rack/rack — pull request #399 by novemberborn (2012-06-26 12:25:19+00:00)
Title: Validate header names according to RFC 2616

Header name validation rules are too strict. [RFC 2616](http://pretty-rfc.herokuapp.com/RFC2616) allows any ASCII character, with a few exceptions. See , or:

```
message-header = field-name ":" [ field-value ]
field-name = token

token = 1*
CHAR =
separators = "(" | ")" | "<" | ">" | "@"
| "," | ";" | ":" | "\" | <">
| "/" | "[" | "]" | "?" | "="
| "{" | "}" | SP | HT
CTL =
SP =
HT =
```

This commit loosens the restrictions in `Rack::Lint`.