d*ply errors on 0-length .variables arg

[btomi]

I would expect

x <- data.frame(a=1)
d_ply(x, character(), print)

to be equivalent to

print(x)

but, I get this error instead (with version 1.2.1):

*** caught segfault ***
address (nil), cause 'memory not mapped'

Traceback:
1: .Call("split_indices", index, group, as.integer(n))
2: split_indices(seq_along(splitv), as.integer(splitv), attr(splitv,     "n"))
3: splitter_d(.data, .variables)
4: d_ply(x, character(), print)

Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace

On the other hand,

d_ply(data.frame(a=c(1,2)), character(), print)

does not error, but loops infinitely.

[hadley]

These are both now fixed in the development version