Reverse solidus followed by null

[romainmenke]

In javascript this is : \\\x00

I am unsure if this is a bug because I don't know if CSSTree applies the preprocessing steps : https://www.w3.org/TR/css-syntax-3/#input-preprocessing

CSSTree tokenizes as :

{
  type: 'delim-token',
  raw: '\\',
  startIndex: 0,
  endIndex: 1
}
{
  type: 'delim-token',
  raw: '\x00',
  startIndex: 1,
  endIndex: 2
}

When processing an actual replacement character CSSTree tokenizes as :

{
  type: 'ident-token',
  raw: '\\�',
  startIndex: 0,
  endIndex: 2
}

I think the first example with a null char should also be an ident.