Proper handling when no params are in batch.

Author: cincuranet

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbBatchCommand.cs

@@ -558,6 +558,10 @@ public int GetCurrentBatchSize()
 		{
 			throw new InvalidOperationException("Batch must be prepared.");
 		}
+		if (!HasParameters)
+		{
+			return 0;
+		}
 		return _batch.ComputeBatchSize(_batchParameters.Count, this);
 	}
 	public async Task<int> GetCurrentBatchSizeAsync(CancellationToken cancellationToken = default)
@@ -566,6 +570,10 @@ public async Task<int> GetCurrentBatchSizeAsync(CancellationToken cancellationTo
 		{
 			throw new InvalidOperationException("Batch must be prepared.");
 		}
+		if (!HasParameters)
+		{
+			return 0;
+		}
 		return await _batch.ComputeBatchSizeAsync(_batchParameters.Count, this, cancellationToken).ConfigureAwait(false);
 	}