[MNG-7563] REGRESSION: User properties now override model properties in dependencies

**[Hervé Guillemet](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=hg@apteryx.fr)** opened **[MNG-7563](https://issues.apache.org/jira/browse/MNG-7563?redirect=false)** and commented

An important change has been introduced in 3.8.5 that breaks some existing builds: Java system properties now take precedence over default values of user properties in dependency POMs. This look like a bug since it's now easy to affect dependency behaviors with system properties, a practice that has been discouraged. But maybe do you consider this as a new feature ?

As an example, 3 poms are attached to this ticket.
After installing projects b and c, building project a with:
`mvn package -Ddep=x`
used to succeed until 3.8.4 (-D is ignored) but throws error with 3.8.5 and 3.8.6 (-D override the default).

Note that without the setting of the default value for property `dep` in project b, the build fails with any version of Maven.


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**Affects:** 3.8.5, 3.8.6

**Attachments:**
- [poms.zip](https://issues.apache.org/jira/secure/attachment/13050857/poms.zip) (_1.23 kB_)

**Issue Links:**
- [MNG-7634](https://issues.apache.org/jira/browse/MNG-7634) Revert MNG-5982 and MNG-7417
 (_**"is fixed by"**_)
- [MNG-7635](https://issues.apache.org/jira/browse/MNG-7635) Investigate how to safely propagate user properties to dependencies (see MNG-5982 and MNG-7417)
 (_**"causes"**_)
- [MNG-7417](https://issues.apache.org/jira/browse/MNG-7417) Several classes do not set properties properly for building requests
 (_**"is caused by"**_)
- [MNG-5982](https://issues.apache.org/jira/browse/MNG-5982) The POM for ... is invalid, transitive dependencies ... while property was overriden


**Backported to:** [4.0.0-alpha-4](https://github.com/apache/maven/milestone/3?closed=1), [3.9.0](https://github.com/apache/maven/milestone/2?closed=1), [3.8.7](https://github.com/apache/maven/milestone/108?closed=1)

0 votes, 5 watchers

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