title: mvn versions:set not changing the child modules version when they would match their parent, which is not the same as the aggregator pom
body: <p>I am facing the need of changing the version of an aggregator maven project and the two modules it has, using <code>versions:set</code>. One of the use cases does not work and I do not know whether I'm missing something or this use case in particular is not well-supported by the plugin. Child modules versions are not updated to 1.4.0 as they would match the versions of <code>someother-parentartifact-1</code> and <code>someother-parentartifact-2</code>. I have been unable to reproduce the problem using a version different to <code>1.4.0</code> so I guessed the plugin gets confused somehow.</p>
  
  <p>Aggregator:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;com.mygroupId&lt;/groupId&gt;
      &lt;artifactId&gt;my-aggregator&lt;/artifactId&gt;
      &lt;version&gt;1.4.0-RC1&lt;/version&gt;
      &lt;packaging&gt;pom&lt;/packaging&gt;
  
      &lt;properties&gt;
          &lt;maven.deploy.skip&gt;true&lt;/maven.deploy.skip&gt;
      &lt;/properties&gt;
  
      &lt;modules&gt;
          &lt;module&gt;module-1&lt;/module&gt;
          &lt;module&gt;module-2&lt;/module&gt;
      &lt;/modules&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>Module 1:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;com.mygroupId&lt;/groupId&gt;
      &lt;artifactId&gt;module-1&lt;/artifactId&gt;
      &lt;version&gt;1.4.0-RC1&lt;/version&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
  
      &lt;parent&gt;
          &lt;groupId&gt;com.myanothergroupId&lt;/groupId&gt;
          &lt;artifactId&gt;someother-parentartifact-1&lt;/artifactId&gt;
          &lt;version&gt;1.4.0&lt;/version&gt;
          &lt;relativePath/&gt; &lt;!-- lookup parent from repository --&gt;
      &lt;/parent&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.myanothergroupId&lt;/groupId&gt;
              &lt;artifactId&gt;some-lib&lt;/artifactId&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>Module 2:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;com.mygroupId&lt;/groupId&gt;
      &lt;artifactId&gt;module-2&lt;/artifactId&gt;
      &lt;version&gt;1.4.0-RC1&lt;/version&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
  
      &lt;parent&gt;
          &lt;groupId&gt;com.myanothergroupId&lt;/groupId&gt;
          &lt;artifactId&gt;someother-parentartifact-2&lt;/artifactId&gt;
          &lt;version&gt;1.4.0&lt;/version&gt;
          &lt;relativePath/&gt;&lt;!-- lookup parent from repository --&gt;
      &lt;/parent&gt;
  
      &lt;dependencies&gt;
  
           (bunch of dependencies)
  
      &lt;/dependencies&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>Some insights:</p>
  
  <ul>
  <li>The parent projects of both modules are not the aggregator. This is intentional, and not to be changed unless there is no other option.</li>
  <li>The value of <code>maven.deploy.skip</code> does not change the outcome.</li>
  <li>I have only seen this when the version to be set (<code>1.4.0</code>) matches the version of the parents of the child modules.</li>
  <li>The command used was: <code>mvn versions:set -DgenerateBackupPoms=false -DnewVersion=1.4.0 -DprocessAllModules</code>.</li>
  <li>Also tried to use <code>update-child-modules</code>. No success.</li>
  </ul>
  
  <p>Some logs:</p>
  
  <pre><code>[INFO]
  [INFO] ----------&lt; com.mygroupId:my-aggregator &gt;----------
  [INFO] Building my-aggregator 1.4.0-RC1                                      [1/3]
  [INFO] --------------------------------[ pom ]---------------------------------
  [INFO]
  [INFO] --- versions-maven-plugin:2.7:set (default-cli) @ my-aggregator ---
  [INFO] Searching for local aggregator root...
  [INFO] Local aggregation root: C:\somedirectory\my-aggregator
  [INFO] Processing change of com.mygroupId:my-aggregator:1.4.0-RC1 -&gt; 1.4.0
  [INFO] Processing com.mygroupId:module-1
  [INFO]     Updating project com.mygroupId:module-1
  [INFO]         from version 1.4.0-RC1 to 1.4.0
  [INFO]     Updating project com.mygroupId:module-1
  [INFO]         from version 1.4.0 to 1.4.0-RC1
  [INFO]
  [INFO] Processing com.mygroupId:module-2
  [INFO]     Updating project com.mygroupId:module-2
  [INFO]         from version 1.4.0-RC1 to 1.4.0
  [INFO]     Updating project com.mygroupId:module-2
  [INFO]         from version 1.4.0 to 1.4.0-RC1
  [INFO]
  [INFO] Processing com.mygroupId:my-aggregator
  [INFO]     Updating project com.mygroupId:my-aggregator
  [INFO]         from version 1.4.0-RC1 to 1.4.0
  [INFO]
  [INFO] ------------------------------------------------------------------------
  [INFO] Reactor Summary for my-aggregator 1.4.0-RC1:
  [INFO]
  [INFO] module-1 .................................... SKIPPED
  [INFO] module-2 .................................. SKIPPED
  [INFO] my-aggregator ......................................... SUCCESS [  3.445 s]
  [INFO] ------------------------------------------------------------------------
  [INFO] BUILD SUCCESS
  [INFO] ------------------------------------------------------------------------
  [INFO] Total time:  23.637 s
  [INFO] Finished at: 2019-07-04T17:02:37+02:00
  [INFO] ------------------------------------------------------------------------
  </code></pre>
  
  <p>Thanks in advance for your help.</p>