`cur_data_all()` for rowwise tibble un-nests list variables

[Fuco1]

When accessing current group in a rowwise tibble, the list column's nested values should probably not be expanded. If I have a column with tibbles, they are un-nested and this prevents further processing of the tibble as-is.

library(dplyr, warn.conflicts = FALSE)

f <- function(x) { print(x, n = nrow(x) )}
bla <- tibble(i = 1:2, x = list(tibble(a = 1), tibble(a = 2))) %>% 
  rowwise() %>% 
  summarise(f(cur_data_all()))
#> # A tibble: 1 x 2
#>       i   x$a
#>   <int> <dbl>
#> 1     1     1
#> # A tibble: 1 x 2
#>       i   x$a
#>   <int> <dbl>
#> 1     2     2

^{Created on 2021-06-03 by the reprex package (v2.0.0)}

The same code with group_by(i) does not un-nest the tibble.