I18N: Check that $wp_locale global is set before calling its methods.

This avoids a fatal error if these functions are called in a mu-plugin before `$wp_locale` is set:
* `wp_get_list_item_separator()`
* `wp_get_word_count_type()`

Follow-up to [52929], [52933], [55279], [55295].

Props kraftbj.
Fixes #56698.

git-svn-id: https://develop.svn.wordpress.org/trunk@55351 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-locale.php

@@ -235,7 +235,7 @@ class WP_Locale {
 
 		$this->number_format['decimal_point'] = ( 'number_format_decimal_point' === $decimal_point ) ? '.' : $decimal_point;
 
-		/* translators: used between list items, there is a space after the comma */
+		/* translators: Used between list items, there is a space after the comma. */
 		$this->list_item_separator = __( ', ' );
 
 		// Set text direction.

src/wp-includes/l10n.php

@@ -1807,6 +1807,12 @@ function translate_settings_using_i18n_schema( $i18n_schema, $settings, $textdom
 function wp_get_list_item_separator() {
 	global $wp_locale;
 
+	if ( ! ( $wp_locale instanceof WP_Locale ) ) {
+		// Default value of WP_Locale::get_list_item_separator().
+		/* translators: Used between list items, there is a space after the comma. */
+		return __( ', ' );
+	}
+
 	return $wp_locale->get_list_item_separator();
 }
 
@@ -1823,5 +1829,10 @@ function wp_get_list_item_separator() {
 function wp_get_word_count_type() {
 	global $wp_locale;
 
+	if ( ! ( $wp_locale instanceof WP_Locale ) ) {
+		// Default value of WP_Locale::get_word_count_type().
+		return 'words';
+	}
+
 	return $wp_locale->get_word_count_type();
 }

tests/phpunit/tests/l10n/wpGetListItemSeparator.php

@@ -0,0 +1,28 @@
+<?php
+
+/**
+ * @group l10n
+ * @group i18n
+ *
+ * @covers ::wp_get_list_item_separator
+ */
+class Tests_L10n_wpGetListItemSeparator extends WP_UnitTestCase {
+
+	/**
+	 * Tests that the function returns a value when the $wp_locale global is not set.
+	 *
+	 * @ticket 56698
+	 */
+	public function test_should_return_default_value_if_wp_locale_is_not_set() {
+		global $wp_locale;
+
+		$original_locale = $wp_locale;
+		$wp_locale       = null;
+
+		$actual = wp_get_list_item_separator();
+
+		$wp_locale = $original_locale;
+
+		$this->assertSame( __( ', ' ), $actual );
+	}
+}

tests/phpunit/tests/l10n/wpGetWordCountType.php

@@ -0,0 +1,28 @@
+<?php
+
+/**
+ * @group l10n
+ * @group i18n
+ *
+ * @covers ::wp_get_word_count_type
+ */
+class Tests_L10n_wpGetWordCountType extends WP_UnitTestCase {
+
+	/**
+	 * Tests that the function returns a value when the $wp_locale global is not set.
+	 *
+	 * @ticket 56698
+	 */
+	public function test_should_return_default_value_if_wp_locale_is_not_set() {
+		global $wp_locale;
+
+		$original_locale = $wp_locale;
+		$wp_locale       = null;
+
+		$actual = wp_get_word_count_type();
+
+		$wp_locale = $original_locale;
+
+		$this->assertSame( 'words', $actual );
+	}
+}