[MNG-2591] Plugins are merged incorrectly

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.0.4
• Fix Version/s: 2.0.8
• Environment: Windows XP
• Assignee: John Dennis Casey
• Reporter: Allan Shoup
• Created: 05/Oct/06 09:47
• Updated: 06/Apr/15 00:47
• Resolved: 07/Jun/07 16:23

Description

This bug is similar to http://jira.codehaus.org/browse/MANTRUN-57;jsessionid=awtyLFBPEQN6vVmwu4 - the difference being the plugins are not correctly merged.

In the parent's POM, the following was defined:

<build>
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-eclipse-plugin</artifactId>
        <configuration>
          <downloadSources>true</downloadSources>
          <additionalBuildcommands>
            <buildcommand>
              parentBuildCommand
            </buildcommand>
          </additionalBuildcommands>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</build>

in the child's POM, the following was defined.

<build>
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-eclipse-plugin</artifactId>
        <configuration>
          <additionalBuildcommands>
            <buildcommand>
              childBuildCommand
            </buildcommand>
          </additionalBuildcommands>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</build>

I expect the effective POM to look like this:

<build>
  <pluginManagement>
    <plugins>
      <plugin>
        <artifactId>maven-eclipse-plugin</artifactId>
        <configuration>
          <additionalBuildcommands>
            <buildcommand>
              parentBuildCommand
            </buildcommand>
            <buildcommand>
              childBuildCommand
            </buildcommand>
          </additionalBuildcommands>
          <downloadSources>true</downloadSources>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</build>

Outside of the common problem of the <plugin> element being duplicated, here's the issue this bug is trying to address:
In the effective pom, the the <downloadSources> element was correctly merged, however, the <buildCommand> element was not. It seems like the merging only correctly happens down to a given level.

I noticed that http://jira.codehaus.org/browse/MNG-2297;jsessionid=awtyLFBPEQN6vVmwu4 has a patch attached, so this may be fixed in 2.0.5, I just wanted to raise the use case in case that patch did not address this specific problem.

I'm attaching the POMs needed to reproduce the problem and the effective POM for the child.

Issue Links

• is related to: MNG-732 Improve plugin configuration property merge algorithm
• relates to: MNG-3836 [regression] Inherited collection from plugin configuration is merged with configuration from child whereas child config should completely override collection
• relates to: MNGSITE-99 POM reference not discuss configuration merging