Modified TaskPrincipal to handle odd condition #835 where UserId is stored as DOMAIN\User rather than the SID. The Account property will now always display the name.

Author: dahall

TaskService/Task.cs

@@ -2227,7 +2227,12 @@ public string Account
 						{
 							var un = pn["UserId"] ?? pn["GroupId"];
 							if (un != null)
-								try { return User.FromSidString(un.InnerText).Name; } catch { return un.Value; }
+								try { return User.FromSidString(un.InnerText).Name; }
+								catch
+								{
+									try { return new User(un.InnerText).Name; }
+									catch { }
+								}
 						}
 					}
 					return new User(ToString()).Name;

TaskService/User.cs

@@ -6,48 +6,48 @@ namespace Microsoft.Win32.TaskScheduler
 	/// <summary>Represents a system account.</summary>
 	internal class User : IEquatable<User>, IDisposable
 	{
-		private WindowsIdentity acct;
+		private static readonly WindowsIdentity cur = WindowsIdentity.GetCurrent();
 		private SecurityIdentifier sid;
 
 		/// <summary>Initializes a new instance of the <see cref="User"/> class.</summary>
 		/// <param name="userName">
-		/// Name of the user. This can be in the format <c>DOMAIN\username</c> or <c>username@domain.com</c> or <c>username</c> or <c>null</c> (for current user).
+		/// Name of the user. This can be in the format <c>DOMAIN\username</c> or <c>username@domain.com</c> or <c>username</c> or
+		/// <c>null</c> (for current user).
 		/// </param>
 		public User(string userName = null)
 		{
-			var cur = WindowsIdentity.GetCurrent();
 			if (string.IsNullOrEmpty(userName)) userName = null;
-			// 2018-03-02: Hopefully not a breaking change, but by adding in the comparison of an account name without a domain and the current user, there is a
-			// chance that current implementations will break given the condition that a local account with the same name as a domain account exists and the
-			// intention was to prefer the local account. In such a case, the developer should prepend the user name in TaskDefinition.Principal.UserId with the
-			// machine name of the local machine.
+			// 2018-03-02: Hopefully not a breaking change, but by adding in the comparison of an account name without a domain and the
+			// current user, there is a chance that current implementations will break given the condition that a local account with the same
+			// name as a domain account exists and the intention was to prefer the local account. In such a case, the developer should
+			// prepend the user name in TaskDefinition.Principal.UserId with the machine name of the local machine.
 			if (userName == null || cur.Name.Equals(userName, StringComparison.InvariantCultureIgnoreCase) || GetUser(cur.Name).Equals(userName, StringComparison.InvariantCultureIgnoreCase))
 			{
-				acct = cur;
-				sid = acct.User;
+				Identity = cur;
+				sid = Identity.User;
 			}
 			else if (userName.Contains("\\") && !userName.StartsWith(@"NT AUTHORITY\"))
 			{
 				try
 				{
 					using (var ds = new NativeMethods.DomainService())
 					{
-						acct = new WindowsIdentity(ds.CrackName(userName));
-						sid = acct.User;
+						Identity = new WindowsIdentity(ds.CrackName(userName));
+						sid = Identity.User;
 					}
 				}
 				catch { }
 			}
 
-			if (acct == null)
+			if (Identity == null)
 			{
 				if (userName != null && userName.Contains("@"))
 				{
-					acct = new WindowsIdentity(userName);
-					sid = acct.User;
+					Identity = new WindowsIdentity(userName);
+					sid = Identity.User;
 				}
 
-				if (acct == null && userName != null)
+				if (Identity == null && userName != null)
 				{
 					var ntacct = new NTAccount(userName);
 					try { sid = (SecurityIdentifier)ntacct.Translate(typeof(SecurityIdentifier)); } catch { }
@@ -63,23 +63,23 @@ string GetUser(string domUser)
 
 		/// <summary>Initializes a new instance of the <see cref="User"/> class.</summary>
 		/// <param name="wid">The <see cref="WindowsIdentity"/>.</param>
-		internal User(WindowsIdentity wid) { acct = wid; sid = wid.User; }
+		internal User(WindowsIdentity wid) { Identity = wid; sid = wid.User; }
 
 		/// <summary>Gets the current user.</summary>
 		/// <value>The current user.</value>
-		public static User Current => new User(WindowsIdentity.GetCurrent());
+		public static User Current => new User(cur);
 
 		/// <summary>Gets the identity.</summary>
 		/// <value>The identity.</value>
-		public WindowsIdentity Identity => acct;
+		public WindowsIdentity Identity { get; private set; }
 
 		/// <summary>Gets a value indicating whether this instance is in an administrator role.</summary>
 		/// <value><c>true</c> if this instance is an admin; otherwise, <c>false</c>.</value>
-		public bool IsAdmin => acct != null ? new WindowsPrincipal(acct).IsInRole(WindowsBuiltInRole.Administrator) : false;
+		public bool IsAdmin => Identity != null ? new WindowsPrincipal(Identity).IsInRole(WindowsBuiltInRole.Administrator) : false;
 
 		/// <summary>Gets a value indicating whether this instance is the interactive user.</summary>
 		/// <value><c>true</c> if this instance is the current user; otherwise, <c>false</c>.</value>
-		public bool IsCurrent => acct?.User.Equals(WindowsIdentity.GetCurrent().User) ?? false;
+		public bool IsCurrent => Identity?.User.Equals(cur.User) ?? false;
 
 		/// <summary>Gets a value indicating whether this instance is a service account.</summary>
 		/// <value><c>true</c> if this instance is a service account; otherwise, <c>false</c>.</value>
@@ -106,18 +106,15 @@ public bool IsServiceAccount
 
 		/// <summary>Gets the NT name (DOMAIN\username).</summary>
 		/// <value>The name of the user.</value>
-		public string Name => acct?.Name ?? ((NTAccount)sid?.Translate(typeof(NTAccount)))?.Value;
+		public string Name => Identity?.Name ?? ((NTAccount)sid?.Translate(typeof(NTAccount)))?.Value;
 
 		/// <summary>Create a <see cref="User"/> instance from a SID string.</summary>
 		/// <param name="sid">The SID string.</param>
 		/// <returns>A <see cref="User"/> instance.</returns>
 		public static User FromSidString(string sid) => new User(((NTAccount)new SecurityIdentifier(sid).Translate(typeof(NTAccount))).Value);
 
 		/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
-		public void Dispose()
-		{
-			acct?.Dispose();
-		}
+		public void Dispose() => Identity?.Dispose();
 
 		/// <summary>Determines whether the specified <see cref="System.Object"/>, is equal to this instance.</summary>
 		/// <param name="obj">The <see cref="System.Object"/> to compare with this instance.</param>