Related: rhbz#1281906 set a min size on un-resizeable non-layout dialogs

a min size equates to a size-request which is reliable under gtk3+wayland
as the dialog contents size.

a default size equates to the size of the dialog, which includes decorations
under wayland

Change-Id: I20baf00fb5952ab93628f4dd6891779ce682783c
diff --git a/vcl/source/window/syswin.cxx b/vcl/source/window/syswin.cxx
index 8589db6..3f2cde1 100644
--- a/vcl/source/window/syswin.cxx
+++ b/vcl/source/window/syswin.cxx
@@ -1135,6 +1135,10 @@ void SystemWindow::DoInitialLayout()
        mbIsCalculatingInitialLayoutSize = false;
        mbInitialLayoutDone = true;
    }
    else if (!(GetStyle() & WB_SIZEABLE))
    {
        SetMinOutputSizePixel(GetSizePixel());
    }
}

void SystemWindow::doDeferredInit(WinBits /*nBits*/)