Fixing missing arguments for TransfoXL tokenizer when using TextGenerationPipeline (#5465)

* overriding _parse_and_tokenize in `TextGenerationPipeine` to allow for TransfoXl tokenizer arguments

src/transformers/pipelines.py

@@ -615,6 +615,28 @@ class TextGenerationPipeline(Pipeline):
         "TFCTRLLMHeadModel",
     ]
 
+    # overriding _parse_and_tokenize to allow for unusual language-modeling tokenizer arguments
+
+    def _parse_and_tokenize(self, *args, padding=True, add_special_tokens=True, **kwargs):
+        """
+        Parse arguments and tokenize
+        """
+        # Parse arguments
+        if self.model.__class__.__name__ in ["TransfoXLLMHeadModel"]:
+            tokenizer_kwargs = {"add_space_before_punct_symbol": True}
+        else:
+            tokenizer_kwargs = {}
+        inputs = self._args_parser(*args, **kwargs)
+        inputs = self.tokenizer(
+            inputs,
+            add_special_tokens=add_special_tokens,
+            return_tensors=self.framework,
+            padding=padding,
+            **tokenizer_kwargs,
+        )
+
+        return inputs
+
     def __call__(
         self, *args, return_tensors=False, return_text=True, clean_up_tokenization_spaces=False, **generate_kwargs
     ):