From 7bd678a553114bee22154718bcd24e1406b6c6a0 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Mon, 4 Jan 2021 16:56:20 +0000
Subject: [PATCH] Docs: Synchronize and correct documentation for
 `has_filter()` and `WP_Hook::has_filter()`.

`WP_Hook::has_filter()` returns true if `$function_to_check` is omitted and the hook being checked has one or more registered callbacks.

Follow-up to [49927].

See #51800.

git-svn-id: https://develop.svn.wordpress.org/trunk@49928 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-wp-hook.php |  8 +++++---
 src/wp-includes/plugin.php        | 26 +++++++++++++-------------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/src/wp-includes/class-wp-hook.php b/src/wp-includes/class-wp-hook.php
index d8bf6aae72..4b03862814 100644
--- a/src/wp-includes/class-wp-hook.php
+++ b/src/wp-includes/class-wp-hook.php
@@ -187,14 +187,16 @@ final class WP_Hook implements Iterator, ArrayAccess {
 	/**
 	 * Checks if a specific action has been registered for this hook.
 	 *
-	 * When using the $function_to_check argument, this function may return a non-boolean value
-	 * that evaluates to false (e.g. 0), so use the === operator for testing the return value.
+	 * When using the `$function_to_check` argument, this function may return a non-boolean value
+	 * that evaluates to false (e.g. 0), so use the `===` operator for testing the return value.
 	 *
 	 * @since 4.7.0
 	 *
 	 * @param string         $tag               Optional. The name of the filter hook. Default empty.
 	 * @param callable|false $function_to_check Optional. The callback to check for. Default false.
-	 * @return false|int The priority of that hook is returned, or false if the function is not attached.
+	 * @return int|bool If `$function_to_check` is omitted, returns boolean for whether the hook has
+	 *                  anything registered. When checking a specific function, the priority of that
+	 *                  hook is returned, or false if the function is not attached.
 	 */
 	public function has_filter( $tag = '', $function_to_check = false ) {
 		if ( false === $function_to_check ) {
diff --git a/src/wp-includes/plugin.php b/src/wp-includes/plugin.php
index 28440e7a2b..3228ad6949 100644
--- a/src/wp-includes/plugin.php
+++ b/src/wp-includes/plugin.php
@@ -121,7 +121,10 @@ function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1
 }
 
 /**
- * Check if any filter has been registered for a hook.
+ * Checks if any filter has been registered for a hook.
+ *
+ * When using the `$function_to_check` argument, this function may return a non-boolean value
+ * that evaluates to false (e.g. 0), so use the `===` operator for testing the return value.
  *
  * @since 2.5.0
  *
@@ -129,12 +132,9 @@ function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1
  *
  * @param string         $tag               The name of the filter hook.
  * @param callable|false $function_to_check Optional. The callback to check for. Default false.
- * @return false|int If $function_to_check is omitted, returns boolean for whether the hook has
- *                   anything registered. When checking a specific function, the priority of that
- *                   hook is returned, or false if the function is not attached. When using the
- *                   $function_to_check argument, this function may return a non-boolean value
- *                   that evaluates to false (e.g. 0), so use the === operator for testing the
- *                   return value.
+ * @return int|bool If `$function_to_check` is omitted, returns boolean for whether the hook has
+ *                  anything registered. When checking a specific function, the priority of that
+ *                  hook is returned, or false if the function is not attached.
  */
 function has_filter( $tag, $function_to_check = false ) {
 	global $wp_filter;
@@ -554,7 +554,10 @@ function do_action_ref_array( $tag, $args ) {
 }
 
 /**
- * Check if any action has been registered for a hook.
+ * Checks if any action has been registered for a hook.
+ *
+ * When using the `$function_to_check` argument, this function may return a non-boolean value
+ * that evaluates to false (e.g. 0), so use the `===` operator for testing the return value.
  *
  * @since 2.5.0
  *
@@ -562,12 +565,9 @@ function do_action_ref_array( $tag, $args ) {
  *
  * @param string         $tag               The name of the action hook.
  * @param callable|false $function_to_check Optional. The callback to check for. Default false.
- * @return bool|int If $function_to_check is omitted, returns boolean for whether the hook has
+ * @return int|bool If `$function_to_check` is omitted, returns boolean for whether the hook has
  *                  anything registered. When checking a specific function, the priority of that
- *                  hook is returned, or false if the function is not attached. When using the
- *                  $function_to_check argument, this function may return a non-boolean value
- *                  that evaluates to false (e.g. 0), so use the === operator for testing the
- *                  return value.
+ *                  hook is returned, or false if the function is not attached.
  */
 function has_action( $tag, $function_to_check = false ) {
 	return has_filter( $tag, $function_to_check );