Make QAbstractHttpServer::listen return 0 on fail

Which then makes it compatible with other listen() functions in Qt
in the sense that doing if (server.listen()) will behave
consistently.
Ports being listened to can then be gotten from the new serverPorts()
function, mirroring serverPort() from QTcpServer etc., except it's a
QVector.

This is a source incompatible change, but is allowed because this
module is still in tech preview.

Fixes: QTBUG-79411
Change-Id: I09764afbf8fd866af4f43ab90fcf9c2e9a373237
Reviewed-by: Mikhail Svetkin <mikhail.svetkin@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/examples/httpserver/simple/main.cpp b/examples/httpserver/simple/main.cpp
index 0bf21e2..1f10553 100644
--- a/examples/httpserver/simple/main.cpp
+++ b/examples/httpserver/simple/main.cpp
@@ -113,9 +113,9 @@ int main(int argc, char *argv[])
     });
 
     const auto port = httpServer.listen(QHostAddress::Any);
-    if (port == -1) {
+    if (!port) {
         qDebug() << QCoreApplication::translate(
-                "QHttpServerExample", "Could not run on http://127.0.0.1:%1/").arg(port);
+                "QHttpServerExample", "Server failed to listen on a port.");
         return 0;
     }