From 10b611b0c3081428d7f67c14824072e263d33116 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Thu, 20 Nov 2014 01:51:38 +0000
Subject: [PATCH] Return an empty array from `get_approved_comments()` when
 `$post_id` is empty.

This behavior was broken when moving the internals to `WP_Comment_Query` in
[30098]. As a result, `get_approved_comments( 0 )` was fetching *all* approved
comments, causing performance issues.

Props dd32.
Fixes #30412.

git-svn-id: https://develop.svn.wordpress.org/trunk@30402 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/comment.php           |  6 +++++-
 tests/phpunit/tests/comment.php       | 12 ++++++++++++
 tests/phpunit/tests/comment/query.php | 12 ++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index a3e4ac1b4b..5d5689b9df 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -136,7 +136,11 @@ function check_comment($author, $email, $url, $comment, $user_ip, $user_agent, $
  * @return int|array $comments The approved comments, or number of comments if `$count`
  *                             argument is true.
  */
-function get_approved_comments( $post_id = 0, $args = array() ) {
+function get_approved_comments( $post_id, $args = array() ) {
+	if ( ! $post_id ) {
+		return array();
+	}
+
 	$defaults = array(
 		'status'  => 1,
 		'post_id' => $post_id,
diff --git a/tests/phpunit/tests/comment.php b/tests/phpunit/tests/comment.php
index bd24396068..6271696201 100644
--- a/tests/phpunit/tests/comment.php
+++ b/tests/phpunit/tests/comment.php
@@ -30,4 +30,16 @@ class Tests_Comment extends WP_UnitTestCase {
 		// all comments types will be returned
 		$this->assertEquals( array( $ca1, $ca2, $c2, $c3, $c4, $c5 ), wp_list_pluck( $found, 'comment_ID' ) );
 	}
+
+	/**
+	 * @ticket 30412
+	 */
+	public function test_get_approved_comments_with_post_id_0_should_return_empty_array() {
+		$p = $this->factory->post->create();
+		$ca1 = $this->factory->comment->create( array( 'comment_post_ID' => $p, 'comment_approved' => '1' ) );
+
+		$found = get_approved_comments( 0 );
+
+		$this->assertSame( array(), $found );
+	}
 }
diff --git a/tests/phpunit/tests/comment/query.php b/tests/phpunit/tests/comment/query.php
index 77be42c4d7..dbdcf6aa58 100644
--- a/tests/phpunit/tests/comment/query.php
+++ b/tests/phpunit/tests/comment/query.php
@@ -30,6 +30,18 @@ class Tests_Comment_Query extends WP_UnitTestCase {
 		$this->assertEqualSets( array( $c1, $c2, $c3, $c4, $c5 ), $found );
 	}
 
+	public function test_query_post_id_0() {
+		$c1 = $this->factory->comment->create( array( 'comment_post_ID' => $this->post_id, 'comment_approved' => '1' ) );
+
+		$q = new WP_Comment_Query();
+		$found = $q->query( array(
+			'post_id' => 0,
+			'fields' => 'ids',
+		) );
+
+		$this->assertEqualSets( array( $c1 ), $found );
+	}
+
 	/**
 	 * @ticket 12668
 	 */