Incorrect comment handling in some edge-case

[holblin]

Expected Behaviour

Comments are properly ignored in all places.

Actual Behaviour

Comment in the selector that contains a { break the parsing because the { evaluation is done before the comment escaping.

Steps to Reproduce

• Change the file test/cases/comment/input.css by:

/* 1 */

head, /* footer, */body/*, nav */ { /* 2 */
  /* 3 */
  /**/foo: 'bar';
  /* 4 */
} /* 5 */

/* 6 */

• Run yarn test

Logs taken while reproducing the problem

$jest
 PASS  test/parse.test.ts
 FAIL  test/cases.test.ts
  ● cases/comment › should match ast.json

    input.css:3:37: property missing ':'

      77 |
      78 |   function error(msg: string) {
    > 79 |     const err = new CssParseError(
         |                 ^
      80 |       options?.source || '',
      81 |       msg,
      82 |       lineno,

      at error (src/parse/index.ts:79:17)
      at declaration (src/parse/index.ts:263:14)
      at declarations (src/parse/index.ts:294:20)
      at rule (src/parse/index.ts:716:21)
      at rules (src/parse/index.ts:134:71)
      at stylesheet (src/parse/index.ts:98:23)
      at parse (src/parse/index.ts:720:20)
      at parseInput (test/cases.test.ts:39:19)
      at Object.<anonymous> (test/cases.test.ts:15:19)

Potential fix

• Add a special condition in the regex for the selector to skip the comments. This should not reduce performance or introduce a dos vulnerability.
• Change the parsing to skip the comment while doing the parsing.