Fix #878

* Add exception handler

* revert content reader changes

* Add test for and fix exception handler

* Fix warning in test

* Readd exception test, improve readme note, don't rethrow errors, remove exception handler response

README.md

@@ -7,7 +7,7 @@ A C++11 single-file header-only cross platform HTTP/HTTPS library.
 
 It's extremely easy to setup. Just include the **httplib.h** file in your code!
 
-NOTE: This is a 'blocking' HTTP library. If you are looking for a 'non-blocking' library, this is not the one that you want.
+NOTE: This is a multi-threaded 'blocking' HTTP library. If you are looking for a 'non-blocking' library, this is not the one that you want.
 
 Simple examples
 ---------------
@@ -177,15 +177,28 @@ svr.set_error_handler([](const auto& req, auto& res) {
 });
 ```
 
+### Exception handler
+The exception handler gets called if a user routing handler throws an error.
+
+```cpp
+svr.set_exception_handler([](const auto& req, auto& res, std::exception &e) {
+  res.status = 500;
+  auto fmt = "<h1>Error 500</h1><p>%s</p>";
+  char buf[BUFSIZ];
+  snprintf(buf, sizeof(buf), fmt, e.what());
+  res.set_content(buf, "text/html");
+});
+```
+
 ### Pre routing handler
 
 ```cpp
 svr.set_pre_routing_handler([](const auto& req, auto& res) -> bool {
   if (req.path == "/hello") {
     res.set_content("world", "text/html");
-    return true; // This request is handled
+    return Server::HandlerResponse::Handled;
   }
-  return false; // Let the router handle this request
+  return Server::HandlerResponse::Unhandled;
 });
 ```
 

httplib.h

@@ -204,6 +204,7 @@ using socket_t = int;
 #include <string>
 #include <sys/stat.h>
 #include <thread>
+#include <set>
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 #include <openssl/err.h>
@@ -390,6 +391,9 @@ struct Request {
   Match matches;
 
   // for client
+  ResponseHandler response_handler;
+  ContentReceiverWithProgress content_receiver;
+  Progress progress;
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
   const SSL *ssl;
 #endif
@@ -413,12 +417,9 @@ struct Request {
 
   // private members...
   size_t redirect_count_ = CPPHTTPLIB_REDIRECT_MAX_COUNT;
-  ResponseHandler response_handler_;
-  ContentReceiverWithProgress content_receiver_;
   size_t content_length_ = 0;
   ContentProvider content_provider_;
   bool is_chunked_content_provider_ = false;
-  Progress progress_;
   size_t authorization_count_ = 0;
 };
 
@@ -598,6 +599,9 @@ class Server {
 public:
   using Handler = std::function<void(const Request &, Response &)>;
 
+  using ExceptionHandler =
+      std::function<void(const Request &, Response &, std::exception &e)>;
+
   enum class HandlerResponse {
     Handled,
     Unhandled,
@@ -652,6 +656,7 @@ public:
 
   Server &set_error_handler(HandlerWithResponse handler);
   Server &set_error_handler(Handler handler);
+  Server &set_exception_handler(ExceptionHandler handler);
   Server &set_pre_routing_handler(HandlerWithResponse handler);
   Server &set_post_routing_handler(Handler handler);
 
@@ -762,6 +767,7 @@ private:
   HandlersForContentReader delete_handlers_for_content_reader_;
   Handlers options_handlers_;
   HandlerWithResponse error_handler_;
+  ExceptionHandler exception_handler_;
   HandlerWithResponse pre_routing_handler_;
   Handler post_routing_handler_;
   Logger logger_;
@@ -789,8 +795,11 @@ enum Error {
 
 class Result {
 public:
-  Result(std::unique_ptr<Response> res, Error err)
-      : res_(std::move(res)), err_(err) {}
+  Result(std::unique_ptr<Response> &&res, Error err,
+         Headers &&request_headers = Headers{})
+      : res_(std::move(res)), err_(err),
+        request_headers_(std::move(request_headers)) {}
+  // Response
   operator bool() const { return res_ != nullptr; }
   bool operator==(std::nullptr_t) const { return res_ == nullptr; }
   bool operator!=(std::nullptr_t) const { return res_ != nullptr; }
@@ -800,11 +809,21 @@ public:
   Response &operator*() { return *res_; }
   const Response *operator->() const { return res_.get(); }
   Response *operator->() { return res_.get(); }
+
+  // Error
   Error error() const { return err_; }
 
+  // Request Headers
+  bool has_request_header(const char *key) const;
+  std::string get_request_header_value(const char *key, size_t id = 0) const;
+  template <typename T>
+  T get_request_header_value(const char *key, size_t id = 0) const;
+  size_t get_request_header_value_count(const char *key) const;
+
 private:
   std::unique_ptr<Response> res_;
   Error err_;
+  Headers request_headers_;
 };
 
 class ClientImpl {
@@ -934,7 +953,7 @@ public:
   Result Options(const char *path);
   Result Options(const char *path, const Headers &headers);
 
-  bool send(const Request &req, Response &res, Error &error);
+  bool send(Request &req, Response &res, Error &error);
