From 9b0c765df63728ecc9c1a9f283d8562155ac0c78 Mon Sep 17 00:00:00 2001
From: markjaquith <markjaquith@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Tue, 31 Oct 2006 05:49:14 +0000
Subject: [PATCH] Better preservation of query string when using
 add_query_arg().  Props in self- and Andy-flavored varieties.  fixes #3308

git-svn-id: http://svn.automattic.com/wordpress/trunk@4435 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/functions.php | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 441a5043a8..513a5dd351 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -667,10 +667,13 @@ function add_query_arg() {
 	}
 
 	foreach($qs as $k => $v) {
-		if ( $v != '' ) {
+		if ( $v !== FALSE ) {
 			if ( $ret != '' )
 				$ret .= '&';
-			$ret .= "$k=$v";
+			if ( empty($v) && !preg_match('|[?&]' . preg_quote($k, '|') . '=|', $query) )
+				$ret .= $k;
+			else
+				$ret .= "$k=$v";
 		}
 	}
 	$ret = $protocol . $base . $ret . $frag;
@@ -692,10 +695,10 @@ remove_query_arg(removekeyarray, [oldquery_or_uri])
 function remove_query_arg($key, $query='') {
 	if ( is_array($key) ) { // removing multiple keys
 		foreach ( (array) $key as $k )
-			$query = add_query_arg($k, '', $query);
+			$query = add_query_arg($k, FALSE, $query);
 		return $query;
 	}
-	return add_query_arg($key, '', $query);
+	return add_query_arg($key, FALSE, $query);
 }
 
 function add_magic_quotes($array) {