Program: 177324
Project: 177324
Buggy source:
public void doInput(){
  if (activePlayer == null) {
    return;
  }
  if (Mouse.isGrabbed()) {
    Transform ts=activePlayer.getTransform().getTransform();
    float pitch=ts.getRotation().getPitch();
    float yaw=ts.getRotation().getYaw();
    float mouseDX=-Mouse.getDX() * 0.16f;
    float mouseDY=Mouse.getDY() * 0.16f;
    if (yaw + mouseDX >= 360)     yaw+=mouseDX - 360;
 else     if (yaw + mouseDX < 0)     yaw+=mouseDX + 360;
 else     yaw+=mouseDX;
    if (pitch + mouseDY >= -80 && pitch + mouseDY <= 80)     pitch+=mouseDY;
 else     if (pitch + mouseDY < -80)     pitch=-80;
 else     if (pitch + mouseDY > 80)     pitch=80;
    ts.setRotation(MathHelper.rotation(pitch,yaw,ts.getRotation().getRoll()));
    activePlayer.getTransform().setTransform(ts);
  }
  boolean keyUp=Keyboard.isKeyDown(Keyboard.KEY_UP) || Keyboard.isKeyDown(Keyboard.KEY_Z);
  boolean keyDown=Keyboard.isKeyDown(Keyboard.KEY_DOWN) || Keyboard.isKeyDown(Keyboard.KEY_S);
  boolean keyLeft=Keyboard.isKeyDown(Keyboard.KEY_LEFT) || Keyboard.isKeyDown(Keyboard.KEY_Q);
  boolean keyRight=Keyboard.isKeyDown(Keyboard.KEY_RIGHT) || Keyboard.isKeyDown(Keyboard.KEY_D);
  boolean flyUp=Keyboard.isKeyDown(Keyboard.KEY_SPACE);
  boolean flyDown=Keyboard.isKeyDown(Keyboard.KEY_LSHIFT);
  if (keyUp && !keyLeft && !keyRight&& !keyDown) {
    activePlayer.getTransform().setPosition(activePlayer.getTransform().getPosition().add(activePlayer.getTransform().getTransform().forwardVector()));
  }
  if (keyDown && !keyUp && !keyLeft&& !keyRight) {
    activePlayer.getTransform().setPosition(activePlayer.getTransform().getPosition().subtract(activePlayer.getTransform().getTransform().forwardVector()));
  }
  if (keyLeft && !keyRight && !keyUp&& !keyDown) {
    activePlayer.getTransform().setPosition(activePlayer.getTransform().getPosition().add(activePlayer.getTransform().getTransform().rightVector()));
  }
  if (keyRight && !keyLeft && !keyUp&& !keyDown) {
    activePlayer.getTransform().setPosition(activePlayer.getTransform().getPosition().subtract(activePlayer.getTransform().getTransform().rightVector()));
  }
}

Fixed version (ground truth):
public void doInput(){
  if (activePlayer == null) {
    return;
  }
  if (Mouse.isGrabbed()) {
    Transform ts=activePlayer.getTransform().getTransform();
    float pitch=ts.getRotation().getPitch();
    float yaw=ts.getRotation().getYaw();
    float mouseDX=-Mouse.getDX() * 0.16f;
    float mouseDY=Mouse.getDY() * 0.16f;
    if (yaw + mouseDX >= 360)     yaw+=mouseDX - 360;
 else     if (yaw + mouseDX < 0)     yaw+=mouseDX + 360;
 else     yaw+=mouseDX;
    if (pitch + mouseDY >= -80 && pitch + mouseDY <= 80)     pitch+=mouseDY;
 else     if (pitch + mouseDY < -80)     pitch=-80;
 else     if (pitch + mouseDY > 80)     pitch=80;
    ts.setRotation(MathHelper.rotation(pitch,yaw,ts.getRotation().getRoll()));
    activePlayer.getTransform().setTransform(ts);
  }
  boolean keyUp=Keyboard.isKeyDown(Keyboard.KEY_UP) || Keyboard.isKeyDown(Keyboard.KEY_Z);
  boolean keyDown=Keyboard.isKeyDown(Keyboard.KEY_DOWN) || Keyboard.isKeyDown(Keyboard.KEY_S);
  boolean keyLeft=Keyboard.isKeyDown(Keyboard.KEY_LEFT) || Keyboard.isKeyDown(Keyboard.KEY_Q);
  boolean keyRight=Keyboard.isKeyDown(Keyboard.KEY_RIGHT) || Keyboard.isKeyDown(Keyboard.KEY_D);
  boolean flyUp=Keyboard.isKeyDown(Keyboard.KEY_SPACE);
  boolean flyDown=Keyboard.isKeyDown(Keyboard.KEY_LSHIFT);
  Point point=new Point(Point.ONE,activePlayer.getWorld());
  if (keyUp) {
    point=point.multiply(activePlayer.getTransform().getTransform().forwardVector());
  }
  if (keyDown) {
    point=point.multiply(activePlayer.getTransform().getTransform().forwardVector().multiply(-1));
  }
  if (keyLeft) {
    point=point.multiply(activePlayer.getTransform().getTransform().rightVector());
  }
  if (keyRight) {
    point=point.multiply(activePlayer.getTransform().getTransform().rightVector().multiply(-1));
  }
  if (flyUp) {
    point=point.multiply(activePlayer.getTransform().getTransform().upVector());
  }
  if (flyDown) {
    point=point.multiply(activePlayer.getTransform().getTransform().upVector().multiply(-1));
  }
  if (keyUp || keyDown || keyLeft|| keyRight|| flyUp|| flyDown) {
    System.out.println("String_Node_Str" + point.getX() + "String_Node_Str"+ point.getY()+ "String_Node_Str"+ point.getZ());
    System.out.println("String_Node_Str" + activePlayer.getTransform().getPosition().getX() + "String_Node_Str"+ activePlayer.getTransform().getPosition().getY()+ "String_Node_Str"+ activePlayer.getTransform().getPosition().getZ());
    activePlayer.getTransform().setPosition(activePlayer.getTransform().getPosition().add(point));
  }
}