id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
29348	"""-"" and ""_"" in language code should be consistent"	Shen Li	nobody	"for some languages eg, en-us hyphen is used
but in zh_hans underscore is used.

If zh-hans is used, django would not show the translation. Here's some tests and resutls

Language code: zh_hans, folder zh_hans  -> works
Language code: zh_hans, folder zh-hans  -> ` No translation files found for default language zh_hans.`
Language code: zh-hans, folder zh-hans  -> does not work. No errors, no translations
Language code: zh-hans, folder zh_hans  -> does not work. No erros, no translations

looks like django does not treat zh-hans as a valid language code, which is very very confusing because the default en-us is valid. 
It look me a very long time to figure this out.


Edit: even zh_hans is not working with browser language detection, the folder has to be named 'zh_Hans' even though request.LANGUAGE is 'zh-hans'

is there somether in the doc that pointed this out?
"	Cleanup/optimization	closed	Internationalization	2.0	Normal	invalid	i18n, inconsistency		Unreviewed	0	0	0	0	0	0