   Result send(const Request &req);
 
   size_t is_socket_open() const;
@@ -988,6 +1007,8 @@ protected:
     bool is_open() const { return sock != INVALID_SOCKET; }
   };
 
+  Result send_(Request &&req);
+
   virtual bool create_and_connect_socket(Socket &socket, Error &error);
 
   // All of:
@@ -1005,7 +1026,7 @@ protected:
   // concurrently with a DIFFERENT thread sending requests from the socket
   void lock_socket_and_shutdown_and_close();
 
-  bool process_request(Stream &strm, const Request &req, Response &res,
+  bool process_request(Stream &strm, Request &req, Response &res,
                        bool close_connection, Error &error);
 
   bool write_content_with_provider(Stream &strm, const Request &req,
@@ -1081,13 +1102,14 @@ protected:
 private:
   socket_t create_client_socket(Error &error) const;
   bool read_response_line(Stream &strm, const Request &req, Response &res);
-  bool write_request(Stream &strm, const Request &req, bool close_connection,
+  bool write_request(Stream &strm, Request &req, bool close_connection,
                      Error &error);
-  bool redirect(const Request &req, Response &res, Error &error);
-  bool handle_request(Stream &strm, const Request &req, Response &res,
+  bool redirect(Request &req, Response &res, Error &error);
+  bool handle_request(Stream &strm, Request &req, Response &res,
                       bool close_connection, Error &error);
   std::unique_ptr<Response> send_with_content_provider(
-      const char *method, const char *path, const Headers &headers,
+      Request &req,
+      // const char *method, const char *path, const Headers &headers,
       const char *body, size_t content_length, ContentProvider content_provider,
       ContentProviderWithoutLength content_provider_without_length,
       const char *content_type, Error &error);
@@ -1233,7 +1255,7 @@ public:
   Result Options(const char *path);
   Result Options(const char *path, const Headers &headers);
 
-  bool send(const Request &req, Response &res, Error &error);
+  bool send(Request &req, Response &res, Error &error);
   Result send(const Request &req);
 
   size_t is_socket_open() const;
@@ -2484,7 +2506,7 @@ public:
       strm_.next_out = reinterpret_cast<Bytef *>(buff.data());
 
       ret = deflate(&strm_, flush);
-      assert(ret != Z_STREAM_ERROR);
+      if (ret == Z_STREAM_ERROR) { return false; }
 
       if (!callback(buff.data(), buff.size() - strm_.avail_out)) {
         return false;
@@ -2917,17 +2939,8 @@ bool read_content(Stream &strm, T &x, size_t payload_max_length, int &status,
       });
 }
 
-template <typename T>
-inline ssize_t write_headers(Stream &strm, const T &info,
-                             const Headers &headers) {
+inline ssize_t write_headers(Stream &strm, const Headers &headers) {
   ssize_t write_len = 0;
-  for (const auto &x : info.headers) {
-    if (x.first == "EXCEPTION_WHAT") { continue; }
-    auto len =
-        strm.write_format("%s: %s\r\n", x.first.c_str(), x.second.c_str());
-    if (len < 0) { return len; }
-    write_len += len;
-  }
   for (const auto &x : headers) {
     auto len =
         strm.write_format("%s: %s\r\n", x.first.c_str(), x.second.c_str());
@@ -3114,7 +3127,7 @@ inline bool write_content_chunked(Stream &strm,
 }
 
 template <typename T>
-inline bool redirect(T &cli, const Request &req, Response &res,
+inline bool redirect(T &cli, Request &req, Response &res,
                      const std::string &path, const std::string &location,
                      Error &error) {
   Request new_req = req;
@@ -3131,8 +3144,9 @@ inline bool redirect(T &cli, const Request &req, Response &res,
 
   auto ret = cli.send(new_req, new_res, error);
   if (ret) {
-    new_res.location = location;
+    req = new_req;
     res = new_res;
+    res.location = location;
   }
   return ret;
 }
@@ -3158,7 +3172,14 @@ inline std::string append_query_params(const char *path, const Params &params) {
 }
 
 inline void parse_query_text(const std::string &s, Params &params) {
+  std::set<std::string> cache;
   split(s.data(), s.data() + s.size(), '&', [&](const char *b, const char *e) {
+    std::string kv(b, e);
+    if (cache.find(kv) != cache.end()) {
+      return;
+    }
+    cache.insert(kv);
+
     std::string key;
     std::string val;
     split(b, e, '=', [&](const char *b2, const char *e2) {
@@ -3762,7 +3783,7 @@ inline std::string random_string(size_t length) {
                            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                            "abcdefghijklmnopqrstuvwxyz";
     const size_t max_index = (sizeof(charset) - 1);
-    return charset[static_cast<size_t>(rand()) % max_index];
+    return charset[static_cast<size_t>(std::rand()) % max_index];
   };
   std::string str(length, 0);
