freeldr: Heap Assertion when starting ReactOS with custom-boot options specified via FreeLdr

1- Start ReactOS
2- At Bootloader, press F8
3- Select "Custom Boot"
4- Select "ReactOS"
5- Fill-in the different fields
6- Boot

You obtain:

Assertion '*REDZONE_HI(Block) == REDZONE_MARK' failed at /reactos/boot/freeldr/freeldr/mm/heap.c line 174

in the debug log. Highly probable we're doing a buffer overrun.