issueManagement/system not used by changes:changes, must override

[garydgregory]

Affected version

3.0.0-M3

Bug description

When generating a site, the generating a page for changes.xml does NOT use the POM's /issueManagement/system value to select, for example "JIRA" and instead uses the "defauit", which generates broken URLs on that page.

For example:

git clone https://github.com/apache/commons-validator.git
cd commons-validator
git checkout 4c9a0660a0d29bc7e9891f24be86f9539f42e419
mvn clean verify site -DskipTests
open target/site/changes.html#a1.10.1

Youi'll see the link to VALIDATOR-502 with the href https://issues.apache.org/jira/browse/ViewIssue.jspa?key=VALIDATOR-502 which uses the "default" key instead of the "JIRA" key defined in /issueManagement/system

Note that /issueManagement/system is inherited from the parent POM, which works since the JIRA report is OK; it's the changes.xml report that's broken.

I see in changes.mdo that an action supports a system attribute. Shouldn't that inherit /issueManagement/system? Otherwise, you need to specify system on each action, which seems redundant.