Strange formatting for 'more than one codepoint in char' error message

[frewsxcv]

Code (playpen)

fn main() {
    let heart = '❤️';
}

Error:

error: character literal may only contain one codepoint: '❤
 --> <anon>:2:17
  |
2 |     let heart = '❤️';
  |                 ^^

error: aborting due to previous error

Why do we only show one quotation mark ('❤) in the first line of the error? Seems like we should either display both or none

[frewsxcv]

If this gets addressed, make sure to update the error message in this section:

https://doc.rust-lang.org/std/primitive.char.html#representation

[frewsxcv]

Actually, it's a little more obvious to me what's going on here now that I see how GitHub formats the hearts. It's displaying <quotation mark><first code point>.

I think this is a duplicate, but am not sure.

Similar to #36998 (which I want to address), but this is more about the error message

[frewsxcv]

Interestingly, in this case, we show the entire contents of the character literal with both quotes in the error:

Code:

fn main() {
    let meow = 'hello';
} 

Error (playpen):

error: character literal may only contain one codepoint: 'hello'
 --> <anon>:2:16
  |
2 |     let meow = 'hello';
  |                ^^^^^^^

error: aborting due to previous error

[tbu-]

U+0066  f       [Ll] LATIN SMALL LETTER F
U+006E  n       [Ll] LATIN SMALL LETTER N
U+0020          [Zs] SPACE
U+006D  m       [Ll] LATIN SMALL LETTER M
U+0061  a       [Ll] LATIN SMALL LETTER A
U+0069  i       [Ll] LATIN SMALL LETTER I
U+006E  n       [Ll] LATIN SMALL LETTER N
U+0028  (       [Ps] LEFT PARENTHESIS
U+0029  )       [Pe] RIGHT PARENTHESIS
U+0020          [Zs] SPACE
U+007B  {       [Ps] LEFT CURLY BRACKET
U+000A  \n      [Cc] <unknown>
U+0020          [Zs] SPACE
U+0020          [Zs] SPACE
U+0020          [Zs] SPACE
U+0020          [Zs] SPACE
U+006C  l       [Ll] LATIN SMALL LETTER L
U+0065  e       [Ll] LATIN SMALL LETTER E
U+0074  t       [Ll] LATIN SMALL LETTER T
U+0020          [Zs] SPACE
U+0068  h       [Ll] LATIN SMALL LETTER H
U+0065  e       [Ll] LATIN SMALL LETTER E
U+0061  a       [Ll] LATIN SMALL LETTER A
U+0072  r       [Ll] LATIN SMALL LETTER R
U+0074  t       [Ll] LATIN SMALL LETTER T
U+0020          [Zs] SPACE
U+003D  =       [Sm] EQUALS SIGN
U+0020          [Zs] SPACE
U+0027  '       [Po] APOSTROPHE
U+2764  ❤       [So] HEAVY BLACK HEART
U+FE0F  ️       [Mn] VARIATION SELECTOR-16
U+0027  '       [Po] APOSTROPHE
U+003B  ;       [Po] SEMICOLON
U+000A  \n      [Cc] <unknown>
U+007D  }       [Pe] RIGHT CURLY BRACKET
U+0020          [Zs] SPACE
U+000A  \n      [Cc] <unknown>

It looks like rustc can't deal with the combining character VARIATION SELECTOR-16.

[estebank]

No longer valid in current beta.