[MSHADE-439] Relocate does not relocate the other JVM variants in Multi Release jar.

**[Niels Basjes](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=nielsbasjes)** opened **[MSHADE-439](https://issues.apache.org/jira/browse/MSHADE-439?redirect=false)** and commented

The 2.0 release of snakeyaml is a _Multi Release jar (See this [commit](https://bitbucket.org/snakeyaml/snakeyaml/commits/b33f0ca7507fd61fc945722b5d14de4b0aff5262))_.
For 2 class files they actually package a **standard** and a **java 9** variant of the same thing.

```java
$ unzip -l ~/.m2/repository/org/yaml/snakeyaml/2.0/snakeyaml-2.0.jar | fgrep Logger
1545 2023-02-26 11:06 META-INF/versions/9/org/yaml/snakeyaml/internal/Logger$Level.class
1365 2023-02-26 11:06 META-INF/versions/9/org/yaml/snakeyaml/internal/Logger.class
1446 2023-02-26 11:06 org/yaml/snakeyaml/internal/Logger$Level.class
1264 2023-02-26 11:06 org/yaml/snakeyaml/internal/Logger.class
```

When I use the maven-shade-plugin 3.4.1 (latest at the time of writing) to shade this dependency in my project and relocate (!) it to a different package the final jar contains this:

```java
1678 2023-02-26 11:06 META-INF/versions/9/org/yaml/snakeyaml/internal/Logger$Level.class
1484 2023-02-26 11:06 META-INF/versions/9/org/yaml/snakeyaml/internal/Logger.class
1579 2023-02-26 11:06 nl/basjes/shaded/org/yaml/snakeyaml/internal/Logger$Level.class
1383 2023-02-26 11:06 nl/basjes/shaded/org/yaml/snakeyaml/internal/Logger.class
```

Note that the **standard** variants have been shaded correctly and the **java 9** variants have not been relocated at all.

---

**Affects:** 3.4.1

**Attachments:**
- [pom.xml](https://issues.apache.org/jira/secure/attachment/13056215/pom.xml) (_3.32 kB_)

1 votes, 3 watchers

Start by reproducing the shaded output with the attached pom.xml, using the snakeyaml 2.0 dependency and checking both standard classes and META-INF/versions/9 classes. Then trace the relocation handling for multi-release JAR entries. Done means the Java 9 variants are relocated consistently with the standard variants and the resulting JAR matches the expected package layout.

Written by the indexing model from the issue text.