From c4f8e2f7b197bd37b8c14b0b29da4f11019fd395 Mon Sep 17 00:00:00 2001
From: Sergei Morozov <morozov@tut.by>
Date: Mon, 22 Feb 2021 18:41:51 -0800
Subject: [PATCH 1/2] Do not call strelen() on null

---
 src/JsonSchema/Constraints/Constraint.php | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/JsonSchema/Constraints/Constraint.php b/src/JsonSchema/Constraints/Constraint.php
index 389e0f53..fee66e56 100644
--- a/src/JsonSchema/Constraints/Constraint.php
+++ b/src/JsonSchema/Constraints/Constraint.php
@@ -43,12 +43,15 @@ abstract class Constraint extends BaseConstraint implements ConstraintInterface
     protected function incrementPath(JsonPointer $path = null, $i)
     {
         $path = $path ?: new JsonPointer('');
-        $path = $path->withPropertyPaths(
-            array_merge(
-                $path->getPropertyPaths(),
-                array_filter(array($i), 'strlen')
-            )
-        );
+
+        if ($i !== null && $i !== '') {
+            $path = $path->withPropertyPaths(
+                array_merge(
+                    $path->getPropertyPaths(),
+                    array($i)
+                )
+            );
+        }
 
         return $path;
     }

From 1ad303a9b7d65bfd73c0c54fbc9f5944b98c16ae Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Wed, 21 Jul 2021 15:56:22 +0200
Subject: [PATCH 2/2] Switch to do early return

---
 src/JsonSchema/Constraints/Constraint.php | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/JsonSchema/Constraints/Constraint.php b/src/JsonSchema/Constraints/Constraint.php
index fee66e56..f792da5e 100644
--- a/src/JsonSchema/Constraints/Constraint.php
+++ b/src/JsonSchema/Constraints/Constraint.php
@@ -44,15 +44,17 @@ protected function incrementPath(JsonPointer $path = null, $i)
     {
         $path = $path ?: new JsonPointer('');
 
-        if ($i !== null && $i !== '') {
-            $path = $path->withPropertyPaths(
-                array_merge(
-                    $path->getPropertyPaths(),
-                    array($i)
-                )
-            );
+        if ($i === null || $i === '') {
+            return $path;
         }
 
+        $path = $path->withPropertyPaths(
+            array_merge(
+                $path->getPropertyPaths(),
+                array($i)
+            )
+        );
+
         return $path;
     }