (packageFacade.SpecificPackageSymbol is WixBundleMsiPackageSymbol wixBundleMsiPackageSymbol)
+                {
+                    this.ValidateMsiPackage(wixBundleMsiPackageSymbol, packageFacade.PackageSymbol);
+                }
+                else if (packageFacade.SpecificPackageSymbol is WixBundleMspPackageSymbol wixBundleMspPackageSymbol)
+                {
+                    this.ValidateMspPackage(wixBundleMspPackageSymbol, packageFacade.PackageSymbol);
+                }
+                else if (packageFacade.SpecificPackageSymbol is WixBundleMsuPackageSymbol wixBundleMsuPackageSymbol)
+                {
+                    this.ValidateMsuPackage(wixBundleMsuPackageSymbol, packageFacade.PackageSymbol);
+                }
+            }
+        }
+
+        private void ValidateBundle(WixBundleSymbol symbol)
+        {
+            if (symbol.Condition != null)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "Bundle", "Condition", symbol.Condition, BundleConditionPhase.Startup);
+            }
+        }
+
+        private void ValidateChainPackage(WixBundlePackageSymbol symbol, string elementName)
+        {
+            if (!String.IsNullOrEmpty(symbol.InstallCondition))
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, elementName, "InstallCondition", symbol.InstallCondition, BundleConditionPhase.Plan);
+            }
+        }
+
+        private void ValidateExePackage(WixBundleExePackageSymbol symbol, WixBundlePackageSymbol packageSymbol)
+        {
+            this.ValidateChainPackage(packageSymbol, "ExePackage");
+
+            if (!packageSymbol.Permanent)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "ExePackage", "DetectCondition", symbol.DetectCondition, BundleConditionPhase.Detect);
+            }
+        }
+
+        private void ValidateMsiPackage(WixBundleMsiPackageSymbol symbol, WixBundlePackageSymbol packageSymbol)
+        {
+            this.ValidateChainPackage(packageSymbol, "MsiPackage");
+        }
+
+        private void ValidateMsiProperty(WixBundleMsiPropertySymbol symbol)
+        {
+            this.BackendHelper.ValidateBundleMsiPropertyName(symbol.SourceLineNumbers, "MsiProperty", "Name", symbol.Name);
+
+            if (symbol.Condition != null)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "MsiProperty", "Condition", symbol.Condition, BundleConditionPhase.Execute);
+            }
+        }
+
+        private void ValidateMspPackage(WixBundleMspPackageSymbol symbol, WixBundlePackageSymbol packageSymbol)
+        {
+            this.ValidateChainPackage(packageSymbol, "MspPackage");
+        }
+
+        private void ValidateMsuPackage(WixBundleMsuPackageSymbol symbol, WixBundlePackageSymbol packageSymbol)
+        {
+            this.ValidateChainPackage(packageSymbol, "MsuPackage");
+
+            if (!packageSymbol.Permanent)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "MsuPackage", "DetectCondition", symbol.DetectCondition, BundleConditionPhase.Detect);
+            }
+        }
+
+        private void ValidatePackageCommandLine(WixBundlePackageCommandLineSymbol symbol)
+        {
+            if (symbol.Condition != null)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "CommandLine", "Condition", symbol.Condition, BundleConditionPhase.Execute);
+            }
+        }
+
+        private void ValidateSearch(WixSearchSymbol symbol)
+        {
+            this.BackendHelper.ValidateBundleVariableName(symbol.SourceLineNumbers, "*Search", "Variable", symbol.Variable);
+
+            if (symbol.Condition != null)
+            {
+                this.BackendHelper.ValidateBundleCondition(symbol.SourceLineNumbers, "*Search", "Condition", symbol.Condition, BundleConditionPhase.Detect);
+            }
+        }
+
+        private void ValidateVariable(WixBundleVariableSymbol symbol)
+        {
+            this.BackendHelper.ValidateBundleVariableName(symbol.SourceLineNumbers, "Variable", "Name", symbol.Id.Id);
+        }
+    }
+}
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/ProcessPayloadsCommand.cs b/src/wix/WixToolset.Core.Burn/Bundles/ProcessPayloadsCommand.cs
index 3bd1f938..c3285884 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/ProcessPayloadsCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/ProcessPayloadsCommand.cs
@@ -15,7 +15,7 @@ namespace WixToolset.Core.Burn.Bundles
 
     internal class ProcessPayloadsCommand
     {
-        public ProcessPayloadsCommand(IBackendHelper backendHelper, IPayloadHarvester payloadHarvester, IEnumerable<WixBundlePayloadSymbol> payloads, PackagingType defaultPackaging, string layoutDirectory)
+        public ProcessPayloadsCommand(IBurnBackendHelper backendHelper, IPayloadHarvester payloadHarvester, IEnumerable<WixBundlePayloadSymbol> payloads, PackagingType defaultPackaging, string layoutDirectory)
         {
             this.BackendHelper = backendHelper;
             this.PayloadHarvester = payloadHarvester;
@@ -28,7 +28,7 @@ namespace WixToolset.Core.Burn.Bundles
 
         public IEnumerable<ITrackedFile> TrackedFiles { get; private set; }
 
-        private IBackendHelper BackendHelper { get; }
+        private IBurnBackendHelper BackendHelper { get; }
 
         private IPayloadHarvester PayloadHarvester { get; }
 
diff --git a/src/wix/WixToolset.Core.Burn/ExtensibilityServices/BurnBackendHelper.cs b/src/wix/WixToolset.Core.Burn/ExtensibilityServices/BurnBackendHelper.cs
index e4d2b0c9..d77606fb 100644
--- a/src/wix/WixToolset.Core.Burn/ExtensibilityServices/BurnBackendHelper.cs
+++ b/src/wix/WixToolset.Core.Burn/ExtensibilityServices/BurnBackendHelper.cs
@@ -20,6 +20,7 @@ namespace WixToolset.Core.Burn.ExtensibilityServices
         public static readonly XmlWriterSettings WriterSettings = new XmlWriterSettings { ConformanceLevel = ConformanceLevel.Fragment };
 
         private readonly IBackendHelper backendHelper;
+        private readonly IBundleValidator bundleValidator;
 
         private ManifestData BootstrapperApplicationManifestData { get; } = new ManifestData();
 
@@ -28,49 +29,105 @@ namespace WixToolset.Core.Burn.ExtensibilityServices
         public BurnBackendHelper(IServiceProvider serviceProvider)
         {
             this.backendHelper = serviceProvider.GetService<IBackendHelper>();
+            this.bundleValidator = serviceProvider.GetService<IBundleValidator>();
         }
 
