From fb691a449bc5dfd49610ddda7bea07392e329f3f Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Fri, 16 Jan 2015 15:49:25 +0000
Subject: [PATCH] In `paginate_links()`, don't override custom format arguments
 when setting up default 'add_args'.

Since 4.1 [29780], the default value of the 'add_args' argument in
`paginate_links()` has been determined by parsing the current URL. This change
had the side effect of overriding custom values of 'format' that changed the
pagination query var, with the result that plugins using `paginate_links()`
with a custom format generated the incorrect links unless explicitly
declaring 'add_args=false' to prevent the default values from overriding. We
fix this behavior by parsing URL query vars into the 'add_args' array only
after the explicit function params have been parsed, and by skipping the
current page's pagination query var when doing this parsing (to avoid the
override).

Props obenland.
Fixes #30831 for trunk.
Built from https://develop.svn.wordpress.org/trunk@31203


git-svn-id: http://core.svn.wordpress.org/trunk@31184 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/general-template.php | 29 +++++++++++++++++++----------
 wp-includes/version.php          |  2 +-
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index de0f921dab..51cc66bb23 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -2582,20 +2582,18 @@ function language_attributes($doctype = 'html') {
 function paginate_links( $args = '' ) {
 	global $wp_query, $wp_rewrite;
 
-	$total        = ( isset( $wp_query->max_num_pages ) ) ? $wp_query->max_num_pages : 1;
-	$current      = ( get_query_var( 'paged' ) ) ? intval( get_query_var( 'paged' ) ) : 1;
+	// Setting up default values based on the current URL.
 	$pagenum_link = html_entity_decode( get_pagenum_link() );
-	$query_args   = array();
 	$url_parts    = explode( '?', $pagenum_link );
 
-	if ( isset( $url_parts[1] ) ) {
-		wp_parse_str( $url_parts[1], $query_args );
-		$query_args = urlencode_deep( $query_args );
-	}
+	// Get max pages and current page out of the current query, if available.
+	$total   = isset( $wp_query->max_num_pages ) ? $wp_query->max_num_pages : 1;
+	$current = get_query_var( 'paged' ) ? intval( get_query_var( 'paged' ) ) : 1;
 
-	$pagenum_link = remove_query_arg( array_keys( $query_args ), $pagenum_link );
-	$pagenum_link = trailingslashit( $pagenum_link ) . '%_%';
+	// Append the format placeholder to the base URL.
+	$pagenum_link = trailingslashit( $url_parts[0] ) . '%_%';
 
+	// URL base depends on permalink settings.
 	$format  = $wp_rewrite->using_index_permalinks() && ! strpos( $pagenum_link, 'index.php' ) ? 'index.php/' : '';
 	$format .= $wp_rewrite->using_permalinks() ? user_trailingslashit( $wp_rewrite->pagination_base . '/%#%', 'paged' ) : '?paged=%#%';
 
@@ -2611,7 +2609,7 @@ function paginate_links( $args = '' ) {
 		'end_size' => 1,
 		'mid_size' => 2,
 		'type' => 'plain',
-		'add_args' => $query_args, // array of query args to add
+		'add_args' => array(), // array of query args to add
 		'add_fragment' => '',
 		'before_page_number' => '',
 		'after_page_number' => ''
@@ -2619,6 +2617,17 @@ function paginate_links( $args = '' ) {
 
 	$args = wp_parse_args( $args, $defaults );
 
+	// Merge additional query vars found in the original URL into 'add_args' array.
+	if ( isset( $url_parts[1] ) ) {
+		// Find the format argument.
+		$format_query = parse_url( str_replace( '%_%', $args['format'], $args['base'] ), PHP_URL_QUERY );
+		wp_parse_str( $format_query, $format_arg );
+
+		// Remove the format argument from the array of query arguments, to avoid overwriting custom format.
+		wp_parse_str( remove_query_arg( array_keys( $format_arg ), $url_parts[1] ), $query_args );
+		$args['add_args'] = array_merge( $args['add_args'], urlencode_deep( $query_args ) );
+	}
+
 	// Who knows what else people pass in $args
 	$total = (int) $args['total'];
 	if ( $total < 2 ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 24465fbec8..7b5500185b 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31202';
+$wp_version = '4.2-alpha-31203';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.