Does glColorMask affect glClear

Question

What should the following code do assuming something was drawn before the code below?

glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_TRUE);
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

Should this code just set the alpha to 1 or will it clear the color buffer?

Or in other words, does glColorMask affect what glClear does or does it only apply to normal draw operations?

I am asking specifically with regards to OpenGL ES 2.0 so any reference to a spec will be appreciated.

Answer 1

It will clear the alpha channel only.

The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of glClear