         #region IBackendHelper interfaces
 
-        public IFileFacade CreateFileFacade(FileSymbol file, AssemblySymbol assembly) => this.backendHelper.CreateFileFacade(file, assembly);
-
-        public IFileFacade CreateFileFacade(FileRow fileRow) => this.backendHelper.CreateFileFacade(fileRow);
+        public IFileFacade CreateFileFacade(FileSymbol file, AssemblySymbol assembly)
+        {
+            return this.backendHelper.CreateFileFacade(file, assembly);
+        }
 
-        public IFileFacade CreateFileFacadeFromMergeModule(FileSymbol fileSymbol) => this.backendHelper.CreateFileFacadeFromMergeModule(fileSymbol);
+        public IFileFacade CreateFileFacade(FileRow fileRow)
+        {
+            return this.backendHelper.CreateFileFacade(fileRow);
+        }
 
-        public IFileTransfer CreateFileTransfer(string source, string destination, bool move, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.CreateFileTransfer(source, destination, move, sourceLineNumbers);
+        public IFileFacade CreateFileFacadeFromMergeModule(FileSymbol fileSymbol)
+        {
+            return this.backendHelper.CreateFileFacadeFromMergeModule(fileSymbol);
+        }
 
-        public string CreateGuid() => this.backendHelper.CreateGuid();
+        public IFileTransfer CreateFileTransfer(string source, string destination, bool move, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.CreateFileTransfer(source, destination, move, sourceLineNumbers);
+        }
 
-        public string CreateGuid(Guid namespaceGuid, string value) => this.backendHelper.CreateGuid(namespaceGuid, value);
+        public string CreateGuid()
+        {
+            return this.backendHelper.CreateGuid();
+        }
 
-        public IResolvedDirectory CreateResolvedDirectory(string directoryParent, string name) => this.backendHelper.CreateResolvedDirectory(directoryParent, name);
+        public string CreateGuid(Guid namespaceGuid, string value)
+        {
+            return this.backendHelper.CreateGuid(namespaceGuid, value);
+        }
 
-        public IReadOnlyList<ITrackedFile> ExtractEmbeddedFiles(IEnumerable<IExpectedExtractFile> embeddedFiles) => this.backendHelper.ExtractEmbeddedFiles(embeddedFiles);
+        public IResolvedDirectory CreateResolvedDirectory(string directoryParent, string name)
+        {
+            return this.backendHelper.CreateResolvedDirectory(directoryParent, name);
+        }
 
-        public string GenerateIdentifier(string prefix, params string[] args) => this.backendHelper.GenerateIdentifier(prefix, args);
+        public IReadOnlyList<ITrackedFile> ExtractEmbeddedFiles(IEnumerable<IExpectedExtractFile> embeddedFiles)
+        {
+            return this.backendHelper.ExtractEmbeddedFiles(embeddedFiles);
+        }
 
-        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath) => this.backendHelper.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath);
+        public string GenerateIdentifier(string prefix, params string[] args)
+        {
+            return this.backendHelper.GenerateIdentifier(prefix, args);
+        }
 
-        public int GetValidCodePage(string value, bool allowNoChange, bool onlyAnsi = false, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.GetValidCodePage(value, allowNoChange, onlyAnsi, sourceLineNumbers);
+        public int GetValidCodePage(string value, bool allowNoChange, bool onlyAnsi = false, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.GetValidCodePage(value, allowNoChange, onlyAnsi, sourceLineNumbers);
+        }
 
-        public string GetMsiFileName(string value, bool source, bool longName) => this.backendHelper.GetMsiFileName(value, source, longName);
+        public string GetMsiFileName(string value, bool source, bool longName)
+        {
+            return this.backendHelper.GetMsiFileName(value, source, longName);
+        }
 
-        public bool IsValidBinderVariable(string variable) => this.backendHelper.IsValidBinderVariable(variable);
+        public bool IsValidBinderVariable(string variable)
+        {
+            return this.backendHelper.IsValidBinderVariable(variable);
+        }
 
-        public bool IsValidFourPartVersion(string version) => this.backendHelper.IsValidFourPartVersion(version);
+        public bool IsValidFourPartVersion(string version)
+        {
+            return this.backendHelper.IsValidFourPartVersion(version);
+        }
 
-        public bool IsValidIdentifier(string id) => this.backendHelper.IsValidIdentifier(id);
+        public bool IsValidIdentifier(string id)
+        {
+            return this.backendHelper.IsValidIdentifier(id);
+        }
 
-        public bool IsValidLongFilename(string filename, bool allowWildcards, bool allowRelative) => this.backendHelper.IsValidLongFilename(filename, allowWildcards, allowRelative);
+        public bool IsValidLongFilename(string filename, bool allowWildcards, bool allowRelative)
+        {
+            return this.backendHelper.IsValidLongFilename(filename, allowWildcards, allowRelative);
+        }
 
-        public bool IsValidShortFilename(string filename, bool allowWildcards) => this.backendHelper.IsValidShortFilename(filename, allowWildcards);
+        public bool IsValidShortFilename(string filename, bool allowWildcards)
+        {
+            return this.backendHelper.IsValidShortFilename(filename, allowWildcards);
+        }
 
-        public void ResolveDelayedFields(IEnumerable<IDelayedField> delayedFields, Dictionary<string, string> variableCache) => this.backendHelper.ResolveDelayedFields(delayedFields, variableCache);
+        public void ResolveDelayedFields(IEnumerable<IDelayedField> delayedFields, Dictionary<string, string> variableCache)
+        {
+            this.backendHelper.ResolveDelayedFields(delayedFields, variableCache);
+        }
 
-        public string[] SplitMsiFileName(string value) => this.backendHelper.SplitMsiFileName(value);
+        public string[] SplitMsiFileName(string value)
+        {
+            return this.backendHelper.SplitMsiFileName(value);
+        }
 
-        public ITrackedFile TrackFile(string path, TrackedFileType type, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.TrackFile(path, type, sourceLineNumbers);
+        public ITrackedFile TrackFile(string path, TrackedFileType type, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.TrackFile(path, type, sourceLineNumbers);
+        }
 
