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. Without the ability to at least override this, we're stuck with django 2.0 since we can't very well have the english message in our apps.

[Mariusz Felisiak]

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