Request with HTTP_ACCEPT header of : */*

[fschwahn]

Hi,
my rails app threw an exception because of a ActionView::MissingTemplate-exception. This was because a request had a http header ACCEPT with the value : */*. The app couldn't find a template for this format (which is what I expect to happen). The user agent was set to Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36.

I'm curious about what this means. Is this a problem with rails, or a problem with my app? I'd like to now if : */* is an acceptable value for ACCEPT, and which browser would set it like that.

The app is using rails 3.2.13.

[steveklabnik]

*/* is a valid value for the ACCEPT header, but I'm not sure where the bug is.

Could you try to reproduce this on 4.0 or master? I feel like we merged something related to this.

[fschwahn]

I'm sorry if I wasn't clear on this, the ACCEPT header is not */*, but : */*. In words: Colon Space Star Dash Star

Is this also a valid value? It is really hard to google this ;-)

[steveklabnik]

http://tools.ietf.org/html/rfc2616#section-4.2

       message-header = field-name ":" [ field-value ]
       field-name     = token
       token          = 1*<any CHAR except CTLs or separators>

Nope, you must have at least one character before the colon.

[fschwahn]

Ok, I guess everything is alright then. I was a bit suspicious if somebody is trying to exploit some attack vector, but there seems to be nothing there.

Thanks!