message: Fix mask ignored using RenderTexture on Firefox/Linux
diff: @@ -47,6 +47,8 @@ export class StencilSystem extends AbstractMaskSystem
  {
  // force use stencil texture in current framebuffer
  this.renderer.framebuffer.forceStencil();
  + gl.clearStencil(0);
  + gl.clear(gl.STENCIL_BUFFER_BIT);
  gl.enable(gl.STENCIL_TEST);
  }
  @@ -78,8 +80,6 @@ export class StencilSystem extends AbstractMaskSystem
  {
  // the stack is empty!
  gl.disable(gl.STENCIL_TEST);
  - gl.clearStencil(0);
  - gl.clear(gl.STENCIL_BUFFER_BIT);
  }
  else
  {
  