Root cause (by read, verified live): a glGenQueries name does not become
a QUERY OBJECT until its first glBeginQuery - GetQueryObject on a
never-begun name is GL_INVALID_OPERATION. The N.6 gpu_us ring assumed
ONE dispatcher Draw per frame with both passes always non-empty; the
pview pipeline issues MANY small Draws per frame (landscape slices,
per-cell static buckets, dynamics), where zero-draw passes routinely
skip BeginQuery. Under ACDREAM_WB_DIAG=1 the slot read queued an
InvalidOperation EVERY frame - silently, until WB's diligent
texture-path glGetError checks ate the stale errors and treated their
own successful uploads as failures ([wb-error] + the sticky drop) and
ProcessDirtyUpdates' check threw (process death, tower-wbdiag3.log).
The GL-error-attribution trap, textbook form.
Fix: begun-flags per ring slot per target; the read path only queries
slots that were actually begun (a skipped pass contributes 0 ns).
Live verification (tower-wbdiag4.log, in-tower spawn): zero [wb-error]
(was 7), no crash, gpu_us reads real values (9-11 us) for the first
time under the pview pipeline, meshMissing=0 / entSeen==entDrawn.
Consequences: (1) the #119 missing-stairs mechanism theory via sticky
GL upload failures is RETIRED for normal runs (WB_DIAG off = no query
calls = no errors; clean runs confirmed zero wb-error) - and the
in-tower screenshot on the current build shows the spiral staircase
RENDERING, so the stairs were most plausibly a #120 flood-corruption
casualty (the tower threshold cells portal back to 0x0107 exactly in
the ping-pong window); user verdict pending. (2) The sticky-drop
defect (upload failure never retried) stays filed under #125 as
defense-in-depth debt - the trigger is gone but the design flaw isn't.
Suites: App 236, Core 1419+2skip, UI 420, Net 294.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>