Fix bug in Async ExecuteXmlReader implementation

Fixes #781

Author: cheenamalhotra

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlCommand.cs

@@ -1779,7 +1779,7 @@ private XmlReader EndExecuteXmlReaderInternal(IAsyncResult asyncResult)
             try
             {
                 success = true;
-                return CompleteXmlReader(InternalEndExecuteReader(asyncResult, false, nameof(EndExecuteXmlReader)));
+                return CompleteXmlReader(InternalEndExecuteReader(asyncResult, false, nameof(EndExecuteXmlReader)), true);
             }
             catch (Exception e)
             {

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

@@ -2265,7 +2265,7 @@ private XmlReader EndExecuteXmlReaderInternal(IAsyncResult asyncResult)
             int? sqlExceptionNumber = null;
             try
             {
-                XmlReader result = CompleteXmlReader(InternalEndExecuteReader(asyncResult, ADP.EndExecuteXmlReader, isInternal: false));
+                XmlReader result = CompleteXmlReader(InternalEndExecuteReader(asyncResult, ADP.EndExecuteXmlReader, isInternal: false), true);
                 success = true;
                 return result;
             }
@@ -2299,7 +2299,7 @@ private XmlReader EndExecuteXmlReaderInternal(IAsyncResult asyncResult)
             }
         }
 
-        private XmlReader CompleteXmlReader(SqlDataReader ds)
+        private XmlReader CompleteXmlReader(SqlDataReader ds, bool async = false)
         {
             XmlReader xr = null;
 
@@ -2313,7 +2313,7 @@ private XmlReader CompleteXmlReader(SqlDataReader ds)
                 try
                 {
                     SqlStream sqlBuf = new SqlStream(ds, true /*addByteOrderMark*/, (md[0].SqlDbType == SqlDbType.Xml) ? false : true /*process all rows*/);
-                    xr = sqlBuf.ToXmlReader();
+                    xr = sqlBuf.ToXmlReader(async);
                 }
                 catch (Exception e)
                 {

src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/AsyncTest/XmlReaderAsyncTest.cs

@@ -4,22 +4,23 @@
 
 using System;
 using System.Xml;
+using System.Xml.Linq;
 using Xunit;
 
 namespace Microsoft.Data.SqlClient.ManualTesting.Tests
 {
     public static class XmlReaderAsyncTest
     {
-        private static string commandText =
+        private const string CommandText =
             "SELECT * from dbo.Customers FOR XML AUTO, XMLDATA;";
 
         // Synapse: Parse error at line: 1, column: 29: Incorrect syntax near 'FOR'.
         [ConditionalFact(typeof(DataTestUtility), nameof(DataTestUtility.AreConnStringsSetup), nameof(DataTestUtility.IsNotAzureSynapse))]
         public static void ExecuteTest()
         {
             using (SqlConnection connection = new SqlConnection(DataTestUtility.TCPConnectionString))
+            using (SqlCommand command = new SqlCommand(CommandText, connection))
             {
-                SqlCommand command = new SqlCommand(commandText, connection);
                 connection.Open();
 
                 IAsyncResult result = command.BeginExecuteXmlReader();
@@ -28,10 +29,13 @@ public static void ExecuteTest()
                     System.Threading.Thread.Sleep(100);
                 }
 
-                XmlReader reader = command.EndExecuteXmlReader(result);
-
-                reader.ReadToDescendant("dbo.Customers");
-                Assert.Equal("ALFKI", reader["CustomerID"]);
+                using (XmlReader xmlReader = command.EndExecuteXmlReader(result))
+                {
+                    // Issue #781: Test failed here as xmlReader.Settings.Async was set to false
+                    Assert.True(xmlReader.Settings.Async);
+                    xmlReader.ReadToDescendant("dbo.Customers");
+                    Assert.Equal("ALFKI", xmlReader["CustomerID"]);
+                }
             }
         }
 
@@ -40,8 +44,8 @@ public static void ExecuteTest()
         public static void ExceptionTest()
         {
             using (SqlConnection connection = new SqlConnection(DataTestUtility.TCPConnectionString))
+            using (SqlCommand command = new SqlCommand(CommandText, connection))
             {
-                SqlCommand command = new SqlCommand(commandText, connection);
                 connection.Open();
 
                 //Try to execute a synchronous query on same command
@@ -55,10 +59,39 @@ public static void ExceptionTest()
                     System.Threading.Thread.Sleep(100);
                 }
 
-                XmlReader reader = command.EndExecuteXmlReader(result);
+                using (XmlReader xmlReader = command.EndExecuteXmlReader(result))
+                {
+                    // Issue #781: Test failed here as xmlReader.Settings.Async was set to false
+                    Assert.True(xmlReader.Settings.Async);
+                    xmlReader.ReadToDescendant("dbo.Customers");
+                    Assert.Equal("ALFKI", xmlReader["CustomerID"]);
+                }
+            }
+        }
+
+        // Synapse: Parse error at line: 1, column: 29: Incorrect syntax near 'FOR'.
+        [ConditionalFact(typeof(DataTestUtility), nameof(DataTestUtility.AreConnStringsSetup), nameof(DataTestUtility.IsNotAzureSynapse))]
+        public static async void MoveToContentAsyncTest()
+        {
+            using (SqlConnection connection = new SqlConnection(DataTestUtility.TCPConnectionString))
+            using (SqlCommand command = new SqlCommand(CommandText, connection))
+            {
+                connection.Open();
 
-                reader.ReadToDescendant("dbo.Customers");
-                Assert.Equal("ALFKI", reader["CustomerID"]);
+                using (XmlReader xmlReader = await command.ExecuteXmlReaderAsync().ConfigureAwait(false))
+                {
+                    try
+                    {
+                        // Issue #781: Test failed here as xmlReader.Settings.Async was set to false
+                        Assert.True(xmlReader.Settings.Async);
+                        xmlReader.ReadToDescendant("dbo.Customers");
+                        Assert.Equal("ALFKI", xmlReader["CustomerID"]);
+                    }
+                    catch (Exception ex)
+                    {
+                        Assert.False(true, "Exception occurred: " + ex.Message);
+                    }
+                }
             }
         }
     }