fallback to sourcecode if pluralform exists but is not translated

[Blaimi]

If a po-File has the msgid but no translations, translatePlural() translates to an empty string.

This change makes it consistent with the behaviour of translate() which also returns the source-code version if the message is not translated.

example:

msgid "Total (%1$s dataset)"
msgid_plural "Total (%1$s datasets)"
msgstr[0] ""
msgstr[1] ""

[Blaimi]

UnitTest is missing

[dennybrandes]

Maybe better to use empty()

[Blaimi]

translate() checks also against the empty string – but check against null is missing here 😱

[dennybrandes]

empty() will check empty string and null

[michalbundyra]

@Blaimi

UnitTest is missing

Are you willing to add it? It can't be merged without tests. Adding it shouldn't be complicated. Thanks!

[Blaimi]

Are you willing to add it? It can't be merged without tests. Adding it shouldn't be complicated. Thanks!
Jep, that's a good task for one of our Junior-Developers ;)

[weierophinney]

Thanks, @Blaimi; merged to develop for release with 2.10.0.

[weierophinney]

I rebased off of develop and resolved conflicts when merging.