         #endregion
 
@@ -100,6 +157,28 @@ namespace WixToolset.Core.Burn.ExtensibilityServices
 
         #endregion
 
+        #region IBundleValidator
+        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath)
+        {
+            return this.bundleValidator.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath);
+        }
+
+        public bool ValidateBundleMsiPropertyName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string propertyName)
+        {
+            return this.bundleValidator.ValidateBundleMsiPropertyName(sourceLineNumbers, elementName, attributeName, propertyName);
+        }
+
+        public bool ValidateBundleVariableName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string variableName)
+        {
+            return this.bundleValidator.ValidateBundleVariableName(sourceLineNumbers, elementName, attributeName, variableName);
+        }
+
+        public bool ValidateBundleCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition, BundleConditionPhase phase)
+        {
+            return this.bundleValidator.ValidateBundleCondition(sourceLineNumbers, elementName, attributeName, condition, phase);
+        }
+        #endregion
+
         #region IInternalBurnBackendHelper interfaces
 
         public void WriteBootstrapperApplicationData(XmlWriter writer)
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/ExtensibilityServices/WindowsInstallerBackendHelper.cs b/src/wix/WixToolset.Core.WindowsInstaller/ExtensibilityServices/WindowsInstallerBackendHelper.cs
index 8305b5e6..b3b4421a 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/ExtensibilityServices/WindowsInstallerBackendHelper.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/ExtensibilityServices/WindowsInstallerBackendHelper.cs
@@ -23,45 +23,100 @@ namespace WixToolset.Core.WindowsInstaller.ExtensibilityServices
 
         #region IBackendHelper interfaces
 
-        public IFileFacade CreateFileFacade(FileSymbol file, AssemblySymbol assembly) => this.backendHelper.CreateFileFacade(file, assembly);
-
-        public IFileFacade CreateFileFacade(FileRow fileRow) => this.backendHelper.CreateFileFacade(fileRow);
+        public IFileFacade CreateFileFacade(FileSymbol file, AssemblySymbol assembly)
+        {
+            return this.backendHelper.CreateFileFacade(file, assembly);
+        }
 
-        public IFileFacade CreateFileFacadeFromMergeModule(FileSymbol fileSymbol) => this.backendHelper.CreateFileFacadeFromMergeModule(fileSymbol);
+        public IFileFacade CreateFileFacade(FileRow fileRow)
+        {
+            return this.backendHelper.CreateFileFacade(fileRow);
+        }
 
-        public IFileTransfer CreateFileTransfer(string source, string destination, bool move, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.CreateFileTransfer(source, destination, move, sourceLineNumbers);
+        public IFileFacade CreateFileFacadeFromMergeModule(FileSymbol fileSymbol)
+        {
+            return this.backendHelper.CreateFileFacadeFromMergeModule(fileSymbol);
+        }
 
-        public string CreateGuid() => this.backendHelper.CreateGuid();
+        public IFileTransfer CreateFileTransfer(string source, string destination, bool move, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.CreateFileTransfer(source, destination, move, sourceLineNumbers);
+        }
 
-        public string CreateGuid(Guid namespaceGuid, string value) => this.backendHelper.CreateGuid(namespaceGuid, value);
+        public string CreateGuid()
+        {
+            return this.backendHelper.CreateGuid();
+        }
 
-        public IResolvedDirectory CreateResolvedDirectory(string directoryParent, string name) => this.backendHelper.CreateResolvedDirectory(directoryParent, name);
+        public string CreateGuid(Guid namespaceGuid, string value)
+        {
+            return this.backendHelper.CreateGuid(namespaceGuid, value);
+        }
 
-        public IReadOnlyList<ITrackedFile> ExtractEmbeddedFiles(IEnumerable<IExpectedExtractFile> embeddedFiles) => this.backendHelper.ExtractEmbeddedFiles(embeddedFiles);
+        public IResolvedDirectory CreateResolvedDirectory(string directoryParent, string name)
+        {
+            return this.backendHelper.CreateResolvedDirectory(directoryParent, name);
+        }
 
-        public string GenerateIdentifier(string prefix, params string[] args) => this.backendHelper.GenerateIdentifier(prefix, args);
+        public IReadOnlyList<ITrackedFile> ExtractEmbeddedFiles(IEnumerable<IExpectedExtractFile> embeddedFiles)
+        {
+            return this.backendHelper.ExtractEmbeddedFiles(embeddedFiles);
+        }
 
-        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath) => this.backendHelper.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath);
+        public string GenerateIdentifier(string prefix, params string[] args)
+        {
+            return this.backendHelper.GenerateIdentifier(prefix, args);
+        }
 
-        public int GetValidCodePage(string value, bool allowNoChange, bool onlyAnsi = false, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.GetValidCodePage(value, allowNoChange, onlyAnsi, sourceLineNumbers);
+        public int GetValidCodePage(string value, bool allowNoChange, bool onlyAnsi = false, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.GetValidCodePage(value, allowNoChange, onlyAnsi, sourceLineNumbers);
+        }
 
-        public string GetMsiFileName(string value, bool source, bool longName) => this.backendHelper.GetMsiFileName(value, source, longName);
+        public string GetMsiFileName(string value, bool source, bool longName)
+        {
+            return this.backendHelper.GetMsiFileName(value, source, longName);
+        }
 
-        public bool IsValidBinderVariable(string variable) => this.backendHelper.IsValidBinderVariable(variable);
+        public bool IsValidBinderVariable(string variable)
+        {
+            return this.backendHelper.IsValidBinderVariable(variable);
+        }
 
-        public bool IsValidFourPartVersion(string version) => this.backendHelper.IsValidFourPartVersion(version);
+        public bool IsValidFourPartVersion(string version)
+        {
+            return this.backendHelper.IsValidFourPartVersion(version);
+        }
 
-        public bool IsValidIdentifier(string id) => this.backendHelper.IsValidIdentifier(id);
+        public bool IsValidIdentifier(string id)
+        {
+            return this.backendHelper.IsValidIdentifier(id);
+        }
 
-        public bool IsValidLongFilename(string filename, bool allowWildcards, bool allowRelative) => this.backendHelper.IsValidLongFilename(filename, allowWildcards, allowRelative);
+        public bool IsValidLongFilename(string filename, bool allowWildcards, bool allowRelative)
+        {
+            return this.backendHelper.IsValidLongFilename(filename, allowWildcards, allowRelative);
+        }
 
-        public bool IsValidShortFilename(string filename, bool allowWildcards) => this.backendHelper.IsValidShortFilename(filename, allowWildcards);
+        public bool IsValidShortFilename(string filename, bool allowWildcards)
+        {
+            return this.backendHelper.IsValidShortFilename(filename, allowWildcards);
+        }
 
-        public void ResolveDelayedFields(IEnumerable<IDelayedField> delayedFields, Dictionary<string, string> variableCache) => this.backendHelper.ResolveDelayedFields(delayedFields, variableCache);
+        public void ResolveDelayedFields(IEnumerable<IDelayedField> delayedFields, Dictionary<string, string> variableCache)
+        {
+            this.backendHelper.ResolveDelayedFields(delayedFields, variableCache);
+        }
 
-        public string[] SplitMsiFileName(string value) => this.backendHelper.SplitMsiFileName(value);
+        public string[] SplitMsiFileName(string value)
+        {
+            return this.backendHelper.SplitMsiFileName(value);
+        }
 
