RFR: JDK-8317804: com/sun/jdi/JdwpAllowTest.java fails on Alpine 3.17 / 3.18

[Matthias Baesken]

On Wed, 10 Jan 2024 01:53:02 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

> The change fixes workaround introduced by [[JDK-8250630]](https://bugs.openjdk.org/browse/JDK-8250630).
> The root cause of the test failure was identified by JDK-8250630:
> On Apline Linux getaddrinfo function returns 2 entries for "any" address - mapped IPv4 (`::ffff:0.0.0.0`) and IPv6 (`::`) and IPv4 is returned first.
> When JDWP agent listens on mapped IPv4, it accepts only connections from IPv4 addresses, connections from IPv6 addresses fail with "connection refused" error.
> Fix for JDK-8250630 introduced workaround for the case - if we get `::ffff:0.0.0.0` (`mappedAny`) and `::` (`in6addr_any`) is also returned by getaddrinfo, agent uses `in6addr_any` for listening.
> 
> But the fix had a typo - the loop goes through returned addresses (`ai` variable), but checks if `listenAddr` equals `in6addr_any`. This is always false (because `listenAddr` equals `mappedAny`), so the workaround does not work.
> 
> Submitter confirmed that the fix resolves the issue.
> 
> Testing: tier1, all JDI-related tests (test/hotspot/jtreg/vmTestbase/nsk/jdwp, test/hotspot/jtreg/vmTestbase/nsk/jdi, test/hotspot/jtreg/vmTestbase/nsk/jdb, test/jdk/com/sun/jdi)

Marked as reviewed by mbaesken (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/17334#pullrequestreview-1812629326