Program: 91726
Project: 91726
Buggy source:
/** 
 * Implementation of   {@link #tryAdvance(Consumer)} and {@link #forEachRemaining(Consumer)}. The   {@code all} argument specifies whether this method is invoked for a single element or for all remaining ones.
 */
private boolean advance(final Consumer<? super String> action,final boolean all){
  final int digits=digits();
  final String separator=getSeparator();
  if (normalized == null) {
    normalized=new DirectPosition2D();
  }
  boolean found=false;
  try {
    do {
      if (pending != null) {
        action.accept(pending);
        pending=null;
        found=true;
        continue;
      }
      cell.setRect(gridX,gridY,step,step);
      if (areaOfInterest.intersects(Shapes2D.transform(gridToAOI,cell,cell))) {
        int x=gridX;
        if (x < xCenter) {
          x+=step - 1;
        }
        normalized.setOrdinate(0,x);
        normalized.setOrdinate(1,gridY);
        String ref=encoder.encode(this,normalized,false,separator,digits);
        if (ref != null) {
          final char previous=latitudeBand;
          latitudeBand=encoder.latitudeBand;
          if (latitudeBand != previous && previous != 0) {
            pending=ref;
            normalized.setOrdinate(1,gridY - 1);
            ref=encoder.encode(this,normalized,false,separator,digits);
            if (ref == null || encoder.latitudeBand == previous) {
              ref=pending;
              pending=null;
            }
          }
          action.accept(ref);
          found=true;
        }
      }
 else       if (optimize) {
        gridY=yEnd;
      }
      final boolean end=downward ? ((gridY-=step) <= yEnd) : ((gridY+=step) >= yEnd);
      if (end) {
        gridY=yStart;
        latitudeBand=0;
        if ((gridX+=step) >= xEnd) {
          break;
        }
      }
    }
 while (all || !found);
  }
 catch (  FactoryException|TransformException e) {
    throw (ArithmeticException)new ArithmeticException(Errors.format(Errors.Keys.OutsideDomainOfValidity)).initCause(e);
  }
  return found;
}

Fixed version (ground truth):
/** 
 * Implementation of   {@link #tryAdvance(Consumer)} and {@link #forEachRemaining(Consumer)}. The   {@code all} argument specifies whether this method is invoked for a single element or for all remaining ones.
 */
private boolean advance(final Consumer<? super String> action,final boolean all){
  final int digits=digits();
  final String separator=getSeparator();
  if (normalized == null) {
    normalized=new DirectPosition2D();
  }
  boolean found=false;
  try {
    do {
      if (pending != null) {
        action.accept(pending);
        pending=null;
        found=true;
        continue;
      }
      cell.setRect(gridX,gridY,step,step);
      if (areaOfInterest.intersects(Shapes2D.transform(gridToAOI,cell,cell))) {
        int x=gridX;
        if (x < xCenter) {
          x+=step - 1;
        }
        normalized.setOrdinate(0,x);
        normalized.setOrdinate(1,gridY);
        String ref=encoder.encode(this,normalized,false,separator,digits);
        if (ref != null) {
          char previous=latitudeBand;
          latitudeBand=encoder.latitudeBand;
          if (latitudeBand != previous && previous != 0) {
            pending=ref;
            int y=gridY - 1;
            if (downward) {
              y+=step;
              previous=latitudeBand;
            }
            normalized.setOrdinate(1,y);
            ref=encoder.encode(this,normalized,false,separator,digits);
            if (ref == null || encoder.latitudeBand == previous) {
              ref=pending;
              pending=null;
            }
          }
          action.accept(ref);
          found=true;
        }
      }
 else       if (optimize) {
        gridY=yEnd;
      }
      final boolean end=downward ? ((gridY-=step) <= yEnd) : ((gridY+=step) >= yEnd);
      if (end) {
        gridY=yStart;
        latitudeBand=0;
        if ((gridX+=step) >= xEnd) {
          break;
        }
      }
    }
 while (all || !found);
  }
 catch (  FactoryException|TransformException e) {
    throw (ArithmeticException)new ArithmeticException(Errors.format(Errors.Keys.OutsideDomainOfValidity)).initCause(e);
  }
  return found;
}