-        public ITrackedFile TrackFile(string path, TrackedFileType type, SourceLineNumber sourceLineNumbers = null) => this.backendHelper.TrackFile(path, type, sourceLineNumbers);
+        public ITrackedFile TrackFile(string path, TrackedFileType type, SourceLineNumber sourceLineNumbers = null)
+        {
+            return this.backendHelper.TrackFile(path, type, sourceLineNumbers);
+        }
 
         #endregion
 
diff --git a/src/wix/WixToolset.Core/Common.cs b/src/wix/WixToolset.Core/Common.cs
index 848f009a..8e341c52 100644
--- a/src/wix/WixToolset.Core/Common.cs
+++ b/src/wix/WixToolset.Core/Common.cs
@@ -27,27 +27,6 @@ namespace WixToolset.Core
         internal static readonly char[] IllegalRelativeLongFilenameCharacters = new[] { '?', '*', '|', '>', '<', ':', '\"' }; // like illegal, but we allow '\' and '/'
         internal static readonly char[] IllegalWildcardLongFilenameCharacters = new[] { '\\', '/', '|', '>', '<', ':', '\"' };   // like illegal: but we allow '*' and '?'
 
-        public static string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath, IMessaging messageHandler)
-        {
-            const string root = @"C:\";
-            if (!Path.IsPathRooted(relativePath))
-            {
-                var normalizedPath = Path.GetFullPath(root + relativePath);
-                if (normalizedPath.StartsWith(root))
-                {
-                    var canonicalizedPath = normalizedPath.Substring(root.Length);
-                    if (canonicalizedPath != relativePath)
-                    {
-                        messageHandler.Write(WarningMessages.PathCanonicalized(sourceLineNumbers, elementName, attributeName, relativePath, canonicalizedPath));
-                    }
-                    return canonicalizedPath;
-                }
-            }
-
-            messageHandler.Write(ErrorMessages.PayloadMustBeRelativeToCache(sourceLineNumbers, elementName, attributeName, relativePath));
-            return relativePath;
-        }
-
         /// <summary>
         /// Gets a valid code page from the given web name or integer value.
         /// </summary>
diff --git a/src/wix/WixToolset.Core/CompilerCore.cs b/src/wix/WixToolset.Core/CompilerCore.cs
index dc44f1b6..7effa0b9 100644
--- a/src/wix/WixToolset.Core/CompilerCore.cs
+++ b/src/wix/WixToolset.Core/CompilerCore.cs
@@ -17,24 +17,6 @@ namespace WixToolset.Core
     using WixToolset.Extensibility.Data;
     using WixToolset.Extensibility.Services;
 
-    internal enum ValueListKind
-    {
-        /// <summary>
-        /// A list of values with nothing before the final value.
-        /// </summary>
-        None,
-
-        /// <summary>
-        /// A list of values with 'and' before the final value.
-        /// </summary>
-        And,
-
-        /// <summary>
-        /// A list of values with 'or' before the final value.
-        /// </summary>
-        Or
-    }
-
     /// <summary>
     /// Core class for the compiler.
     /// </summary>
@@ -43,80 +25,6 @@ namespace WixToolset.Core
         internal static readonly XNamespace W3SchemaPrefix = "http://www.w3.org/";
         internal static readonly XNamespace WixNamespace = "http://wixtoolset.org/schemas/v4/wxs";
 
-        // Built-in variables (from burn\engine\variable.cpp, "vrgBuiltInVariables", around line 113)
-        private static readonly List<string> BuiltinBundleVariables = new List<string>(
-            new string[] {
-                "AdminToolsFolder",
-                "AppDataFolder",
-                "CommonAppDataFolder",
-                "CommonFiles64Folder",
-                "CommonFilesFolder",
-                "CompatibilityMode",
-                "Date",
-                "DesktopFolder",
-                "FavoritesFolder",
-                "FontsFolder",
-                "InstallerName",
-                "InstallerVersion",
-                "LocalAppDataFolder",
-                "LogonUser",
-                "MyPicturesFolder",
-                "NativeMachine",
-                "NTProductType",
-                "NTSuiteBackOffice",
-                "NTSuiteDataCenter",
-                "NTSuiteEnterprise",
-                "NTSuitePersonal",
-                "NTSuiteSmallBusiness",
-                "NTSuiteSmallBusinessRestricted",
-                "NTSuiteWebServer",
-                "PersonalFolder",
-                "Privileged",
-                "ProgramFiles64Folder",
-                "ProgramFiles6432Folder",
-                "ProgramFilesFolder",
-                "ProgramMenuFolder",
-                "RebootPending",
-                "SendToFolder",
-                "ServicePackLevel",
-                "StartMenuFolder",
-                "StartupFolder",
-                "System64Folder",
-                "SystemFolder",
-                "TempFolder",
-                "TemplateFolder",
-                "TerminalServer",
-                "UserLanguageID",
-                "UserUILanguageID",
-                "VersionMsi",
-                "VersionNT",
-                "VersionNT64",
-                "WindowsFolder",
-                "WindowsVolume",
-                "WixBundleAction",
-                "WixBundleCommandLineAction",
-                "WixBundleForcedRestartPackage",
-                "WixBundleElevated",
-                "WixBundleInstalled",
-                "WixBundleProviderKey",
-                "WixBundleTag",
-                "WixBundleVersion",
-            });
-
-        private static readonly List<string> DisallowedMsiProperties = new List<string>(
-            new string[] {
-                "ACTION",
-                "ADDLOCAL",
-                "ADDSOURCE",
-                "ADDDEFAULT",
-                "ADVERTISE",
-                "ALLUSERS",
-                "REBOOT",
-                "REINSTALL",
-                "REINSTALLMODE",
-                "REMOVE"
-            });
-
         private readonly Dictionary<XNamespace, ICompilerExtension> extensions;
         private readonly IParseHelper parseHelper;
         private readonly Intermediate intermediate;
@@ -857,11 +765,7 @@ namespace WixToolset.Core
 
             if (!String.IsNullOrEmpty(value))
             {
-                if (CompilerCore.BuiltinBundleVariables.Contains(value))
-                {
-                    string illegalValues = CompilerCore.CreateValueList(ValueListKind.Or, CompilerCore.BuiltinBundleVariables);
-                    this.Write(ErrorMessages.IllegalAttributeValueWithIllegalList(sourceLineNumbers, attribute.Parent.Name.LocalName, attribute.Name.LocalName, value, illegalValues));
-                }
+                this.parseHelper.ValidateBundleVariableName(sourceLineNumbers, attribute.Parent.Name.LocalName, attribute.Name.LocalName, value);
             }
 
