Fix th-TH culture info issue on Managed SNI

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SNIProxy.cs

@@ -675,7 +675,7 @@ private void ReportSNIError(SNIProviders provider)
         private bool InferNamedPipesInformation()
         {
             // If we have a datasource beginning with a pipe or we have already determined that the protocol is Named Pipe
-            if (_dataSourceAfterTrimmingProtocol.StartsWith(PipeBeginning) || _connectionProtocol == Protocol.NP)
+            if (_dataSourceAfterTrimmingProtocol.StartsWith(PipeBeginning, StringComparison.OrdinalIgnoreCase) || _connectionProtocol == Protocol.NP)
             {
                 // If the data source is "np:servername"
                 if (!_dataSourceAfterTrimmingProtocol.Contains(PipeBeginning))
@@ -714,7 +714,7 @@ private bool InferNamedPipesInformation()
                         return false;
                     }
 
-                    if (tokensByBackSlash[4].StartsWith(NamedPipeInstanceNameHeader))
+                    if (tokensByBackSlash[4].StartsWith(NamedPipeInstanceNameHeader, StringComparison.OrdinalIgnoreCase))
                     {
                         InstanceName = tokensByBackSlash[4].Substring(NamedPipeInstanceNameHeader.Length);
                     }

src/Microsoft.Data.SqlClient/tests/FunctionalTests/SqlConnectionBasicTests.cs

@@ -5,8 +5,10 @@
 using System;
 using System.Data;
 using System.Data.Common;
+using System.Globalization;
 using System.Reflection;
 using System.Security;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SqlServer.TDS.Servers;
 using Xunit;
@@ -23,6 +25,27 @@ public void ConnectionTest()
             connection.Open();
         }
 
+        [Fact]
+        public void ConnectionTestWithCultureTH()
+        {
+            // Save current cultures
+            CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
+            CultureInfo currentUICulture = Thread.CurrentThread.CurrentUICulture;
+
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("th-TH");
+            Thread.CurrentThread.CurrentUICulture = new CultureInfo("th-TH");
+
+            using TestTdsServer server = TestTdsServer.StartTestServer();
+            using SqlConnection connection = new SqlConnection(server.ConnectionString);
+            connection.Open();
+
+            // Restore saved cultures
+            Thread.CurrentThread.CurrentCulture = currentCulture;
+            Thread.CurrentThread.CurrentUICulture = currentUICulture;
+
+            Assert.Equal(ConnectionState.Open, connection.State);
+        }
+
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsNotArmProcess))]
         [ActiveIssue(4830, TestPlatforms.AnyUnix)]
         [PlatformSpecific(TestPlatforms.Windows)]