Use correct host on redirect. (#180)

src/test/redirect.rs

@@ -1,3 +1,9 @@
+use std::{
+    io::{self, Write},
+    net::TcpStream,
+};
+use test::testserver::{self, TestServer};
+
 use crate::test;
 
 use super::super::*;
@@ -76,6 +82,25 @@ fn redirect_get() {
     assert_eq!(resp.header("x-foo").unwrap(), "bar");
 }
 
+#[test]
+fn redirect_host() {
+    // Set up a redirect to a host that doesn't exist; it should fail.
+    let srv = TestServer::new(|mut stream: TcpStream| -> io::Result<()> {
+        testserver::read_headers(&stream);
+        write!(stream, "HTTP/1.1 302 Found\r\n")?;
+        write!(stream, "Location: http://example.invalid/\r\n")?;
+        write!(stream, "\r\n")?;
+        Ok(())
+    });
+    let url = format!("http://localhost:{}/", srv.port);
+    let resp = crate::get(&url).call();
+    assert!(
+        matches!(resp.synthetic_error(), Some(Error::DnsFailed(_))),
+        "{:?}",
+        resp.synthetic_error()
+    );
+}
+
 #[test]
 fn redirect_post() {
     test::set_handler("/redirect_post1", |_| {