             return value;
@@ -879,11 +783,7 @@ namespace WixToolset.Core
 
             if (0 < value.Length)
             {
-                if (CompilerCore.DisallowedMsiProperties.Contains(value))
-                {
-                    string illegalValues = CompilerCore.CreateValueList(ValueListKind.Or, CompilerCore.DisallowedMsiProperties);
-                    this.Write(ErrorMessages.DisallowedMsiProperty(sourceLineNumbers, value, illegalValues));
-                }
+                this.parseHelper.ValidateBundleMsiPropertyName(sourceLineNumbers, attribute.Parent.Name.LocalName, attribute.Name.LocalName, value);
             }
 
             return value;
@@ -1095,74 +995,5 @@ namespace WixToolset.Core
         {
             return this.parseHelper.ScheduleActionSymbol(this.ActiveSection, sourceLineNumbers, access, sequence, actionName, condition, beforeAction, afterAction, overridable);
         }
-
-        private static string CreateValueList(ValueListKind kind, IEnumerable<string> values)
-        {
-            // Ideally, we could denote the list kind (and the list itself) directly in the
-            // message XML, and detect and expand in the MessageHandler.GenerateMessageString()
-            // method.  Doing so would make vararg-style messages much easier, but impacts
-            // every single message we format.  For now, callers just have to know when a
-            // message takes a list of values in a single string argument, the caller will
-            // have to do the expansion themselves.  (And, unfortunately, hard-code the knowledge
-            // that the list is an 'and' or 'or' list.)
-
-            // For a localizable solution, we need to be able to get the list format string
-            // from resources. We aren't currently localized right now, so the values are
-            // just hard-coded.
-            const string valueFormat = "'{0}'";
-            const string valueSeparator = ", ";
-            string terminalTerm = String.Empty;
-
-            switch (kind)
-            {
-                case ValueListKind.None:
-                    terminalTerm = "";
-                    break;
-                case ValueListKind.And:
-                    terminalTerm = "and ";
-                    break;
-                case ValueListKind.Or:
-                    terminalTerm = "or ";
-                    break;
-            }
-
-            StringBuilder list = new StringBuilder();
-
-            // This weird construction helps us determine when we're adding the last value
-            // to the list.  Instead of adding them as we encounter them, we cache the current
-            // value and append the *previous* one.
-            string previousValue = null;
-            bool haveValues = false;
-            foreach (string value in values)
-            {
-                if (null != previousValue)
-                {
-                    if (haveValues)
-                    {
-                        list.Append(valueSeparator);
-                    }
-                    list.AppendFormat(valueFormat, previousValue);
-                    haveValues = true;
-                }
-
-                previousValue = value;
-            }
-
-            // If we have no previous value, that means that the list contained no values, and
-            // something has gone very wrong.
-            Debug.Assert(null != previousValue);
-            if (null != previousValue)
-            {
-                if (haveValues)
-                {
-                    list.Append(valueSeparator);
-                    list.Append(terminalTerm);
-                }
-                list.AppendFormat(valueFormat, previousValue);
-                haveValues = true;
-            }
-
-            return list.ToString();
-        }
     }
 }
diff --git a/src/wix/WixToolset.Core/ExtensibilityServices/BackendHelper.cs b/src/wix/WixToolset.Core/ExtensibilityServices/BackendHelper.cs
index 9d657e1a..3348ad0b 100644
--- a/src/wix/WixToolset.Core/ExtensibilityServices/BackendHelper.cs
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/BackendHelper.cs
@@ -64,11 +64,6 @@ namespace WixToolset.Core.ExtensibilityServices
             return Common.GenerateIdentifier(prefix, args);
         }
 
