From 1a999bce25a6d4ed7afa53b963e1c5333b1a39d6 Mon Sep 17 00:00:00 2001
From: Drew Jaynes <drewapicture@git.wordpress.org>
Date: Tue, 20 Oct 2015 06:32:16 +0000
Subject: [PATCH] Query: Introduce the `content_pagination` filter, which makes
 it possible to manipulate how post content is split into "pages" in
 `WP_Query::setup_postdata()`.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The "pages" — or chunks of post content – are determined by splitting based on the presence of `<!-- nextpage -->` tags in the post content.

Props sirzooro, chriscct7.
Fixes #9911.


git-svn-id: https://develop.svn.wordpress.org/trunk@35285 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/query.php | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/wp-includes/query.php b/src/wp-includes/query.php
index 84eda07365..2a77cc468e 100644
--- a/src/wp-includes/query.php
+++ b/src/wp-includes/query.php
@@ -4771,8 +4771,6 @@ class WP_Query {
 
 		$content = $post->post_content;
 		if ( false !== strpos( $content, '<!--nextpage-->' ) ) {
-			if ( $page > 1 )
-				$more = 1;
 			$content = str_replace( "\n<!--nextpage-->\n", '<!--nextpage-->', $content );
 			$content = str_replace( "\n<!--nextpage-->", '<!--nextpage-->', $content );
 			$content = str_replace( "<!--nextpage-->\n", '<!--nextpage-->', $content );
@@ -4782,13 +4780,35 @@ class WP_Query {
 				$content = substr( $content, 15 );
 
 			$pages = explode('<!--nextpage-->', $content);
-			$numpages = count($pages);
-			if ( $numpages > 1 )
-				$multipage = 1;
 		} else {
 			$pages = array( $post->post_content );
 		}
 
+		/**
+		 * Filter the "pages" derived from splitting the post content.
+		 *
+		 * "Pages" are determined by splitting the post content based on the presence
+		 * of `<!-- nextpage -->` tags.
+		 *
+		 * @since 4.4.0
+		 *
+		 * @param array   $pages Array of "pages" derived from the post content.
+		 *                       of `<!-- nextpage -->` tags..
+		 * @param WP_Post $post  Current post object.
+		 */
+		$pages = apply_filters( 'content_pagination', $pages, $post );
+
+		$numpages = count( $pages );
+
+		if ( $numpages > 1 ) {
+			if ( $page > 1 ) {
+				$more = 1;
+			}
+			$multipage = 1;
+		} else {
+	 		$multipage = 0;
+	 	}
+
 		/**
 		 * Fires once the post data has been setup.
 		 *