From 4d1c0c85a6b64a399c90eae3ac8c815b2f249832 Mon Sep 17 00:00:00 2001
From: John Blackbourn <johnbillion@git.wordpress.org>
Date: Wed, 6 May 2015 21:02:23 +0000
Subject: [PATCH] WPDB: Allow queries to reference tables in the
 dbname.tablename format, and allow table names to contain any valid
 character, rather than just ASCII.

Merge of [32368] to the 4.1 branch.

Props pento, willstedt for the initial patch.

See #32090.

Built from https://develop.svn.wordpress.org/branches/4.1@32412


git-svn-id: http://core.svn.wordpress.org/branches/4.1@32382 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/wp-db.php | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index 5ac1027c3c..613f5bbb7f 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -2246,7 +2246,10 @@ class wpdb {
 		}
 
 		$charsets = $columns = array();
-		$results = $this->get_results( "SHOW FULL COLUMNS FROM `$table`" );
+
+		$table_parts = explode( '.', $table );
+		$table = '`' . implode( '`.`', $table_parts ) . '`';
+		$results = $this->get_results( "SHOW FULL COLUMNS FROM $table" );
 		if ( ! $results ) {
 			return new WP_Error( 'wpdb_get_table_charset_failure' );
 		}
@@ -2819,16 +2822,16 @@ class wpdb {
 				. '|REPLACE(?:\s+LOW_PRIORITY|\s+DELAYED)?(?:\s+INTO)?'
 				. '|UPDATE(?:\s+LOW_PRIORITY)?(?:\s+IGNORE)?'
 				. '|DELETE(?:\s+LOW_PRIORITY|\s+QUICK|\s+IGNORE)*(?:\s+FROM)?'
-				. ')\s+`?([\w-]+)`?/is', $query, $maybe ) ) {
-			return $maybe[1];
+				. ')\s+((?:[0-9a-zA-Z$_.`]|[\xC2-\xDF][\x80-\xBF])+)/is', $query, $maybe ) ) {
+			return str_replace( '`', '', $maybe[1] );
 		}
 
 		// SHOW TABLE STATUS and SHOW TABLES
 		if ( preg_match( '/^\s*(?:'
 				. 'SHOW\s+TABLE\s+STATUS.+(?:LIKE\s+|WHERE\s+Name\s*=\s*)'
 				. '|SHOW\s+(?:FULL\s+)?TABLES.+(?:LIKE\s+|WHERE\s+Name\s*=\s*)'
-				. ')\W([\w-]+)\W/is', $query, $maybe ) ) {
-			return $maybe[1];
+				. ')\W((?:[0-9a-zA-Z$_.`]|[\xC2-\xDF][\x80-\xBF])+)\W/is', $query, $maybe ) ) {
+			return str_replace( '`', '', $maybe[1] );
 		}
 
 		// Big pattern for the rest of the table-related queries.
@@ -2846,8 +2849,8 @@ class wpdb {
 				. '|LOAD\s+DATA.*INFILE.*INTO\s+TABLE'
 				. '|(?:GRANT|REVOKE).*ON\s+TABLE'
 				. '|SHOW\s+(?:.*FROM|.*TABLE)'
-				. ')\s+\(*\s*`?([\w-]+)`?\s*\)*/is', $query, $maybe ) ) {
-			return $maybe[1];
+				. ')\s+\(*\s*((?:[0-9a-zA-Z$_.`]|[\xC2-\xDF][\x80-\xBF])+)\s*\)*/is', $query, $maybe ) ) {
+			return str_replace( '`', '', $maybe[1] );
 		}
 
 		return false;