[License-discuss] Does this license combination make (legal) sense?

[Josh Berkus]

I ran across this[1], which is apparently a popular license disclaimer 
in the Rust community:

 > Licensed under either of Apache License, Version 2.0 or MIT license 
at your option.
 > Unless you explicitly state otherwise, any contribution intentionally 
submitted for inclusion in this crate by you, as defined in the 
Apache-2.0 license, shall be dual licensed as above, without any 
additional terms or conditions.

... this doesn't seem like it's legally valid to my non-lawyer eyes. 
For example, if someone was using the code under the MIT license, then 
presumably they wouldn't enjoy any of the APL's patent claim 
protections.  And, if you were a downstream recipient of the code, how 
would you know what license you were receiving it under?

Am I missing something here?

[1]: https://crates.io/crates/syn

-- 
Josh Berkus