BlockTrans 1.01 (06 Sep 2020)  nemo 2000-2020
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BlockTrans demotes Wimp_TransferBlock from a general-purpose hacking tool
into purely a mechanism for implementing RamFetch. This somewhat improves
security and reliability, but does prevent some debugging tools from working,
such as Zap's Read Memory window.

Wimp_TransferBlock can always be used within a task's application slot to move
memory around, but if another task handle is specified it can ONLY be used to
write to the buffer nominated by the RamFetch message that has just been
delivered, and only until Wimp_Poll is called, at which point permission is
rescinded.

This also prevents the sending task from accidentally writing outside the
nominated buffer, and should arguably have always been checked in this way.

RISC OS is still a fabulously insecure operating system and you should not
use it for anything important!

nemo