[MNG-8432] Add possibility to use BOM properties in child pom.xml

[jira-importer]

Pavel_K opened MNG-8432 and commented

Currently, it is not possible to get BOM properties in child project. For example, if in child project you do:

<dependency>
     <groupId>com.company.bom</groupId>
     <artifactId>bom</artifactId>
     <version>1.0.0</version>
     <type>pom</type>
     <scope>import</scope>
 </dependency>

then you can't not use bom properties (dependency versions) in this child project.

For example, if you want to use maven-dependency-plugin then you need to add all dependency versions manually because otherwise you will get maven-dependency-plugin:3.8.1:copy failed: version can neither be null, empty nor blank.

This problem was also discussed on StackOverflow with 10K views

That's why I suggest to add possibility to use BOM properties in child pom.xml

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Affects: 3.9.10

[Hiteshsai007]

I have opened a PR to address this issue.

Implementation Details:
Currently, when importing a BOM, the DefaultModelBuilder only extracts the DependencyManagement and ignores the model's <properties>. Furthermore, BOM imports happen after the initial model interpolation phase, which prevents BOM properties from resolving placeholders like <version>${lib.version}</version>.

To solve this, I've updated DefaultModelBuilder to:

1. Load the full Model for the imported BOM.
2. Extract the BOM's properties and merge them into the consuming model (with existing properties taking precedence to prevent unwanted overrides).
3. Execute a second pass of interpolateModel immediately after importing the properties, allowing the newly merged BOM properties to resolve any outstanding property placeholders in the model.

I have tested this end-to-end with a reproducer and all tests pass. Looking forward to any feedback on the PR!