[wp-trac] [WordPress Trac] #58321: `_load_textdomain_just_in_time()` firing too often for en_US sites

[WordPress Trac]

#58321: `_load_textdomain_just_in_time()` firing too often for en_US sites
--------------------------+----------------------------
 Reporter:  swissspidy    |      Owner:  swissspidy
     Type:  defect (bug)  |     Status:  assigned
 Priority:  normal        |  Milestone:  Future Release
Component:  I18N          |    Version:  6.2
 Severity:  normal        |   Keywords:  needs-patch
  Focuses:  performance   |
--------------------------+----------------------------
 `_load_textdomain_just_in_time` is supposed to run once on the first
 translation call to see if translations need to be loaded.

 This works great on a localized site. However, I found out now that this
 doesn't work on a bare en_US site.

 At first glance, things to improve:

 1. In `WP_Textdomain_Registry`, change this `! empty()` check to an
 `isset()` check, to distinguish between absent (`null`) and retrieved
 values but missing translation files (`false`):
 https://github.com/WordPress/wordpress-
 develop/blob/f375b68447d392ca7c189ebfadb6b908931d3812/src/wp-includes
 /class-wp-textdomain-registry.php#L100
   This way, `_load_textdomain_just_in_time()` bails earlier
 2. In `get_translations_for_domain()` (or maybe elsewhere), set `$l10n[
 $domain ] = &$noop_translations;` so that `_load_textdomain_just_in_time`
 is only called once.
   Needs some testing with locale switching to see if that actually works.

 Not sure if this is a regression from 6.2, 6.1, or even from 4.6.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/58321>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform