Invalid minification of var() fallback

[JaneOri]

Playground Input:

div {
  border-radius: 10px var(--foobar, );
}

Actual output

div{border-radius:10px var(--foobar,)}

(the empty fallback in var() is invalid and results in the whole rule being ignored. The space is required)

Expected output

div{border-radius:10px var(--foobar, )}

(must have the space in the fallback value to be valid)

Could be an issue somewhere upstream in postcss - happy to submit a PR either way if someone familiar with the code bases could point me roughly near the code that would be responsible.

[alexander-akait]

Yep, PR welcome