From d55c605242f5f291e73f3a16b57921b614189422 Mon Sep 17 00:00:00 2001
From: Gary Pendergast <pento@git.wordpress.org>
Date: Tue, 17 Nov 2015 06:12:08 +0000
Subject: [PATCH] WPDB: Fall back to the connection charset when sanity
 checking strings.

If `DB_CHARSET` isn't defined (or is empty), `wpdb::$charset` will be empty, too. `wpdb::strip_invalid_text()` assumes that it isn't empty, however, so we need to fall back to the connection character set when we're running our sanity checks.

Fixes #34708.



git-svn-id: https://develop.svn.wordpress.org/trunk@35655 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/wp-db.php          | 14 ++++++++++++--
 tests/phpunit/tests/db/charset.php | 22 ++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/wp-db.php b/src/wp-includes/wp-db.php
index 22fa6aa475..caae412afa 100644
--- a/src/wp-includes/wp-db.php
+++ b/src/wp-includes/wp-db.php
@@ -2811,11 +2811,21 @@ class wpdb {
 						$charset = $value['charset'];
 					}
 
+					if ( $this->charset ) {
+						$connection_charset = $this->charset;
+					} else {
+						if ( $this->use_mysqli ) {
+							$connection_charset = mysqli_character_set_name( $this->dbh );
+						} else {
+							$connection_charset = mysql_client_encoding();
+						}
+					}
+
 					if ( is_array( $value['length'] ) ) {
-						$queries[ $col ] = $this->prepare( "CONVERT( LEFT( CONVERT( %s USING $charset ), %.0f ) USING {$this->charset} )", $value['value'], $value['length']['length'] );
+						$queries[ $col ] = $this->prepare( "CONVERT( LEFT( CONVERT( %s USING $charset ), %.0f ) USING $connection_charset )", $value['value'], $value['length']['length'] );
 					} else if ( 'binary' !== $charset ) {
 						// If we don't have a length, there's no need to convert binary - it will always return the same result.
-						$queries[ $col ] = $this->prepare( "CONVERT( CONVERT( %s USING $charset ) USING {$this->charset} )", $value['value'] );
+						$queries[ $col ] = $this->prepare( "CONVERT( CONVERT( %s USING $charset ) USING $connection_charset )", $value['value'] );
 					}
 
 					unset( $data[ $col ]['db'] );
diff --git a/tests/phpunit/tests/db/charset.php b/tests/phpunit/tests/db/charset.php
index cb605d697c..cfd025e003 100644
--- a/tests/phpunit/tests/db/charset.php
+++ b/tests/phpunit/tests/db/charset.php
@@ -865,4 +865,26 @@ class Tests_DB_Charset extends WP_UnitTestCase {
 
 		$this->assertEquals( $safe_query, $stripped_query );
 	}
+
+	/**
+	 * @ticket 34708
+	 */
+	function test_no_db_charset_defined() {
+		$tablename = 'test_cp1251_query_' . rand_str( 5 );
+		if ( ! self::$_wpdb->query( "CREATE TABLE $tablename ( a VARCHAR(50) ) DEFAULT CHARSET 'cp1251'" ) ) {
+			$this->markTestSkipped( "Test requires the 'cp1251' charset" );
+		}
+
+		$charset = self::$_wpdb->charset;
+		self::$_wpdb->charset = '';
+
+		$safe_query = "INSERT INTO $tablename( `a` ) VALUES( 'safe data' )";
+		$stripped_query = self::$_wpdb->strip_invalid_text_from_query( $safe_query );
+
+		self::$_wpdb->query( "DROP TABLE $tablename" );
+
+		self::$_wpdb->charset = $charset;
+
+		$this->assertEquals( $safe_query, $stripped_query );
+	}
 }