As a site administrator, I want to define the fallback language for any language.
The user must be able to select the fallback language for any language.
When a language is added to the list of languages available in the site, the preselected fallback language will be the default language.
When the default language is changed to another language, all those languages pointing to default language for fallback, will point to the new default language.
In the following case, when Spanish (Spain) is removed, Spanish (Mexico) falls into English.
- Starting scenario: English (default lang) <- Spanish (Spain) <- Spanish (Mexico)
- Result: English (default lang) <- Spanish (Mexico)
- Having en-US as default language be able to specify es-ES as the fallback language for es-MX
- The site admin changes the default language
- The site admin removes a language
(can be written in BDD style)