   std::generate_n(str.begin(), length, randchar);
@@ -3973,7 +3994,27 @@ inline void Response::set_chunked_content_provider(
   is_chunked_content_provider_ = true;
 }
 
-// Rstream implementation
+// Result implementation
+inline bool Result::has_request_header(const char *key) const {
+  return request_headers_.find(key) != request_headers_.end();
+}
+
+inline std::string Result::get_request_header_value(const char *key,
+                                                    size_t id) const {
+  return detail::get_header_value(request_headers_, key, id, "");
+}
+
+template <typename T>
+inline T Result::get_request_header_value(const char *key, size_t id) const {
+  return detail::get_header_value<T>(request_headers_, key, id, 0);
+}
+
+inline size_t Result::get_request_header_value_count(const char *key) const {
+  auto r = request_headers_.equal_range(key);
+  return static_cast<size_t>(std::distance(r.first, r.second));
+}
+
+// Stream implementation
 inline ssize_t Stream::write(const char *ptr) {
   return write(ptr, strlen(ptr));
 }
@@ -4281,6 +4322,11 @@ inline Server &Server::set_error_handler(Handler handler) {
   return *this;
 }
 
+inline Server &Server::set_exception_handler(ExceptionHandler handler) {
+  exception_handler_ = std::move(handler);
+  return *this;
+}
+
 inline Server &Server::set_pre_routing_handler(HandlerWithResponse handler) {
   pre_routing_handler_ = std::move(handler);
   return *this;
@@ -4463,7 +4509,7 @@ inline bool Server::write_response_core(Stream &strm, bool close_connection,
       return false;
     }
 
-    if (!detail::write_headers(bstrm, res, Headers())) { return false; }
+    if (!detail::write_headers(bstrm, res.headers)) { return false; }
 
     // Flush buffer
     auto &data = bstrm.get_buffer();
@@ -4835,22 +4881,14 @@ inline bool Server::routing(Request &req, Response &res, Stream &strm) {
 
 inline bool Server::dispatch_request(Request &req, Response &res,
                                      const Handlers &handlers) {
-  try {
-    for (const auto &x : handlers) {
-      const auto &pattern = x.first;
-      const auto &handler = x.second;
+  for (const auto &x : handlers) {
+    const auto &pattern = x.first;
+    const auto &handler = x.second;
 
-      if (std::regex_match(req.path, req.matches, pattern)) {
-        handler(req, res);
-        return true;
-      }
+    if (std::regex_match(req.path, req.matches, pattern)) {
+      handler(req, res);
+      return true;
     }
-  } catch (const std::exception &ex) {
-    res.status = 500;
-    res.set_header("EXCEPTION_WHAT", ex.what());
-  } catch (...) {
-    res.status = 500;
-    res.set_header("EXCEPTION_WHAT", "UNKNOWN");
   }
   return false;
 }
@@ -5064,7 +5102,23 @@ Server::process_request(Stream &strm, bool close_connection,
   }
 
   // Rounting
-  if (routing(req, res, strm)) {
+  bool routed = false;
+  try {
+    routed = routing(req, res, strm);
+  } catch (std::exception &e) {
+    if (exception_handler_) {
+      exception_handler_(req, res, e);
+      routed = true;
+    } else {
+      res.status = 500;
+      res.set_header("EXCEPTION_WHAT", e.what());
+    }
+  } catch (...) {
+    res.status = 500;
+    res.set_header("EXCEPTION_WHAT", "UNKNOWN");
+  }
+
+  if (routed) {
     if (res.status == -1) { res.status = req.ranges.empty() ? 200 : 206; }
     return write_response_with_content(strm, close_connection, req, res);
   } else {
@@ -5211,7 +5265,7 @@ inline bool ClientImpl::read_response_line(Stream &strm, const Request &req,
 
   if (!line_reader.getline()) { return false; }
 
-  const static std::regex re("(HTTP/1\\.[01]) (\\d{3}) (.*?)\r\n");
+  const static std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r\n");
 
   std::cmatch m;
   if (!std::regex_match(line_reader.ptr(), m, re)) {
@@ -5235,7 +5289,7 @@ inline bool ClientImpl::read_response_line(Stream &strm, const Request &req,
   return true;
 }
 
-inline bool ClientImpl::send(const Request &req, Response &res, Error &error) {
+inline bool ClientImpl::send(Request &req, Response &res, Error &error) {
   std::lock_guard<std::recursive_mutex> request_mutex_guard(request_mutex_);
 
   {
@@ -5288,6 +5342,12 @@ inline bool ClientImpl::send(const Request &req, Response &res, Error &error) {
     socket_requests_are_from_thread_ = std::this_thread::get_id();
   }
 
+  for (const auto &header : default_headers_) {
+    if (req.headers.find(header.first) == req.headers.end()) {
+      req.headers.insert(header);
+    }
+  }
+
   auto close_connection = !keep_alive_;
   auto ret = process_socket(socket_, [&](Stream &strm) {
     return handle_request(strm, req, res, close_connection, error);
@@ -5318,13 +5378,18 @@ inline bool ClientImpl::send(const Request &req, Response &res, Error &error) {
 }
 
