Cross-project ${revision} pollution (Maven CI-Friendly Versions)

[stechio]

Component	Version
m2e	2.8.0.20250224
Eclipse IDE	4.35.0.20250306

I'm struggling with an issue already reported years ago (Bug 564796 - Revision of parent POM leaks into project).

CURRENT FAULTY BEHAVIOR

When some projects leveraging the Maven CI-Friendly Versions feature share parent POMs within the same workspace, the ${revision} placeholders of the parent POM are replaced by the revision of the dependent POM instead of being flattened to its own revision.

Let's say the workspace contains two projects:

• parent-project, whose POM declares:

  <groupId>X</groupId>
  <artifactId>parent-project</artifactId>
  <version>${revision}</version>
  <packaging>pom</packaging>
  
  <properties>
    <revision>1.0-SNAPSHOT</revision>
  </properties>
  
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>X</groupId>
        <artifactId>parent-project-mod1</artifactId>
        <version>${revision}</version>
      </dependency>
    </dependencies>
  </dependencyManagement>

• dependent-project (depending on parent-project), whose POM declares:

  <parent>
    <groupId>X</groupId>
    <artifactId>parent-project</artifactId>
    <version>1.0-SNAPSHOT</version>
  </parent>
  
  <artifactId>dependent-project</artifactId>
  <version>${revision}</version>
  
  <properties>
    <revision>3.5-SNAPSHOT</revision>
  </properties>
  
  <dependencies>
    <dependency>
      <groupId>X</groupId>
      <artifactId>parent-project-mod1</artifactId>
    </dependency>
  </dependencies>

The effective POM of dependent-project looks like this:

<parent>
  <groupId>X</groupId>
  <artifactId>parent-project</artifactId>
  <version>1.0-SNAPSHOT</version>
</parent>

<artifactId>dependent-project</artifactId>
<version>3.5-SNAPSHOT</version>

<properties>
  <revision>3.5-SNAPSHOT</revision>
</properties>

<dependencies>
  <dependency>
    <groupId>X</groupId>
    <artifactId>parent-project-mod1</artifactId>
    <version>3.5-SNAPSHOT</version> <!-- WRONG! Should be 1.0-SNAPSHOT -->
  </dependency>
</dependencies>

Apparently, m2e doesn't provide a resolution boundary between projects to isolate CI-Friendly versions belonging to distinct scopes — it just brings all the POM hierarchy together, then resolves ALL the placeholders without caring of their scope.

EXPECTED BEHAVIOR

m2e should flatten the ${revision} placeholders in parent POM (just like the resolveCiFriendliesOnly flattenMode of org.codehaus.mojo:flatten-maven-plugin) before linking the dependent POM hierarchy.

For the purpose, IMO, inside m2e the dependent POM should not link directly the parent POM; instead, it should link the flattened parent POM (re-generated and cached anytime the parent POM is changed).