Program: 187474
Project: 187474
Buggy source:
public void g(float motionSideways,float motionForward){
  if (!hasRider || this.passenger == null) {
    super.g(motionSideways,motionForward);
    return;
  }
  if (rideSkill == null) {
    passenger.mount(null);
    return;
  }
  this.lastYaw=(this.yaw=this.passenger.yaw);
  this.pitch=this.passenger.pitch * 0.5F;
  setYawPitch(this.yaw,this.pitch);
  this.aI=(this.aG=this.yaw);
  motionSideways=((EntityLiving)this.passenger).aZ * 0.5F;
  motionForward=((EntityLiving)this.passenger).ba;
  if (motionForward <= 0.0F) {
    motionForward*=0.25F;
  }
  motionSideways*=0.85F;
  float speed=0.22222F;
  double jumpHeight=0.3D;
  Ride rideSkill=myPet.getSkills().get(RideImpl.class);
  if (rideSkill != null) {
    speed*=1F + (rideSkill.getSpeedIncrease().getValue() / 100F);
    jumpHeight=rideSkill.getJumpHeight().getValue().doubleValue() * 0.18D;
  }
  if (Configuration.HungerSystem.USE_HUNGER_SYSTEM && Configuration.HungerSystem.AFFECT_RIDE_SPEED) {
    double factor=Math.log10(myPet.getSaturation()) / 2;
    speed*=factor;
    jumpHeight*=factor;
  }
  ride(motionSideways,motionForward,speed);
  if (jump != null && this.passenger != null) {
    boolean doJump=false;
    try {
      doJump=jump.getBoolean(passenger);
    }
 catch (    IllegalAccessException ignored) {
    }
    if (doJump) {
      if (onGround) {
        jumpHeight=new BigDecimal(jumpHeight).setScale(1,BigDecimal.ROUND_HALF_UP).doubleValue();
        String jumpHeightString=JumpHelper.JUMP_FORMAT.format(jumpHeight);
        Double jumpVelocity=JumpHelper.JUMP_MAP.get(jumpHeightString);
        jumpVelocity=jumpVelocity == null ? 0.44161199999510264 : jumpVelocity;
        this.motY=jumpVelocity;
      }
    }
  }
  if (Configuration.HungerSystem.USE_HUNGER_SYSTEM && Configuration.Skilltree.Skill.Ride.HUNGER_PER_METER > 0) {
    double dX=locX - lastX;
    double dY=Math.max(0,locY - lastY);
    double dZ=locZ - lastZ;
    if (dX != 0 || dY != 0 || dZ != 0) {
      double distance=Math.sqrt(dX * dX + dY * dY + dZ * dZ);
      myPet.decreaseSaturation(Configuration.Skilltree.Skill.Ride.HUNGER_PER_METER * distance);
    }
  }
}

Fixed version (ground truth):
public void g(float motionSideways,float motionForward){
  if (!hasRider || this.passenger == null) {
    super.g(motionSideways,motionForward);
    return;
  }
  this.lastYaw=(this.yaw=this.passenger.yaw);
  this.pitch=this.passenger.pitch * 0.5F;
  setYawPitch(this.yaw,this.pitch);
  this.aI=(this.aG=this.yaw);
  motionSideways=((EntityLiving)this.passenger).aZ * 0.5F;
  motionForward=((EntityLiving)this.passenger).ba;
  if (motionForward <= 0.0F) {
    motionForward*=0.25F;
  }
  motionSideways*=0.85F;
  float speed=0.22222F;
  double jumpHeight=0.3D;
  Ride rideSkill=myPet.getSkills().get(RideImpl.class);
  if (rideSkill != null) {
    speed*=1F + (rideSkill.getSpeedIncrease().getValue() / 100F);
    jumpHeight=rideSkill.getJumpHeight().getValue().doubleValue() * 0.18D;
  }
  if (Configuration.HungerSystem.USE_HUNGER_SYSTEM && Configuration.HungerSystem.AFFECT_RIDE_SPEED) {
    double factor=Math.log10(myPet.getSaturation()) / 2;
    speed*=factor;
    jumpHeight*=factor;
  }
  ride(motionSideways,motionForward,speed);
  if (jump != null && this.passenger != null) {
    boolean doJump=false;
    try {
      doJump=jump.getBoolean(passenger);
    }
 catch (    IllegalAccessException ignored) {
    }
    if (doJump) {
      if (onGround) {
        jumpHeight=new BigDecimal(jumpHeight).setScale(1,BigDecimal.ROUND_HALF_UP).doubleValue();
        String jumpHeightString=JumpHelper.JUMP_FORMAT.format(jumpHeight);
        Double jumpVelocity=JumpHelper.JUMP_MAP.get(jumpHeightString);
        jumpVelocity=jumpVelocity == null ? 0.44161199999510264 : jumpVelocity;
        this.motY=jumpVelocity;
      }
    }
  }
  if (Configuration.HungerSystem.USE_HUNGER_SYSTEM && Configuration.Skilltree.Skill.Ride.HUNGER_PER_METER > 0) {
    double dX=locX - lastX;
    double dY=Math.max(0,locY - lastY);
    double dZ=locZ - lastZ;
    if (dX != 0 || dY != 0 || dZ != 0) {
      double distance=Math.sqrt(dX * dX + dY * dY + dZ * dZ);
      myPet.decreaseSaturation(Configuration.Skilltree.Skill.Ride.HUNGER_PER_METER * distance);
    }
  }
}