 inline Result ClientImpl::send(const Request &req) {
+  auto req2 = req;
+  return send_(std::move(req2));
+}
+
+inline Result ClientImpl::send_(Request &&req) {
   auto res = detail::make_unique<Response>();
   auto error = Error::Success;
   auto ret = send(req, *res, error);
-  return Result{ret ? std::move(res) : nullptr, error};
+  return Result{ret ? std::move(res) : nullptr, error, std::move(req.headers)};
 }
 
-inline bool ClientImpl::handle_request(Stream &strm, const Request &req,
+inline bool ClientImpl::handle_request(Stream &strm, Request &req,
                                        Response &res, bool close_connection,
                                        Error &error) {
   if (req.path.empty()) {
@@ -5332,12 +5397,16 @@ inline bool ClientImpl::handle_request(Stream &strm, const Request &req,
     return false;
   }
 
+  auto req_save = req;
+
   bool ret;
 
   if (!is_ssl() && !proxy_host_.empty() && proxy_port_ != -1) {
     auto req2 = req;
     req2.path = "http://" + host_and_port_ + req.path;
     ret = process_request(strm, req2, res, close_connection, error);
+    req = req2;
+    req.path = req_save.path;
   } else {
     ret = process_request(strm, req, res, close_connection, error);
   }
@@ -5345,6 +5414,7 @@ inline bool ClientImpl::handle_request(Stream &strm, const Request &req,
   if (!ret) { return false; }
 
   if (300 < res.status && res.status < 400 && follow_location_) {
+    req = req_save;
     ret = redirect(req, res, error);
   }
 
@@ -5380,8 +5450,7 @@ inline bool ClientImpl::handle_request(Stream &strm, const Request &req,
   return ret;
 }
 
-inline bool ClientImpl::redirect(const Request &req, Response &res,
-                                 Error &error) {
+inline bool ClientImpl::redirect(Request &req, Response &res, Error &error) {
   if (req.redirect_count_ == 0) {
     error = Error::ExceedRedirectCount;
     return false;
@@ -5458,75 +5527,74 @@ inline bool ClientImpl::write_content_with_provider(Stream &strm,
   }
 } // namespace httplib
 
-inline bool ClientImpl::write_request(Stream &strm, const Request &req,
+inline bool ClientImpl::write_request(Stream &strm, Request &req,
                                       bool close_connection, Error &error) {
   // Prepare additional headers
-  Headers headers;
-  if (close_connection) { headers.emplace("Connection", "close"); }
+  if (close_connection) { req.headers.emplace("Connection", "close"); }
 
   if (!req.has_header("Host")) {
     if (is_ssl()) {
       if (port_ == 443) {
-        headers.emplace("Host", host_);
+        req.headers.emplace("Host", host_);
       } else {
-        headers.emplace("Host", host_and_port_);
+        req.headers.emplace("Host", host_and_port_);
       }
     } else {
       if (port_ == 80) {
-        headers.emplace("Host", host_);
+        req.headers.emplace("Host", host_);
       } else {
-        headers.emplace("Host", host_and_port_);
+        req.headers.emplace("Host", host_and_port_);
       }
     }
   }
 
-  if (!req.has_header("Accept")) { headers.emplace("Accept", "*/*"); }
+  if (!req.has_header("Accept")) { req.headers.emplace("Accept", "*/*"); }
 
   if (!req.has_header("User-Agent")) {
-    headers.emplace("User-Agent", "cpp-httplib/0.7");
+    req.headers.emplace("User-Agent", "cpp-httplib/0.7");
   }
 
   if (req.body.empty()) {
     if (req.content_provider_) {
       if (!req.is_chunked_content_provider_) {
         auto length = std::to_string(req.content_length_);
-        headers.emplace("Content-Length", length);
+        req.headers.emplace("Content-Length", length);
       }
     } else {
       if (req.method == "POST" || req.method == "PUT" ||
           req.method == "PATCH") {
-        headers.emplace("Content-Length", "0");
+        req.headers.emplace("Content-Length", "0");
       }
     }
   } else {
     if (!req.has_header("Content-Type")) {
-      headers.emplace("Content-Type", "text/plain");
+      req.headers.emplace("Content-Type", "text/plain");
     }
 
     if (!req.has_header("Content-Length")) {
       auto length = std::to_string(req.body.size());
-      headers.emplace("Content-Length", length);
+      req.headers.emplace("Content-Length", length);
     }
   }
 
   if (!basic_auth_password_.empty()) {
-    headers.insert(make_basic_authentication_header(
+    req.headers.insert(make_basic_authentication_header(
         basic_auth_username_, basic_auth_password_, false));
   }
 
   if (!proxy_basic_auth_username_.empty() &&
       !proxy_basic_auth_password_.empty()) {
-    headers.insert(make_basic_authentication_header(
+    req.headers.insert(make_basic_authentication_header(
         proxy_basic_auth_username_, proxy_basic_auth_password_, true));
   }
 
   if (!bearer_token_auth_token_.empty()) {
-    headers.insert(make_bearer_token_authentication_header(
