I was searching for a way to split the column content by a separator and converting a table into a long format. I found `cSplit` from the `splitstackshape` package and it is almost doing what I was looking for.

Problem is now with the `drop` option. I expected my split column to be copied in a way, but this does not happen. Am I doing it wrong? Somebody experienced the problem?

I am not sure if I do something wrong, but the `drop = FALSE` option is not working in my case.

Here is an example:

```
library(splitstackshape)
jnk <- data.table(a = '1,2,3,4,5', b = 5)
jnk
#            a b
# 1: 1,2,3,4,5 5

cSplit(jnk, 'a', ',', 'long', drop = FALSE)
#    a b
# 1: 1 5
# 2: 2 5
# 3: 3 5
# 4: 4 5
# 5: 5 5

```

What I expected was something like this:

```
cSplit(jnk, 'a', ',', 'long', drop = FALSE)
#    a b    a.orig
# 1: 1 5 1,2,3,4,5
# 2: 2 5 1,2,3,4,5
# 3: 3 5 1,2,3,4,5
# 4: 4 5 1,2,3,4,5
# 5: 5 5 1,2,3,4,5

```

I am using version 1.4.2