geckodriver: Send some capabilities with the session response

Source-Repo: https://github.com/mozilla/geckodriver
Source-Revision: da0df07d621003404191002aac96693c1bc8c6b6

--HG--
extra : rebase_source : e8cf28ed88041fe4e40c92445be8edf94bcb6a32

testing/geckodriver/src/httpserver.rs

@@ -46,7 +46,7 @@ fn handle(mut incoming: Incoming) {
                         (err.http_status(), WebDriverResponse::from_err(&err))
                     }
                 };
-                let body = resp_data.to_json().to_string();
+                let body = format!("{}\n", resp_data.to_json().to_string());
                 {
                     let mut status_code = resp.status_mut();
                     *status_code = FromPrimitive::from_int(status).unwrap();

testing/geckodriver/src/response.rs

@@ -56,8 +56,19 @@ impl WebDriverResponse {
                                    json_data.find(&"from".to_string()).unwrap(),
                                    json_data.find(&"value".to_string()).unwrap());
                 };
+                //XXX spec - no idea what capabilities are supposed to be
+                let value = match json_data.find(&"value".to_string()) {
+                    Some(data) => data,
+                    None => {
+                        let error = WebDriverError::new(Some(session.session_id.clone()),
+                                                        UnknownError,
+                                                        "Failed to find value field");
+                        return Some(WebDriverResponse::from_err(&error));
+                    }
+                };
                 Some(WebDriverResponse::new(Some(session.session_id.clone()), status,
-                                            json::Null))
+                                            value.clone()
+                                            ))
             },
             Get(_) => {
                 Some(WebDriverResponse::new(Some(session.session_id.clone()), status,
@@ -65,9 +76,7 @@ impl WebDriverResponse {
             },
             GetCurrentUrl => {
                 let value = match json_data.find(&"value".to_string()) {
-                    Some(ref data) => {
-                        data.clone()
-                    },
+                    Some(data) => data,
                     None => {
                         let error = WebDriverError::new(Some(session.session_id.clone()),
                                                         UnknownError,