Khronos public bugtracker – Bug 712
4.3 core spec references CopyPixels.
Last modified: 2018-01-25 00:52:17 PST
On page 190 (folio page numbers, not PDF page numbers), it states:
> The image is taken from the framebuffer exactly as if these arguments were passed to CopyPixels (see section 18.3)
There is no "CopyPixels" in section 18.3 of the core specification.
Unfortunately this looks simple, but intrinsically references a whole lot of language that would have to be rearranged in the spec to be accessible to both core and compatibility profiles. So it's definitely valid, but very low priority given that both docs are available.