+ if (!strb) {
+ if (surfIndex == ST_SURFACE_FRONT_LEFT) {
+ /* Delayed creation when the window system supplies a fake front buffer */
+ struct st_renderbuffer *strb_back
+ = st_renderbuffer(stfb->Base.Attachment[ST_SURFACE_BACK_LEFT].Renderbuffer);
+ struct gl_renderbuffer *rb
+ = st_new_renderbuffer_fb(surf->format, strb_back->Base.NumSamples, FALSE);
+ _mesa_add_renderbuffer(&stfb->Base, BUFFER_FRONT_LEFT, rb);
+ strb = st_renderbuffer(rb);
+ } else {
+ /* fail */
+ return;
+ }
+ }