RFR: 8279878: java/awt/font/JNICheck/JNICheck.sh test fails on Ubuntu 21.10

[Thomas Stuefe]

On Fri, 14 Jan 2022 19:09:53 GMT, Phil Race <prr at openjdk.org> wrote:

> Some more signal handler related warning strings from the VM need to be excluded from what this test considers a failure 
> 
> See the bug for more info.

In hotspot, we want to explicitly ignore SIGPIPE and SIGXFSZ (see https://bugs.openjdk.java.net/browse/JDK-4229104 and https://bugs.openjdk.java.net/browse/JDK-6499219). But we don't do SIG_IGN, since we still need to give chained handlers the opportunity to handle them. See https://github.com/openjdk/jdk/blob/fef8f2d30004ea75c663752ae6c61b214fb8abc8/src/hotspot/os/posix/signals_posix.cpp#L618-L623.

So now, from the OS perspective, we handle SIGPIPE. We just don't do anything but return from the signal handler (ignoring chained handlers for now). If someone outside sets SIGPIPE to SIG_IGN, then we get subtle changes:
- IO calls would now yield EPIPE, whereas now I am not sure what happens? Does the IO call report success?
- Also, chained handlers would not get called.

It's all pretty unexciting. Nothing would crash. There may be an argument for skipping the test on SIGPIPE if it is SIG_IGN and we don't have chained handlers. If it seems such a standard thing to do for third party libraries. Idk. Maybe open a separate bug?

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PR: https://git.openjdk.java.net/jdk/pull/7091