Generate: min length can't be larger than max length

src/transformers/generation_flax_utils.py

@@ -259,6 +259,7 @@ def generate(
  ```"""
  # set init values
  max_length = max_length if max_length is not None else self.config.max_length
+ min_length = min_length if min_length is not None else self.config.min_length
  bos_token_id = bos_token_id if bos_token_id is not None else self.config.bos_token_id
  pad_token_id = pad_token_id if pad_token_id is not None else self.config.pad_token_id
  eos_token_id = eos_token_id if eos_token_id is not None else self.config.eos_token_id
@@ -269,6 +270,11 @@ def generate(
 
  if decoder_start_token_id is None and self.config.is_encoder_decoder:
  raise ValueError("`decoder_start_token_id` has to be defined for encoder-decoder generation.")
+ if min_length is not None and min_length > max_length:
+ raise ValueError(
+ f"Unfeasable length constraints: the minimum length ({min_length}) is larger than the maximum "
+ f"length ({max_length})"
+ )
 
  if self.config.is_encoder_decoder:
  # add encoder_outputs to model_kwargs
@@ -389,7 +395,6 @@ def _get_logits_processor(
  no_repeat_ngram_size = (
  no_repeat_ngram_size if no_repeat_ngram_size is not None else self.config.no_repeat_ngram_size
  )
- min_length = min_length if min_length is not None else self.config.min_length
  eos_token_id = eos_token_id if eos_token_id is not None else self.config.eos_token_id
  forced_bos_token_id = (
  forced_bos_token_id if forced_bos_token_id is not None else self.config.forced_bos_token_id

src/transformers/generation_tf_utils.py

@@ -1489,6 +1489,11 @@ def _generate(
  if pad_token_id is None and eos_token_id is not None:
  logger.warning(f"Setting `pad_token_id` to {eos_token_id} (first `eos_token_id`) to generate sequence")
  pad_token_id = eos_token_id
+ if min_length is not None and min_length > max_length:
+ raise ValueError(
+ f"Unfeasable length constraints: the minimum length ({min_length}) is larger than the maximum "
+ f"length ({max_length})"
+ )
 
  # 2. Define model inputs
  input_ids = self._prepare_model_inputs(input_ids, bos_token_id)

src/transformers/generation_utils.py

@@ -700,7 +700,6 @@ def _get_logits_processor(
  else self.config.encoder_no_repeat_ngram_size
  )
  bad_words_ids = bad_words_ids if bad_words_ids is not None else self.config.bad_words_ids
- min_length = min_length if min_length is not None else self.config.min_length
  eos_token_id = eos_token_id if eos_token_id is not None else self.config.eos_token_id
  diversity_penalty = diversity_penalty if diversity_penalty is not None else self.config.diversity_penalty
  forced_bos_token_id = (
@@ -1185,7 +1184,13 @@ def generate(
  )
  # default to config if still None
  max_length = max_length if max_length is not None else self.config.max_length
+ min_length = min_length if min_length is not None else self.config.min_length
 
+ if min_length is not None and min_length > max_length:
+ raise ValueError(
+ f"Unfeasable length constraints: the minimum length ({min_length}) is larger than the maximum "
+ f"length ({max_length})"
+ )
  if input_ids_seq_length >= max_length:
  input_ids_string = "decoder_input_ids" if self.config.is_encoder_decoder else "input_ids"
  logger.warning(

tests/generation/test_generation_utils.py

@@ -102,7 +102,7 @@ def _get_logits_processor_and_kwargs(
  diversity_penalty=None,
  ):
  process_kwargs = {
- "min_length": input_length + 1,
+ "min_length": input_length + 1 if max_length is None else max_length - 1,
  "bad_words_ids": [[1, 0]],
  "no_repeat_ngram_size": 2,
  "repetition_penalty": 1.2,