-        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath)
-        {
-            return Common.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath, this.Messaging);
-        }
-
         public int GetValidCodePage(string value, bool allowNoChange = false, bool onlyAnsi = false, SourceLineNumber sourceLineNumbers = null)
         {
             return Common.GetValidCodePage(value, allowNoChange, onlyAnsi, sourceLineNumbers);
diff --git a/src/wix/WixToolset.Core/ExtensibilityServices/BundleValidator.cs b/src/wix/WixToolset.Core/ExtensibilityServices/BundleValidator.cs
new file mode 100644
index 00000000..0149fe94
--- /dev/null
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/BundleValidator.cs
@@ -0,0 +1,326 @@
+// 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.ExtensibilityServices
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Diagnostics;
+    using System.IO;
+    using System.Text;
+    using WixToolset.Data;
+    using WixToolset.Extensibility.Data;
+    using WixToolset.Extensibility.Services;
+
+    internal class BundleValidator : IBundleValidator
+    {
+        public BundleValidator(IServiceProvider serviceProvider)
+        {
+            this.Messaging = serviceProvider.GetService<IMessaging>();
+        }
+
+        protected IMessaging Messaging { get; }
+
+        private enum ValueListKind
+        {
+            /// <summary>
+            /// A list of values with nothing before the final value.
+            /// </summary>
+            None,
+
+            /// <summary>
+            /// A list of values with 'and' before the final value.
+            /// </summary>
+            And,
+
+            /// <summary>
+            /// A list of values with 'or' before the final value.
+            /// </summary>
+            Or,
+        }
+
+        // Built-in variables (from burn\engine\variable.cpp, "vrgBuiltInVariables", around line 207)
+        private static readonly List<string> BuiltinBundleVariables = new List<string>(
+            new string[] {
+                "AdminToolsFolder",
+                "AppDataFolder",
+                "CommonAppDataFolder",
+                "CommonFiles64Folder",
+                "CommonFilesFolder",
+                "CompatibilityMode",
+                "Date",
+                "DesktopFolder",
+                "FavoritesFolder",
+                "FontsFolder",
+                "InstallerName",
+                "InstallerVersion",
+                "LocalAppDataFolder",
+                "LogonUser",
+                "MyPicturesFolder",
+                "NativeMachine",
+                "NTProductType",
+                "NTSuiteBackOffice",
+                "NTSuiteDataCenter",
+                "NTSuiteEnterprise",
+                "NTSuitePersonal",
+                "NTSuiteSmallBusiness",
+                "NTSuiteSmallBusinessRestricted",
+                "NTSuiteWebServer",
+                "PersonalFolder",
+                "Privileged",
+                "ProgramFiles64Folder",
+                "ProgramFiles6432Folder",
+                "ProgramFilesFolder",
+                "ProgramMenuFolder",
+                "RebootPending",
+                "SendToFolder",
+                "ServicePackLevel",
+                "StartMenuFolder",
+                "StartupFolder",
+                "System64Folder",
+                "SystemFolder",
+                "TempFolder",
+                "TemplateFolder",
+                "TerminalServer",
+                "UserLanguageID",
+                "UserUILanguageID",
+                "VersionMsi",
+                "VersionNT",
+                "VersionNT64",
+                "WindowsFolder",
+                "WindowsVolume",
+                "WixBundleAction",
+                "WixBundleCommandLineAction",
+                "WixBundleForcedRestartPackage",
+                "WixBundleElevated",
+                "WixBundleInstalled",
+                "WixBundleProviderKey",
+                "WixBundleTag",
+                "WixBundleVersion",
+            });
+
+        private static readonly List<string> DisallowedMsiProperties = new List<string>(
+            new string[] {
+                "ACTION",
+                "ADDLOCAL",
+                "ADDSOURCE",
+                "ADDDEFAULT",
+                "ADVERTISE",
+                "ALLUSERS",
+                "REBOOT",
+                "REINSTALL",
+                "REINSTALLMODE",
+                "REMOVE"
+            });
+
+        private static readonly List<string> UnavailableStartupVariables = new List<string>(
+            new string[] {
+                "RebootPending",
+                "WixBundleAction",
+                "WixBundleInstalled",
+            });
+
+        private static readonly List<string> UnavailableDetectVariables = new List<string>(
+            new string[] {
+                "WixBundleAction",
+            });
+
+        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath)
+        {
+            const string root = @"C:\";
+            if (!Path.IsPathRooted(relativePath))
+            {
+                var normalizedPath = Path.GetFullPath(root + relativePath);
+                if (normalizedPath.StartsWith(root))
+                {
+                    var canonicalizedPath = normalizedPath.Substring(root.Length);
+                    if (canonicalizedPath != relativePath)
+                    {
+                        this.Messaging.Write(WarningMessages.PathCanonicalized(sourceLineNumbers, elementName, attributeName, relativePath, canonicalizedPath));
+                    }
+                    return canonicalizedPath;
+                }
+            }
+
+            this.Messaging.Write(ErrorMessages.PayloadMustBeRelativeToCache(sourceLineNumbers, elementName, attributeName, relativePath));
+            return relativePath;
+        }
+
+        public bool ValidateBundleVariableName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string variableName)
+        {
+            if (String.IsNullOrEmpty(variableName))
+            {
+                this.Messaging.Write(ErrorMessages.IllegalEmptyAttributeValue(sourceLineNumbers, elementName, attributeName));
+
+                return false;
+            }
+            else if (BuiltinBundleVariables.Contains(variableName))
+            {
+                var illegalValues = CreateValueList(ValueListKind.Or, BuiltinBundleVariables);
+                this.Messaging.Write(ErrorMessages.IllegalAttributeValueWithIllegalList(sourceLineNumbers, elementName, attributeName, variableName, illegalValues));
+
+                return false;
+            }
+            else
+            {
+                return true;
+            }
+        }
+
+        public bool ValidateBundleMsiPropertyName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string propertyName)
+        {
+            if (String.IsNullOrEmpty(propertyName))
+            {
+                this.Messaging.Write(ErrorMessages.IllegalEmptyAttributeValue(sourceLineNumbers, elementName, attributeName));
+
+                return false;
+            }
+            else if (DisallowedMsiProperties.Contains(propertyName))
+            {
+                var illegalValues = CreateValueList(ValueListKind.Or, DisallowedMsiProperties);
+                this.Messaging.Write(ErrorMessages.DisallowedMsiProperty(sourceLineNumbers, propertyName, illegalValues));
+
+                return false;
+            }
+            else
+            {
+                return true;
+            }
+        }
+
+        public bool ValidateBundleCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition, BundleConditionPhase phase)
+        {
+            if (!this.TryParseCondition(sourceLineNumbers, elementName, attributeName, condition))
+            {
+                return false;
+            }
+
+
+            // TODO: These lists are incomplete.
+            List<string> unavailableVariables = null;
+            switch (phase)
+            {
+                case BundleConditionPhase.Startup:
+                    unavailableVariables = UnavailableStartupVariables;
+                    break;
+                case BundleConditionPhase.Detect:
+                    unavailableVariables = UnavailableDetectVariables;
+                    break;
+            }
+
+            if (unavailableVariables != null)
+            {
+                return this.ValidateBundleConditionUnavailableVariables(sourceLineNumbers, elementName, attributeName, condition, unavailableVariables);
+            }
+            else
+            {
+                return true;
+            }
+        }
+
+        private bool ValidateBundleConditionUnavailableVariables(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition, List<string> unavailableVariables)
+        {
+            foreach (var variableName in unavailableVariables)
+            {
+                //TODO: use the results of parsing to validate that the restricted variables are actually used as variables
+                if (condition.Contains(variableName))
+                {
+                    var illegalValues = CreateValueList(ValueListKind.Or, unavailableVariables);
+                    this.Messaging.Write(WarningMessages.UnavailableBundleConditionVariable(sourceLineNumbers, elementName, attributeName, variableName, illegalValues));
+
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        private bool TryParseCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition)
+        {
+            if (String.IsNullOrEmpty(condition))
+            {
+                this.Messaging.Write(ErrorMessages.IllegalEmptyAttributeValue(sourceLineNumbers, elementName, attributeName));
+
+                return false;
+            }
+            //TODO: Actually parse the condition to definitively tell which Variables are referenced.
+            else if (condition.Trim() == "=")
+            {
+                this.Messaging.Write(ErrorMessages.InvalidBundleCondition(sourceLineNumbers, elementName, attributeName, condition));
+                return false;
+            }
+            else
+            {
+                return true;
+            }
+        }
+
+        private static string CreateValueList(ValueListKind kind, IEnumerable<string> values)
+        {
+            // Ideally, we could denote the list kind (and the list itself) directly in the
+            // message XML, and detect and expand in the MessageHandler.GenerateMessageString()
+            // method.  Doing so would make vararg-style messages much easier, but impacts
+            // every single message we format.  For now, callers just have to know when a
+            // message takes a list of values in a single string argument, the caller will
+            // have to do the expansion themselves.  (And, unfortunately, hard-code the knowledge
+            // that the list is an 'and' or 'or' list.)
+
+            // For a localizable solution, we need to be able to get the list format string
+            // from resources. We aren't currently localized right now, so the values are
+            // just hard-coded.
+            const string valueFormat = "'{0}'";
+            const string valueSeparator = ", ";
+            var terminalTerm = String.Empty;
+
+            switch (kind)
+            {
+                case ValueListKind.None:
+                    terminalTerm = "";
+                    break;
+                case ValueListKind.And:
+                    terminalTerm = "and ";
+                    break;
+                case ValueListKind.Or:
+                    terminalTerm = "or ";
+                    break;
+            }
+
+            var list = new StringBuilder();
+
+            // This weird construction helps us determine when we're adding the last value
+            // to the list.  Instead of adding them as we encounter them, we cache the current
+            // value and append the *previous* one.
+            string previousValue = null;
+            var haveValues = false;
+            foreach (var value in values)
+            {
+                if (null != previousValue)
+                {
+                    if (haveValues)
+                    {
+                        list.Append(valueSeparator);
+                    }
+                    list.AppendFormat(valueFormat, previousValue);
+                    haveValues = true;
+                }
+
+                previousValue = value;
+            }
+
+            // If we have no previous value, that means that the list contained no values, and
+            // something has gone very wrong.
+            Debug.Assert(null != previousValue);
+            if (null != previousValue)
+            {
+                if (haveValues)
+                {
+                    list.Append(valueSeparator);
+                    list.Append(terminalTerm);
+                }
+                list.AppendFormat(valueFormat, previousValue);
+                //haveValues = true;
+            }
+
+            return list.ToString();
+        }
+    }
+}
diff --git a/src/wix/WixToolset.Core/ExtensibilityServices/ParseHelper.cs b/src/wix/WixToolset.Core/ExtensibilityServices/ParseHelper.cs
index 1a678b0d..fa4f50ba 100644
--- a/src/wix/WixToolset.Core/ExtensibilityServices/ParseHelper.cs
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/ParseHelper.cs
@@ -22,11 +22,14 @@ namespace WixToolset.Core.ExtensibilityServices
         {
             this.ServiceProvider = serviceProvider;
 
