[MDEP-590] dependency:copy confused when asked to copy artifact with classifier and extension .POM

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0, 3.0.1, 3.0.2
• Component/s: copy
• Assignee: Unassigned
• Reporter: Bertrand Renuart
• Created: 27/Nov/17 17:33
• Updated: 26/Sep/22 18:18

Description

Suppose you ask the maven-dependency-plugin to copy an artifact with the following coordinates:

• groupId: group
• artifactId: artifact
• version: 1.0-SNAPSHOT
• classifier: custom
• type: pom

This is done with the following configuration:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-dependency-plugin</artifactId>
  <version>3.0.2</version>
  <executions>
    <execution>
      <phase>generate-resources</phase>
      <goals>
        <goal>copy</goal>
      </goals>
      <configuration>
        <artifactItems>
          <artifactItem>
            <groupId>group</groupId>
            <artifactId>artifact</artifactId>
            <version>1.0-SNAPSHOT</version>
            <classifier>custom</classifier>
            <type>pom</type>
          </artifactItem>
        </artifactItems>
      </configuration>
    </execution>
  </executions>
</plugin>

The MOJO will fail to copy the artifact with classifier=custom, type=pom but will instead copy the primary .POM artifact. However, things are ok when type is set to xml instead of pom.
It seems the mojo totally ignores the classifier whenever the type is pom...

I have attached a sample project made of two modules to reproduce the issue.
The first module has an additional artifact of type pom and classifier custom attached to it via the build-helper-maven-plugin
The second module attempts to copy that additional artifact with the maven-dependency-plugin.
Run it with mvn package. The result of the copy is in module-b/target/copied-custom.pom.
It is ecpected this file is a copy of module-a/custom.xml but is actually a copy of the primary pom, ie module-a/pom.xml.