Warn for invalid redirect

src/redirect.rs

@@ -51,11 +51,15 @@ impl Middleware for RedirectFollower {
 // See https://github.com/seanmonstar/reqwest/blob/bbeb1ede4e8098481c3de6f2cafb8ecca1db4ede/src/async_impl/client.rs#L1500-L1607
 fn get_next_request(mut request: Request, response: &Response) -> Option<Request> {
     let get_next_url = |request: &Request| {
-        response
-            .headers()
-            .get(LOCATION)
-            .and_then(|location| location.to_utf8_str().ok())
-            .and_then(|location| request.url().join(location).ok())
+        let location = response.headers().get(LOCATION)?;
+        let url = location
+            .to_utf8_str()
+            .ok()
+            .and_then(|location| request.url().join(location).ok());
+        if url.is_none() {
+            log::warn!("Redirect to invalid URL: {location:?}");
+        }
+        url
     };
 
     match response.status() {

tests/cases/logging.rs

@@ -1,3 +1,4 @@
+use hyper::header::HeaderValue;
 use predicates::str::contains;
 
 use crate::prelude::*;
@@ -91,3 +92,35 @@ fn checked_status_is_not_printed_with_double_quiet() {
         .stdout("")
         .stderr("");
 }
+
+#[test]
+fn warning_for_invalid_redirect() {
+    let server = server::http(|_req| async move {
+        hyper::Response::builder()
+            .status(302)
+            .header("location", "//")
+            .body("".into())
+            .unwrap()
+    });
+
+    get_command()
+        .args(["--follow", &server.base_url()])
+        .assert()
+        .stderr("xh: warning: Redirect to invalid URL: \"//\"\n");
+}
+
+#[test]
+fn warning_for_non_utf8_redirect() {
+    let server = server::http(|_req| async move {
+        hyper::Response::builder()
+            .status(302)
+            .header("location", HeaderValue::from_bytes(b"\xFF").unwrap())
+            .body("".into())
+            .unwrap()
+    });
+
+    get_command()
+        .args(["--follow", &server.base_url()])
+        .assert()
+        .stderr("xh: warning: Redirect to invalid URL: \"\\xff\"\n");
+}