set globs have incorrect behavior

[BurntSushi]

Repro:

$ git clone git:https://github.com/bag-man/dotfiles
$ cd dotfiles
$ rg --no-ignore --hidden --follow --files --glob '!{.git,node_modules,plugged}/**' --glob '*.{js,json,php,md,styl,scss,sass,pug,html,config,py,cpp,c,go,hs}'

The output includes files in the .git directory. Interestingly, removing some of the extensions in the second --glob impacts the output in unexpected ways. Changing the first glob to not use a recursive glob also seems to make it work.

If I look at the debug output, it looks like the generated regex for the second glob is:

(?-u)^(?:/?|.*/).*\\.hs|c|cpp|py|config|html|pug|sass|scss|styl|md|php|json|js$

Which is just plain wrong. The alternation should be in a group.

[BurntSushi]

Yup, the bug is here:

ripgrep/globset/src/glob.rs

Lines 657 to 665 in cf750a1

	Token::Alternates(ref patterns) => {
	let mut parts = vec![];
	for pat in patterns {
	let mut altre = String::new();
	self.tokens_to_regex(options, &pat, &mut altre);
	parts.push(altre);
	}
	re.push_str(&parts.join("|"));
	}

All it needs is a regression test and some parens pushed around the alternation.