diff --git a/.gitignore b/.gitignore
index f6c86fa35..f310f9dca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@ Thumbs.db
 /lock/*
 /.vscode/settings.json
 /vendor/**/.git
+/.phpunit.result.cache
diff --git a/classes/urlhelper.php b/classes/urlhelper.php
index 29a9528a8..57046b600 100644
--- a/classes/urlhelper.php
+++ b/classes/urlhelper.php
@@ -26,6 +26,7 @@ class UrlHelper {
 	/** @var string */
 	static $fetch_last_modified;
 
+
 	/** @var string */
 	static $fetch_effective_url;
 
@@ -68,6 +69,8 @@ class UrlHelper {
 
 		$rel_parts = parse_url($rel_url);
 
+		if (!$rel_url) return $base_url;
+
 		/**
 		 * If parse_url failed to parse $rel_url return false to match the current "invalid thing" behavior
 		 * of UrlHelper::validate().
@@ -107,7 +110,7 @@ class UrlHelper {
 			$rel_parts['host'] = $base_parts['host'] ?? "";
 			$rel_parts['scheme'] = $base_parts['scheme'] ?? "";
 
-			if (isset($rel_parts['path'])) {
+			if ($rel_parts['path'] ?? false) {
 
 				// we append dirname() of base path to relative URL path as per RFC 3986 section 5.2.2
 				$base_path = with_trailing_slash(dirname($base_parts['path']));
diff --git a/tests/UrlHelperTest.php b/tests/UrlHelperTest.php
index 2d92c332b..fe4eb5db2 100644
--- a/tests/UrlHelperTest.php
+++ b/tests/UrlHelperTest.php
@@ -1,24 +1,9 @@
 <?php
-set_include_path(dirname(__DIR__) ."/include" . PATH_SEPARATOR .
-		get_include_path());
-
-require_once "autoload.php";
-require_once "functions.php";
 
 use PHPUnit\Framework\TestCase;
 
 final class UrlHelperTest extends TestCase {
-	public function testCanBeUsedAsString(): void {
-		/*$this->assertEquals(
-			'http://example.com/example.html',
-			UrlHelper::rewrite_relative('http://example.com/example/', '/example.html')
-		);
-
-		$this->assertEquals(
-			'http://example.com/example/example.html',
-			UrlHelper::rewrite_relative('http://example.com/example/', 'example.html')
-		);*/
-
+	public function test_rewrite_relative(): void {
 		// protocol-neutral URL
 		$this->assertEquals(
 			'https://example.com/example.html',
@@ -50,5 +35,20 @@ final class UrlHelperTest extends TestCase {
 			UrlHelper::rewrite_relative('https://apod.nasa.gov/apod/ap220315.html', './image/2203/Road2Stars_EsoHoralek_1080.jpg')
 		);
 
+		$this->assertEquals(
+			'http://example.com/test/url',
+			UrlHelper::rewrite_relative('http://example.com/test/url', '')
+		);
+
+		$this->assertEquals(
+			'http://www.example.com/test',
+			UrlHelper::rewrite_relative('http://www.example2.com ', 'http://www.example.com/test')
+		);
+
+		$this->assertEquals(
+			'http://www.example.com/test',
+			UrlHelper::rewrite_relative('http://www.example.com/test2 ', 'http://www.example.com/test')
+		);
+
 	}
 }
diff --git a/tests/autoload.php b/tests/autoload.php
new file mode 100644
index 000000000..1fb33424e
--- /dev/null
+++ b/tests/autoload.php
@@ -0,0 +1,6 @@
+<?php
+	set_include_path(dirname(__DIR__) ."/include" . PATH_SEPARATOR .
+	get_include_path());
+
+	require_once "autoload.php";
+	require_once "functions.php";