Bug 50894: Invoking multiple targets that share the same dependency to augment a path causes NullPointerException

[Steele, Richard]

I keep bumping into the issue I documented in bug
50894<https://issues.apache.org/bugzilla/show_bug.cgi?id=50894>but
there's no feedback about it.  Here's the description:

Using this build file:

<project>
   <target name="foo" depends="aug">
       <echo message="${toString:p}" />
   </target>

   <target name="bar" depends="aug">
       <echo message="${toString:p}" />
   </target>

   <path id="p" />

   <target name="aug">
       <augment id="p">
           <path>
               <pathelement path="/" />
           </path>
       </augment>
   </target>
</project>

I can invoke each target, foo and bar, independently; for example

ant foo
Buildfile:
C:\dev\projects\ant-playground\augment-with-multiple-target\build.xml

aug:

foo:
    [echo] C:\

BUILD SUCCESSFUL

ant bar
Buildfile:
C:\dev\projects\ant-playground\augment-with-multiple-target\build.xml

aug:

bar:
    [echo] C:\

BUILD SUCCESSFUL

However, invoking both on the same command line causes an error:

ant foo bar
Buildfile:
C:\dev\projects\ant-playground\augment-with-multiple-target\build.xml

aug:

foo:
    [echo] C:\

aug:

BUILD FAILED
C:\dev\projects\ant-playground\augment-with-multiple-targets\build.xml:14:
java.lang.NullPointerException
       at
org.apache.tools.ant.RuntimeConfigurable.maybeConfigure(RuntimeConfigurable.java:376)
       at
org.apache.tools.ant.RuntimeConfigurable.maybeConfigure(RuntimeConfigurable.java:344)
       at org.apache.tools.ant.Task.maybeConfigure(Task.java:202)
       at org.apache.tools.ant.Task.perform(Task.java:347)
       at org.apache.tools.ant.Target.execute(Target.java:390)
       at org.apache.tools.ant.Target.performTasks(Target.java:411)
       at
org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
       at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
       at
org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
       at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
       at org.apache.tools.ant.Main.runBuild(Main.java:809)
       at org.apache.tools.ant.Main.startAnt(Main.java:217)
       at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
       at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)

If foo and bar independently use augment, even for the same path (that is,
they
don't use depends on a shared target) like this:

<project>
   <target name="foo">
       <augment id="p">
           <path>
               <pathelement path="/" />
           </path>
       </augment>
       <echo message="${toString:p}" />
   </target>

   <target name="bar">
       <augment id="p">
           <path>
               <pathelement path="/" />
           </path>
       </augment>
       <echo message="${toString:p}" />
   </target>

   <path id="p" />
</project>

the build works.

Any help getting this resolved would be much appreciated.  I've tried
debugging it myself but I get lost somewhere in the deep, dark underbelly of
Ant.

Rich