vec_as_location2("0")

[krlmlr]

gives a weird error, on ebbc500.

library(vctrs)
vec_as_location2("-1", 4, as.character(-1:2))
#> [1] 1
vec_as_location2("0", 4, as.character(-1:2))
#> Error: Must extract element with a single valid subscript.
#> x Subscript has value 0 but must be a positive location.
vec_as_location2("1", 4, as.character(-1:2))
#> [1] 3
vec_as_location2("2", 4, as.character(-1:2))
#> [1] 4

^{Created on 2020-06-01 by the reprex package (v0.3.0)}