title: SQLAlchemy query renders .filter() as "WHERE false"
body: <p>My issues comes down to the following code runned with Python3.8 and SQLAlchemy1.3:</p>
  <pre><code>subquery = (
      session.query(
          Article.id,
          SubscriberArticle.subscriber_id,
          SubscriberArticle.data,
          SubscriberArticle.is_activated,
      )
      .join(SubscriberArticle)
      .filter(and_(
          SubscriberArticle.subscriber_id == 1234,
          Article.is_activated is True
      ))
      .subquery()
  )
  query = (
      session.query(
          Article.id,
          Article.name,
          subquery.c.subscriber_id,
          subquery.c.data,
          subquery.c.is_activated,
      )
      .join(subquery, subquery.c.id == Article.id)
  )
  </code></pre>
  <p>The <code>where</code> clause is not what i expected, here is the SQL request i expected:</p>
  <pre><code>SELECT
      article.id,
      article.name,
      tmp.subscriber_id,
      tmp.data,
      tmp.is_activated
  FROM
      script_pixel
  LEFT JOIN
      (
          SELECT
                  article.id,
                  subscriber_article.subscriber_id,
                  subscriber_article.data,
                  subscriber_article.is_activated
          FROM
              script_pixel
          LEFT JOIN
              subscriber_script_pixel
          ON
              subscriber_article.script_pixel_id = article.id
          WHERE
              subscriber_article.subscriber_id = 1234
              AND
              article.is_activated = true
      ) as tmp
  ON
      tmp.id = article.id;
  </code></pre>
  <p>But when i do a <code>print(&quot;query&quot;, str(query))</code> the result is completely different:</p>
  <pre><code>SELECT 
    script_pixel.id AS script_pixel_id, 
    script_pixel.name AS script_pixel_name, 
    anon_1.subscriber_id AS anon_1_subscriber_id,
    anon_1.data AS anon_1_data,
    anon_1.is_activated AS anon_1_is_activated 
  FROM 
    script_pixel 
    JOIN (
      SELECT 
        script_pixel.id AS id, 
        subscriber_script_pixel.subscriber_id AS subscriber_id, 
        subscriber_script_pixel.data AS data, 
        subscriber_script_pixel.is_activated AS is_activated 
      FROM 
        script_pixel 
        JOIN subscriber_script_pixel ON script_pixel.id = subscriber_script_pixel.script_pixel_id 
      WHERE 
        false
    ) AS anon_1 ON anon_1.id = script_pixel.id
  </code></pre>
  <p>As you can see in my subquery i don't have my <code>where</code> clause, instead i have a <code>where false</code> comes out of nowhere.</p>