User report from the first live 2-window session: throttle worked, A/D turn
did nothing. [mppr] showed the input REACHING the mapper (stickX=-1) but
turnDemand=0 and controlMode = pointer garbage (73583232 / 217478632 --
different per instance), from frame 1, MP only (solo mode=0).
Hunted with a cdb hardware write-breakpoint (ba w4 armed at ctor time on
&controlMode, compiled offset +0x128 from the [mode-ctor] probe). Caught the
writers red-handed: MechControlsMapper::BuildPilotArray / FillPilotArray.
ROOT CAUSE -- a shrunk-span array: the binary reserves a FIXED 10-slot pilot
block @0x15C..0x183 ((pilotArrayBuilt@0x184 - 0x15C)/4 = 10); the recon
declared `Pilot *pilotArray[1]` ("variable length"), so every write past
slot 0 stomps the members declared after it. In MP, FillPilotArray wrote the
PEER's Player pointer into slot 1 = over controlMode -> the turn shaping
dispatched on pointer garbage -> turnDemand 0. MASKED in solo: the zero-loop
overrun wrote 0 there, and 0 == BasicMode. This was ALSO the real cause of
task #48's "turnDemand zeroes out in -net" observation (worked around then
with the direct goto-turn; attribution corrected in the KB).
Fix: pilotArray sized to the binary's own 10-slot span; ctor zeroes all
slots; BuildPilotArray clamps pilotCount to capacity (local + 9 remotes; an
8-pod game fits). Diagnostics kept (BT_MODE_LOG ctor probe; [mppr] line now
prints mapper/&mode).
VERIFIED: MP session holds mode=0 throughout, turnDemand flows nonzero, the
mech turns (heading -1.33) and closes on the peer; solo kill chain intact.
KB: new "shrunk-span array" gotcha (reconstruction-gotchas 5) with the cdb
ba-w4 recipe; multiplayer.md task-#48 note corrected.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
