By defensive with command and reader access due to issues with MySQL …

…provider

Issue #10147

* MySQL provider sometimes has null Parameters collection
* MySQL provider sometimes throws when asking for records affected

Fix is to be defensive in our code and we will file issues on MySQL provider

src/EFCore.Relational/Storage/RelationalDataReader.cs

@@ -111,12 +111,22 @@ public virtual void Dispose()
  {
  if (!_disposed)
  {
+ // Defensively read RecordsAffected since MySQL provider can throw ObjectDisposedException
+ var recordsAffected = -1;
+ try
+ {
+ recordsAffected = _reader.RecordsAffected;
+ }
+ catch
+ {
+ }
+
  _logger.DataReaderDisposing(
  _connection,
  _command,
  _reader,
  _commandId,
- _reader.RecordsAffected,
+ recordsAffected,
  _readCount,
  _startTime,
  _stopwatch.Elapsed);
@@ -125,7 +135,7 @@ public virtual void Dispose()
  if (!AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue9277", out var isEnabled)
  || !isEnabled)
  {
- _command.Parameters.Clear();
+ _command.Parameters?.Clear();
  }
  _command.Dispose();
  _connection?.Close();