Preserve case of css custom variables. Fixes #648

[p-a]

Fix matches var(--somename) and preserve case of the variable name.

Fixes #648

[alexander-akait]

Good work! Maybe we need check other places in postcss-merge-longhand on same problem. Can you be champion this?

[coveralls]

Coverage increased (+0.001%) to 99.201% when pulling 08817ef on p-a:css-custom-property-preserve-case into 1b27f28 on cssnano:master.

[andyjansson]

What happened to the diff?

[p-a]

@evilebottnawi Thanks! Well, sure, but I'm not sure when I will be able to find time to do it! Will put it on my TODO list!

@andyjansson sorry, VS Code must have "helped out" with whitespaces. EDIT: Apparently line breaks are CRLF à la Windows in the original file. On my Mac the default is just LF so VS Code changed all line breaks...

[p-a]

AFAICT there was only one place which lowercased strings, and that was taken care of by the initial commit. However, I added some more tests to ensure this.

[alexander-akait]

/cc @andyjansson

[andyjansson]

It's fine. In the long run, I'd probably prefer distinct formatting functions for widths, styles, and colors so we can handle any potential edge cases.

[p-a]

When do you expect to make the merge? Will there also be a new minor release after that? (would be great)

[alexander-akait]

@p-a Today