RFR: 8366040: Change URL.lookupViaProviders to use ScopedValue to detect recursive lookup

[Daniel Fuchs]

On Fri, 3 Oct 2025 13:14:43 GMT, Volkan Yazici <vyazici at openjdk.org> wrote:

> Replace `ThreadTracker` usage in `java.net.URL` with `ScopedValue` and add a test.

src/java.base/share/classes/java/net/URL.java line 1402:

> 1400:             throw new Error("Circular loading of URL stream handler providers detected");
> 1401:         }
> 1402:         return ScopedValue.where(IN_LOOKUP, true).call(() -> {

We should never reach here if the VM is not booted, or if the protocol is `file:` or `jrt:` - so it may be safe to use a lambda. The alternative would be to use an anonymous class and create a `new Runnable() { ... }` but it's probably not needed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27623#discussion_r2402580089