Avoid using Regex when not necessary (PowerShell#18210)

Author: daxian-dbw

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHostRawUserInterface.cs

@@ -41,23 +41,16 @@ class ConsoleHostRawUserInterface : System.Management.Automation.Host.PSHostRawU
             //   (we may load resources which can take some time)
             Task.Run(() =>
             {
-                WindowsIdentity identity = WindowsIdentity.GetCurrent();
-                WindowsPrincipal principal = new WindowsPrincipal(identity);
+                var identity = WindowsIdentity.GetCurrent();
+                var principal = new WindowsPrincipal(identity);
                 if (principal.IsInRole(WindowsBuiltInRole.Administrator))
                 {
-                    string prefix = ConsoleHostRawUserInterfaceStrings.WindowTitleElevatedPrefix;
-
-                    // check using Regex if the window already has Administrator: prefix
-                    // (i.e. from the parent console process)
-                    string titlePattern = ConsoleHostRawUserInterfaceStrings.WindowTitleTemplate;
-                    titlePattern = Regex.Escape(titlePattern)
-                        .Replace(@"\{1}", ".*")
-                        .Replace(@"\{0}", Regex.Escape(prefix));
-                    if (!Regex.IsMatch(this.WindowTitle, titlePattern))
+                    // Check if the window already has the "Administrator: " prefix (i.e. from the parent console process).
+                    ReadOnlySpan<char> prefix = ConsoleHostRawUserInterfaceStrings.WindowTitleElevatedPrefix;
+                    ReadOnlySpan<char> windowTitle = WindowTitle;
+                    if (!windowTitle.StartsWith(prefix))
                     {
-                        this.WindowTitle = StringUtil.Format(ConsoleHostRawUserInterfaceStrings.WindowTitleTemplate,
-                            prefix,
-                            this.WindowTitle);
+                        WindowTitle = string.Concat(prefix, windowTitle);
                     }
                 }
             });

src/Microsoft.PowerShell.ConsoleHost/resources/ConsoleHostRawUserInterfaceStrings.resx

@@ -172,9 +172,6 @@
     <value>Window title cannot be longer than {0} characters.</value>
   </data>
   <data name="WindowTitleElevatedPrefix" xml:space="preserve">
-    <value>Administrator</value>
-  </data>
-  <data name="WindowTitleTemplate" xml:space="preserve">
-    <value>{0}: {1}</value>
+    <value>Administrator: </value>
   </data>
 </root>

src/System.Management.Automation/engine/PSVersionInfo.cs

@@ -53,20 +53,20 @@ public static class PSVersionInfo
         /// For each later release of PowerShell, this constant needs to
         /// be updated to reflect the right version.
         /// </remarks>
-        private static readonly Version s_psV1Version = new Version(1, 0);
-        private static readonly Version s_psV2Version = new Version(2, 0);
-        private static readonly Version s_psV3Version = new Version(3, 0);
-        private static readonly Version s_psV4Version = new Version(4, 0);
-        private static readonly Version s_psV5Version = new Version(5, 0);
-        private static readonly Version s_psV51Version = new Version(5, 1, NTVerpVars.PRODUCTBUILD, NTVerpVars.PRODUCTBUILD_QFE);
-        private static readonly SemanticVersion s_psV6Version = new SemanticVersion(6, 0, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psV61Version = new SemanticVersion(6, 1, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psV62Version = new SemanticVersion(6, 2, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psV7Version = new SemanticVersion(7, 0, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psV71Version = new SemanticVersion(7, 1, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psV72Version = new SemanticVersion(7, 2, 0, preReleaseLabel: null, buildLabel: null);
-        private static readonly SemanticVersion s_psSemVersion;
+        private static readonly Version s_psV1Version = new(1, 0);
+        private static readonly Version s_psV2Version = new(2, 0);
+        private static readonly Version s_psV3Version = new(3, 0);
+        private static readonly Version s_psV4Version = new(4, 0);
+        private static readonly Version s_psV5Version = new(5, 0);
+        private static readonly Version s_psV51Version = new(5, 1, NTVerpVars.PRODUCTBUILD, NTVerpVars.PRODUCTBUILD_QFE);
+        private static readonly Version s_psV6Version = new(6, 0, 0);
+        private static readonly Version s_psV61Version = new(6, 1, 0);
+        private static readonly Version s_psV62Version = new(6, 2, 0);
+        private static readonly Version s_psV7Version = new(7, 0, 0);
+        private static readonly Version s_psV71Version = new(7, 1, 0);
+        private static readonly Version s_psV72Version = new(7, 2, 0);
         private static readonly Version s_psVersion;
+        private static readonly SemanticVersion s_psSemVersion;
 
         /// <summary>
         /// A constant to track current PowerShell Edition.
@@ -108,13 +108,13 @@ static PSVersionInfo()
             s_psSemVersion = new SemanticVersion(mainVersion);
             s_psVersion = (Version)s_psSemVersion;
 
-            s_psVersionTable[PSVersionInfo.PSVersionName] = s_psSemVersion;
-            s_psVersionTable[PSVersionInfo.PSEditionName] = PSEditionValue;
+            s_psVersionTable[PSVersionName] = s_psSemVersion;
+            s_psVersionTable[PSEditionName] = PSEditionValue;
             s_psVersionTable[PSGitCommitIdName] = rawGitCommitId;
             s_psVersionTable[PSCompatibleVersionsName] = new Version[] { s_psV1Version, s_psV2Version, s_psV3Version, s_psV4Version, s_psV5Version, s_psV51Version, s_psV6Version, s_psV61Version, s_psV62Version, s_psV7Version, s_psV71Version, s_psV72Version, s_psVersion };
-            s_psVersionTable[PSVersionInfo.SerializationVersionName] = new Version(InternalSerializer.DefaultVersion);
-            s_psVersionTable[PSVersionInfo.PSRemotingProtocolVersionName] = RemotingConstants.ProtocolVersion;
-            s_psVersionTable[PSVersionInfo.WSManStackVersionName] = GetWSManStackVersion();
+            s_psVersionTable[SerializationVersionName] = new Version(InternalSerializer.DefaultVersion);
+            s_psVersionTable[PSRemotingProtocolVersionName] = RemotingConstants.ProtocolVersion;
+            s_psVersionTable[WSManStackVersionName] = GetWSManStackVersion();
             s_psVersionTable[PSPlatformName] = Environment.OSVersion.Platform.ToString();
             s_psVersionTable[PSOSName] = Runtime.InteropServices.RuntimeInformation.OSDescription;
         }
@@ -330,12 +330,12 @@ internal static Version PSV51Version
             get { return s_psV51Version; }
         }
 
-        internal static SemanticVersion PSV6Version
+        internal static Version PSV6Version
         {
             get { return s_psV6Version; }
         }
 
-        internal static SemanticVersion PSV7Version
+        internal static Version PSV7Version
         {
             get { return s_psV7Version; }
         }