order optimization does not recognize all order args properly

[jangorecki]

current devel

• rather uncommon case, a non missing method argument

data.table(x=2:1)[base::order(x, method="auto")]
#   x
#1: 1
#2: 2
data.table(x=2:1)[order(x, method="auto")]
#Error: Column 2 is length 1 which differs from length of column 1 (2)

• length 1+ decreasing argument

data.table(x=2:1, y=2L)[order(x, y, decreasing=c(FALSE,FALSE))]
#Error: isTRUEorFALSE(decreasing) is not TRUE

d = data.table(x=3:1, y=c(2L,1L,3L), z=1:3)
with(d, order(x, y, decreasing=c(FALSE,FALSE)))
#[1] 3 2 1
d[with(d, order(x, y, decreasing=c(FALSE,FALSE)))] ## order is masked with forder inside outer `d` thus has to be compatible
#Error: isTRUEorFALSE(decreasing) is not TRUE
d[with(d, base::order(x, y, decreasing=c(FALSE,FALSE)))]
#   x y z
#1: 1 3 3
#2: 2 1 2
#3: 3 2 1