!4 update fastNLP/modules/encoder/seq2seq_encoder.py.

Merge pull request !4 from 刘向阳/N/A

fastNLP/modules/encoder/seq2seq_encoder.py

@@ -132,7 +132,7 @@ class TransformerSeq2SeqEncoder(Seq2SeqEncoder):
         x = self.input_fc(x)
         x = F.dropout(x, p=self.dropout, training=self.training)
 
-        encoder_mask = seq_len_to_mask(seq_len)
+        encoder_mask = seq_len_to_mask(seq_len, max_len=max_src_len)
         encoder_mask = encoder_mask.to(device)
 
         for layer in self.layer_stacks: