[MSHARED-1004] Two (2) issues with symbolic links

**[Jimisola Laursen](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=JIRAUSER281352)** opened **[MSHARED-1004](https://issues.apache.org/jira/browse/MSHARED-1004?redirect=false)** and commented

Two issues with (relative) symbolic links as resources (use attached file for reference and MWE:

 

```
user@earhart:~/dev/test/my-app$ tree
.
├── pom.xml
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com
│   │   │       └── mycompany
│   │   │           └── app
│   │   │               └── App.java
│   │   └── resources
│   │       ├── B -> ../../../to_be_symlinked/B
│   │       └── folder -> ../../../to_be_symlinked/folder
│   └── test
│       └── java
│           └── com
│               └── mycompany
│                   └── app
│                       └── AppTest.java
└── to_be_symlinked
    ├── B
    └── folder
        └── A
```

 

 

 
* Symlinks for directories copies the actual directory (folder/A) whereas symlinks for files copies the symlink (B). Note the difference between file A and B. B is pointing incorrectly since it is relative.

```
user@earhart:~/dev/test/my-app/target/classes$ ls -l
total 8
lrwxrwxrwx 1 user user   26 dec 10 10:19 B -> ../../../to_be_symlinked/B
drwxrwxr-x 3 user user 4096 dec 10 10:19 com
drwxrwxr-x 2 user user 4096 dec 10 10:19 folder
user@earhart:~/dev/test/my-app/target/classes$ ls -l folder/
total 0
-rw-rw-r-- 1 user user 0 dec 10 10:19 A
```

* Resources are not overwritten (java.nio.file.FileAlreadyExistsException). To reproduce run "mvn compile" two (2x) times:

```
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources) on project my-app: copying /home/user/dev/test/my-app/src/main/resources/folder/A to /home/user/dev/test/my-app/target/classes/folder/A failed with FileAlreadyExistsException: /home/user/dev/test/my-app/target/classes/folder/A -
```

 

---

**Affects:** maven-filtering-3.3.0

**Attachments:**
- [my-app.tar.gz](https://issues.apache.org/jira/secure/attachment/13037246/my-app.tar.gz) (_1.56 kB_)
- [my-app-wo-symlinks.tar.gz](https://issues.apache.org/jira/secure/attachment/13037374/my-app-wo-symlinks.tar.gz) (_1.50 kB_)

**Issue Links:**
- [MSHARED-966](https://issues.apache.org/jira/browse/MSHARED-966) Resources are not copied to ${project.build.outputDirectory}

- [MRESOURCES-237](https://issues.apache.org/jira/browse/MRESOURCES-237) Resource plugin's handling of symbolic links changed in 3.0.x, broke existing behavior

- [MRESOURCES-269](https://issues.apache.org/jira/browse/MRESOURCES-269) Symlinks cause copying resources to fail

Start with the attached my-app.tar.gz minimal example and reproduce the behavior with "mvn compile" twice. Compare directory and file symlink handling in target/classes, then verify that repeated resource copying no longer raises FileAlreadyExistsException and that relative links are handled correctly.

Written by the indexing model from the issue text.