Program: 91736
Project: 91736
Buggy source:
/** 
 * Decodes the given MGRS reference into a position. The Coordinate Reference System (CRS) associated to the returned position depends on the given reference.
 * @param reference  MGRS string to decode.
 * @return a new position with the longitude at ordinate 0 and latitude at ordinate 1.
 * @throws TransformException if an error occurred while parsing the given string.
 */
public DirectPosition decode(final CharSequence reference) throws TransformException {
  ArgumentChecks.ensureNonNull("String_Node_Str",reference);
  final int end=CharSequences.skipTrailingWhitespaces(reference,0,reference.length());
  final int base=CharSequences.skipLeadingWhitespaces(reference,0,end);
  int i=endOfDigits(reference,base,end);
  final int zone=parseInt(reference,base,i,Resources.Keys.IllegalUTMZone_1);
  if (zone < 1 || zone > 60) {
    throw new GazetteerException(Resources.format(Resources.Keys.IllegalUTMZone_1,zone));
  }
  double φs=Double.NaN;
  int col=1, row=0;
  boolean hasSquareIdentification=true;
  for (int part=1; part <= 3; part++) {
    if (part == 2 && i >= end) {
      hasSquareIdentification=false;
      break;
    }
    i=nextComponent(reference,base,i,end);
    int c=Character.codePointAt(reference,i);
    final int ni=i + Character.charCount(c);
    if (c < 'A' || c > 'Z') {
      if (c >= 'a' && c <= 'z') {
        c-=('a' - 'A');
      }
 else {
        final short key;
        final CharSequence token;
        if (part == 1) {
          key=Resources.Keys.IllegalLatitudeBand_1;
          token=reference.subSequence(i,ni);
        }
 else {
          key=Resources.Keys.IllegalSquareIdentification_1;
          token=CharSequences.token(reference,i);
        }
        throw new GazetteerException(Resources.format(key,token));
      }
    }
    if (c >= EXCLUDE_O)     c--;
    if (c >= EXCLUDE_I)     c--;
switch (part) {
case 1:
{
        φs=(c - 'C') * LATITUDE_BAND_HEIGHT + TransverseMercator.Zoner.SOUTH_BOUNDS;
        break;
      }
case 2:
{
switch (zone % 3) {
case 1:
        col=c - ('A' - 1);
      break;
case 2:
    col=c - ('J' - 2);
  break;
case 0:
col=c - ('S' - 3);
break;
}
break;
}
case 3:
{
if ((zone & 1) != 0) {
row=c - 'A';
}
 else {
row=c - 'F';
if (row < 0) {
row+=GRID_ROW_COUNT;
}
}
break;
}
}
i=ni;
}
final double λ0=TransverseMercator.Zoner.UTM.centralMeridian(zone);
final ProjectedCRS crs=datum.universal(Math.signum(φs),λ0);
final DirectPosition2D position=new DirectPosition2D(φs,λ0);
final MathTransform projection=crs.getConversionFromBase().getMathTransform();
final double northing=Math.floor(projection.transform(position,position).getOrdinate(1) / (GRID_SQUARE_SIZE * GRID_ROW_COUNT)) * (GRID_SQUARE_SIZE * GRID_ROW_COUNT);
position.setCoordinateReferenceSystem(crs);
position.x=col * GRID_SQUARE_SIZE;
position.y=row * GRID_SQUARE_SIZE + northing;
if (i < end) {
i=nextComponent(reference,base,i,end);
int s=endOfDigits(reference,i,end);
final double x, y;
if (s >= end) {
final int length=s - i;
final int h=i + (length >>> 1);
if ((length & 1) != 0) {
throw new GazetteerException(Resources.format(Resources.Keys.MismatchedResolution_2,reference.subSequence(i,h),reference.subSequence(h,s)));
}
