[3.1.2] Backport: Fix | Default UTF8 collation conflict

src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -3063,20 +3063,13 @@ private bool TryProcessEnvChange(int tokenLength, TdsParserStateObject stateObj,
                             _defaultCollation = env.newCollation;
                             _defaultLCID = env.newCollation.LCID;
 
-                            int newCodePage = GetCodePage(env.newCollation, stateObj);
-
                             if ((env.newCollation.info & TdsEnums.UTF8_IN_TDSCOLLATION) == TdsEnums.UTF8_IN_TDSCOLLATION)
                             { // UTF8 collation
                                 _defaultEncoding = Encoding.UTF8;
-
-                                if (newCodePage != _defaultCodePage)
-                                {
-                                    _defaultCodePage = newCodePage;
-                                }
                             }
                             else
                             {
-
+                                int newCodePage = GetCodePage(env.newCollation, stateObj);
                                 if (newCodePage != _defaultCodePage)
                                 {
                                     _defaultCodePage = newCodePage;

src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/Utf8SupportTest/Utf8SupportTest.cs

@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Text;
+using System;
 using Xunit;
 
 namespace Microsoft.Data.SqlClient.ManualTesting.Tests
@@ -29,6 +31,64 @@ public static void CheckSupportUtf8ConnectionProperty()
             }
         }
 
-        // TODO: Write tests using UTF8 collations
+        // skip creating database on Azure
+        [ConditionalFact(typeof(DataTestUtility), nameof(DataTestUtility.AreConnStringsSetup), nameof(DataTestUtility.IsNotAzureServer), nameof(DataTestUtility.IsNotAzureSynapse))]
+        public static void UTF8databaseTest()
+        {
+            const string letters = @"!\#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\u007f€\u0081‚ƒ„…†‡ˆ‰Š‹Œ\u008dŽ\u008f\u0090‘’“”•–—˜™š›œ\u009džŸ ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ";
+            string dbName = DataTestUtility.GetUniqueNameForSqlServer("UTF8databaseTest", false);
+            string tblName = "Table1";
+
+            SqlConnectionStringBuilder builder = new(DataTestUtility.TCPConnectionString);
+            builder.InitialCatalog = "master";
+
+            using SqlConnection cn = new(builder.ConnectionString);
+            cn.Open();
+
+            try
+            {
+                PrepareDatabaseUTF8(cn, dbName, tblName, letters);
+
+                builder.InitialCatalog = dbName;
+                using SqlConnection cnnTest = new(builder.ConnectionString);
+                // creating a databse is a time consumer action and could be retried.
+                SqlRetryLogicOption retryOption = new() { NumberOfTries = 3, DeltaTime = TimeSpan.FromMilliseconds(200) };
+                cnnTest.RetryLogicProvider = SqlConfigurableRetryFactory.CreateIncrementalRetryProvider(retryOption);
+                cnnTest.Open();
+
+                using SqlCommand cmd = cnnTest.CreateCommand();
+                cmd.CommandText = $"SELECT * FROM {tblName}";
+
+                using SqlDataReader reader = cmd.ExecuteReader();
+
+                Assert.True(reader.Read(), "The test table should have a row!");
+                object[] data = new object[1];
+                reader.GetSqlValues(data);
+                Assert.Equal(letters, data[0].ToString());
+                reader.Close();
+                cnnTest.Close();
+            }
+            finally
+            {
+                DataTestUtility.DropDatabase(cn, dbName);
+            }
+        }
+
+        private static void PrepareDatabaseUTF8(SqlConnection cnn, string dbName, string tblName, string letters)
+        {
+            StringBuilder sb = new();
+
+            using SqlCommand cmd = cnn.CreateCommand();
+
+            cmd.CommandText = $"CREATE DATABASE [{dbName}] COLLATE Latin1_General_100_CI_AS_SC_UTF8;";
+            cmd.ExecuteNonQuery();
+
+            sb.AppendLine($"CREATE TABLE [{dbName}].dbo.[{tblName}] (col VARCHAR(7633) COLLATE Latin1_General_100_CI_AS_SC);");
+            sb.AppendLine($"INSERT INTO [{dbName}].dbo.[{tblName}] VALUES (@letters);");
+
+            cmd.Parameters.Add(new SqlParameter("letters", letters));
+            cmd.CommandText = sb.ToString();
+            cmd.ExecuteNonQuery();
+        }
     }
 }