tdf#135743 only overwrite our geometry with the valid entries

Change-Id: I228ebfed17d922704d72529c714fde220b9d20cc
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/100825
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/vcl/unx/gtk3/gtk3gtkframe.cxx b/vcl/unx/gtk3/gtk3gtkframe.cxx
index bfc587d..48e8f56 100644
--- a/vcl/unx/gtk3/gtk3gtkframe.cxx
+++ b/vcl/unx/gtk3/gtk3gtkframe.cxx
@@ -1527,13 +1527,15 @@ void GtkSalFrame::SetPosSize( long nX, long nY, long nWidth, long nHeight, sal_u
            nY += m_pParent->maGeometry.nY;
        }

        maGeometry.nX = nX;
        maGeometry.nY = nY;
        if (nFlags & SAL_FRAME_POSSIZE_X)
            maGeometry.nX = nX;
        if (nFlags & SAL_FRAME_POSSIZE_Y)
            maGeometry.nY = nY;
        m_bGeometryIsProvisional = true;

        m_bDefaultPos = false;

        moveWindow(nX, nY);
        moveWindow(maGeometry.nX, maGeometry.nY);

        updateScreenNumber();
    }