x=parseCoordinate(reference,i,h);
y=parseCoordinate(reference,h,s);
}
 else {
x=parseCoordinate(reference,i,s);
i=nextComponent(reference,base,s,end);
s=endOfDigits(reference,i,end);
y=parseCoordinate(reference,i,s);
if (s < end) {
throw new GazetteerException(Errors.format(Errors.Keys.UnexpectedCharactersAfter_2,reference.subSequence(base,s),CharSequences.trimWhitespaces(reference,s,end)));
}
}
position.x+=x;
position.y+=y;
}
if (hasSquareIdentification) {
final MathTransform inverse=projection.inverse();
DirectPosition check=inverse.transform(position,null);
double φ=check.getOrdinate(0);
double delta=truncateLastLatitudeBand(φ) - φs;
if ((φs >= 0) ? (delta < 0) : (delta > LATITUDE_BAND_HEIGHT)) {
position.y+=Math.signum(φs) * (GRID_SQUARE_SIZE * GRID_ROW_COUNT);
check=inverse.transform(position,check);
delta=truncateLastLatitudeBand(φ=check.getOrdinate(0)) - φs;
}
final int actual=TransverseMercator.Zoner.UTM.zone(φ,check.getOrdinate(1));
final boolean isHighLat=Math.abs(φ) >= TransverseMercator.Zoner.NORWAY_BOUNDS;
final boolean isZoneValid=Math.abs(actual - zone) <= (isHighLat ? 1 : 0);
final boolean isBandValid=delta >= 0 && delta <= LATITUDE_BAND_HEIGHT;
if (!isBandValid || !isZoneValid) {
final String gzd;
try {
gzd=encoder(crs).encode(this,position,"String_Node_Str",0);
}
 catch (IllegalArgumentException|FactoryException e) {
throw new GazetteerException(e.getLocalizedMessage(),e);
}
final CharSequence ref=reference.subSequence(base,end);
throw new ReferenceVerifyException(Resources.format(Resources.Keys.InconsistentWithGZD_2,ref,gzd));
}
}
return position;
}

Fixed version (ground truth):
/** 
 * Decodes the given MGRS reference into a position. The Coordinate Reference System (CRS) associated to the returned position depends on the given reference.
 * @param reference  MGRS string to decode.
 * @return a new position with the longitude at ordinate 0 and latitude at ordinate 1.
 * @throws TransformException if an error occurred while parsing the given string.
 */
public DirectPosition decode(final CharSequence reference) throws TransformException {
  ArgumentChecks.ensureNonNull("String_Node_Str",reference);
  final int end=CharSequences.skipTrailingWhitespaces(reference,0,reference.length());
  final int base=CharSequences.skipLeadingWhitespaces(reference,0,end);
  int i=endOfDigits(reference,base,end);
  final int zone=parseInt(reference,base,i,Resources.Keys.IllegalUTMZone_1);
  if (zone < 1 || zone > 60) {
    throw new GazetteerException(Resources.format(Resources.Keys.IllegalUTMZone_1,zone));
  }
  double φs=Double.NaN;
  int col=1, row=0;
  boolean hasSquareIdentification=true;
  for (int part=1; part <= 3; part++) {
    if (part == 2 && i >= end) {
      hasSquareIdentification=false;
      break;
    }
    i=nextComponent(reference,base,i,end);
    int c=Character.codePointAt(reference,i);
    final int ni=i + Character.charCount(c);
    if (c < 'A' || c > 'Z') {
      if (c >= 'a' && c <= 'z') {
        c-=('a' - 'A');
      }
 else {
        final short key;
        final CharSequence token;
        if (part == 1) {
          key=Resources.Keys.IllegalLatitudeBand_1;
          token=reference.subSequence(i,ni);
        }
 else {
