Fix crash for passing lambda with captures to QHttpServer::route

QHttpServer::route accepted the lambda by universal reference, but did
not pass it to QHttpServerRouter::addRule by std::forward.

We can not initialize lambda captures with C++11.
So we always need to copy the lambda by value.

Task-number: QTBUG-74882
Change-Id: I3e2dc6003624414d0ff45ba2e2f1af472e219ff1
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 9 insertions, 7 deletions

diff --git a/src/httpserver/qhttpserver.h b/src/httpserver/qhttpserver.h
index 7f61a2a..885c150 100644
--- a/src/httpserver/qhttpserver.h
+++ b/src/httpserver/qhttpserver.h
@@ -88,15 +88,17 @@ private:
     template<typename Rule, typename ViewHandler, typename ViewTraits, typename ... Args>
     bool routeImpl(Args &&...args, ViewHandler &&viewHandler)
     {
-        return router()->addRule<ViewHandler, ViewTraits>(
-                new Rule(std::forward<Args>(args)..., [this, &viewHandler] (
-                        QRegularExpressionMatch &match,
-                        const QHttpServerRequest &request,
-                        QTcpSocket *socket) {
+        auto routerHandler = [this, viewHandler] (
+                    QRegularExpressionMatch &match,
+                    const QHttpServerRequest &request,
+                    QTcpSocket *socket) mutable {
             auto boundViewHandler = router()->bindCaptured<ViewHandler, ViewTraits>(
-                    std::forward<ViewHandler>(viewHandler), match);
+                    std::move(viewHandler), match);
             responseImpl<ViewTraits>(boundViewHandler, request, socket);
-        }));
+        };
+
+        return router()->addRule<ViewHandler, ViewTraits>(
+                new Rule(std::forward<Args>(args)..., std::move(routerHandler)));
     }
 
     template<typename ViewTraits, typename T>