Using glPrimitiveRestartIndex to declare multiple geometries in the same VBO

Seeing this w.r.t. OpenGL triggered some warning neurons, such as:

I guess your MacOS X is prior to that. However, searching the forums for MacOS and primitive restart calls into question whether this ever worked properly on Mac’s OpenGL implementation (…that is, before Apple decided to kick OpenGL developers off of Mac, or onto API mappers like Zink and MoltenVK). For a few of those links, see below.