https://bugs.freedesktop.org/show_bug.cgi?id=72685
--- Comment #26 from smoki smoki00790@gmail.com ---
Yes, as i see shadows are maded in gl_FragData but it touch GL_REPLACE glStencilOp maybe that is because it show artifacts but not sure :).
But comment is more about lockups in other bugs, where i see most lockups come where GL_ZERO is used with glStencilOp/glStencilOpSeparate . I have The Cave game which does not lockup when i just comment GL_ZERO op in state, the same also with trace from Bug 64471 it does not lockup, etc.