Program: 133819
Project: 133819
Buggy source:
@Override public void progress(){
  progressCounter++;
  for (int i=0; i < tasks.size(); i++) {
    BukkitRunnable br=tasks.get(i);
    if (br instanceof FireComboStream) {
      FireComboStream fs=(FireComboStream)br;
      if (fs.isCancelled()) {
        tasks.remove(fs);
      }
    }
  }
  if (!bPlayer.canBendIgnoreBindsCooldowns(this)) {
    remove();
    return;
  }
  if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      Vector eyeDir=player.getEyeLocation().getDirection().normalize().multiply(range);
      destination=player.getEyeLocation().add(eyeDir);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_HORSE_JUMP,0.5f,0f);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,0.5f,1f);
      for (int i=-30; i <= 30; i+=5) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),destination.clone());
        vec=GeneralMethods.rotateXZ(vec,i);
        FireComboStream fs=new FireComboStream(this,vec,player.getLocation(),range,speed,"String_Node_Str");
        fs.setSpread(0.2F);
        fs.setDensity(5);
        fs.setUseNewParticles(true);
        if (tasks.size() % 3 != 0) {
          fs.setCollides(false);
        }
        fs.runTaskTimer(ProjectKorra.plugin,0,1L);
        tasks.add(fs);
        player.getWorld().playSound(player.getLocation(),Sound.ITEM_FLINTANDSTEEL_USE,0.5f,1f);
      }
      location=tasks.get(0).getLocation();
    }
 else     if (tasks.size() == 0) {
      remove();
      return;
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      destination=player.getEyeLocation().add(range,0,range);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,0.5f,0.5f);
      for (int i=0; i <= 360; i+=5) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),destination.clone());
        vec=GeneralMethods.rotateXZ(vec,i - 180);
        vec.setY(0);
        FireComboStream fs=new FireComboStream(this,vec,player.getLocation().clone().add(0,1,0),range,speed,"String_Node_Str");
        fs.setSpread(0.0F);
        fs.setDensity(1);
        fs.setUseNewParticles(true);
        if (tasks.size() % 10 != 0) {
          fs.setCollides(false);
        }
        fs.runTaskTimer(ProjectKorra.plugin,0,1L);
        tasks.add(fs);
      }
    }
    if (tasks.size() == 0) {
      remove();
      return;
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (System.currentTimeMillis() - time > 5000) {
      remove();
      return;
    }
 else     if (hasAbility(player,FireJet.class)) {
      if (firstTime) {
        if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
          remove();
          return;
        }
        bPlayer.addCooldown("String_Node_Str",cooldown);
        firstTime=false;
        float spread=0F;
        ParticleEffect.LARGE_EXPLODE.display(player.getLocation(),spread,spread,spread,0,1);
        player.getWorld().playSound(player.getLocation(),Sound.ENTITY_GENERIC_EXPLODE,15,0F);
      }
      FireJet fj=getAbility(player,FireJet.class);
      fj.setSpeed(speed);
      FireComboStream fs=new FireComboStream(this,player.getVelocity().clone().multiply(-1),player.getLocation(),3,0.5,"String_Node_Str");
      fs.setDensity(1);
      fs.setSpread(0.9F);
      fs.setUseNewParticles(true);
      fs.setCollides(false);
      fs.runTaskTimer(ProjectKorra.plugin,0,1L);
      tasks.add(fs);
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (firstTime) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      firstTime=false;
    }
 else     if (System.currentTimeMillis() - time > 5000) {
      remove();
      return;
    }
 else     if (hasAbility(player,FireJet.class)) {
      direction=player.getVelocity().clone().multiply(-1);
      FireJet fj=getAbility(player,FireJet.class);
      fj.setSpeed(speed);
      FireComboStream fs=new FireComboStream(this,direction,player.getLocation(),5,1,"String_Node_Str");
      fs.setDensity(8);
      fs.setSpread(1.0F);
      fs.setUseNewParticles(true);
      fs.setCollisionRadius(3);
      fs.setParticleEffect(ParticleEffect.LARGE_SMOKE);
      if (progressCounter % 5 != 0) {
        fs.setCollides(false);
