Incorrect handling of empty string in pluralization for n = 0

[anonymous-aka]

Reporting a bug?

In the latest update of vue-i18n (checked on v10.0.1), there seems to be an issue with pluralization when handling an empty string for the n = 0 case. The expected behavior is for the translation function to return an empty string when n is 0, but instead, it returns undefined.

Expected behavior

case n = 0 should return an <empty string> and not 'undefined'.

Reproduction

Please follow the link for the minimal reproduction:
https://stackblitz.com/edit/vitejs-vite-9tydzp?file=src%2FApp.vue

System Info

System:
    OS: macOS 13.6.7
    CPU: (8) arm64 Apple M2
    Memory: 124.00 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
Binaries:
    Node: 20.14.0 - ~/.nvm/versions/node/v20.14.0/bin/node
    npm: 10.7.0 - ~/.nvm/versions/node/v20.14.0/bin/npm
Browsers:
    Chrome: 129.0.6668.59

Screenshot

No response

Additional context

No response

Validations

• Read the Contributing Guidelines
• Read the Documentation
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussions