Summary

Interoperability issue when jlink and jmod module path uses different JDK.

Problem

The JDK-8243666 fixed in JDK15 changed the hash logic computation for jmod files, this was backported to OpenJDK 11.0.16 and Oracle JDK deferred the backport since it leads to compatibility issue within the same release. Since the hash computation logic differs in Open JDK 11.0.16 and Oracle JDK, the verfication of jmod files generated from OpenJDK 11.0.16 with OracleJDK bundled jlink tool or vice versa fails leading to interoperability issue.

Solution

Introduce a fallback mechanism which recomputes the hash upon failure using the same logic as in JDK-8243666. This will fix the compatibility issue with OpenJDK 11, while also retaining the existing logic without affecting the compatibility within the Oracle JDK 11 releases. The issue is specific to JDK 11u release, since the hash computation logic remains same after JDK15 and JDK8u doesn't have support for modules. Also, there is a restriction on usage of jlink with jmod generated from a different JDK release Example: JDK 17 jlink cannot be used to create a installer with jmod file generated using JDK 11

Specification

No Spec change.