LocaleMiddleware does not handle ValueError 'lang_code' exceeds the maximum accepted length

[Lorenzo Peña]

Try any Django powered site where LocaleMiddleware is enanled and visit domain.com/aaaaaaaaaaa.... (where there are 1000 'a').
This line kicks in: ​https://github.com/django/django/blob/main/django/utils/translation/trans_real.py#L520

I think the outcome should be a 404 instead of raising ValueError all the way up.

[Sarah Boyce]

Regression in 9e9792228a6bb5d6402a5d645bc3be4cf364aefb
Perhaps we should raise a LookupError rather than a ValueError, I believe this needs backporting to 4.2, 5.0, 5.1

[Lorenzo Peña]

I'd be happy to break the ice with Django contributions with this one, if possible. In the PR I am catching both ValueError and LookupError in the callers. I am happy to also raise LookupError instead and not modify anything else.

[Lorenzo Peña]

​https://github.com/django/django/pull/18403

[Sarah Boyce <42296566+sarahboyce@…>]

In 0e94f29:

Fixed #35627 -- Raised a LookupError rather than an unhandled ValueError in get_supported_language_variant().

LocaleMiddleware didn't handle the ValueError raised by
get_supported_language_variant() when language codes were
over 500 characters.

Regression in 9e9792228a6bb5d6402a5d645bc3be4cf364aefb.

[Sarah Boyce <42296566+sarahboyce@…>]

In 741f33ea:

[5.1.x] Fixed #35627 -- Raised a LookupError rather than an unhandled ValueError in get_supported_language_variant().

LocaleMiddleware didn't handle the ValueError raised by
get_supported_language_variant() when language codes were
over 500 characters.

Regression in 9e9792228a6bb5d6402a5d645bc3be4cf364aefb.

Backport of 0e94f292cda632153f2b3d9a9037eb0141ae9c2e from main.

[Sarah Boyce <42296566+sarahboyce@…>]

In e186012:

[5.0.x] Fixed #35627 -- Raised a LookupError rather than an unhandled ValueError in get_supported_language_variant().

LocaleMiddleware didn't handle the ValueError raised by
get_supported_language_variant() when language codes were
over 500 characters.

Regression in 9e9792228a6bb5d6402a5d645bc3be4cf364aefb.

Backport of 0e94f292cda632153f2b3d9a9037eb0141ae9c2e from main.

[Sarah Boyce <42296566+sarahboyce@…>]

In 96a34974:

[4.2.x] Fixed #35627 -- Raised a LookupError rather than an unhandled ValueError in get_supported_language_variant().

LocaleMiddleware didn't handle the ValueError raised by
get_supported_language_variant() when language codes were
over 500 characters.

Regression in 9e9792228a6bb5d6402a5d645bc3be4cf364aefb.

Backport of 0e94f292cda632153f2b3d9a9037eb0141ae9c2e from main.