Accept 'ID' as a valid $field in get_user_by().

We already accept 'id'. `ID` more closely matches the database and
`WP_User` schemas.

Props Shelob9.
Fixes #33869.

git-svn-id: https://develop.svn.wordpress.org/trunk@34125 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -165,18 +165,24 @@ class WP_User {
 	 * Return only the main user fields
 	 *
 	 * @since 3.3.0
+	 * @since 4.4.0 Added 'ID' as an alias of 'id' for the `$field` parameter.
 	 *
 	 * @static
 	 *
 	 * @global wpdb $wpdb
 	 *
-	 * @param string $field The field to query against: 'id', 'slug', 'email' or 'login'
+	 * @param string $field The field to query against: 'id', 'ID', 'slug', 'email' or 'login'.
 	 * @param string|int $value The field value
 	 * @return object|false Raw user object
 	 */
 	public static function get_data_by( $field, $value ) {
 		global $wpdb;
 
+		// 'ID' is an alias of 'id'.
+		if ( 'ID' === $field ) {
+			$field = 'id';
+		}
+
 		if ( 'id' == $field ) {
 			// Make sure the value is numeric to avoid casting objects, for example,
 			// to int 1.

src/wp-includes/pluggable.php

@@ -145,8 +145,9 @@ if ( !function_exists('get_user_by') ) :
  * Retrieve user info by a given field
  *
  * @since 2.8.0
+ * @since 4.4.0 Added 'ID' as an alias of 'id' for the `$field` parameter.
  *
- * @param string     $field The field to retrieve the user with. id | slug | email | login
+ * @param string     $field The field to retrieve the user with. id | ID | slug | email | login.
  * @param int|string $value A value for $field. A user ID, slug, email address, or login name.
  * @return WP_User|false WP_User object on success, false on failure.
  */

tests/phpunit/tests/user.php

@@ -445,6 +445,16 @@ class Tests_User extends WP_UnitTestCase {
 		$this->assertEquals( false, $user );
 	}
 
+	/**
+	 * @ticket 33869
+	 */
+	public function test_user_get_data_by_ID_should_alias_to_id() {
+		$u = $this->factory->user->create();
+
+		$user = WP_User::get_data_by( 'ID', $u );
+		$this->assertEquals( $u, $user->ID );
+	}
+
 	/**
 	 * @ticket 21431
 	 */