+            this.BundleValidator = serviceProvider.GetService<IBundleValidator>();
             this.Messaging = serviceProvider.GetService<IMessaging>();
         }
 
         private IServiceProvider ServiceProvider { get; }
 
+        private IBundleValidator BundleValidator { get; }
+
         private IMessaging Messaging { get; }
 
         private ISymbolDefinitionCreator Creator { get; set; }
@@ -239,11 +242,14 @@ namespace WixToolset.Core.ExtensibilityServices
 
         public void CreateWixSearchSymbol(IntermediateSection section, SourceLineNumber sourceLineNumbers, string elementName, Identifier id, string variable, string condition, string after, string bundleExtensionId)
         {
-            // TODO: verify variable is not a standard bundle variable
             if (variable == null)
             {
                 this.Messaging.Write(ErrorMessages.ExpectedAttribute(sourceLineNumbers, elementName, "Variable"));
             }
+            else
+            {
+                this.BundleValidator.ValidateBundleVariableName(sourceLineNumbers, elementName, "Variable", variable);
+            }
 
             section.AddSymbol(new WixSearchSymbol(sourceLineNumbers, id)
             {
@@ -623,11 +629,6 @@ namespace WixToolset.Core.ExtensibilityServices
             }
         }
 
-        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath)
-        {
-            return Common.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath, this.Messaging);
-        }
-
         public SourceLineNumber GetSourceLineNumbers(XElement element)
         {
             return Preprocessor.GetSourceLineNumbers(element);
@@ -858,5 +859,27 @@ namespace WixToolset.Core.ExtensibilityServices
 
