Program: 51125
Project: 51125
Buggy source:
private void parseName(CharacterIterator ci){
  char c=consumeWhiteSpace(ci);
  StringBuffer nameBuffer=new StringBuffer();
  if (Character.isLetterOrDigit(c) || c == '_') {
    nameBuffer.append(c);
  }
 else {
    throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
  }
  String nameRegexString="String_Node_Str";
  while (true) {
    c=ci.next();
    if (Character.isLetterOrDigit(c) || c == '_' || c == '-' || c == '.') {
      nameBuffer.append(c);
    }
 else     if (c == ':') {
      nameRegexString=parseRegex(ci);
      break;
    }
 else     if (c == '}') {
      break;
    }
 else     if (c == ' ') {
      c=consumeWhiteSpace(ci);
      if (c == ':') {
        nameRegexString=parseRegex(ci);
        break;
      }
 else       if (c == '}') {
        break;
      }
 else {
        throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
      }
    }
 else {
      throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
    }
  }
  String name=nameBuffer.toString();
  names.add(name);
  try {
    if (nameRegexString.length() > 0)     numOfExplicitRegexes++;
    Pattern namePattern=(nameRegexString.length() == 0) ? TEMPLATE_VALUE_PATTERN : Pattern.compile(nameRegexString);
    if (nameToPattern.containsKey(name)) {
      if (!nameToPattern.get(name).equals(namePattern)) {
        throw new IllegalArgumentException("String_Node_Str" + name + "String_Node_Str"+ "String_Node_Str");
      }
    }
 else {
      nameToPattern.put(name,namePattern);
    }
    Matcher m=namePattern.matcher("String_Node_Str");
    int g=m.groupCount();
    groupCounts.add(g + 1);
    regex.append('(').append(namePattern).append(')');
    normalizedTemplate.append('{').append(name).append('}');
  }
 catch (  PatternSyntaxException ex) {
    throw new IllegalArgumentException("String_Node_Str" + nameRegexString + "String_Node_Str"+ name+ "String_Node_Str",ex);
  }
}

Fixed version (ground truth):
private void parseName(final CharacterIterator ci){
  char c=consumeWhiteSpace(ci);
  StringBuilder nameBuffer=new StringBuilder();
  if (Character.isLetterOrDigit(c) || c == '_') {
    nameBuffer.append(c);
  }
 else {
    throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
  }
  String nameRegexString="String_Node_Str";
  while (true) {
    c=ci.next();
    if (Character.isLetterOrDigit(c) || c == '_' || c == '-' || c == '.') {
      nameBuffer.append(c);
    }
 else     if (c == ':') {
      nameRegexString=parseRegex(ci);
      break;
    }
 else     if (c == '}') {
      break;
    }
 else     if (c == ' ') {
      c=consumeWhiteSpace(ci);
      if (c == ':') {
        nameRegexString=parseRegex(ci);
        break;
      }
 else       if (c == '}') {
        break;
      }
 else {
        throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
      }
    }
 else {
      throw new IllegalArgumentException("String_Node_Str" + c + "String_Node_Str"+ ci.pos()+ "String_Node_Str");
    }
  }
  String name=nameBuffer.toString();
  names.add(name);
  try {
    if (nameRegexString.length() > 0) {
      numOfExplicitRegexes++;
    }
    Pattern namePattern=(nameRegexString.length() == 0) ? TEMPLATE_VALUE_PATTERN : Pattern.compile(nameRegexString);
    if (nameToPattern.containsKey(name)) {
      if (!nameToPattern.get(name).equals(namePattern)) {
        throw new IllegalArgumentException("String_Node_Str" + name + "String_Node_Str"+ "String_Node_Str");
      }
    }
 else {
      nameToPattern.put(name,namePattern);
    }
    Matcher m=namePattern.matcher("String_Node_Str");
    int g=m.groupCount();
    groupCounts.add(g + 1);
    regex.append('(').append(namePattern).append(')');
    normalizedTemplate.append('{').append(name).append('}');
  }
 catch (  PatternSyntaxException ex) {
    throw new IllegalArgumentException("String_Node_Str" + nameRegexString + "String_Node_Str"+ name+ "String_Node_Str",ex);
  }
}