The desktop legend gets :export-enabled and @export from this file's template, so
a reader at a desk can print a poster or a packet. LegendMobile does not read
props from here. It reaches for an injected handler and decides whether to offer
the control at all by whether one exists -- mobileExportEnabled is
`typeof onLegendExport === 'function'`. Nothing here provided it, so the phone
showed no export while the same map on a desktop showed both.
That is why it went unreported for so long: it is an ABSENCE, not a broken
button. Nobody clicks a control that was never drawn, and the desktop, where this
kind of thing gets checked, was always correct.
The provide carries EXPORT_FEATURE_ENABLED rather than the bare function. The
desktop already passes that flag, so providing unconditionally would hand a phone
an affordance the desktop deliberately hides when the flag is off; and because
"is there a handler" IS the mobile switch, passing null when it is off is exactly
what makes the sheet hide the control. countries-map fixed this first and its
comment records the same two causes on my-upg-100-list, so this is the third
instance of one pattern rather than a new bug.
Measured before building: the sibling item in the same diff, the RTL-safe CSS the
research map was said to owe the country map, is already done -- zero physical
declarations remain once comments are excluded, and the one apparent hit is prose
describing why a padding exists.
closes#15 of COUNTRY-RESEARCH-MAP-DIFF
7e6d3324ec