wp-includes/pomo/translations.php:238Merges originals with existing entries.
$otherTranslations public function merge_originals_with( &$other ) { foreach ( $other->entries as $entry ) { if ( ! isset( $this->entries[ $entry->key() ] ) ) { $this->entries[ $entry->key() ] = $entry; } else { $this->entries[ $entry->key() ]->merge_with( $entry ); } } }Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/pomo/translations.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.