RFR (14): JDK-8233655: NPE at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitApply

[Jan Lahoda]

Hi,

Under bug JDK-8177068, the speculative attribution was improved to 
better handle missing classes. Before that, errors reported outside of 
the speculative tree were propagated outside of the speculative 
attribution. This was removed, as it seemed unnecessary due to the new 
handling of missing classes. But it turns out it is still needed, as 
shown in this bug. A simple testcase is:
---
public class JDK8233655 {
     public void t() {
         Class<?> c= test(test(JDK8233655Helper.class));
     }
     private <T> T test(Class<?> c) {
         return null;
     }
}
---
public class JDK8233655Helper extends Unknown {}
---

$ javac JDK8233655.java
... the exception from Flow ...

The proposed fix is to restore the error handling similarly to what 
existed before JDK-8177068.

Webrev: http://cr.openjdk.java.net/~jlahoda/8233655/webrev.00/
JBS: https://bugs.openjdk.java.net/browse/JDK-8233655

How does this look?

Thanks,
     Jan