From 44733f9635958dd46a563f8201cb23fba7125399 Mon Sep 17 00:00:00 2001
From: ryan <ryan@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Sat, 20 Nov 2010 21:10:20 +0000
Subject: [PATCH] If the queried term does not exist make sure no posts are
 returned in the query rather than falling through to querying all posts. 
 Fixes 404s when querying cats that do not exist. see #12891

git-svn-id: http://svn.automattic.com/wordpress/trunk@16511 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/query.php    | 8 ++++++--
 wp-includes/taxonomy.php | 3 ++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/wp-includes/query.php b/wp-includes/query.php
index 756e5e5c5..09c507b47 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -1947,8 +1947,12 @@ class WP_Query {
 		if ( !empty( $this->tax_query ) ) {
 			$clauses = call_user_func_array( 'get_tax_sql', array( $this->tax_query, $wpdb->posts, 'ID', &$this) );
 
-			$join .= $clauses['join'];
-			$where .= $clauses['where'];
+			if ( empty($clauses['join']) && empty($clauses['where']) ) {
+				$where .= ' AND 0 = 1';	
+			} else {
+				$join .= $clauses['join'];
+				$where .= $clauses['where'];
+			}
 
 			if ( $this->is_tax ) {
 				if ( empty($post_type) ) {
diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 8135cdddd..977e9bf16 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -539,7 +539,7 @@ function get_tax_sql( $tax_query, $primary_table, $primary_id_column ) {
 
 		foreach ( $taxonomies as $taxonomy ) {
 			if ( ! taxonomy_exists( $taxonomy ) )
-				return ' AND 0 = 1';
+				return array( 'join' => '', 'where' => ' AND 0 = 1');
 		}
 
 		$taxonomies = "'" . implode( "', '", $taxonomies ) . "'";
@@ -592,6 +592,7 @@ function get_tax_sql( $tax_query, $primary_table, $primary_id_column ) {
 			)";
 		}
 	}
+
 	return compact( 'join', 'where' );
 }