Program: 12046
Project: 12046
Buggy source:
private void sortVariables(List<AbstractVariable> variables1,List<AbstractVariable> variables2,List<AbstractVariable> sortedVariables1,List<AbstractVariable> sortedVariables2){
  boolean requireVariableNameMatch=getRenamedVariables().isEmpty();
  for (int i=0; i < variables1.size(); i++) {
    AbstractVariable variable1=variables1.get(i);
    boolean found=false;
    for (int j=0; j < variables2.size(); j++) {
      AbstractVariable variable2=variables2.get(j);
      if (requireVariableNameMatch) {
        if (variable2.getVariableName().equals(variable1.getVariableName()) && variable2.getVariableType().equals(variable1.getVariableType()) && !sortedVariables2.contains(variable2)) {
          sortedVariables2.add(variable2);
          found=true;
          break;
        }
      }
 else {
        String renamedVariableName=findRenamedVariableName2(variable2);
        if (renamedVariableName != null) {
          if (variable2.getVariableType().equals(variable1.getVariableType()) && variable1.getVariableName().equals(renamedVariableName) && !sortedVariables2.contains(variable2)) {
            sortedVariables2.add(variable2);
            found=true;
            break;
          }
        }
 else         if (findRenamedVariableName1(variable1) == null) {
          if (variable2.getVariableType().equals(variable1.getVariableType()) && !sortedVariables2.contains(variable2)) {
            sortedVariables2.add(variable2);
            found=true;
            break;
          }
        }
      }
    }
    if (found) {
      sortedVariables1.add(variable1);
    }
  }
}

Fixed version (ground truth):
private void sortVariables(List<AbstractVariable> variables1,List<AbstractVariable> variables2,List<AbstractVariable> sortedVariables1,List<AbstractVariable> sortedVariables2){
  boolean requireVariableNameMatch=getRenamedVariables().isEmpty();
  for (int i=0; i < variables1.size(); i++) {
    AbstractVariable variable1=variables1.get(i);
    boolean found=false;
    for (int j=0; j < variables2.size(); j++) {
      AbstractVariable variable2=variables2.get(j);
      if (requireVariableNameMatch) {
        if (variable2.getVariableName().equals(variable1.getVariableName()) && variable2.getVariableType().equals(variable1.getVariableType()) && !sortedVariables2.contains(variable2)) {
          sortedVariables2.add(variable2);
          found=true;
          break;
        }
      }
 else {
        String renamedVariableName=findRenamedVariableName2(variable2);
        if (renamedVariableName != null) {
          if (variable2.getVariableType().equals(variable1.getVariableType()) && variable1.getVariableName().equals(renamedVariableName) && !sortedVariables2.contains(variable2)) {
            sortedVariables2.add(variable2);
            found=true;
            break;
          }
        }
 else         if (findRenamedVariableName1(variable1) == null) {
          if (variable2.getVariableType().equals(variable1.getVariableType()) && !sortedVariables2.contains(variable2) && !appearsInMultipleDifferences(variable1)&& !appearsInMultipleDifferences(variable2)) {
            sortedVariables2.add(variable2);
            found=true;
            break;
          }
        }
      }
    }
    if (found) {
      sortedVariables1.add(variable1);
    }
  }
}