Normalize domains containing Unicode characters.

database/Cargo.toml

@@ -19,6 +19,7 @@ url = "1.6"
 hex = "0.3"
 base64 = "0.10"
 pathdiff = "0.1"
+idna = "0.1"
 
 [lib]
 name = "hagrid_database"

database/src/lib.rs

@@ -12,6 +12,7 @@ use std::str::FromStr;
 extern crate failure;
 use failure::Error;
 use failure::Fallible as Result;
+extern crate idna;
 #[macro_use] extern crate log;
 extern crate parking_lot;
 use parking_lot::MutexGuard;

database/src/types.rs

@@ -52,6 +52,11 @@ impl FromStr for Email {
 
     fn from_str(s: &str) -> Result<Email> {
         let (localpart, domain) = parse2822address(s)?;
+
+        // Normalize Unicode in domains.
+        let domain = idna::domain_to_ascii(domain)
+            .map_err(|e| failure::format_err!(
+                "punycode conversion failed: {:?}", e))?;
         Ok(Email(format!("{}@{}", localpart, domain)))
     }
 }
@@ -167,5 +172,7 @@ mod tests {
         assert_eq!(c("Foo Bar <foo@example.org>").as_str(), "foo@example.org");
         assert_eq!(c("\"Foo Bar\" <foo@example.org>").as_str(),
                    "foo@example.org");
+        assert_eq!(c("foo@👍.example.org").as_str(),
+                   "foo@xn--yp8h.example.org");
     }
 }