JDK-8322811 fixes help output for the System.dump_map -F argument so instead of

 -F : [optional] file path (defaults: "vm_memory_map_<pid>.txt") (STRING, no default value)
 
It instead reads:

 -F : [optional] file path (STRING, "vm_memory_map_<pid>.txt")

Although the implementation produces the correct output, there is a bug in it. If you specify the literal "vm_memory_map_<pid>.txt" as the map file name, <pid> is still replaced with the actual process ID, but it shouldn't be.

The correct way to check if a default was provided is to use _filename.is_set() rather than strcmp to "vm_memory_map_<pid>.txt". See the fix for JDK-8323546 as an example.