[jdk17u-dev] RFR: 8283911: DEFAULT_PROMOTED_VERSION_PRE not reset to 'ea' for jdk-17.0.4

[Andrew John Hughes]

On Wed, 30 Mar 2022 09:17:54 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

> I'm on the fence about this. On the one hand it indicates when we have an `EA` build (if we happen to define EA for update releases too) in the sources. On the other hand this would be prone to error to switch to "GA" mode at the right time. Would this need a separate bug when switching back to GA?

The whole process of switching back and forth between EA and GA is error-prone, but, as far as I can see, unavoidable if one wishes to make pre-release builds rather than just moving directly from one GA release to another. Not having the value in the JDK itself doesn't solve the problem. It just makes it more likely that downstream distributors get it wrong, especially if they are not active in JDK development themselves. Having an inaccurate value, as we do now, is even worse.

I think a similar argument could be made for the other values in that file; they also require someone to remember to update them at certain points in the release cycle, but having one authoritative source helps all distributors. We have done without them in the past and I think having them in the JDK sources has improved things.  We can certainly make the process clear by documenting what these changes are and when they need to be made in the release process documentation.

You may remember that there was a mishap in the past, when Debian was publishing EA code as a GA build. At that time, we adapted the Fedora & RHEL RPMs to handle EA & GA builds with appropriate naming. When I spotted the addition of `DEFAULT_PROMOTED_VERSION_PRE` by Oracle - who I guess from the logs have similar issues with switching this back and forth - I updated our RPMs to check their value against the value in the sources.

This PR arises from that check doing its job, though in the opposite direction to what I expected when I wrote it. I was packaging 17.0.3+1, correctly changed the build to EA mode... and then it failed because the build correctly detected a mismatch and said "Hey, this should be GA!"

I think there is no need for jdk<x>-dev to ever be anything but `ea`. The switch to `<empty>` ('ga') should happen as part of the final changes along with the jdk*-ga tag in the jdk<x> tree, and then we should avoid merging that change back into -dev. Yes, it would need a bug, but then we also have bugs for the version bump. It can be reviewed and approved in the same manner as the other security fixes, without having to go through the public process.

> Given that most downstream distributors probably don't rely on this (what would they have done up to this point if they did?) anyway, I'm questioning its usefulness. No strong feelings though.

The field was only added in May 2019. I only spotted it myself when updating to OpenJDK 16 last February. It's not been publicised, OpenJDK 17 is the first time it has been in an LTS release and 17.0.3 is the first 17u release where the value is being maintained by someone other than Oracle. Our logic has not caught it for 17.0.1 & 17.0.2 because we've hopped from GA release to GA release.

So the question for me is not whether distributors already rely on it (we haven't had much opportunity to, it being either unavailable or wrong), but whether it is going to be maintained enough for us to rely on it. I think the check we have is useful for keeping the status in sync between the sources and the RPM. It may well help those who are more divorced from the JDK development process even more in obtaining their downstream builds. I'd actually prefer that `configure` used it, but I can see there is resistance to that, so it's not something I'd push for. I'm happy for the value to remain as a helpful hint.

Either way, I think having an inaccurate value in there is helpful. If we don't wish to update this value in sync with JDK updates development, it should be removed from the updates tree.

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PR: https://git.openjdk.java.net/jdk17u-dev/pull/307