If validation throws, getIssueSummary() throws NPE

[fabtagon]

If a validations throws an exceptions, it is caught and, if other than GuardException or NPE, added to a FluentIssueCollection which in turn is evaluated.

As such an exception doesn't posses a URI, getIssueSummary() fails with an NPE in here. Note that the exception thrown by getIssueSummary() is not the exception that the validation has thrown before.

In the best of all worlds, validations do of course not throw, but in reality this might happen (in the best of all worlds where no mistakes occour, validations probably won't be needed at all) - and Xtend seems prepared to deal with exceptions, at least with those other than NPE.

[fabtagon]

How things do (not) fit together:

• validates
• notices exception
• Creates Diagnostic with Diagnostic.data[0] = encountered exception

Later on,

• in convertValidatorDiagnostic(), getCauser() gets invoked which returns the EObject under (failing) validation, or in our case of an exception, null
• this prevents setting the diagnostic's URI two lines later

Suggestion how to resolve:

• diagnostic should contain text/stack trace of exception, but otherwise refer to the object whose validation has raised the exception (extend functionality in createExceptionDiagnostic())

[kthoms]

NPE confirmed.