goal in multiproject:goal isn't correctly called if the tag is used several times in a build with different goals

• Testcase included:

  yes

This issue isn't in the multiproject plugin but in the core (MAVEN-1691) . I create it to avoid others users to search for this problem.

Let's imagine we have the following projects :
myProject

You create a custom goal in myProject (myGoal) which calls the goal goalLevel1 in each direct subproject (*/project.xml)
In mySubProjectA and mySubProjectB you do the same and call another goal in subprojects (goalLevel2)
Here is what maven do :

myProject => myGoal OK

The multiproject fails because it forgot that in mySubProjectB, it should call goalLevel1.

The problem is when the second multiproject is called, it replace the value of the variable goal for the project myProject.
A testcase is given in MAVEN-1691.