Czech plural-forms is incorrect in translations.

[Jakub Kaláb]

The plural czech translations for "This password is too short. It must contain at least %(min_length)d character." are broken in django versions 2.1.0 and higher for n >= 5. Can be easily reproduced:

• create django project
• set LANGUAGE_CODE = 'cs-CZ' and USE_I18N = True
• open shell
• import django.utils.translation.ngettext
• run ngettext("This password is too short. It must contain at least %(min_length)d character.", "This password is too short. It must contain at least %(min_length)d characters.", 5) - returns original english message instead of the localized one

Translations for n <= 4 work correctly.

I thing this bug was introduced in ​https://github.com/django/django/commit/3e01aab5335394201701710d7fcd67f523878c5b#diff-59a8943fbf4bd5fd330ef8d22e40bd3f , but am not completely sure, since the commit was created after the 2.1.0 release. Could this be backported? Frankly, I'm not even sure why this change was necessary - in czech there are only 3 forms of the message needed - they differ in the last word 'znak' (which means character) thusly:

• 1 znak
• 2, 3, 4 znaky
• 5 and more znaků and also 0 znaků

I tested this behavior on python 3.6.8 and 3.7.3 and django 2.1.0 and 2.1.8.

[Jakub Kaláb]

screenshot of bug reproduced in django shell

[Jakub Kaláb]

Also, before this is resolved, can anyone please tell me how to override this? I tried to add the original translations (before linked commit) to my app, while also adding the much simpler Plural-Forms setting:

"Plural-Forms: nplurals=3; plural=(n==1) ? 0 : (n>=2 && n<=4) ? 1 : 2;\n"

The app is higher then django.contrib.auth in INSTALLED_APPS, but my override seems to be completely ignored.

[Mariusz Felisiak]

Thanks for the report, however, translations are handled at ​Transifex and not in this tracker.