Make QtDBus work again with D-Bus 1.0 and 1.1

The dbus_get_version function was introduced in 1.2, so we'd need to
detect pre-1.2 by the absence of the function. But if we're going to
detect the presence or absence of any function, we might as well do it
on dbus_connection_can_send_type, which is the function we wanted anyway.

Change-Id: I6e17a3a8f1382c6a489490084f6e3f61aa5a1947
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index 3fb72e34d9..2b3ee901a5 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -1687,24 +1687,23 @@ void QDBusConnectionPrivate::setPeer(DBusConnection *c, const QDBusErrorInternal
 static QDBusConnection::ConnectionCapabilities connectionCapabilies(DBusConnection *connection)
 {
     QDBusConnection::ConnectionCapabilities result = 0;
+    typedef dbus_bool_t (*can_send_type_t)(DBusConnection *, int);
+    static can_send_type_t can_send_type = 0;
 
-#if defined(QT_LINKED_LIBDBUS) && DBUS_VERSION < 0x010400
-    // no capabilities are possible
+#if defined(QT_LINKED_LIBDBUS)
+# if DBUS_VERSION-0 >= 0x010400
+    can_send_type = dbus_connection_can_send_type;
+# endif
 #else
-# if !defined(QT_LINKED_LIBDBUS)
     // run-time check if the next functions are available
-    int major, minor, micro;
-    q_dbus_get_version(&major, &minor, &micro);
-    if (major == 1 && minor < 4)
-        return result;
-# endif
+    can_send_type = (can_send_type_t)qdbus_resolve_conditionally("dbus_connection_can_send_type");
+#endif
 
 #ifndef DBUS_TYPE_UNIX_FD
 # define DBUS_TYPE_UNIX_FD int('h')
 #endif
-    if (q_dbus_connection_can_send_type(connection, DBUS_TYPE_UNIX_FD))
+    if (can_send_type && can_send_type(connection, DBUS_TYPE_UNIX_FD))
         result |= QDBusConnection::UnixFileDescriptorPassing;
-#endif
 
     return result;
 }