join() with type = "left" fails if order of common variables is not equal in each data frame

[gavinsimpson]

Richard Telford reports the following bug:

spp <- data.frame(cat = 1:2, dog = 2:3, fish = 3:4)
fos <- data.frame(mouse = 7:8,dog = 9:10, cat = 5:6)

library("analogue")

join(spp, fos, type = "outer")#works
join(spp, fos, type = "left") #fails - dog and cat entries are switched

Notice that cat in fos in the join()ed output is c(9,10) but is c(5,6) upon input

> join(spp, fos, type = "left")
$spp
  cat dog fish
1   1   2    3
2   2   3    4

$fos
  cat dog fish
1   9   5    0
2  10   6    0

attr(,"class")
[1] "join"
attr(,"type")
[1] "left"
> fos
  mouse dog cat
1     7   9   5
2     8  10   6