From 980668299c4756c0f7019d2265cc679d895ebabc Mon Sep 17 00:00:00 2001
From: Gary Pendergast <gary@pento.net>
Date: Mon, 9 Feb 2015 22:28:28 +0000
Subject: [PATCH] WPDB: When checking to see if we can use utf8mb4, we also
 need to make sure PHP's MySQL client library is capable of using utf8mb4.

See #21212


Built from https://develop.svn.wordpress.org/trunk@31391


git-svn-id: http://core.svn.wordpress.org/trunk@31372 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/version.php | 2 +-
 wp-includes/wp-db.php   | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/wp-includes/version.php b/wp-includes/version.php
index 37fdc83791..04cf13a367 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31390';
+$wp_version = '4.2-alpha-31391';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index c8f456ef63..539324091d 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -2801,7 +2801,14 @@ class wpdb {
 			case 'set_charset' :
 				return version_compare( $version, '5.0.7', '>=' );
 			case 'utf8mb4' :      // @since 4.1.0
-				return version_compare( $version, '5.5.3', '>=' );
+				if ( version_compare( $version, '5.5.3', '<' ) ) {
+					return false;
+				}
+				if ( $this->use_mysqli ) {
+					return mysqli_get_client_version( $this->dbh ) >= 50503;
+				} else {
+					return mysql_get_client_version( $this->dbh ) >= 50503;
+				}
 		}
 
 		return false;