check:popup-pan-controls proves the ARITHMETIC: given a band height, the pan
clears it. Nothing proves the band height is real. If bottomControlInset returns
0 -- a selector typo, an engine renaming its control classes, a control moving
outside the container -- then panPlanFor is handed bottomInset 0, behaves exactly
as it did before the fix, and check:popup-pan-controls still passes every case
because its arithmetic is still correct. The bug would be back with both gates
green. That is the failure this guards.
Seven cases against a real DOM, running the SHIPPED bottomControlInset read out
of the SFC (it is not exported), never a re-typed copy: a visible attribution
reserves a band EQUAL to what the DOM independently says, not merely non-zero,
which a stub returning 1 would satisfy; no controls reserves exactly 0; a
zero-sized control reserves nothing, since counting it would reserve the whole
map and refuse every popup; the taller of two corners wins, because the pin hint
is bottom-left while the attribution is bottom-right; a wrapped attribution
reserves more than one line, which is what a hard-coded constant gets wrong at
390; a control outside the container is ignored; a null container returns 0
rather than throwing.
It needs a real browser: every assertion rests on getBoundingClientRect, and no
DOM library here computes layout, so a headless stand-in would return zeros and
pass vacuously.
NOT REGISTERED. Browsers are rega's seat, so this has not been run, and
verify-browser-all's rule is that every gate listed there was run before it was
listed. It is registered only after rega's PASS.
