Default Link Label on Next and Previous Links Functions not Tanslated

[CharlesClarkson]

The default link $label parameter on these Previous/Next posts functions is not translatable.

get_next_posts_link()
next_posts_link()
get_previous_posts_link()
previous_posts_link()

The path handles the label text the same way as the comment Previous/Next links in the same file (/wp-includes/link-template.php).

This patch might break a plugin or theme which relies on passing in the function call. I'm not sure why anyone would do that to a link text label, but ...

[CharlesClarkson]

This patch might break a plugin or theme which relies on passing an empty string in the function call. I'm not sure why anyone would do that to a link text label, but ...

get_next_posts_link('')

[nathanrice]

+1

Having the default text non-translatable is bad form for international users, and places the burden on theme developers to pass their own translatable text to these functions in order to use them properly.

[nacin]

We can change this to null as the default. Then a strict check would avoid any edge cases with an empty string.

[nathanrice]

Translate $label, use null and is_null for backward compatibility

[nathanrice]

Translate $label, use null and a strict check for backward compatibility

[ryan]

(In [17728]) Translate default link labels for *posts_link(). Props nathanrice, CharlesClarkson. fixes #16998

[ryan]

I tweaked the patches a bit to do null === like we do elsewhere for default labels.