By my reading, it's not merely that the standard doesn't require the "d" suffix, it's that the standard doesn't allow the "d" suffix, and the code won't compile on anything but gcc.
Agreed, although things I immediately think of are:
1. Is "anything but gcc" actually supported by the project? Do they have a goal of supporting other compilers or possibly an explicit decision not to support other compilers?
2. If they do support other compilers, how did the "d" suffix make it in the first place? That's something I would expect the dev or CI to catch pretty quickly.
3. Does gcc behave any differently with the "d" suffix not there? (I would think a core dev would know that off the top of their head, so it's possible they looked at it and decided it wasn't worth it. One would hope they'd comment on the PR though if they did that). If it does, this could introduce a really hard-to-track-down bug.
I'm not defending Oracle here (in fact I hate Oracle and think they are a scourge on humanity) but trying to approach this with an objective look.
That again assumes a project is looking to onboard contributors.
I absolutely get that it was an unfortunate interaction from the email writer's perspective, and it's really unfortunate.
But there are a lot of concerns/bureaucracy, etc in case of large projects like this. It may just never got to the person responsible, because it is a cross-cutting concern (so no clear way to assign it to someone) with a low priority.
They keep stringing him along in the process to onboard him as a contributor. The issue is the split personality in wanting but not acting on onboarding, with no meaningful communication. Your last paragraph about bureaucracy is exactly the complaint of the post. I don't see it as a defense. We can all throw our hands up and say "shit happens", and we can all agree it invariably does happen sometimes, but it's not a defense, per se.
Is the project clearly documented as being written in GNU C++ rather than standard C++? If not, anything that's accidentally invalid C++ is fair game for bug fixes, is it not?
If all of these things are about making it build under clang though they need to better explain it or maybe group these changes together though.
My initial comment was maybe unfair but I can completely sympathise with the maintainers etc. that separately these PRs look like random small edits (e.g. from a linter) with no specific goal
Even if the changes aren't "meaningful" (which it seems like they are), they still have an impact in how it makes the contributor more comfortable with working on the project. No new contributor is going to start with making massive patches without starting out with some smaller things to get a feel for working with the project.
Agreed, these seem like ideal patches to me for a first contribution. Solves a specific problem, doesn't require a lot of effort on maintainers side to review, and should give them a straightforward path to familiarise themselves with the process.