          key=Resources.Keys.IllegalSquareIdentification_1;
          token=CharSequences.token(reference,i);
        }
        throw new GazetteerException(Resources.format(key,token));
      }
    }
    if (c >= EXCLUDE_O)     c--;
    if (c >= EXCLUDE_I)     c--;
switch (part) {
case 1:
{
        φs=(c - 'C') * LATITUDE_BAND_HEIGHT + TransverseMercator.Zoner.SOUTH_BOUNDS;
        break;
      }
case 2:
{
switch (zone % 3) {
case 1:
        col=c - ('A' - 1);
      break;
case 2:
    col=c - ('J' - 2);
  break;
case 0:
col=c - ('S' - 3);
break;
}
break;
}
case 3:
{
if ((zone & 1) != 0) {
row=c - 'A';
}
 else {
row=c - 'F';
if (row < 0) {
row+=GRID_ROW_COUNT;
}
}
break;
}
}
i=ni;
}
final double λ0=TransverseMercator.Zoner.UTM.centralMeridian(zone);
final ProjectedCRS crs=datum.universal(Math.signum(φs),λ0);
final DirectPosition2D position=new DirectPosition2D(φs,λ0);
final MathTransform projection=crs.getConversionFromBase().getMathTransform();
double northing=projection.transform(position,position).getOrdinate(1) / (GRID_SQUARE_SIZE * GRID_ROW_COUNT);
northing=(φs >= 0) ? Math.floor(northing) : Math.ceil(northing);
northing*=(GRID_SQUARE_SIZE * GRID_ROW_COUNT);
position.setCoordinateReferenceSystem(crs);
position.x=col * GRID_SQUARE_SIZE;
position.y=row * GRID_SQUARE_SIZE + northing;
if (i < end) {
i=nextComponent(reference,base,i,end);
int s=endOfDigits(reference,i,end);
final double x, y;
if (s >= end) {
final int length=s - i;
final int h=i + (length >>> 1);
if ((length & 1) != 0) {
throw new GazetteerException(Resources.format(Resources.Keys.MismatchedResolution_2,reference.subSequence(i,h),reference.subSequence(h,s)));
}
x=parseCoordinate(reference,i,h);
y=parseCoordinate(reference,h,s);
}
 else {
x=parseCoordinate(reference,i,s);
i=nextComponent(reference,base,s,end);
s=endOfDigits(reference,i,end);
y=parseCoordinate(reference,i,s);
if (s < end) {
throw new GazetteerException(Errors.format(Errors.Keys.UnexpectedCharactersAfter_2,reference.subSequence(base,s),CharSequences.trimWhitespaces(reference,s,end)));
}
}
position.x+=x;
position.y+=y;
}
if (hasSquareIdentification) {
final MathTransform inverse=projection.inverse();
DirectPosition check=inverse.transform(position,null);
double φ=check.getOrdinate(0);
double delta=truncateLastLatitudeBand(φ) - φs;
if ((φs >= 0) ? (delta < 0) : (delta > LATITUDE_BAND_HEIGHT)) {
position.y+=Math.signum(φs) * (GRID_SQUARE_SIZE * GRID_ROW_COUNT);
check=inverse.transform(position,check);
delta=truncateLastLatitudeBand(φ=check.getOrdinate(0)) - φs;
}
final int actual=TransverseMercator.Zoner.UTM.zone(φ,check.getOrdinate(1));
final boolean isHighLat=Math.abs(φ) >= TransverseMercator.Zoner.NORWAY_BOUNDS;
final boolean isZoneValid=Math.abs(actual - zone) <= (isHighLat ? 1 : 0);
final boolean isBandValid=delta >= 0 && delta <= LATITUDE_BAND_HEIGHT;
if (!isBandValid || !isZoneValid) {
final String gzd;
try {
gzd=encoder(crs).encode(this,position,"String_Node_Str",0);
}
 catch (IllegalArgumentException|FactoryException e) {
throw new GazetteerException(e.getLocalizedMessage(),e);
}
final CharSequence ref=reference.subSequence(base,end);
throw new ReferenceVerifyException(Resources.format(Resources.Keys.InconsistentWithGZD_2,ref,gzd));
}
}
return position;
}