rbindlist segfault

[arunsrinivasan]

Commit 2706 segfaults rbindlist when used with idcol argument.

require(data.table)
dt <- setDT(lapply(1:11, function(x) sample(letters, 1e4L, TRUE)))

ll <- lapply(1:3000, function(x) {
  if (runif(1) > 0.5) data.table() else dt[sample(1000L)]
})

# works fine
for (i in 1:50) {
  ans1 <- rbindlist(ll)
}

# segfaults
for (i in 1:50) {
  ans2 <- rbindlist(ll, idcol="id")
}

The current CRAN version segfaults. Narrowed it down to commit 2706.

[mllg]

Here is an example which is easier to reproduce:

require(data.table)
x <- list(list(a = 1), list(), list(a = 2))
rbindlist(x, idcol = "id")

This is fixed with #2077, but I'm not sure where to put the test.