From bf3504089878ffb53ad2035689ab1ce8c42a095d Mon Sep 17 00:00:00 2001
From: Mark Jaquith <mark@wordpress.org>
Date: Thu, 20 Jun 2013 17:21:13 +0000
Subject: [PATCH] Squash some PHP notices in taxonomy queries.

props hakre, wonderboymusic. fixes #16465.

git-svn-id: http://core.svn.wordpress.org/trunk@24456 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/query.php | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/wp-includes/query.php b/wp-includes/query.php
index 29b2661165..6ba10c4f73 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -2265,25 +2265,30 @@ class WP_Query {
 				}
 
 				$cat_query = wp_list_filter( $tax_query_in_and, array( 'taxonomy' => 'category' ) );
-				if ( !empty( $cat_query ) ) {
+				if ( ! empty( $cat_query ) ) {
 					$cat_query = reset( $cat_query );
-					$the_cat = get_term_by( $cat_query['field'], $cat_query['terms'][0], 'category' );
-					if ( $the_cat ) {
-						$this->set( 'cat', $the_cat->term_id );
-						$this->set( 'category_name', $the_cat->slug );
+
+					if ( ! empty( $cat_query['terms'][0] ) ) {
+						$the_cat = get_term_by( $cat_query['field'], $cat_query['terms'][0], 'category' );
+						if ( $the_cat ) {
+							$this->set( 'cat', $the_cat->term_id );
+							$this->set( 'category_name', $the_cat->slug );
+						}
+						unset( $the_cat );
 					}
-					unset( $the_cat );
 				}
 				unset( $cat_query );
 
 				$tag_query = wp_list_filter( $tax_query_in_and, array( 'taxonomy' => 'post_tag' ) );
-				if ( !empty( $tag_query ) ) {
+				if ( ! empty( $tag_query ) ) {
 					$tag_query = reset( $tag_query );
-					$the_tag = get_term_by( $tag_query['field'], $tag_query['terms'][0], 'post_tag' );
-					if ( $the_tag ) {
-						$this->set( 'tag_id', $the_tag->term_id );
+
+					if ( ! empty( $tag_query['terms'][0] ) ) {
+						$the_tag = get_term_by( $tag_query['field'], $tag_query['terms'][0], 'post_tag' );
+						if ( $the_tag )
+							$this->set( 'tag_id', $the_tag->term_id );
+						unset( $the_tag );
 					}
-					unset( $the_tag );
 				}
 				unset( $tag_query );
 			}