From 129843e1497cb21ea241eafd3df9b65c9394f66e Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Tue, 23 May 2023 21:58:56 +0000
Subject: [PATCH] General: Improve performance of the `_wp_array_get()`
 function.

When using a block theme, `_wp_array_get()` is the most called function on the front end of a site.

This commit makes a few minor performance optimizations, which add up to a noticeable improvement.

Follow-up to [49135], [49143], [49580].

Props aristath, jrf, afercia, costdev, swissspidy, flixos90, spacedmonkey, mukesh27, samiamnot, SergeyBiryukov.
Fixes #58376.

git-svn-id: https://develop.svn.wordpress.org/trunk@55851 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/functions.php | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 52c447d996..d7ad450680 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -4947,14 +4947,35 @@ function _wp_array_get( $input_array, $path, $default_value = null ) {
 	}
 
 	foreach ( $path as $path_element ) {
-		if (
-			! is_array( $input_array ) ||
-			( ! is_string( $path_element ) && ! is_integer( $path_element ) && ! is_null( $path_element ) ) ||
-			! array_key_exists( $path_element, $input_array )
-		) {
+		if ( ! is_array( $input_array ) ) {
 			return $default_value;
 		}
-		$input_array = $input_array[ $path_element ];
+
+		if ( is_string( $path_element )
+			|| is_integer( $path_element )
+			|| null === $path_element
+		) {
+			/*
+			 * Check if the path element exists in the input array.
+			 * We check with `isset()` first, as it is a lot faster
+			 * than `array_key_exists()`.
+			 */
+			if ( isset( $input_array[ $path_element ] ) ) {
+				$input_array = $input_array[ $path_element ];
+				continue;
+			}
+
+			/*
+			 * If `isset()` returns false, we check with `array_key_exists()`,
+			 * which also checks for `null` values.
+			 */
+			if ( array_key_exists( $path_element, $input_array ) ) {
+				$input_array = $input_array[ $path_element ];
+				continue;
+			}
+		}
+
+		return $default_value;
 	}
 
 	return $input_array;