fixed #364.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@2553 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/maven/MavenModuleSetBuild.java

@@ -192,7 +192,11 @@ public final class MavenModuleSetBuild extends AbstractBuild<MavenModuleSet,Mave
                 MavenUtil.resolveModules(embedder,mp,getRootPath(),relPath);
 
                 List<PomInfo> infos = new ArrayList<PomInfo>();
-                toPomInfo(mp,relPath,infos);
+                toPomInfo(mp,null,relPath,infos);
+
+                for (PomInfo pi : infos)
+                    pi.cutCycle();
+
                 return infos;
             } catch (MavenEmbedderException e) {
                 // TODO: better error handling needed
@@ -202,10 +206,11 @@ public final class MavenModuleSetBuild extends AbstractBuild<MavenModuleSet,Mave
             }
         }
 
-        private void toPomInfo(MavenProject mp, Map<MavenProject,String> relPath, List<PomInfo> infos) {
-            infos.add(new PomInfo(mp,relPath.get(mp)));
+        private void toPomInfo(MavenProject mp, PomInfo parent, Map<MavenProject,String> relPath, List<PomInfo> infos) {
+            PomInfo pi = new PomInfo(mp, parent, relPath.get(mp));
+            infos.add(pi);
             for (MavenProject child : (List<MavenProject>)mp.getCollectedProjects())
-                toPomInfo(child,relPath,infos);
+                toPomInfo(child,pi,relPath,infos);
         }
 
         private static final long serialVersionUID = 1L;

core/src/main/java/hudson/maven/PomInfo.java

@@ -52,18 +52,24 @@ final class PomInfo implements Serializable {
      */
     public final String defaultGoal;
 
-    public PomInfo(MavenProject project, String relPath) {
+    /**
+     * Parent module.
+     */
+    public final PomInfo parent;
+
+    public PomInfo(MavenProject project, PomInfo parent, String relPath) {
         this.name = new ModuleName(project);
         this.displayName = project.getName();
         this.defaultGoal = project.getDefaultGoal();
         this.relativePath = relPath;
+        this.parent = parent;
 
         for (Dependency dep : (List<Dependency>)project.getDependencies())
             dependencies.add(new ModuleName(dep));
 
-        MavenProject parent = project.getParent();
-        if(parent!=null)
-            dependencies.add(new ModuleName(parent));
+        MavenProject parentProject = project.getParent();
+        if(parentProject!=null)
+            dependencies.add(new ModuleName(parentProject));
 
         addPluginsAsDependencies(project.getBuildPlugins(),dependencies);
         addReportPluginsAsDependencies(project.getReportPlugins(),dependencies);
@@ -86,5 +92,20 @@ final class PomInfo implements Serializable {
             dependencies.add(new ModuleName(p));
     }
 
+    /**
+     * Avoids dependency cycles.
+     *
+     * <p>
+     * People often write configuration in parent POMs that use the plugin
+     * which is a part of the build. To avoid this kind of dependency,
+     * make sure parent POMs don't depend on a child module.
+     */
+    /*package*/ void cutCycle() {
+        for(PomInfo p=parent; p!=null; p=p.parent) {
+            if(p.dependencies.contains(name))
+                p.dependencies.remove(name);
+        }
+    }
+
     private static final long serialVersionUID = 1L;
 }