      }
      fs.runTaskTimer(ProjectKorra.plugin,0,1L);
      tasks.add(fs);
      if (progressCounter % 4 == 0) {
        player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,1,0F);
      }
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (location == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      origin=player.getLocation();
      if (GeneralMethods.getTopBlock(player.getLocation(),3,3) == null) {
        remove();
        return;
      }
      location=player.getLocation();
      direction=player.getEyeLocation().getDirection().clone().normalize();
      direction.setY(0);
    }
 else     if (location.distanceSquared(origin) > range * range) {
      remove();
      return;
    }
    Block topBlock=GeneralMethods.getTopBlock(location,2,-4);
    if (topBlock == null || (WaterAbility.isWaterbendable(player,ability,topBlock) && !isPlant(topBlock))) {
      remove();
      return;
    }
 else     if (topBlock.getType() == Material.FIRE || ElementalAbility.isPlant(topBlock)) {
      topBlock=topBlock.getLocation().add(0,-1,0).getBlock();
    }
    location.setY(topBlock.getY() + height);
    FireComboStream fs=new FireComboStream(this,direction,location.clone().add(0,-1,0),5,1,"String_Node_Str");
    fs.setDensity(0);
    fs.setSinglePoint(true);
    fs.setCollisionRadius(1.5);
    fs.setCollides(true);
    fs.runTaskTimer(ProjectKorra.plugin,0,1L);
    tasks.add(fs);
    for (double i=-180; i <= 180; i+=3) {
      Location tempLoc=location.clone();
      Vector newDir=direction.clone().multiply(radius * Math.cos(Math.toRadians(i)));
      tempLoc.add(newDir);
      tempLoc.setY(tempLoc.getY() + (radius * Math.sin(Math.toRadians(i))));
      ParticleEffect.FLAME.display(tempLoc,0,0,0,0,1);
    }
    location=location.add(direction.clone().multiply(speed));
    location.getWorld().playSound(location,Sound.BLOCK_FIRE_AMBIENT,1,1);
  }
}

Fixed version (ground truth):
@Override public void progress(){
  progressCounter++;
  for (int i=0; i < tasks.size(); i++) {
    BukkitRunnable br=tasks.get(i);
    if (br instanceof FireComboStream) {
      FireComboStream fs=(FireComboStream)br;
      if (fs.isCancelled()) {
        tasks.remove(fs);
      }
    }
  }
  if (!bPlayer.canBendIgnoreBindsCooldowns(this)) {
    remove();
    return;
  }
  if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      Vector eyeDir=player.getEyeLocation().getDirection().normalize().multiply(range);
      destination=player.getEyeLocation().add(eyeDir);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_HORSE_JUMP,0.5f,0f);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,0.5f,1f);
      for (int i=-30; i <= 30; i+=5) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),destination.clone());
        vec=GeneralMethods.rotateXZ(vec,i);
        FireComboStream fs=new FireComboStream(this,vec,player.getLocation(),range,speed,"String_Node_Str");
        fs.setSpread(0.2F);
        fs.setDensity(5);
        fs.setUseNewParticles(true);
        if (tasks.size() % 3 != 0) {
          fs.setCollides(false);
        }
        fs.runTaskTimer(ProjectKorra.plugin,0,1L);
        tasks.add(fs);
        player.getWorld().playSound(player.getLocation(),Sound.ITEM_FLINTANDSTEEL_USE,0.5f,1f);
      }
      location=tasks.get(0).getLocation();
    }
 else     if (tasks.size() == 0) {
      remove();
      return;
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      destination=player.getEyeLocation().add(range,0,range);
      player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,0.5f,0.5f);
      for (int i=0; i <= 360; i+=5) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),destination.clone());
        vec=GeneralMethods.rotateXZ(vec,i - 180);
        vec.setY(0);
        FireComboStream fs=new FireComboStream(this,vec,player.getLocation().clone().add(0,1,0),range,speed,"String_Node_Str");
        fs.setSpread(0.0F);
        fs.setDensity(1);
        fs.setUseNewParticles(true);
        if (tasks.size() % 10 != 0) {
          fs.setCollides(false);
        }
        fs.runTaskTimer(ProjectKorra.plugin,0,1L);
