Program: 92387
Project: 92387
Buggy source:
private void fillMixins(List<Mixin> mixinList,Map<String,Mixin> mixinMap,Model model,MavenProject currentProject,MavenSession mavenSession) throws MavenExecutionException {
  model=model.clone();
  Properties origProperties=model.getProperties() != null ? model.getProperties() : new Properties();
  origProperties.putAll(currentProject.getProperties());
  model.setProperties(origProperties);
  MixinModelProblemCollector problems=new MixinModelProblemCollector();
  modelInterpolator.interpolateModel(model,currentProject.getBasedir(),modelBuildingRequest,problems);
  if (model.getBuild() == null) {
    model.setBuild(new Build());
  }
  List<Plugin> plugins=model.getBuild().getPlugins();
  for (  Plugin plugin : plugins) {
    if (plugin.getGroupId().equals(PLUGIN_GROUPID) && plugin.getArtifactId().equals(PLUGIN_ARTIFACTID)) {
      Mixins mixins=loadConfiguration(plugin.getConfiguration());
      for (      Mixin mixin : mixins.getMixins()) {
        if (!mixinMap.containsKey(mixin.getKey())) {
          logger.debug(String.format("String_Node_Str",mixin.getKey()));
          mixinModelCache.getModel(mixin,currentProject,mavenSession,mavenXpp3reader,artifactFetcher);
          mixinMap.put(mixin.getKey(),mixin);
          mixinList.add(mixin);
        }
      }
      for (      Mixin mixin : mixins.getMixins()) {
        if (mixin.isRecurse()) {
          Model mixinModel=mixinModelCache.getModel(mixin,currentProject,mavenSession,mavenXpp3reader,artifactFetcher);
          fillMixins(mixinList,mixinMap,mixinModel,currentProject,mavenSession);
        }
      }
    }
  }
}

Fixed version (ground truth):
private void fillMixins(List<Mixin> mixinList,Map<String,Mixin> mixinMap,Model model,MavenProject currentProject,MavenSession mavenSession) throws MavenExecutionException {
  model=model.clone();
  Properties origProperties=model.getProperties() != null ? model.getProperties() : new Properties();
  origProperties.putAll(currentProject.getProperties());
  model.setProperties(origProperties);
  MixinModelProblemCollector problems=new MixinModelProblemCollector();
  ModelBuildingRequest request=new DefaultModelBuildingRequest(modelBuildingRequest);
  request.setSystemProperties(mavenSession.getSystemProperties());
  request.setUserProperties(mavenSession.getUserProperties());
  modelInterpolator.interpolateModel(model,currentProject.getBasedir(),request,problems);
  if (model.getBuild() == null) {
    model.setBuild(new Build());
  }
  List<Plugin> plugins=model.getBuild().getPlugins();
  for (  Plugin plugin : plugins) {
    if (plugin.getGroupId().equals(PLUGIN_GROUPID) && plugin.getArtifactId().equals(PLUGIN_ARTIFACTID)) {
      Mixins mixins=loadConfiguration(plugin.getConfiguration());
      for (      Mixin mixin : mixins.getMixins()) {
        if (!mixinMap.containsKey(mixin.getKey())) {
          logger.debug(String.format("String_Node_Str",mixin.getKey()));
          mixinModelCache.getModel(mixin,currentProject,mavenSession,mavenXpp3reader,artifactFetcher);
          mixinMap.put(mixin.getKey(),mixin);
          mixinList.add(mixin);
        }
      }
      for (      Mixin mixin : mixins.getMixins()) {
        if (mixin.isRecurse()) {
          Model mixinModel=mixinModelCache.getModel(mixin,currentProject,mavenSession,mavenXpp3reader,artifactFetcher);
          fillMixins(mixinList,mixinMap,mixinModel,currentProject,mavenSession);
        }
      }
    }
  }
}