Program: 9483
Project: 9483
Buggy source:
/** 
 * Render message differently. If abort, then prefix stack trace with feedback request. If the actual message is empty, then use toString on the whole. Prefix message part with file:line; If it has context, suffix message with context.
 * @param message the IMessage to render
 * @return String rendering IMessage (never null)
 */
protected String render(IMessage message){
  StringBuffer sb=new StringBuffer();
  String text=message.getMessage();
  if (text.equals(AbortException.NO_MESSAGE_TEXT)) {
    text=null;
  }
  boolean toString=(LangUtil.isEmpty(text));
  if (toString) {
    text=message.toString();
  }
  ISourceLocation loc=message.getSourceLocation();
  String context=null;
  if (null != loc) {
    File file=loc.getSourceFile();
    if (null != file) {
      String name=file.getName();
      if (!toString || (-1 == text.indexOf(name))) {
        sb.append(FileUtil.getBestPath(file));
        if (loc.getLine() > 0) {
          sb.append("String_Node_Str" + loc.getLine());
        }
        int col=loc.getColumn();
        if (0 < col) {
          sb.append("String_Node_Str" + col);
        }
        sb.append("String_Node_Str");
      }
    }
    context=loc.getContext();
  }
  if (message.getKind() == IMessage.ERROR) {
    sb.append("String_Node_Str");
  }
 else   if (message.getKind() == IMessage.WARNING) {
    sb.append("String_Node_Str");
  }
  sb.append(text);
  if (null != context) {
    sb.append(LangUtil.EOL);
    sb.append(context);
  }
  Throwable thrown=message.getThrown();
  if (null != thrown) {
    sb.append(LangUtil.EOL);
    sb.append(Main.renderExceptionForUser(thrown));
  }
  if (message.getExtraSourceLocations().isEmpty()) {
    return sb.toString();
  }
 else {
    return MessageUtil.addExtraSourceLocations(message,sb.toString());
  }
}

Fixed version (ground truth):
/** 
 * Render message differently. If abort, then prefix stack trace with feedback request. If the actual message is empty, then use toString on the whole. Prefix message part with file:line; If it has context, suffix message with context.
 * @param message the IMessage to render
 * @return String rendering IMessage (never null)
 */
protected String render(IMessage message){
  StringBuffer sb=new StringBuffer();
  String text=message.getMessage();
  if (text.equals(AbortException.NO_MESSAGE_TEXT)) {
    text=null;
  }
  boolean toString=(LangUtil.isEmpty(text));
  if (toString) {
    text=message.toString();
  }
  ISourceLocation loc=message.getSourceLocation();
  String context=null;
  if (null != loc) {
    File file=loc.getSourceFile();
    if (null != file) {
      String name=file.getName();
      if (!toString || (-1 == text.indexOf(name))) {
        sb.append(FileUtil.getBestPath(file));
        if (loc.getLine() > 0) {
          sb.append("String_Node_Str" + loc.getLine());
        }
        int col=loc.getColumn();
        if (0 < col) {
          sb.append("String_Node_Str" + col);
        }
        sb.append("String_Node_Str");
      }
    }
    context=loc.getContext();
  }
  if (message.getKind() == IMessage.ERROR) {
    sb.append("String_Node_Str");
  }
 else   if (message.getKind() == IMessage.WARNING) {
    sb.append("String_Node_Str");
  }
  sb.append(text);
  if (null != context) {
    sb.append(LangUtil.EOL);
    sb.append(context);
  }
  String details=message.getDetails();
  if (details != null) {
    sb.append(LangUtil.EOL);
    sb.append('\t');
    sb.append(details);
  }
  Throwable thrown=message.getThrown();
  if (null != thrown) {
    sb.append(LangUtil.EOL);
    sb.append(Main.renderExceptionForUser(thrown));
  }
  if (message.getExtraSourceLocations().isEmpty()) {
    return sb.toString();
  }
 else {
    return MessageUtil.addExtraSourceLocations(message,sb.toString());
  }
}