[FlaxGenerate] Fix bug in decoder_start_token_id

[sanchit-gandhi]

In Python, bool is a subclass of int, and False has the value 0. We observe this by calling the __bool__ method of 0:

print((0).__bool__())
print((1).__bool__())

False
True

transformers/src/transformers/generation_flax_utils.py

Lines 266 to 268 in da47c26

	decoder_start_token_id = (
	decoder_start_token_id if decoder_start_token_id else self.config.decoder_start_token_id
	)

In the preceding lines of code, if decoder_start_token_id has the value 0 (valid):

• if decoder_start_token_id will be False
• decoder_start_token_id will be set to self.config.decoder_start_token_id

The correct behaviour should be that if decoder_start_token_id has the value 0, it remains set to 0, and not changed to self.config.decoder_start_token_id.

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[patrickvonplaten]

Great catch!