[java] PreserveStackTrace not handling Throwable.addSuppressed(...)

[lars-sh]

Affects PMD Version: 6.19.0

Rule: PreserveStackTrace

Description: The below code generates a false-positive PreserveStackTrace error while the outer exception really is preserved as part of the inner exception using addSuppressed.

This is really a rare case and I'm fine with suppressing it for now, but wanted to let you know about it and maybe this report even helps someone.

Code Sample demonstrating the issue:

try {
	return ...;
} catch (IOException outerException) {
	try {
		return ...;
	} catch (IOException innerException) {
		innerException.addSuppressed(outerException);
		throw new UncheckedIOException(innerException);
	}
}

[adangel]

This has been fixed with PMD 7.0.0-rc1.