bug#20859: 25.0.50; css-mode: Comments within URIs

[Simen Heggestøyl]

In CSS, the syntax of URIs is described as follows:

  The format of a URI value is 'url(' followed by optional white space

  followed by an optional single quote (') or double quote (")

  character followed by the URI itself, followed by an optional single

  quote (') or double quote (") character followed by optional white

  space followed by ')'. The two quote characters must be the

  same. [1]

This means that all of the following are legal URI entries:

  url("http://www.example.com/")

  url('http://www.example.com/')

  url(http://www.example.com/)

However, css-mode doesn't currently interpret the stuff between the

parenthesis in the quote-less form as strings. This means that URIs

containing /* (or // in scss-mode, which is more common for URIs) will

be interpreted as comment starters by Emacs.

I attempted to fix this by setting syntax-propertize-function to the

following:

  (syntax-propertize-rules

     ("url\\(\(\\)[[:space:]]*[[:graph:]]*[[:space:]]*\\(\)\\)"

      (1 "|") (2 "|")))

This almost solves the problem, but with the quirk that "(" and ")"

are interpreted as part of the string.

Would it be possible to assign string syntax to the stuff between the

two parenthesis without having any visible string delimiters? I'm

thankful for any hints for getting closer to a solution!

-- Simen

[1] http://www.w3.org/TR/CSS21/syndata.html#uri