issue with Xm effect L about mikmod HOT 2 CLOSED

/********************************************************************/
        /// <summary>
        /// Effect L: Set envelope position
        /// </summary>
/********************************************************************/
        private int DoXmEffectL(ushort tick, ModuleFlag flags, Mp_Control a, Module mod, short channel)
        {
            byte dat = uniTrk.UniGetByte();

            if ((tick == 0) && (a.Main.I != null))
            {
                Instrument i = a.Main.I;

                Mp_Voice aOut;
                if ((aOut = a.Slave) != null)
                {
                    if (aOut.VEnv.Env != null)
                        SetEnvelopePosition(ref aOut.VEnv, i.VolEnv, dat);

                    if (aOut.PEnv.Env != null)
                    {
                        // Because of a bug in FastTracker II, only the panning envelope
                        // position is set if the volume sustain flag is set. Other players
                        // may set the panning all the time
                        if (((mod.Flags & ModuleFlag.Ft2Quirks) == 0) || ((i.VolFlg & EnvelopeFlag.Sustain) != 0))
                            SetEnvelopePosition(ref aOut.PEnv, i.PanEnv, dat);
                    }
                }
            }

            return 0;
        }

/********************************************************************/
        /// <summary>
        /// Set the envelope tick to the position given
        /// </summary>
/********************************************************************/
        private void SetEnvelopePosition(ref EnvPr t, EnvPt[] p, short pos)
        {
            if (t.Pts > 0)
            {
                bool found = false;

                for (ushort i = 0; i < t.Pts - 1; i++)
                {
                    if ((pos >= p[i].Pos) && (pos < p[i + 1].Pos))
                    {
                        t.A = i;
                        t.B = (ushort)(i + 1);
                        t.P = pos;
                        found = true;
                        break;
                    }
                }

                // If position is after the last envelope point, just set
                // it to the last one
                if (!found)
                {
                    t.A = (ushort)(t.Pts - 1);
                    t.B = t.Pts;
                    t.P = p[t.A].Pos;
                }
            }
        }