             return extension != null;
         }
+
+        #region IBundleValidator
+        public string GetCanonicalRelativePath(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string relativePath)
+        {
+            return this.BundleValidator.GetCanonicalRelativePath(sourceLineNumbers, elementName, attributeName, relativePath);
+        }
+
+        public bool ValidateBundleMsiPropertyName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string propertyName)
+        {
+            return this.BundleValidator.ValidateBundleMsiPropertyName(sourceLineNumbers, elementName, attributeName, propertyName);
+        }
+
+        public bool ValidateBundleVariableName(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string variableName)
+        {
+            return this.BundleValidator.ValidateBundleVariableName(sourceLineNumbers, elementName, attributeName, variableName);
+        }
+
+        public bool ValidateBundleCondition(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string condition, BundleConditionPhase phase)
+        {
+            return this.BundleValidator.ValidateBundleCondition(sourceLineNumbers, elementName, attributeName, condition, phase);
+        }
+        #endregion
     }
 }
diff --git a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
index a74ba6b3..9fbf6717 100644
--- a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
+++ b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
@@ -20,6 +20,7 @@ namespace WixToolset.Core
             // Singletons.
             this.AddService((provider, singletons) => AddSingleton<IExtensionManager>(singletons, new ExtensionManager(provider)));
             this.AddService((provider, singletons) => AddSingleton<IMessaging>(singletons, new Messaging()));
+            this.AddService((provider, singletons) => AddSingleton<IBundleValidator>(singletons, new BundleValidator(provider)));
             this.AddService((provider, singletons) => AddSingleton<ISymbolDefinitionCreator>(singletons, new SymbolDefinitionCreator(provider)));
             this.AddService((provider, singletons) => AddSingleton<IParseHelper>(singletons, new ParseHelper(provider)));
             this.AddService((provider, singletons) => AddSingleton<IPreprocessHelper>(singletons, new PreprocessHelper(provider)));
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
index f91c0ab0..e5d6ecf1 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
@@ -4,6 +4,7 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System;
     using System.IO;
+    using System.Linq;
     using WixBuildTools.TestSupport;
     using WixToolset.Core.TestPackage;
     using Xunit;
@@ -129,5 +130,47 @@ namespace WixToolsetTest.CoreIntegration
                 Assert.Equal(193, result.ExitCode);
             }
         }
+
+        [Fact]
+        public void GuardsAgainstVariousBundleValuesFromLoc()
+        {
+            var folder = TestData.Get(@"TestData");
+
+            using (var fs = new DisposableFileSystem())
+            {
+                var baseFolder = fs.GetFolder();
+                var intermediateFolder = Path.Combine(baseFolder, "obj");
+
+                var result = WixRunner.Execute(new[]
+                {
+                    "build",
+                    Path.Combine(folder, "BundleWithInvalid", "BundleWithInvalidLocValues.wxs"),
+                    "-loc", Path.Combine(folder, "BundleWithInvalid", "BundleWithInvalidLocValues.wxl"),
+                    "-bindpath", Path.Combine(folder, ".Data"),
+                    "-bindpath", Path.Combine(folder, "DecompileSingleFileCompressed"),
+                    "-bindpath", Path.Combine(folder, "SimpleBundle", "data"),
+                    "-intermediateFolder", intermediateFolder,
+                    "-o", Path.Combine(baseFolder, @"bin\test.exe")
+                });
+
+                Assert.InRange(result.ExitCode, 2, Int32.MaxValue);
+
+                var messages = result.Messages.Select(m => m.ToString()).ToList();
+                messages.Sort();
+
+                WixAssert.CompareLineByLine(new[]
+                {
+                    "*Search/@Condition contains the built-in Variable 'WixBundleAction', which is not available when it is evaluated. (Unavailable Variables are: 'WixBundleAction'.). Rewrite the condition to avoid Variables that are never valid during its evaluation.",
+                    "Bundle/@Condition contains the built-in Variable 'WixBundleInstalled', which is not available when it is evaluated. (Unavailable Variables are: 'RebootPending', 'WixBundleAction', or 'WixBundleInstalled'.). Rewrite the condition to avoid Variables that are never valid during its evaluation.",
+                    "ExePackage/@DetectCondition contains the built-in Variable 'WixBundleAction', which is not available when it is evaluated. (Unavailable Variables are: 'WixBundleAction'.). Rewrite the condition to avoid Variables that are never valid during its evaluation.",
+                    "The *Search/@Variable attribute's value, 'WixBundleInstalled', is one of the illegal options: 'AdminToolsFolder', 'AppDataFolder', 'CommonAppDataFolder', 'CommonFiles64Folder', 'CommonFilesFolder', 'CompatibilityMode', 'Date', 'DesktopFolder', 'FavoritesFolder', 'FontsFolder', 'InstallerName', 'InstallerVersion', 'LocalAppDataFolder', 'LogonUser', 'MyPicturesFolder', 'NativeMachine', 'NTProductType', 'NTSuiteBackOffice', 'NTSuiteDataCenter', 'NTSuiteEnterprise', 'NTSuitePersonal', 'NTSuiteSmallBusiness', 'NTSuiteSmallBusinessRestricted', 'NTSuiteWebServer', 'PersonalFolder', 'Privileged', 'ProgramFiles64Folder', 'ProgramFiles6432Folder', 'ProgramFilesFolder', 'ProgramMenuFolder', 'RebootPending', 'SendToFolder', 'ServicePackLevel', 'StartMenuFolder', 'StartupFolder', 'System64Folder', 'SystemFolder', 'TempFolder', 'TemplateFolder', 'TerminalServer', 'UserLanguageID', 'UserUILanguageID', 'VersionMsi', 'VersionNT', 'VersionNT64', 'WindowsFolder', 'WindowsVolume', 'WixBundleAction', 'WixBundleCommandLineAction', 'WixBundleForcedRestartPackage', 'WixBundleElevated', 'WixBundleInstalled', 'WixBundleProviderKey', 'WixBundleTag', or 'WixBundleVersion'.",
+                    "The CommandLine/@Condition attribute's value '=' is not a valid bundle condition.",
+                    "The MsiPackage/@InstallCondition attribute's value '=' is not a valid bundle condition.",
+                    "The MsiProperty/@Condition attribute's value '=' is not a valid bundle condition.",
+                    //"The Variable/@Name attribute's value, 'WixBundleInstalled', is one of the illegal options: 'AdminToolsFolder', 'AppDataFolder', 'CommonAppDataFolder', 'CommonFiles64Folder', 'CommonFilesFolder', 'CompatibilityMode', 'Date', 'DesktopFolder', 'FavoritesFolder', 'FontsFolder', 'InstallerName', 'InstallerVersion', 'LocalAppDataFolder', 'LogonUser', 'MyPicturesFolder', 'NativeMachine', 'NTProductType', 'NTSuiteBackOffice', 'NTSuiteDataCenter', 'NTSuiteEnterprise', 'NTSuitePersonal', 'NTSuiteSmallBusiness', 'NTSuiteSmallBusinessRestricted', 'NTSuiteWebServer', 'PersonalFolder', 'Privileged', 'ProgramFiles64Folder', 'ProgramFiles6432Folder', 'ProgramFilesFolder', 'ProgramMenuFolder', 'RebootPending', 'SendToFolder', 'ServicePackLevel', 'StartMenuFolder', 'StartupFolder', 'System64Folder', 'SystemFolder', 'TempFolder', 'TemplateFolder', 'TerminalServer', 'UserLanguageID', 'UserUILanguageID', 'VersionMsi', 'VersionNT', 'VersionNT64', 'WindowsFolder', 'WindowsVolume', 'WixBundleAction', 'WixBundleCommandLineAction', 'WixBundleForcedRestartPackage', 'WixBundleElevated', 'WixBundleInstalled', 'WixBundleProviderKey', 'WixBundleTag', or 'WixBundleVersion'.",
+                    "The 'REINSTALLMODE' MsiProperty is controlled by the bootstrapper and cannot be authored. (Illegal properties are: 'ACTION', 'ADDLOCAL', 'ADDSOURCE', 'ADDDEFAULT', 'ADVERTISE', 'ALLUSERS', 'REBOOT', 'REINSTALL', 'REINSTALLMODE', or 'REMOVE'.) Remove the MsiProperty element.",
+                }, messages.ToArray());
+            }
+        }
     }
 }
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxl b/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxl
new file mode 100644
index 00000000..0b5fac56
--- /dev/null
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxl
@@ -0,0 +1,8 @@
+<WixLocalization xmlns="http://wixtoolset.org/schemas/v4/wxl" Culture="en-US">
+  <String Id="BuiltinMsiPropertyName">REINSTALLMODE</String>
+  <String Id="BuiltinBurnVariableName">WixBundleInstalled</String>
+  <String Id="NonsenseDetectCondition">WixBundleAction = 4</String>
+  <String Id="NonsenseExecuteCondition">=</String>
+  <String Id="NonsenseGlobalCondition">WixBundleInstalled &lt;&gt; 1</String>
+  <String Id="NonsensePlanCondition">=</String>
+</WixLocalization>
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxs b/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxs
new file mode 100644
index 00000000..504f6e48
--- /dev/null
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/TestData/BundleWithInvalid/BundleWithInvalidLocValues.wxs
@@ -0,0 +1,18 @@
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+    <Bundle Name="BundleWithInvalidUpgradeCode" Condition="!(loc.NonsenseGlobalCondition)"
+            Version="1.0.0.0" Manufacturer="Example Corporation" UpgradeCode="{F2A56B65-2105-44C8-A532-A93A8C169D07}">
+        <BootstrapperApplication>
+            <BootstrapperApplicationDll SourceFile="fakeba.dll" />
+        </BootstrapperApplication>
+        <Chain>
+            <MsiPackage SourceFile="example.msi" InstallCondition="!(loc.NonsensePlanCondition)">
+                <MsiProperty Condition="!(loc.NonsenseExecuteCondition)" Name="!(loc.BuiltinMsiPropertyName)" Value="1" />
+            </MsiPackage>
+            <ExePackage DetectCondition="!(loc.NonsenseDetectCondition)" UninstallArguments="-uninstall" SourceFile="burn.exe">
+                <CommandLine Condition="!(loc.NonsenseExecuteCondition)" />
+            </ExePackage>
+        </Chain>
+        <Variable Name="!(loc.BuiltinBurnVariableName)" Value="1" />
+        <SetVariable Id="Builtin" Condition="!(loc.NonsenseDetectCondition)" Variable="!(loc.BuiltinBurnVariableName)" Value="1" />
+    </Bundle>
+</Wix>