Upgrade 1-11.38

vendor/rmccue/requests/src/Utility/CaseInsensitiveDictionary.php

@@ -49,6 +49,10 @@ class CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {
 			$offset = strtolower($offset);
 		}
 
+		if ($offset === null) {
+			$offset = '';
+		}
+
 		return isset($this->data[$offset]);
 	}
 
@@ -64,6 +68,10 @@ class CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {
 			$offset = strtolower($offset);
 		}
 
+		if ($offset === null) {
+			$offset = '';
+		}
+
 		if (!isset($this->data[$offset])) {
 			return null;
 		}
@@ -103,6 +111,10 @@ class CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {
 			$offset = strtolower($offset);
 		}
 
+		if ($offset === null) {
+			$offset = '';
+		}
+
 		unset($this->data[$offset]);
 	}