Implement GetFieldValue<Stream>. Fixes #631

Author: bgrainger

src/MySqlConnector/MySql.Data.MySqlClient/MySqlDataReader.cs

@@ -268,6 +268,8 @@ public override T GetFieldValue<T>(int ordinal)
 				return (T) Convert.ChangeType(GetDateTimeOffset(ordinal), typeof(T));
 			if (typeof(T) == typeof(TextReader) || typeof(T) == typeof(StringReader))
 				return (T) (object) GetTextReader(ordinal);
+			if (typeof(T) == typeof(Stream))
+				return (T) (object) GetStream(ordinal);
 
 			return base.GetFieldValue<T>(ordinal);
 		}

tests/SideBySide/DataTypes.cs

@@ -17,9 +17,11 @@
 #if BASELINE
 using GetValueWhenNullException = System.Data.SqlTypes.SqlNullValueException;
 using GetGuidWhenNullException = MySql.Data.MySqlClient.MySqlException;
+using GetBytesWhenNullException = System.NullReferenceException;
 #else
 using GetValueWhenNullException = System.InvalidCastException;
 using GetGuidWhenNullException = System.InvalidCastException;
+using GetBytesWhenNullException = System.InvalidCastException;
 #endif
 
 namespace SideBySide
@@ -824,13 +826,20 @@ public void QueryBlob(string column, int padLength)
 			if (data.Length < padLength)
 				Array.Resize(ref data, padLength);
 
-#if BASELINE
-			DoQuery<NullReferenceException>("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetBytes);
-			// https://bugs.mysql.com/bug.php?id=93374
-			// DoQuery<NullReferenceException>("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetStreamBytes);
-#else
-			DoQuery<InvalidCastException>("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetBytes);
-			DoQuery<InvalidCastException>("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetStreamBytes);
+			DoQuery<GetBytesWhenNullException>("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetBytes);
+#if !BASELINE // https://bugs.mysql.com/bug.php?id=93374
+			DoQuery("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, GetStreamBytes);
+			DoQuery("blobs", "`" + column + "`", "BLOB", new object[] { null, data }, reader => reader.GetStream(0), matchesDefaultType: false, assertEqual: (e, a) =>
+			{
+				using (var stream = (Stream) a)
+				{
+					Assert.True(stream.CanRead);
+					Assert.False(stream.CanWrite);
+					var bytes = new byte[stream.Length];
+					Assert.Equal(bytes.Length, stream.Read(bytes, 0, bytes.Length));
+					Assert.Equal(e, bytes);
+				}
+			}, getFieldValueType: typeof(Stream));
 #endif
 		}