CSS multiline string incorrect syntax highlighting

[niwazukihon]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.89.0
• OS Version: Windows 11

Steps to Reproduce:

1. Create a css file. Write, for example

@import url('a-really-long\
    -url');

2. The syntax highlighting is wrong. It seems to not interpret the string as a whole.

This was mentioned in issue microsoft/vscode#125739, which was closed and locked with a reference to another repo, but that repo was archived. Is there a plan to fix this bug?

[RedCMD]

should move report to https://github.com/microsoft/vscode-css

caused by \\s*. it matches the ending newline.
resulting in the begin anchor \\G being placed at the beginning of the next line (VSCode TextMate bug?)
causing ^(?<!\\G) to always fail

I don't know why \\s* was placed there
as it does nothing other than cause issues

[RedCMD]

caused by atom/language-css#123 2bc6abb
the anchor moving bug also happens in TextMate2.0
microsoft/vscode-textmate#237

I still don't know why capturing the newline is needed
and why (?<!\\G) is needed
as removing either or both fixes it

vscode-css/grammars/css.cson

Lines 720 to 721 in c216f77

	'begin': '\\\\$\\s*'
	'end': '^(?<!\\G)'