Program: 12207
Project: 12207
Buggy source:
private void replaceTargetClassVariableNameWithThisExpressionInInfixExpressions(MethodDeclaration newMethodDeclaration){
  ExpressionExtractor extractor=new ExpressionExtractor();
  List<Expression> infixExpressions=extractor.getInfixExpressions(newMethodDeclaration.getBody());
  for (  Expression expression : infixExpressions) {
    InfixExpression infixExpression=(InfixExpression)expression;
    if (infixExpression.getLeftOperand() instanceof SimpleName) {
      SimpleName leftOperand=(SimpleName)infixExpression.getLeftOperand();
      if (leftOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.LEFT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
    if (infixExpression.getRightOperand() instanceof SimpleName) {
      SimpleName rightOperand=(SimpleName)infixExpression.getRightOperand();
      if (rightOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.RIGHT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
  }
}

Fixed version (ground truth):
private void replaceTargetClassVariableNameWithThisExpressionInInfixExpressions(MethodDeclaration newMethodDeclaration){
  ExpressionExtractor extractor=new ExpressionExtractor();
  List<Expression> infixExpressions=extractor.getInfixExpressions(newMethodDeclaration.getBody());
  for (  Expression expression : infixExpressions) {
    InfixExpression infixExpression=(InfixExpression)expression;
    if (infixExpression.getLeftOperand() instanceof SimpleName) {
      SimpleName leftOperand=(SimpleName)infixExpression.getLeftOperand();
      if (leftOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.LEFT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
 else     if (infixExpression.getLeftOperand() instanceof FieldAccess) {
      FieldAccess fieldAccess=(FieldAccess)infixExpression.getLeftOperand();
      SimpleName leftOperand=fieldAccess.getName();
      if (leftOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.LEFT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
    if (infixExpression.getRightOperand() instanceof SimpleName) {
      SimpleName rightOperand=(SimpleName)infixExpression.getRightOperand();
      if (rightOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.RIGHT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
 else     if (infixExpression.getRightOperand() instanceof FieldAccess) {
      FieldAccess fieldAccess=(FieldAccess)infixExpression.getRightOperand();
      SimpleName rightOperand=fieldAccess.getName();
      if (rightOperand.getIdentifier().equals(targetClassVariableName)) {
        AST ast=newMethodDeclaration.getAST();
        targetRewriter.set(infixExpression,InfixExpression.RIGHT_OPERAND_PROPERTY,ast.newThisExpression(),null);
      }
    }
  }
}