fetchTile coalesced concurrent requests for one tile onto a single
upstream fetch, but that fetch ran on the first caller's signal. When the
first request was abandoned (an older pan), every joined request lost a
tile it still needed; and a joined caller that aborted stayed subscribed
until the shared fetch finished.
A flight now owns its AbortController and counts waiters, the pattern the
weather and wind providers use. Each caller's own abort rejects that caller
at once; the upstream fetch is cancelled only when the last waiter leaves,
and a later request after that starts a fresh fetch.
Regression tests (fail on the previous tiles.js, pass now): a joined
request survives the first caller aborting with one upstream request; a
joined caller that aborts leaves at once while the first still gets the
tile; both waiters leaving cancels the owned fetch.
Reported by kvnloo in review.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Camera-driven Mapillary coverage (z0–5 overview points from orbit, z11–14
ground-clamped sequence lines below 60 km), per-sequence image cones, an
embedded MapillaryJS viewer bridge with a camera-follow mode, sprite icons
for map features, and a query engine that turns a plan into a streamed
z14 tile fan-out. Registers an on-globe CC BY-SA 4.0 credit while enabled.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
