Fix utf-8 handling when reading malformed messages.

src/lib.rs

@@ -2,7 +2,6 @@
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
 #![feature(old_orphan_check)]
-#![feature(associated_types)]
 
 extern crate "rustc-serialize" as rustc_serialize;
 

src/reader.rs

@@ -1,4 +1,5 @@
 use std::io::{Buffer, Reader, IoError, IoResult, OtherIoError};
+use std::error::Error;
 
 use rustc_serialize::Decoder;
 
@@ -72,7 +73,11 @@ impl<'a, R: Reader+Buffer> Decoder for DecoderReader<'a, R> {
     fn read_str(&mut self) -> IoResult<String> {
         let len = try!(self.read_uint());
         let vector = try!(self.reader.read_exact(len));
-        Ok(String::from_utf8(vector).unwrap())
+        String::from_utf8(vector).map_err(|e| IoError {
+            kind: OtherIoError,
+            desc: "invalid utf-8",
+            detail: e.detail()
+        })
     }
     fn read_enum<T, F>(&mut self, _: &str, f: F) -> IoResult<T> where
         F: FnOnce(&mut DecoderReader<'a, R>) -> IoResult<T> {

src/test.rs

@@ -165,3 +165,13 @@ fn unicode() {
     the_same("å".to_string());
     the_same("aåååååååa".to_string());
 }
+
+#[test]
+fn bad_unicode() {
+    // This is a malformed message that contains bad utf8.
+    // The decoding should return Err but not panic.
+    let encoded = vec![0,0,0,0, 0,0,0,2, 97, 195];
+    let decoded: Result<String, _> = decode(encoded, Infinite);
+
+    assert!(decoded.is_err());
+}