Program: 63785
Project: 63785
Buggy source:
/** 
 * INTERNAL:
 */
public void openStartElement(XPathFragment xPathFragment,NamespaceResolver namespaceResolver){
  try {
    Level newLevel=null;
    Level position=null;
    if (null == level) {
      level=new Level(true,true);
    }
 else {
      position=level;
      level=new Level(true,true,level);
      if (position.isFirst()) {
        position.setFirst(false);
      }
 else {
        writer.write(',');
      }
    }
    if (xPathFragment.nameIsText()) {
      if (position != null && position.isCollection() && position.isEmptyCollection()) {
        writer.write('[');
        writer.write(' ');
        position.setEmptyCollection(false);
        position.setNeedToOpenComplex(false);
        numberOfTabs++;
        return;
      }
    }
    this.addPositionalNodes(xPathFragment,namespaceResolver);
    if (position.isNeedToOpenComplex()) {
      writer.write('{');
      position.setNeedToOpenComplex(false);
      position.setNeedToCloseComplex(true);
    }
    if (!isLastEventText) {
      if (position.isCollection() && !position.isEmptyCollection()) {
        writer.write(' ');
      }
 else {
        writer.writeCR();
        for (int x=0; x < numberOfTabs; x++) {
          writeValue(tab(),false);
        }
      }
    }
    if (!(position.isCollection() && !position.isEmptyCollection())) {
      super.writeKey(xPathFragment);
      if (position.isCollection() && position.isEmptyCollection()) {
        writer.write('[');
        writer.write(' ');
        position.setEmptyCollection(false);
      }
    }
    numberOfTabs++;
    isLastEventText=false;
    charactersAllowed=true;
  }
 catch (  IOException e) {
    throw XMLMarshalException.marshalException(e);
  }
}

Fixed version (ground truth):
/** 
 * INTERNAL:
 */
public void openStartElement(XPathFragment xPathFragment,NamespaceResolver namespaceResolver){
  try {
    if (level.isFirst()) {
      level.setFirst(false);
    }
 else {
      writer.write(',');
    }
    if (xPathFragment.nameIsText()) {
      if (level.isCollection() && level.isEmptyCollection()) {
        writer.write('[');
        writer.write(' ');
        level.setEmptyCollection(false);
        level.setNeedToOpenComplex(false);
        level=new Level(true,true,level);
        numberOfTabs++;
        return;
      }
    }
    if (level.isNeedToOpenComplex()) {
      writer.write('{');
      level.setNeedToOpenComplex(false);
      level.setNeedToCloseComplex(true);
    }
    if (!isLastEventText) {
      if (level.isCollection() && !level.isEmptyCollection()) {
        writer.write(' ');
      }
 else {
        writer.writeCR();
        for (int x=0; x < numberOfTabs; x++) {
          writeValue(tab(),false);
        }
      }
    }
    if (!(level.isCollection() && !level.isEmptyCollection())) {
      super.writeKey(xPathFragment);
      if (level.isCollection() && level.isEmptyCollection()) {
        writer.write('[');
        writer.write(' ');
        level.setEmptyCollection(false);
      }
    }
    numberOfTabs++;
    isLastEventText=false;
    charactersAllowed=true;
    level=new Level(true,true,level);
  }
 catch (  IOException e) {
    throw XMLMarshalException.marshalException(e);
  }
}