diff --git a/htdocs/core/lib/functions2.lib.php b/htdocs/core/lib/functions2.lib.php
index f5e95da450c..e2a8569e710 100644
--- a/htdocs/core/lib/functions2.lib.php
+++ b/htdocs/core/lib/functions2.lib.php
@@ -1431,23 +1431,28 @@ function get_next_value($db, $mask, $table, $field, $where = '', $objsoc = '', $
 }
 
 /**
- * Get string between
+ * Get string from "$start" up to "$end"
+ *
+ * If string is "STARTcontentEND" and $start is "START" and $end is "END",
+ * then this function returns "content"
  *
  * @param   string  $string     String to test
- * @param   int     $start      Value for start
- * @param   int     $end        Value for end
+ * @param   string  $start      String Value for start
+ * @param   string  $end        String Value for end
  * @return  string              Return part of string
  */
 function get_string_between($string, $start, $end)
 {
-	$string = " ".$string;
 	$ini = strpos($string, $start);
-	if ($ini == 0) {
-		return "";
+	if ($ini === false) {
+		return '';
 	}
 	$ini += strlen($start);
-	$len = strpos($string, $end, $ini) - $ini;
-	return substr($string, $ini, $len);
+	$endpos = strpos($string, $end, $ini);
+	if ($endpos === false) {
+		return '';
+	}
+	return substr($string, $ini, $endpos - $ini);
 }
 
 /**
diff --git a/test/phpunit/Functions2LibTest.php b/test/phpunit/Functions2LibTest.php
index 1d987d5aac5..081061a08ed 100644
--- a/test/phpunit/Functions2LibTest.php
+++ b/test/phpunit/Functions2LibTest.php
@@ -1,6 +1,7 @@
 <?php
 /* Copyright (C) 2010-2012 Laurent Destailleur  <eldy@users.sourceforge.net>
  * Copyright (C) 2023      Alexandre Janniaux   <alexandre.janniaux@gmail.com>
+ * Copyright (C) 2024		MDW							<mdeweerd@users.noreply.github.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -205,4 +206,42 @@ class Functions2LibTest extends CommonClassTest
 		print __METHOD__." for ".$ip." result=".$result."\n";
 		$this->assertEquals(2, $result, $ip);
 	}
+
+
+	/**
+	 * Dataprovider for testGetStringBetween
+	 *
+	 * @return array<string,string[]}
+	 */
+	public function stringBetweenDataProvider()
+	{
+		return [
+			// string, start, end, expected
+			'matches' => [ "STARTcontentEND", "START", "END", "content"],
+			'start does not match' => [ "ScontentEND", "START", "END", ""],
+			'end does not match' => [ "STARTcontentN", "START", "END", ""],
+			'no match' => [ "content", "START", "END", ""],
+			'end before start' => [ "ENDcontentSTART", "START", "END", ""],
+			'end inside start' => [ "BAB", "BA", "AB", ""],
+			'multiple matches' => [ "BAcontentABBAdoneAB", "BA", "AB", "content"],
+		];
+	}
+
+
+	/**
+	 * Test get_string_between()
+	 *
+	 * @param string $string String to search in.
+	 * @param string $start String indicating start
+	 * @param string $end String indicating end
+	 * @param string $expected Expected result
+	 *
+	 * @return void
+	 *
+	 * @dataProvider stringBetweenDataProvider
+	 */
+	public function testGetStringBetween($string, $start, $end, $expected)
+	{
+		$this->assertEquals($expected, get_string_between($string, $start, $end));
+	}
 }