Unexpected failures when vector inherits from character

[hadley]

library(vctrs)
library(glue)

x <- glue("abc")
vec_c(x, x)
#> Only bare vectors have shapes.

    █
 1. ├─vctrs::vec_c(x, x)
 2. ├─vctrs:::vec_type2_dispatch(x = x, y = y, x_arg = x_arg, y_arg = y_arg)
 3. ├─vctrs::vec_ptype2.character(x = x, y = y, x_arg = x_arg, y_arg = y_arg)
 4. └─vctrs:::vec_ptype2.character.character(...)
 5.   └─vctrs:::shape_match(character(), x, y)
 6.     └─vctrs:::shape_common(x, y)
 7.       ├─vctrs:::n_dim2(shape(x), shape(y))
 8.       └─vctrs:::shape(x)

^{Created on 2019-07-22 by the reprex package (v0.3.0)}

From tidyverse/tidyr#676.

[hadley]

@DavisVaughan relaxed in https://github.com/r-lib/rray/blob/90793f06821280b19fe02610dae0dcf73df1968c/R/shape.R#L3

[yutannihilation]

Is this issue only about the error message? I think no error is the expected result.

[lionel-]

x <- structure(letters[1:3], class = "foo")
vctrs::vec_match(x, x)
#> [1] 1 2 3

x <- structure(letters[1:3], class = "character")
vctrs::vec_match(x, x)
#> <error/rlang_error>
#> Only bare vectors have shapes.
#> Backtrace:
#>  1. vctrs::vec_match(x, x)
#>  4. vctrs:::vec_ptype2.character.character(...)
#>  5. vctrs:::shape_match(character(), x, y)
#>  6. vctrs:::shape_common(x, y)
#>  8. vctrs:::shape(x)