RFR: 8275319 java.net.NetworkInterface throws java.lang.Error instead of SocketException [v4]

[Daniel Fuchs]

On Tue, 19 Oct 2021 09:32:19 GMT, Daniel Jeliński <duke at openjdk.java.net> wrote:

>> Per Java documentation, "[Error](https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/lang/Error.java#L30) [..] indicates serious problems that a reasonable application should not try to catch". Failure to enumerate network interfaces or addresses is not a serious enough situation; many applications can recover from this pretty easily.
>> 
>> All native methods (except `init()`) in [NetworkInterface](https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/net/NetworkInterface.java#L436) are declared with `throws SocketException`, so throwing SocketExceptions instead of Errors will match the declared interface.
>> 
>> Unix version of [NetworkInterface](https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libnet/NetworkInterface.c#L1189) already throws `SocketException`s in similar situations, and does not throw `Error` under any circumstances.
>> 
>> I searched the bug database and mail archives, but could not find any discussion on the topic; if there's a reason to keep throwing `Error`s, I couldn't find it.
>> 
>> `tier1` tests pass, `java.net` tests pass. No new regression tests as I couldn't find any list of steps to reproduce the problem.
>> 
>> I don't have write access to JBS. I could use some help with creating a ticket.
>
> Daniel Jeliński has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Adapt line length to 80 column display

Hmm... JDK-8225239 might have introduced a bug. 
I see that with the current code neither `enumAddresses_win` nor `enumAddresses_win_ipaddrtable` will return -2 - so there appears to be some dead code. I suspect that this line here is wrong:
 https://github.com/openjdk/jdk/blob/a6c89e231872e7fab236ed87b5ccf44a189d6786/src/java.base/windows/native/libnet/NetworkInterface.c#L516
 it should be returning `ret` not `NULL`

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PR: https://git.openjdk.java.net/jdk/pull/5956