Program: 2103
Project: 2103
Buggy source:
/** 
 * Worker method for rearranging history stack. Implements the function of moving all activities for a specific task (gathering them if disjoint) into a single group at the bottom of the stack. If a watcher is installed, the action is preflighted and the watcher has an opportunity to premeptively cancel the move.
 * @param task The taskId to collect and move to the bottom.
 * @return Returns true if the move completed, false if not.
 */
final boolean moveTaskToBackLocked(int task,ActivityRecord reason){
  Slog.i(TAG,"String_Node_Str" + task);
  if (mStackSupervisor.isFrontStack(this) && mService.mController != null) {
    ActivityRecord next=topRunningActivityLocked(null,task);
    if (next == null) {
      next=topRunningActivityLocked(null,0);
    }
    if (next != null) {
      boolean moveOK=true;
      try {
        moveOK=mService.mController.activityResuming(next.packageName);
      }
 catch (      RemoteException e) {
        mService.mController=null;
      }
      if (!moveOK) {
        return false;
      }
    }
  }
  if (DEBUG_TRANSITION)   Slog.v(TAG,"String_Node_Str" + task);
  final TaskRecord tr=taskForIdLocked(task);
  if (tr == null) {
    return false;
  }
  mTaskHistory.remove(tr);
  mTaskHistory.add(0,tr);
  if (reason != null && (reason.intent.getFlags() & Intent.FLAG_ACTIVITY_NO_ANIMATION) != 0) {
    mWindowManager.prepareAppTransition(AppTransition.TRANSIT_NONE,false);
    ActivityRecord r=topRunningActivityLocked(null);
    if (r != null) {
      mNoAnimActivities.add(r);
    }
  }
 else {
    mWindowManager.prepareAppTransition(AppTransition.TRANSIT_TASK_TO_BACK,false);
  }
  mWindowManager.moveTaskToBottom(task);
  if (VALIDATE_TOKENS) {
    validateAppTokensLocked();
  }
  if (mResumedActivity != null && mResumedActivity.task == tr && mResumedActivity.mLaunchHomeTaskNext) {
    mResumedActivity.mLaunchHomeTaskNext=false;
    return mStackSupervisor.resumeHomeActivity(null);
  }
  mStackSupervisor.getFocusedStack().resumeTopActivityLocked(null);
  return true;
}

Fixed version (ground truth):
/** 
 * Worker method for rearranging history stack. Implements the function of moving all activities for a specific task (gathering them if disjoint) into a single group at the bottom of the stack. If a watcher is installed, the action is preflighted and the watcher has an opportunity to premeptively cancel the move.
 * @param task The taskId to collect and move to the bottom.
 * @return Returns true if the move completed, false if not.
 */
final boolean moveTaskToBackLocked(int task,ActivityRecord reason){
  Slog.i(TAG,"String_Node_Str" + task);
  if (mStackSupervisor.isFrontStack(this) && mService.mController != null) {
    ActivityRecord next=topRunningActivityLocked(null,task);
    if (next == null) {
      next=topRunningActivityLocked(null,0);
    }
    if (next != null) {
      boolean moveOK=true;
      try {
        moveOK=mService.mController.activityResuming(next.packageName);
      }
 catch (      RemoteException e) {
        mService.mController=null;
      }
      if (!moveOK) {
        return false;
      }
    }
  }
  if (DEBUG_TRANSITION)   Slog.v(TAG,"String_Node_Str" + task);
  final TaskRecord tr=taskForIdLocked(task);
  if (tr == null) {
    return false;
  }
  mTaskHistory.remove(tr);
  mTaskHistory.add(0,tr);
  if (reason != null && (reason.intent.getFlags() & Intent.FLAG_ACTIVITY_NO_ANIMATION) != 0) {
    mWindowManager.prepareAppTransition(AppTransition.TRANSIT_NONE,false);
    ActivityRecord r=topRunningActivityLocked(null);
    if (r != null) {
      mNoAnimActivities.add(r);
    }
  }
 else {
    mWindowManager.prepareAppTransition(AppTransition.TRANSIT_TASK_TO_BACK,false);
  }
  mWindowManager.moveTaskToBottom(task);
  if (VALIDATE_TOKENS) {
    validateAppTokensLocked();
  }
  if (mResumedActivity != null && mResumedActivity.task == tr && mResumedActivity.mLaunchHomeTaskNext) {
    mResumedActivity.mLaunchHomeTaskNext=false;
    return mStackSupervisor.resumeHomeActivity(null);
  }
  mStackSupervisor.resumeTopActivitiesLocked();
  return true;
}