+    req.headers.insert(make_bearer_token_authentication_header(
         bearer_token_auth_token_, false));
   }
 
   if (!proxy_bearer_token_auth_token_.empty()) {
-    headers.insert(make_bearer_token_authentication_header(
+    req.headers.insert(make_bearer_token_authentication_header(
         proxy_bearer_token_auth_token_, true));
   }
 
@@ -5537,7 +5605,7 @@ inline bool ClientImpl::write_request(Stream &strm, const Request &req,
     const auto &path = detail::encode_url(req.path);
     bstrm.write_format("%s %s HTTP/1.1\r\n", req.method.c_str(), path.c_str());
 
-    detail::write_headers(bstrm, req, headers);
+    detail::write_headers(bstrm, req.headers);
 
     // Flush buffer
     auto &data = bstrm.get_buffer();
@@ -5558,16 +5626,16 @@ inline bool ClientImpl::write_request(Stream &strm, const Request &req,
 }
 
 inline std::unique_ptr<Response> ClientImpl::send_with_content_provider(
-    const char *method, const char *path, const Headers &headers,
+    Request &req,
+    // const char *method, const char *path, const Headers &headers,
     const char *body, size_t content_length, ContentProvider content_provider,
     ContentProviderWithoutLength content_provider_without_length,
     const char *content_type, Error &error) {
 
-  Request req;
-  req.method = method;
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
-  req.path = path;
+  // Request req;
+  // req.method = method;
+  // req.headers = headers;
+  // req.path = path;
 
   if (content_type) { req.headers.emplace("Content-Type", content_type); }
 
@@ -5649,14 +5717,23 @@ inline Result ClientImpl::send_with_content_provider(
     const char *body, size_t content_length, ContentProvider content_provider,
     ContentProviderWithoutLength content_provider_without_length,
     const char *content_type) {
+  Request req;
+  req.method = method;
+  req.headers = headers;
+  req.path = path;
+
   auto error = Error::Success;
+
   auto res = send_with_content_provider(
-      method, path, headers, body, content_length, std::move(content_provider),
+      req,
+      // method, path, headers,
+      body, content_length, std::move(content_provider),
       std::move(content_provider_without_length), content_type, error);
-  return Result{std::move(res), error};
+
+  return Result{std::move(res), error, std::move(req.headers)};
 }
 
-inline bool ClientImpl::process_request(Stream &strm, const Request &req,
+inline bool ClientImpl::process_request(Stream &strm, Request &req,
                                         Response &res, bool close_connection,
                                         Error &error) {
   // Send request
@@ -5669,8 +5746,8 @@ inline bool ClientImpl::process_request(Stream &strm, const Request &req,
     return false;
   }
 
-  if (req.response_handler_) {
-    if (!req.response_handler_(res)) {
+  if (req.response_handler) {
+    if (!req.response_handler(res)) {
       error = Error::Canceled;
       return false;
     }
@@ -5679,10 +5756,10 @@ inline bool ClientImpl::process_request(Stream &strm, const Request &req,
   // Body
   if ((res.status != 204) && req.method != "HEAD" && req.method != "CONNECT") {
     auto out =
-        req.content_receiver_
+        req.content_receiver
             ? static_cast<ContentReceiverWithProgress>(
                   [&](const char *buf, size_t n, uint64_t off, uint64_t len) {
-                    auto ret = req.content_receiver_(buf, n, off, len);
+                    auto ret = req.content_receiver(buf, n, off, len);
                     if (!ret) { error = Error::Canceled; }
                     return ret;
                   })
@@ -5697,8 +5774,8 @@ inline bool ClientImpl::process_request(Stream &strm, const Request &req,
                   });
 
     auto progress = [&](uint64_t current, uint64_t total) {
-      if (!req.progress_) { return true; }
-      auto ret = req.progress_(current, total);
+      if (!req.progress) { return true; }
+      auto ret = req.progress(current, total);
       if (!ret) { error = Error::Canceled; }
       return ret;
     };
@@ -5760,11 +5837,10 @@ inline Result ClientImpl::Get(const char *path, const Headers &headers,
   Request req;
   req.method = "GET";
   req.path = path;
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
-  req.progress_ = std::move(progress);
+  req.headers = headers;
+  req.progress = std::move(progress);
 
-  return send(req);
+  return send_(std::move(req));
 }
 
 inline Result ClientImpl::Get(const char *path,
@@ -5820,17 +5896,16 @@ inline Result ClientImpl::Get(const char *path, const Headers &headers,
   Request req;
   req.method = "GET";
   req.path = path;
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
-  req.response_handler_ = std::move(response_handler);
