From eb2f85d7ee5ad5c91af0943ffe936ee8ccfdab0d Mon Sep 17 00:00:00 2001
From: Bob Arnson <bob@firegiant.com>
Date: Sat, 3 Feb 2024 22:52:23 -0500
Subject: [PATCH] Improve error when virtual action symbols collide.

---
 .../TestData/CloseApplication/Package.wxs          | 14 +++++++++-----
 .../Link/ReportConflictingSymbolsCommand.cs        | 11 ++++++++++-
 src/wix/WixToolset.Core/LinkerErrors.cs            |  6 ++++++
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/ext/Util/test/WixToolsetTest.Util/TestData/CloseApplication/Package.wxs b/src/ext/Util/test/WixToolsetTest.Util/TestData/CloseApplication/Package.wxs
index 8e0542569..8dba33b42 100644
--- a/src/ext/Util/test/WixToolsetTest.Util/TestData/CloseApplication/Package.wxs
+++ b/src/ext/Util/test/WixToolsetTest.Util/TestData/CloseApplication/Package.wxs
@@ -1,4 +1,4 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:util="http://wixtoolset.org/schemas/v4/wxs/util">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:util="http://wixtoolset.org/schemas/v4/wxs/util">
     <Package Name="MsiPackage" Language="1033" Version="1.0.0.0" Manufacturer="Example Corporation" UpgradeCode="047730a5-30fe-4a62-a520-da9381b8226a">
         <MajorUpgrade DowngradeErrorMessage="!(loc.DowngradeError)" />
 
@@ -7,11 +7,15 @@
         </Feature>
 
         <util:CloseApplication Id="CloseMyApp" CloseMessage="yes" Property="MYAPPISRUNNING" Target="explorer.exe" />
+
+        <InstallExecuteSequence>
+            <Custom Action="override Wix4CloseApplications_$(sys.BUILDARCHSHORT)" After="InstallInitialize" />
+        </InstallExecuteSequence>
     </Package>
 
     <Fragment>
-            <StandardDirectory Id="ProgramFilesFolder">
-                <Directory Id="INSTALLFOLDER" Name="MsiPackage" />
-            </StandardDirectory>
-        </Fragment>
+        <StandardDirectory Id="ProgramFilesFolder">
+            <Directory Id="INSTALLFOLDER" Name="MsiPackage" />
+        </StandardDirectory>
+    </Fragment>
 </Wix>
diff --git a/src/wix/WixToolset.Core/Link/ReportConflictingSymbolsCommand.cs b/src/wix/WixToolset.Core/Link/ReportConflictingSymbolsCommand.cs
index 2851fa60a..b1db46a2d 100644
--- a/src/wix/WixToolset.Core/Link/ReportConflictingSymbolsCommand.cs
+++ b/src/wix/WixToolset.Core/Link/ReportConflictingSymbolsCommand.cs
@@ -5,6 +5,7 @@ namespace WixToolset.Core.Link
     using System.Collections.Generic;
     using System.Linq;
     using WixToolset.Data;
+    using WixToolset.Data.Symbols;
     using WixToolset.Extensibility.Services;
 
     internal class ReportConflictingSymbolsCommand
@@ -62,7 +63,15 @@ public void Execute()
 
                             reportDuplicates = virtualConflicts;
 
-                            this.Messaging.Write(LinkerErrors.VirtualSymbolMustBeOverridden(first.Symbol, referencingSourceLineNumber));
+                            switch (first.Symbol)
+                            {
+                                case WixActionSymbol action:
+                                    this.Messaging.Write(LinkerErrors.VirtualSymbolMustBeOverridden(action));
+                                    break;
+                                default:
+                                    this.Messaging.Write(LinkerErrors.VirtualSymbolMustBeOverridden(first.Symbol, referencingSourceLineNumber));
+                                    break;
+                            }
                         }
                         else
                         {
diff --git a/src/wix/WixToolset.Core/LinkerErrors.cs b/src/wix/WixToolset.Core/LinkerErrors.cs
index c234087e3..ab30e8c6a 100644
--- a/src/wix/WixToolset.Core/LinkerErrors.cs
+++ b/src/wix/WixToolset.Core/LinkerErrors.cs
@@ -3,6 +3,7 @@
 namespace WixToolset.Core
 {
     using WixToolset.Data;
+    using WixToolset.Data.Symbols;
 
     internal static class LinkerErrors
     {
@@ -101,6 +102,11 @@ public static Message VirtualSymbolMustBeOverridden(IntermediateSymbol symbol)
             return Message(symbol.SourceLineNumbers, Ids.VirtualSymbolMustBeOverridden, "The {0} symbol '{1}' conflicts with a virtual symbol. Use the 'override' access modifier to override the virtual symbol or use a different Id to avoid the conflict.", symbol.Definition.Name, symbol.Id.Id);
         }
 
+        public static Message VirtualSymbolMustBeOverridden(WixActionSymbol actionSymbol)
+        {
+            return Message(actionSymbol.SourceLineNumbers, Ids.VirtualSymbolMustBeOverridden, "The action '{0}' conflicts with a virtual symbol with the same id. To override the virtual symbol (e.g., to reschedule a custom action), use the 'override' access modifier: 'override {0}'. If you didn't intend to override a virtual symbol, use a different id to avoid the conflict.", actionSymbol.Action);
+        }
+
         public static Message VirtualSymbolMustBeOverridden(IntermediateSymbol symbol, SourceLineNumber referencingSourceLineNumber)
         {
             if (referencingSourceLineNumber is null)