Fix git-transport reqwest client: Support redirect

Fixed #974

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

gix-transport/src/client/blocking_io/http/mod.rs

@@ -517,5 +517,5 @@ pub fn connect(url: gix_url::Url, desired_version: Protocol) -> Transport<Impl>
 }
 
 ///
-#[cfg(feature = "http-client-curl")]
+#[cfg(any(feature = "http-client-curl", feature = "http-client-reqwest"))]
 pub mod redirect;

gix-transport/src/client/blocking_io/http/reqwest/remote.rs

@@ -3,14 +3,12 @@ use std::{
     convert::TryFrom,
     io::{Read, Write},
     str::FromStr,
+    sync::{atomic, Arc},
 };
 
 use gix_features::io::pipe;
 
-use crate::client::{
-    http,
-    http::{reqwest::Remote, traits::PostBodyDataKind},
-};
+use crate::client::http::{self, options::FollowRedirects, redirect, reqwest::Remote, traits::PostBodyDataKind};
 
 /// The error returned by the 'remote' helper, a purely internal construct to perform http requests.
 #[derive(Debug, thiserror::Error)]
@@ -22,6 +20,8 @@ pub enum Error {
     ReadPostBody(#[from] std::io::Error),
     #[error("Request configuration failed")]
     ConfigureRequest(#[from] Box<dyn std::error::Error + Send + Sync + 'static>),
+    #[error(transparent)]
+    Redirect(#[from] redirect::Error),
 }
 
 impl crate::IsSpuriousError for Error {
@@ -40,23 +40,51 @@ impl Default for Remote {
         let (req_send, req_recv) = std::sync::mpsc::sync_channel(0);
         let (res_send, res_recv) = std::sync::mpsc::sync_channel(0);
         let handle = std::thread::spawn(move || -> Result<(), Error> {
+            let mut follow = None;
+            let mut redirected_base_url = None::<String>;
+
+            // This initial value is just a place holder, it will get modified
+            // before `client.execute` is called.
+            let current_follow_policy = Arc::new(atomic::AtomicBool::new(false));
+
+            let follow_policy = Arc::clone(&current_follow_policy);
+
             // We may error while configuring, which is expected as part of the internal protocol. The error will be
             // received and the sender of the request might restart us.
             let client = reqwest::blocking::ClientBuilder::new()
                 .connect_timeout(std::time::Duration::from_secs(20))
                 .http1_title_case_headers()
+                .redirect(reqwest::redirect::Policy::custom(move |attempt| {
+                    if follow_policy.load(atomic::Ordering::Relaxed) {
+                        let curr_url = attempt.url();
+                        let prev_urls = attempt.previous();
+
+                        match prev_urls.first() {
+                            Some(prev_url) if prev_url.host_str() != curr_url.host_str() => {
+                                // gix does not want to be redirected to a different host.
+                                attempt.stop()
+                            }
+                            _ => attempt.follow(),
+                        }
+                    } else {
+                        attempt.stop()
+                    }
+                }))
                 .build()?;
+
             for Request {
                 url,
+                base_url,
                 headers,
                 upload_body_kind,
                 config,
             } in req_recv
             {
+                let effective_url = redirect::swap_tails(redirected_base_url.as_deref(), &base_url, url.clone());
                 let mut req_builder = if upload_body_kind.is_some() {
-                    client.post(url)
+                    client.post(&effective_url)
                 } else {
-                    client.get(url)
+                    client.get(&effective_url)
                 }
                 .headers(headers);
                 let (post_body_tx, mut post_body_rx) = pipe::unidirectional(0);
@@ -91,6 +119,21 @@ impl Default for Remote {
                         }
                     }
                 }
+
+                let follow = follow.get_or_insert(config.follow_redirects);
+
+                current_follow_policy.store(
+                    match *follow {
+                        FollowRedirects::None => false,
+                        FollowRedirects::Initial | FollowRedirects::All => true,
+                    },
+                    atomic::Ordering::Relaxed,
+                );
+
+                if *follow == FollowRedirects::Initial {
+                    *follow = FollowRedirects::None;
+                }
+
                 let mut res = match client
                     .execute(req)
                     .and_then(reqwest::blocking::Response::error_for_status)
@@ -116,6 +159,11 @@ impl Default for Remote {
                     }
                 };
 
+                let actual_url = res.url().as_str();
+                if actual_url != effective_url.as_str() {
+                    redirected_base_url = redirect::base_url(actual_url, &base_url, url)?.into();
+                }
+
                 let send_headers = {
                     let headers = res.headers();
                     move || -> std::io::Result<()> {
@@ -172,7 +220,7 @@ impl Remote {
     fn make_request(
         &mut self,
         url: &str,
-        _base_url: &str,
+        base_url: &str,
         headers: impl IntoIterator<Item = impl AsRef<str>>,
         upload_body_kind: Option<PostBodyDataKind>,
     ) -> Result<http::PostResponse<pipe::Reader, pipe::Reader, pipe::Writer>, http::Error> {
@@ -197,6 +245,7 @@ impl Remote {
             .request
             .send(Request {
                 url: url.to_owned(),
+                base_url: base_url.to_owned(),
                 headers: header_map,
                 upload_body_kind,
                 config: self.config.clone(),
@@ -259,6 +308,7 @@ impl http::Http for Remote {
 
 pub(crate) struct Request {
     pub url: String,
+    pub base_url: String,
     pub headers: reqwest::header::HeaderMap,
     pub upload_body_kind: Option<PostBodyDataKind>,
     pub config: http::Options,