-  req.content_receiver_ =
+  req.headers = headers;
+  req.response_handler = std::move(response_handler);
+  req.content_receiver =
       [content_receiver](const char *data, size_t data_length,
                          uint64_t /*offset*/, uint64_t /*total_length*/) {
         return content_receiver(data, data_length);
       };
-  req.progress_ = std::move(progress);
+  req.progress = std::move(progress);
 
-  return send(req);
+  return send_(std::move(req));
 }
 
 inline Result ClientImpl::Get(const char *path, const Params &params,
@@ -5858,7 +5933,7 @@ inline Result ClientImpl::Get(const char *path, const Params &params,
   }
 
   std::string path_with_query = detail::append_query_params(path, params);
-  return Get(path_with_query.c_str(), params, headers, response_handler,
+  return Get(path_with_query.c_str(), headers, response_handler,
              content_receiver, progress);
 }
 
@@ -5869,11 +5944,10 @@ inline Result ClientImpl::Head(const char *path) {
 inline Result ClientImpl::Head(const char *path, const Headers &headers) {
   Request req;
   req.method = "HEAD";
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
+  req.headers = headers;
   req.path = path;
 
-  return send(req);
+  return send_(std::move(req));
 }
 
 inline Result ClientImpl::Post(const char *path) {
@@ -6133,14 +6207,13 @@ inline Result ClientImpl::Delete(const char *path, const Headers &headers,
                                  const char *content_type) {
   Request req;
   req.method = "DELETE";
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
+  req.headers = headers;
   req.path = path;
 
   if (content_type) { req.headers.emplace("Content-Type", content_type); }
   req.body.assign(body, content_length);
 
-  return send(req);
+  return send_(std::move(req));
 }
 
 inline Result ClientImpl::Delete(const char *path, const std::string &body,
@@ -6161,11 +6234,10 @@ inline Result ClientImpl::Options(const char *path) {
 inline Result ClientImpl::Options(const char *path, const Headers &headers) {
   Request req;
   req.method = "OPTIONS";
-  req.headers = default_headers_;
-  req.headers.insert(headers.begin(), headers.end());
+  req.headers = headers;
   req.path = path;
 
-  return send(req);
+  return send_(std::move(req));
 }
 
 inline size_t ClientImpl::is_socket_open() const {
@@ -7285,7 +7357,7 @@ inline Result Client::Options(const char *path, const Headers &headers) {
   return cli_->Options(path, headers);
 }
 
-inline bool Client::send(const Request &req, Response &res, Error &error) {
+inline bool Client::send(Request &req, Response &res, Error &error) {
   return cli_->send(req, res, error);
 }
 

test/test.cc

@@ -5,6 +5,7 @@
 #include <atomic>
 #include <chrono>
 #include <future>
+#include <stdexcept>
 #include <thread>
 
 #define SERVER_CERT_FILE "./cert.pem"
@@ -416,16 +417,16 @@ TEST(ChunkedEncodingTest, WithResponseHandlerAndContentReceiver) {
   cli.set_connection_timeout(2);
 
   std::string body;
-  auto res = cli.Get(
-      "/httpgallery/chunked/chunkedimage.aspx?0.4153841143030137",
-      [&](const Response &response) {
-        EXPECT_EQ(200, response.status);
-        return true;
-      },
-      [&](const char *data, size_t data_length) {
-        body.append(data, data_length);
-        return true;
-      });
+  auto res =
+      cli.Get("/httpgallery/chunked/chunkedimage.aspx?0.4153841143030137",
+              [&](const Response &response) {
+                EXPECT_EQ(200, response.status);
+                return true;
+              },
+              [&](const char *data, size_t data_length) {
+                body.append(data, data_length);
+                return true;
+              });
   ASSERT_TRUE(res);
 
   std::string out;
@@ -548,12 +549,11 @@ TEST(ConnectionErrorTest, InvalidHost2) {
 
 TEST(ConnectionErrorTest, InvalidPort) {
   auto host = "localhost";
+  auto port = 44380;
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
-  auto port = 44380;
   SSLClient cli(host, port);
 #else
-  auto port = 8080;
   Client cli(host, port);
 #endif
   cli.set_connection_timeout(2);
@@ -978,6 +978,42 @@ TEST(ErrorHandlerTest, ContentLength) {
   ASSERT_FALSE(svr.is_running());
 }
 
+TEST(ExceptionHandlerTest, ContentLength) {
+  Server svr;
+
+  svr.set_exception_handler(
+      [](const Request & /*req*/, Response &res, std::exception & /*e*/) {
+        res.status = 500;
+        res.set_content("abcdefghijklmnopqrstuvwxyz",
+                        "text/html"); // <= Content-Length still 13
+      });
+
+  svr.Get("/hi", [](const Request & /*req*/, Response &res) {
+    res.set_content("Hello World!\n", "text/plain");
+    throw std::runtime_error("abc");
+  });
+
+  auto thread = std::thread([&]() { svr.listen(HOST, PORT); });
+
+  // Give GET time to get a few messages.
