distinct() doesn't respect user-specified column order

[sfirke]

I'm again experiencing behavior that was reported as #3195, then closed years ago. I'll use the same reprex. Running dplyr 1.0.7.

starwars %>% distinct(skin_color, hair_color)

#> # A tibble: 50 x 2
#>    hair_color    skin_color 
#>    <chr>         <chr>      
#>  1 blond         fair       
#>  2 <NA>          gold       
#>  3 <NA>          white, blue
#>  4 none          white      
#>  5 brown         light      
#>  6 brown, grey   light      
#>  7 <NA>          white, red 
#>  8 black         light      
#>  9 auburn, white fair       
#> 10 auburn, grey  fair       
#> # ... with 40 more rows
Created on 2022-01-14 by the reprex package (v2.0.1)

[hadley]

Actual reprex:

library(dplyr, warn.conflicts = FALSE)
starwars %>% distinct(skin_color, hair_color)
#> # A tibble: 50 × 2
#>    hair_color    skin_color 
#>    <chr>         <chr>      
#>  1 blond         fair       
#>  2 <NA>          gold       
#>  3 <NA>          white, blue
#>  4 none          white      
#>  5 brown         light      
#>  6 brown, grey   light      
#>  7 <NA>          white, red 
#>  8 black         light      
#>  9 auburn, white fair       
#> 10 auburn, grey  fair       
#> # … with 40 more rows

^{Created on 2022-04-16 by the reprex package (v2.0.1)}

[hadley]

Looks like I broke this by accident in #4691

[machow]

It seems like this may have resurfaced (reprex using v1.0.10):

library(dplyr, warn.conflicts = FALSE)

head(mtcars, 2)
#>               mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> Mazda RX4      21   6  160 110  3.9 2.620 16.46  0  1    4    4
#> Mazda RX4 Wag  21   6  160 110  3.9 2.875 17.02  0  1    4    4

distinct(mtcars, cyl, mpg) %>% head(2)
#>             mpg cyl
#> Mazda RX4  21.0   6
#> Datsun 710 22.8   4

^{Created on 2022-10-06 by the reprex package (v2.0.1)}

[DavisVaughan]

Fixed in the dev version though!

library(dplyr, warn.conflicts = FALSE)

distinct(mtcars, cyl, mpg) %>% head(2)
#>            cyl  mpg
#> Mazda RX4    6 21.0
#> Datsun 710   4 22.8

^{Created on 2022-10-06 with reprex v2.0.2.9000}