From 3b89b3ca2825d0f565adb355e5f2d60eecec6f98 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Sat, 3 Oct 2015 19:25:25 +0000
Subject: [PATCH] Use 'comments_per_page' option as fallback in
 `get_page_of_comment()`.

The function now uses the following order of precedence when calculating
comment pagination: 1. the 'per_page' value passed in the `$args` array,
2. the 'comments_per_page' query var in `$wp_query`, and 3. the
'comments_per_page' setting from options-discussion.php. This change allows
`get_page_of_comment()` to return an accurate value before the main query
has been run.

Props laceous.
See #13939.

git-svn-id: https://develop.svn.wordpress.org/trunk@34806 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/comment-functions.php            | 11 +++++++++--
 tests/phpunit/tests/comment/getPageOfComment.php | 16 ++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/comment-functions.php b/src/wp-includes/comment-functions.php
index ce6c2d0e82..280e15035e 100644
--- a/src/wp-includes/comment-functions.php
+++ b/src/wp-includes/comment-functions.php
@@ -855,8 +855,15 @@ function get_page_of_comment( $comment_ID, $args = array() ) {
 	$defaults = array( 'type' => 'all', 'page' => '', 'per_page' => '', 'max_depth' => '' );
 	$args = wp_parse_args( $args, $defaults );
 
-	if ( '' === $args['per_page'] )
-		$args['per_page'] = get_query_var('comments_per_page');
+	// Order of precedence: 1. `$args['per_page']`, 2. 'comments_per_page' query_var, 3. 'comments_per_page' option.
+	if ( '' === $args['per_page'] ) {
+		$args['per_page'] = get_query_var( 'comments_per_page' );
+	}
+
+	if ( '' === $args['per_page'] ) {
+		$args['per_page'] = get_option( 'comments_per_page' );
+	}
+
 	if ( empty($args['per_page']) ) {
 		$args['per_page'] = 0;
 		$args['page'] = 0;
diff --git a/tests/phpunit/tests/comment/getPageOfComment.php b/tests/phpunit/tests/comment/getPageOfComment.php
index b61a6a62af..78151d24f0 100644
--- a/tests/phpunit/tests/comment/getPageOfComment.php
+++ b/tests/phpunit/tests/comment/getPageOfComment.php
@@ -226,4 +226,20 @@ class Tests_Comment_GetPageOfComment extends WP_UnitTestCase {
 			$this->assertSame( 2, (int) get_page_of_comment( $comment_children[ $p2i ], $args ) );
 		}
 	}
+
+	/**
+	 * @ticket 13939
+	 */
+	public function test_comments_per_page_option_should_be_fallback_when_query_var_is_not_available() {
+		$now = time();
+
+		$p = $this->factory->post->create();
+		$c1 = $this->factory->comment->create( array( 'comment_post_ID' => $p, 'comment_date_gmt' => date( 'Y-m-d H:i:s', $now ) ) );
+		$c2 = $this->factory->comment->create( array( 'comment_post_ID' => $p, 'comment_date_gmt' => date( 'Y-m-d H:i:s', $now - 20 ) ) );
+		$c3 = $this->factory->comment->create( array( 'comment_post_ID' => $p, 'comment_date_gmt' => date( 'Y-m-d H:i:s', $now - 30 ) ) );
+
+		update_option( 'comments_per_page', 2 );
+
+		$this->assertEquals( 2, get_page_of_comment( $c1 ) );
+	}
 }