Fix computation of app path when published as a "single file"

src/shared/Git-Credential-Manager/Program.cs

@@ -3,6 +3,7 @@
 using System;
 using System.IO;
 using System.Reflection;
+using System.Runtime.InteropServices;
 using Atlassian.Bitbucket;
 using GitHub;
 using Microsoft.AzureRepos;
@@ -36,16 +37,19 @@ public static void Main(string[] args)
 
         private static string GetApplicationPath()
         {
-            Assembly entryAssembly = Assembly.GetExecutingAssembly();
-            if (entryAssembly is null)
-            {
-                throw new InvalidOperationException();
-            }
+            // Assembly::Location always returns an empty string if the application was published as a single file
+#pragma warning disable IL3000
+            bool isSingleFile = string.IsNullOrEmpty(Assembly.GetEntryAssembly()?.Location);
+#pragma warning restore IL3000
 
-            string candidatePath = entryAssembly.Location;
+            // Use "argv[0]" to get the full path to the entry executable - this is consistent across
+            // .NET Framework and .NET >= 5 when published as a single file.
+            string[] args = Environment.GetCommandLineArgs();
+            string candidatePath = args[0];
 
-            // Strip the .dll from assembly name on Mac and Linux
-            if (!PlatformUtils.IsWindows() && Path.HasExtension(candidatePath))
+            // If we have not been published as a single file on .NET 5 then we must strip the ".dll" file extension
+            // to get the default AppHost/SuperHost name.
+            if (!isSingleFile && Path.HasExtension(candidatePath))
             {
                 return Path.ChangeExtension(candidatePath, null);
             }

src/shared/Microsoft.Git.CredentialManager/Application.cs

@@ -76,8 +76,13 @@ protected override async Task<int> RunInternalAsync(string[] args)
                 rootCommand.AddCommand(providerCommand);
             }
 
-            // Trace the current version and program arguments
-            Context.Trace.WriteLine($"{Constants.GetProgramHeader()} '{string.Join(" ", args)}'");
+            // Trace the current version, OS, runtime, and program arguments
+            PlatformInformation info = PlatformUtils.GetPlatformInformation();
+            Context.Trace.WriteLine($"Version: {Constants.GcmVersion}");
+            Context.Trace.WriteLine($"Runtime: {info.ClrVersion}");
+            Context.Trace.WriteLine($"Platform: {info.OperatingSystemType} ({info.CpuArchitecture})");
+            Context.Trace.WriteLine($"AppPath: {_appPath}");
+            Context.Trace.WriteLine($"Arguments: {string.Join(" ", args)}");
 
             try
             {

src/shared/Microsoft.Git.CredentialManager/Constants.cs

@@ -1,6 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
-using System.Diagnostics;
+using System;
 using System.Reflection;
 
 namespace Microsoft.Git.CredentialManager
@@ -105,35 +105,35 @@ public static class HelpUrls
             public const string GcmLinuxCredStores     = "https://aka.ms/gcmcore-linuxcredstores";
         }
 
-        private static string _gcmVersion;
+        private static Version _gcmVersion;
 
-        /// <summary>
-        /// The current version of Git Credential Manager.
-        /// </summary>
-        public static string GcmVersion
+        public static Version GcmVersion
         {
             get
             {
                 if (_gcmVersion is null)
                 {
-                    _gcmVersion = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location).ProductVersion;
+                    var assembly = Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly();
+                    var attr = assembly.GetCustomAttribute<AssemblyFileVersionAttribute>();
+                    if (attr is null)
+                    {
+                        _gcmVersion = assembly.GetName().Version;
+                    }
+                    else if (Version.TryParse(attr.Version, out Version asmVersion))
+                    {
+                        _gcmVersion = asmVersion;
+                    }
+                    else
+                    {
+                        // Unknown version!
+                        _gcmVersion = new Version(0, 0);
+                    }
                 }
 
                 return _gcmVersion;
             }
         }
 
-        /// <summary>
-        /// Get standard program header title for Git Credential Manager, including the current version and OS information.
-        /// </summary>
-        /// <returns>Standard program header.</returns>
-        public static string GetProgramHeader()
-        {
-            PlatformInformation info = PlatformUtils.GetPlatformInformation();
-
-            return $"Git Credential Manager version {GcmVersion} ({info.OperatingSystemType}, {info.ClrVersion})";
-        }
-
         /// <summary>
         /// Get the HTTP user-agent for Git Credential Manager.
         /// </summary>