A monitor unplugged mid-session left the teardown replaying a snapshot whose
paths reference an absent target — SetDisplayConfig rejects the WHOLE array
with 0x57 ERROR_INVALID_PARAMETER, nothing restores, the desk stays dark, and
the next session snapshots the wreckage (the poisoned-snapshot chain; field
2026-08-12: rc=0x57 across a mid-session unplug, then sessions flipping
between black and working at random, incl. one that genuinely encoded black).
The restore now prunes the snapshot against a live QDC_ALL_PATHS availability
sweep before replaying: stale paths drop, the mode table is rebuilt with only
the entries the survivors reference (an orphaned mode entry is itself an
0x57), and an empty survivor set skips the apply so the dark-desk backstop
decides. Verbatim behavior is unchanged when everything is still attached or
when the availability query itself fails.
enricobuehler
d6b9862f1e