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+
+  {
+    Client cli(HOST, PORT);
+
+    auto res = cli.Get("/hi");
+    ASSERT_TRUE(res);
+    EXPECT_EQ(500, res->status);
+    EXPECT_EQ("text/html", res->get_header_value("Content-Type"));
+    EXPECT_EQ("26", res->get_header_value("Content-Length"));
+    EXPECT_EQ("abcdefghijklmnopqrstuvwxyz", res->body);
+  }
+
+  svr.stop();
+  thread.join();
+  ASSERT_FALSE(svr.is_running());
+}
+
 TEST(NoContentTest, ContentLength) {
   Server svr;
 
@@ -1608,6 +1644,7 @@ TEST_F(ServerTest, GetMethod200) {
   ASSERT_TRUE(res);
   EXPECT_EQ("HTTP/1.1", res->version);
   EXPECT_EQ(200, res->status);
+  EXPECT_EQ("OK", res->reason);
   EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
   EXPECT_EQ(1, res->get_header_value_count("Content-Type"));
   EXPECT_EQ("Hello World!", res->body);
@@ -2279,7 +2316,8 @@ TEST_F(ServerTest, ClientStop) {
       auto res = cli_.Get("/streamed-cancel",
                           [&](const char *, uint64_t) { return true; });
       ASSERT_TRUE(!res);
-      EXPECT_TRUE(res.error() == Error::Canceled || res.error() == Error::Read);
+      EXPECT_TRUE(res.error() == Error::Canceled ||
+                  res.error() == Error::Read || res.error() == Error::Write);
     }));
   }
 
@@ -2424,13 +2462,13 @@ TEST_F(ServerTest, SlowPost) {
   char buffer[64 * 1024];
   memset(buffer, 0x42, sizeof(buffer));
 
-  auto res = cli_.Post(
-      "/slowpost", 64 * 1024 * 1024,
-      [&](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
-        sink.write(buffer, sizeof(buffer));
-        return true;
-      },
-      "text/plain");
+  auto res =
+      cli_.Post("/slowpost", 64 * 1024 * 1024,
+                [&](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
+                  sink.write(buffer, sizeof(buffer));
+                  return true;
+                },
+                "text/plain");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
@@ -2441,13 +2479,13 @@ TEST_F(ServerTest, SlowPostFail) {
   memset(buffer, 0x42, sizeof(buffer));
 
   cli_.set_write_timeout(0, 0);
-  auto res = cli_.Post(
-      "/slowpost", 64 * 1024 * 1024,
-      [&](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
-        sink.write(buffer, sizeof(buffer));
-        return true;
-      },
-      "text/plain");
+  auto res =
+      cli_.Post("/slowpost", 64 * 1024 * 1024,
+                [&](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
+                  sink.write(buffer, sizeof(buffer));
+                  return true;
+                },
+                "text/plain");
 
   ASSERT_TRUE(!res);
   EXPECT_EQ(Error::Write, res.error());
@@ -2461,14 +2499,13 @@ TEST_F(ServerTest, Put) {
 }
 
 TEST_F(ServerTest, PutWithContentProvider) {
-  auto res = cli_.Put(
-      "/put", 3,
-      [](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
-        EXPECT_TRUE(sink.is_writable());
-        sink.os << "PUT";
-        return true;
-      },
-      "text/plain");
+  auto res = cli_.Put("/put", 3,
+                      [](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
+                        EXPECT_TRUE(sink.is_writable());
+                        sink.os << "PUT";
+                        return true;
+                      },
+                      "text/plain");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
@@ -2476,27 +2513,24 @@ TEST_F(ServerTest, PutWithContentProvider) {
 }
 
 TEST_F(ServerTest, PostWithContentProviderAbort) {
-  auto res = cli_.Post(
-      "/post", 42,
-      [](size_t /*offset*/, size_t /*length*/, DataSink & /*sink*/) {
-        return false;
-      },
-      "text/plain");
+  auto res = cli_.Post("/post", 42,
+                       [](size_t /*offset*/, size_t /*length*/,
+                          DataSink & /*sink*/) { return false; },
+                       "text/plain");
 
   ASSERT_TRUE(!res);
   EXPECT_EQ(Error::Canceled, res.error());
 }
 
 TEST_F(ServerTest, PutWithContentProviderWithoutLength) {
-  auto res = cli_.Put(
-      "/put",
-      [](size_t /*offset*/, DataSink &sink) {
-        EXPECT_TRUE(sink.is_writable());
-        sink.os << "PUT";
-        sink.done();
-        return true;
-      },
-      "text/plain");
+  auto res = cli_.Put("/put",
+                      [](size_t /*offset*/, DataSink &sink) {
+                        EXPECT_TRUE(sink.is_writable());
+                        sink.os << "PUT";
+                        sink.done();
+                        return true;
+                      },
+                      "text/plain");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
@@ -2515,14 +2549,13 @@ TEST_F(ServerTest, PostWithContentProviderWithoutLengthAbort) {
 #ifdef CPPHTTPLIB_ZLIB_SUPPORT
 TEST_F(ServerTest, PutWithContentProviderWithGzip) {
   cli_.set_compress(true);
-  auto res = cli_.Put(
-      "/put", 3,
-      [](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
-        EXPECT_TRUE(sink.is_writable());
-        sink.os << "PUT";
-        return true;
-      },
-      "text/plain");
+  auto res = cli_.Put("/put", 3,
+                      [](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
+                        EXPECT_TRUE(sink.is_writable());
+                        sink.os << "PUT";
+                        return true;
+                      },
+                      "text/plain");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
@@ -2531,12 +2564,10 @@ TEST_F(ServerTest, PutWithContentProviderWithGzip) {
 
