Presence flag for a round attribute: '' when a radius applies, else
undefined. A bare round ? '' : undefined wrongly drops round={0} — the
caller asking for square corners — since 0 is falsy; this keeps it (and drops
false / undefined / ''). Mirrors what roundStyle emits a variable for.
Presence flag for a
roundattribute:''when a radius applies, elseundefined. A bareround ? '' : undefinedwrongly dropsround={0}— the caller asking for square corners — since0is falsy; this keeps it (and dropsfalse/undefined/''). Mirrors whatroundStyleemits a variable for.