        tasks.add(fs);
      }
    }
    if (tasks.size() == 0) {
      remove();
      return;
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (System.currentTimeMillis() - time > 5000) {
      remove();
      return;
    }
 else     if (hasAbility(player,FireJet.class)) {
      if (firstTime) {
        if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
          remove();
          return;
        }
        bPlayer.addCooldown("String_Node_Str",cooldown);
        firstTime=false;
        float spread=0F;
        ParticleEffect.LARGE_EXPLODE.display(player.getLocation(),spread,spread,spread,0,1);
        player.getWorld().playSound(player.getLocation(),Sound.ENTITY_GENERIC_EXPLODE,15,0F);
      }
      FireJet fj=getAbility(player,FireJet.class);
      fj.setSpeed(speed);
      FireComboStream fs=new FireComboStream(this,player.getVelocity().clone().multiply(-1),player.getLocation(),3,0.5,"String_Node_Str");
      fs.setDensity(1);
      fs.setSpread(0.9F);
      fs.setUseNewParticles(true);
      fs.setCollides(false);
      fs.runTaskTimer(ProjectKorra.plugin,0,1L);
      tasks.add(fs);
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (firstTime) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      firstTime=false;
    }
 else     if (System.currentTimeMillis() - time > 5000) {
      remove();
      return;
    }
 else     if (hasAbility(player,FireJet.class)) {
      direction=player.getVelocity().clone().multiply(-1);
      FireJet fj=getAbility(player,FireJet.class);
      fj.setSpeed(speed);
      FireComboStream fs=new FireComboStream(this,direction,player.getLocation(),5,1,"String_Node_Str");
      fs.setDensity(8);
      fs.setSpread(1.0F);
      fs.setUseNewParticles(true);
      fs.setCollisionRadius(3);
      fs.setParticleEffect(ParticleEffect.LARGE_SMOKE);
      if (progressCounter % 5 != 0) {
        fs.setCollides(false);
      }
      fs.runTaskTimer(ProjectKorra.plugin,0,1L);
      tasks.add(fs);
      if (progressCounter % 4 == 0) {
        player.getWorld().playSound(player.getLocation(),Sound.ENTITY_CREEPER_PRIMED,1,0F);
      }
    }
  }
 else   if (ability.equalsIgnoreCase("String_Node_Str")) {
    if (location == null) {
      if (bPlayer.isOnCooldown("String_Node_Str") && !bPlayer.isAvatarState()) {
        remove();
        return;
      }
      bPlayer.addCooldown("String_Node_Str",cooldown);
      origin=player.getLocation();
      if (GeneralMethods.getTopBlock(player.getLocation(),3,3) == null) {
        remove();
        return;
      }
      location=player.getLocation();
      direction=player.getEyeLocation().getDirection().clone().normalize();
      direction.setY(0);
    }
 else     if (location.distanceSquared(origin) > range * range) {
      remove();
      return;
    }
    Block topBlock=GeneralMethods.getTopBlock(location,2,-4);
    if (topBlock.getType().equals(Material.SNOW)) {
      topBlock=topBlock.getLocation().add(0,-1,0).getBlock();
    }
    if (topBlock == null || (WaterAbility.isWaterbendable(player,ability,topBlock) && !isPlant(topBlock))) {
      remove();
      return;
    }
 else     if (topBlock.getType() == Material.FIRE || ElementalAbility.isPlant(topBlock)) {
      topBlock=topBlock.getLocation().add(0,-1,0).getBlock();
    }
    location.setY(topBlock.getY() + height);
    FireComboStream fs=new FireComboStream(this,direction,location.clone().add(0,-1,0),5,1,"String_Node_Str");
    fs.setDensity(0);
    fs.setSinglePoint(true);
    fs.setCollisionRadius(1.5);
    fs.setCollides(true);
    fs.runTaskTimer(ProjectKorra.plugin,0,1L);
    tasks.add(fs);
    for (double i=-180; i <= 180; i+=3) {
      Location tempLoc=location.clone();
      Vector newDir=direction.clone().multiply(radius * Math.cos(Math.toRadians(i)));
      tempLoc.add(newDir);
      tempLoc.setY(tempLoc.getY() + (radius * Math.sin(Math.toRadians(i))));
      ParticleEffect.FLAME.display(tempLoc,0,0,0,0,1);
    }
    location=location.add(direction.clone().multiply(speed));
    location.getWorld().playSound(location,Sound.BLOCK_FIRE_AMBIENT,1,1);
  }
}