Retry transient 400s with body logging; garage reserve default 27

tests/http_tests.rs

@@ -69,6 +69,57 @@ async fn test_get_file_server_error_retries() {
     m_ok.assert();
 }
 
+#[tokio::test]
+async fn test_get_file_bad_request_retries_then_recovers() {
+    let mut server = Server::new_async().await;
+    // The records API occasionally serves transient 400s — return 400 three
+    // times, then 200. Three requests must hit the 400 mock.
+    let m_fail = server
+        .mock("GET", "/data.json")
+        .with_status(400)
+        .with_body("upstream overloaded")
+        .expect(3)
+        .create();
+    let m_ok = mock_success(&mut server, "recovered");
+
+    let dir = tempfile::tempdir().unwrap();
+    let out_path = dir.path().join("output.txt");
+    let url = format!("{}/data.json", server.url());
+
+    get_file(&url, out_path.to_str().unwrap()).await.unwrap();
+
+    assert_eq!(fs::read_to_string(&out_path).unwrap(), "recovered");
+    m_fail.assert();
+    m_ok.assert();
+}
+
+#[tokio::test]
+async fn test_get_file_persistent_bad_request_fails_after_retries() {
+    let mut server = Server::new_async().await;
+    // 400 every time — should retry 3 times then fail with the body in the message
+    let m = server
+        .mock("GET", "/data.json")
+        .with_status(400)
+        .with_body("upstream overloaded")
+        .expect(4) // 1 initial + 3 retries
+        .create();
+
+    let dir = tempfile::tempdir().unwrap();
+    let out_path = dir.path().join("output.txt");
+    let url = format!("{}/data.json", server.url());
+
+    let result = get_file(&url, out_path.to_str().unwrap()).await;
+    assert!(result.is_err(), "Persistent 400 should fail after retries");
+    let err_msg = format!("{}", result.unwrap_err());
+    assert!(err_msg.contains("400"), "Error should mention HTTP 400: {err_msg}");
+    assert!(
+        err_msg.contains("upstream overloaded"),
+        "Error should carry the response body: {err_msg}"
+    );
+    assert!(!out_path.exists(), "No file should be written on persistent failure");
+    m.assert();
+}
+
 #[tokio::test]
 async fn test_get_file_client_error_fails_immediately() {
     let mut server = Server::new_async().await;