From ae8af5d0dd10b5bc9f871e7bb41e05c4c63235a0 Mon Sep 17 00:00:00 2001
From: nacin <nacin@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Fri, 2 Mar 2012 18:56:54 +0000
Subject: [PATCH] Introduce get_page_template_slug( $id = null ) to return a
 page's template (like "showcase.php"). Returns false if post ID is not a
 page, and an empty string for the default page template. Use the function
 across core. props billerickson for initial patch. fixes #18750.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20075 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/class-wp-xmlrpc-server.php |  2 +-
 wp-includes/post-template.php          | 44 +++++++++++++++++---------
 wp-includes/post.php                   |  3 +-
 wp-includes/template.php               |  9 ++----
 4 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/wp-includes/class-wp-xmlrpc-server.php b/wp-includes/class-wp-xmlrpc-server.php
index 7449c39866..9ed3c31493 100644
--- a/wp-includes/class-wp-xmlrpc-server.php
+++ b/wp-includes/class-wp-xmlrpc-server.php
@@ -1177,7 +1177,7 @@ class wp_xmlrpc_server extends IXR_Server {
 			// Get the author info.
 			$author = get_userdata($page->post_author);
 
-			$page_template = get_post_meta( $page->ID, '_wp_page_template', true );
+			$page_template = get_page_template_slug( $page->ID );
 			if ( empty( $page_template ) )
 				$page_template = 'default';
 
diff --git a/wp-includes/post-template.php b/wp-includes/post-template.php
index 3eed04df48..7a60672d25 100644
--- a/wp-includes/post-template.php
+++ b/wp-includes/post-template.php
@@ -487,7 +487,7 @@ function get_body_class( $class = '' ) {
 		}
 		if ( is_page_template() ) {
 			$classes[] = 'page-template';
-			$classes[] = 'page-template-' . sanitize_html_class( str_replace( '.', '-', get_post_meta( $page_id, '_wp_page_template', true ) ), '' );
+			$classes[] = 'page-template-' . sanitize_html_class( str_replace( '.', '-', get_page_template_slug( $page_id ) ) );
 		} else {
 			$classes[] = 'page-template-default';
 		}
@@ -1241,29 +1241,43 @@ function get_the_password_form() {
  * @param string $template The specific template name if specific matching is required.
  * @return bool False on failure, true if success.
  */
-function is_page_template($template = '') {
-	if (!is_page()) {
+function is_page_template( $template = '' ) {
+	if ( ! is_page() )
 		return false;
-	}
 
-	global $wp_query;
+	$page_template = get_page_template_slug( get_queried_object_id() );
 
-	$page = $wp_query->get_queried_object();
-	$custom_fields = get_post_custom_values('_wp_page_template',$page->ID);
-	$page_template = $custom_fields[0];
+	if ( empty( $template ) )
+		return (bool) $page_template;
 
-	// We have no argument passed so just see if a page_template has been specified
-	if ( empty( $template ) ) {
-		if ( !empty( $page_template ) and ( 'default' != $page_template ) ) {
-			return true;
-		}
-	} elseif ( $template == $page_template) {
+	if ( $template == $page_template )
+		return true;
+
+	if ( 'default' == $template && ! $page_template )
 		return true;
-	}
 
 	return false;
 }
 
+/**
+ * Get the specific template name for a page.
+ *
+ * @since 3.4.0
+ *
+ * @param int $id The page ID to check. Defaults to the current post, when used in the loop.
+ * @return string|bool Page template filename. Returns an empty string when the default page template
+ * 	is in use. Returns false if the post is not a page.
+ */
+function get_page_template_slug( $post_id = null ) {
+	$post = get_post( $post_id );
+	if ( 'page' != $post->post_type )
+		return false;
+	$template = get_post_meta( $post->ID, '_wp_page_template', true );
+	if ( ! $template || 'default' == $template )
+		return '';
+	return $template;
+}
+
 /**
  * Retrieve formatted date timestamp of a revision (linked to that revisions's page).
  *
diff --git a/wp-includes/post.php b/wp-includes/post.php
index 076bd9c323..3fcaa46edc 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -5338,5 +5338,4 @@ function _prime_post_caches( $ids, $update_term_cache = true, $update_meta_cache
 
 		update_post_caches( $fresh_posts, 'any', $update_term_cache, $update_meta_cache );
 	}
-}
-
+}
\ No newline at end of file
diff --git a/wp-includes/template.php b/wp-includes/template.php
index bcf9a2e5b5..6f3e252ae3 100644
--- a/wp-includes/template.php
+++ b/wp-includes/template.php
@@ -225,20 +225,17 @@ function get_front_page_template() {
  */
 function get_page_template() {
 	$id = get_queried_object_id();
-	$template = get_post_meta($id, '_wp_page_template', true);
+	$template = get_page_template_slug();
 	$pagename = get_query_var('pagename');
 
-	if ( !$pagename && $id > 0 ) {
+	if ( ! $pagename && $id ) {
 		// If a static page is set as the front page, $pagename will not be set. Retrieve it from the queried object
 		$post = get_queried_object();
 		$pagename = $post->post_name;
 	}
 
-	if ( 'default' == $template )
-		$template = '';
-
 	$templates = array();
-	if ( !empty($template) && !validate_file($template) )
+	if ( $template && 0 === validate_file( $template ) )
 		$templates[] = $template;
 	if ( $pagename )
 		$templates[] = "page-$pagename.php";