[R] Groups before conversion to a Table must not be restored after `collect()`

[asfimport]

Perhaps metadata$r$attributes$.group_vars needs to be removed when it becomes an arrow dplyr query.
And it must also be written back again when converted to a Table.

mtcars |> dplyr::group_by(cyl) |> arrow::arrow_table() |> dplyr::ungroup() |> as.data.frame() |> dplyr::group_vars()
#> character(0)
mtcars |> dplyr::group_by(cyl) |> arrow:::as_adq() |> dplyr::ungroup() |> as.data.frame() |> dplyr::group_vars()
#> [1] "cyl"

mtcars |> dplyr::group_by(cyl) |> arrow::arrow_table() |> dplyr::group_by(vs, .add = TRUE) |> dplyr::ungroup() |> dplyr::collect()
#> # A tibble: 32 × 11
#> # Groups: cyl [3]
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 21 6 160 110 3.9 2.62 16.5 0 1 4 4
#> 2 21 6 160 110 3.9 2.88 17.0 0 1 4 4
#> 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1
#> 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1
#> 5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2
#> 6 18.1 6 225 105 2.76 3.46 20.2 1 0 3 1
#> 7 14.3 8 360 245 3.21 3.57 15.8 0 0 3 4
#> 8 24.4 4 147. 62 3.69 3.19 20 1 0 4 2
#> 9 22.8 4 141. 95 3.92 3.15 22.9 1 0 4 2
#> 10 19.2 6 168. 123 3.92 3.44 18.3 1 0 4 4
#> # … with 22 more rows

Reporter: SHIMA Tatsuya / @eitsupi
Assignee: SHIMA Tatsuya / @eitsupi

Related issues:

• [R] dplyr::compute should convert from grouped arrow_dplyr_query to arrow Table (relates to)

PRs and other links:

• GitHub Pull Request #14175

_{Note: This issue was originally created as ARROW-17737. Please see the migration documentation for further details.}

[asfimport]

Neal Richardson / @nealrichardson:
Issue resolved by pull request 14175
#14175