Merge pull request #60799 from Calinou/doc-os-cmdline-args-3.x

doc/classes/OS.xml

@@ -161,6 +161,10 @@
 				    if argument.find("=") > -1:
 				        var key_value = argument.split("=")
 				        arguments[key_value[0].lstrip("--")] = key_value[1]
+				    else:
+				        # Options without an argument will be present in the dictionary,
+				        # with the value set to an empty string.
+				        arguments[argument.lstrip("--")] = ""
 				[/codeblock]
 			</description>
 		</method>