`struct object_rw` is poisoned prior to initializing and sending it.
However, some fields are legitimately unininitialized (other than their
memset or poison value) at send time. Add and use a poison variant that
can clear those fields, without marking them unreadable.
Clang rejects a declared (but never defined and never used) `static`
function. Change the declaration to be the value of a macro that will
be expanded only when the function is both defined and used.
Reported-by: kreatordxx <https://github.com/dxx-rebirth/dxx-rebirth/issues/295>
Fixes: 55822d0b4d ("Add wrappers for more precise Valgrind physfs diagnostics")
Valgrind warns when writing uninitialized data to a file. The Descent
savegame format requires writing certain fields that are no longer used.
Set those fields to 0 to prevent leaking stack data into the file.
zicodxx reports that f7d0c85 made the thief bot passive and timid.
His analysis suggests that the problem is because f7d0c85 changed
find_connected_distance to return vm_distance::maximum_value() in places
where it previously returned magic values that were not maximum (caching
a distance of F1_0*1000 and returning a distance of -1). Rather than
try to fix the underlying code that relied on these magic values, revert
those return paths to return these unusual values. Move the unusual
values to named constants in file scope so that they are easier to find
and correlate.
Reported-by: zicodxx <https://github.com/dxx-rebirth/dxx-rebirth/issues/286>
Analyzed-by: zicodxx
Fixes: f7d0c853ba ("Use special types for distance/magnitude")