chore: error response on unhandled route

Author: vinniefalco

example/server/main.cpp

@@ -67,23 +67,8 @@ int server_main( int argc, char* argv[] )
             (unsigned short)std::atoi(argv[2]),
             std::atoi(argv[4]));
 
-        srv.wwwroot.use("/log", serve_log_admin(app));
-        srv.wwwroot.use("/", serve_static( argv[3] ));
-
-        // unhandled errors
-        srv.wwwroot.err(
-            []( Request&, Response& res,
-                system::error_code const& ec)
-            {
-                http_proto::status sc;
-                if(ec == system::errc::no_such_file_or_directory)
-                    sc = http_proto::status::not_found;
-                else
-                    sc = http_proto::status::internal_server_error;
-                res.status(sc);
-                res.set_body(ec.message());
-                return error::success;
-            });
+        //srv.wwwroot.use("/log", serve_log_admin(app));
+        //srv.wwwroot.use("/", serve_static( argv[3] ));
 
         app.start();
         srv.attach();

include/boost/beast2/server/http_session.hpp

@@ -13,6 +13,7 @@
 #include <boost/beast2/detail/config.hpp>
 #include <boost/beast2/application.hpp>
 #include <boost/beast2/log_service.hpp>
+#include <boost/beast2/format.hpp>
 #include <boost/beast2/read.hpp>
 #include <boost/beast2/write.hpp>
 #include <boost/beast2/server/any_lambda.hpp>
@@ -217,16 +218,34 @@ on_read(
     route_state_ = {};
     ec = rr_(*preq_, *pres_, route_state_);
 
+    if(! ec.failed())
+        goto do_write;
+
     if(ec == error::detach)
     {
         // make sure they called detach()
         BOOST_ASSERT(pwg_);
         return;
     }
 
-    if(ec.failed())
+    if(ec == error::next)
     {
-        // give a default error response?
+        // unhandled
+        pres_->status(http_proto::status::not_found);
+        std::string s;
+        format_to(s, "The requested URL {} was not found on this server.", preq_->target);
+        pres_->set_body(s);
+        pres_->m.set_keep_alive(false);
+        goto do_write;
+    }
+
+    // error message of last resort
+    {
+        pres_->status(http_proto::status::internal_server_error);
+        std::string s;
+        format_to(s, "An internal server error occurred: {}", ec.message());
+        pres_->set_body(s);
+        pres_->m.set_keep_alive(false);
     }
 
 do_write: