Outer spaces in wp_sprintf_l() strings are easily lost in translation

[andy]

wp_sprintf_l() uses the following strings:

	$l = apply_filters( 'wp_sprintf_l', array(
		/* translators: used between list items, there is a space after the comma */
		'between'          => __(', '),
		/* translators: used between list items, there is a space after the and */
		'between_last_two' => __(', and '),
		/* translators: used between only two list items, there is a space after the and */
		'between_only_two' => __(' and '),
	) );

The leading and trailing spaces are frequently omitted by translators despite the translator comments.

Elsewhere, nbachiyski suggests using placeholders (%s) to assist translators.

The attached patch does just that, and then strips the placeholders before passing the array of strings through the filter.

[andy]

Add temporary placeholders to preserve whitespace in translated strings

[MattyRob]

Should we also perhaps consider using the _x() function rather than __() so the 'context' information is passed into the POT file?

[SergeyBiryukov]

Replying to MattyRob:

Should we also perhaps consider using the _x() function rather than __() so the 'context' information is passed into the POT file?

_x() is meant to distinguish the same string used in different context. A translator comment is fine here.

[nacin]

In 27284:

Use placeholders in strings in wp_sprintf_l() to ensure spaces are not lost in translation.

props andy.
fixes #26651.