 TEST_F(ServerTest, PostWithContentProviderWithGzipAbort) {
   cli_.set_compress(true);
-  auto res = cli_.Post(
-      "/post", 42,
-      [](size_t /*offset*/, size_t /*length*/, DataSink & /*sink*/) {
-        return false;
-      },
-      "text/plain");
+  auto res = cli_.Post("/post", 42,
+                       [](size_t /*offset*/, size_t /*length*/,
+                          DataSink & /*sink*/) { return false; },
+                       "text/plain");
 
   ASSERT_TRUE(!res);
   EXPECT_EQ(Error::Canceled, res.error());
@@ -2544,15 +2575,14 @@ TEST_F(ServerTest, PostWithContentProviderWithGzipAbort) {
 
 TEST_F(ServerTest, PutWithContentProviderWithoutLengthWithGzip) {
   cli_.set_compress(true);
-  auto res = cli_.Put(
-      "/put",
-      [](size_t /*offset*/, DataSink &sink) {
-        EXPECT_TRUE(sink.is_writable());
-        sink.os << "PUT";
-        sink.done();
-        return true;
-      },
-      "text/plain");
+  auto res = cli_.Put("/put",
+                      [](size_t /*offset*/, DataSink &sink) {
+                        EXPECT_TRUE(sink.is_writable());
+                        sink.os << "PUT";
+                        sink.done();
+                        return true;
+                      },
+                      "text/plain");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
@@ -2578,6 +2608,24 @@ TEST_F(ServerTest, PutLargeFileWithGzip) {
   EXPECT_EQ(LARGE_DATA, res->body);
 }
 
+TEST_F(ServerTest, PutLargeFileWithGzip2) {
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  Client cli("https://localhost:1234");
+  cli.enable_server_certificate_verification(false);
+#else
+  Client cli("http://localhost:1234");
+#endif
+  cli.set_compress(true);
+
+  auto res = cli.Put("/put-large", LARGE_DATA, "text/plain");
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(200, res->status);
+  EXPECT_EQ(LARGE_DATA, res->body);
+  EXPECT_EQ(101942u, res.get_request_header_value<uint64_t>("Content-Length"));
+  EXPECT_EQ("gzip", res.get_request_header_value("Content-Encoding"));
+}
+
 TEST_F(ServerTest, PutContentWithDeflate) {
   cli_.set_compress(false);
   Headers headers;
@@ -2854,9 +2902,8 @@ TEST_F(ServerTest, KeepAlive) {
   EXPECT_EQ("empty", res->body);
   EXPECT_EQ("close", res->get_header_value("Connection"));
 
-  res = cli_.Post(
-      "/empty", 0, [&](size_t, size_t, DataSink &) { return true; },
-      "text/plain");
+  res = cli_.Post("/empty", 0, [&](size_t, size_t, DataSink &) { return true; },
+                  "text/plain");
   ASSERT_TRUE(res);
   EXPECT_EQ(200, res->status);
   EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
@@ -3369,7 +3416,8 @@ TEST(ExceptionTest, ThrowExceptionInHandler) {
   auto res = cli.Get("/hi");
   ASSERT_TRUE(res);
   EXPECT_EQ(500, res->status);
-  ASSERT_FALSE(res->has_header("EXCEPTION_WHAT"));
+  ASSERT_TRUE(res->has_header("EXCEPTION_WHAT"));
+  EXPECT_EQ("exception...", res->get_header_value("EXCEPTION_WHAT"));
 
   svr.stop();
   listen_thread.join();
@@ -3447,6 +3495,69 @@ TEST(ErrorHandlerWithContentProviderTest, ErrorHandler) {
   ASSERT_FALSE(svr.is_running());
 }
 
+TEST(GetWithParametersTest, GetWithParameters) {
+  Server svr;
+
+  svr.Get("/", [&](const Request & req, Response &res) {
+    auto text = req.get_param_value("hello");
+    res.set_content(text, "text/plain");
+  });
+
+  auto listen_thread = std::thread([&svr]() { svr.listen("localhost", PORT); });
+  while (!svr.is_running()) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+
+  Client cli("localhost", PORT);
+
+  Params params;
+  params.emplace("hello", "world");
+  auto res = cli.Get("/", params, Headers{});
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(200, res->status);
+  EXPECT_EQ("world", res->body);
+
+  svr.stop();
+  listen_thread.join();
+  ASSERT_FALSE(svr.is_running());
+}
+
+TEST(GetWithParametersTest, GetWithParameters2) {
+  Server svr;
+
+  svr.Get("/", [&](const Request & req, Response &res) {
+    auto text = req.get_param_value("hello");
+    res.set_content(text, "text/plain");
+  });
+
+  auto listen_thread = std::thread([&svr]() { svr.listen("localhost", PORT); });
+  while (!svr.is_running()) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+
+  Client cli("localhost", PORT);
+
+  Params params;
+  params.emplace("hello", "world");
+
+  std::string body;
+  auto res = cli.Get("/", params, Headers{}, [&](const char *data, size_t data_length) {
+    body.append(data, data_length);
+    return true;
+  });
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(200, res->status);
+  EXPECT_EQ("world", body);
+
+  svr.stop();
+  listen_thread.join();
+  ASSERT_FALSE(svr.is_running());
+}
+
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 TEST(KeepAliveTest, ReadTimeoutSSL) {
   SSLServer svr(SERVER_CERT_FILE, SERVER_PRIVATE_KEY_FILE);
@@ -3927,7 +4038,6 @@ TEST(NoSSLSupport, SimpleInterface) {
 }
 #endif
 
-#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 TEST(InvalidScheme, SimpleInterface) {
   ASSERT_ANY_THROW(Client cli("scheme://yahoo.com"));
 }
@@ -3937,6 +4047,19 @@ TEST(NoScheme, SimpleInterface) {
   ASSERT_TRUE(cli.is_valid());
 }
 
+TEST(SendAPI, SimpleInterface) {
+  Client cli("http://yahoo.com");
+
+  Request req;
+  req.method = "GET";
+  req.path = "/";
+  auto res = cli.send(req);
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(301, res->status);
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 TEST(YahooRedirectTest2, SimpleInterface) {
   Client cli("http://yahoo.com");