[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