Add support for external parents in a multi-module project

[driseley]

We have multi-module maven projects where some child projects have parents that are external to the project structure ( for example spring-boot parent poms: https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-build-systems.html#using-boot-maven-parent-pom ).

These are identified by the fact that the relativePath for the parent is set to be empty <relativePath/>

http://maven.apache.org/ref/3.0/maven-model/maven.html#parent

Set the value to an empty string in case you want to disable the feature and always resolve the parent POM from the repositories

I have added an integration test ( multi-external-parent ) which fails to build under the current code and then passes with my proposed fix. The build fails as the version number for the external parent pom is incorrectly re-written by the jgitver-maven-plugin.

Could you review this change and see if you agree?

Many thanks
David

[McFoggy]

thank you for this very promising contribution, will review ASAP.

[McFoggy]

Thank you very much for your help.

I integrated your commit in 167c67c.

[driseley]

@McFoggy - many thanks for accepting this , is there any chance we could have a release of this fix, as this would allow us to stop using our locally forked version?

[McFoggy]

It is tagged & released on sonatype. Just wait few hours for central to be in synch.

[driseley]

That's brilliant - many thanks for that!