a433bd8e9e
Previously CoglVertexBuffer would always set the flush options flags to at least contain COGL_MATERIAL_FLUSH_FALLBACK_MASK. The code then later checks whether any flags are set before deciding whether to copy the material to implement the overrides. This means that it would always end up copying the material even if there are no fallback layers. This patch changes it so that it only sets COGL_MATERIAL_FLUSH_FALLBACK_MASK if fallback_layers != 0.