title: How to use allowed_domains with relative paths?
body: <p>I'm new to scrapy and want to build a simple web crawler. Unfortunately, if I'm using a allowed_domain, scrapy filters out all subpages as the domain is using relative path. How can this be fixed?</p>
  
  <pre><code>class ExampleSpider(CrawlSpider):
      name = "example_crawler"
      allowed_domains = ["www.example.com"]
      start_urls = ["https://www.example.com"]
  
      rules = (
          Rule(LinkExtractor(),
               callback="parse_text",
               follow=True),)
  
      def parse_text(self, response):
          pass
  </code></pre>
  
  <p>If I remove the allowed_domains all subpages are crawled. However, if I'm using a allowed domain all subpages are getting filtered because of the relative path issue. Can this be solved?</p>