Expired / inactive polls in blocks still render but disappear from admin/structure/block

I just spent several hours on a client's site tracking down what seemed like either bad data or serious misconfiguration of blocks or views, only to discover that it's actual a critical flaw in Advanced Poll.

The Problem

The client had created several advanced polls a few months ago and had chosen to create them as blocks. The polls were set to expire after a few weeks, and some of the polls were restricted only to show up on certain pages.

Flashing forward to now, the client created a few new pages on site and suddenly several of these older polls started showing up. Except that the poll blocks were nowhere to be found under admin/structure/block, and editing the block nodes themselves didn't seem to indicate any options for blocks at all.

The Root Cause

As it turns out, the issue is that Advanced Poll uses a different query to control the blocks it exposes in hook_block_info() than the one that Drupal uses when rendering pages via block_list() (the query is in _block_load_blocks()). When polls expire, they stop being exposed by advpoll_block_info(), but all that does is hide them from the admin area -- the blocks will continue to appear in pages, except without any way (other than deleting the nodes) to make them stop appearing in blocks on the site.

Here's the query that is invoked in advpoll_get_poll_info_blocks() that drives what Drupal presents to admins (offending code denoted):

  $result = db_query("SELECT n.title, n.nid FROM {node} n
                      LEFT JOIN {field_data_advpoll_dates} d
                      ON d.revision_id = n.vid
                      LEFT JOIN {field_data_advpoll_closed} c
                      ON c.revision_id = n.vid
                      LEFT JOIN {field_data_advpoll_options} o
                      ON o.revision_id = n.vid
                      WHERE
                      n.type = 'advpoll' AND
                      o.advpoll_options_value = 'block' AND
                      n.status = 1 AND
                      c.advpoll_closed_value = 'open' AND
                      d.advpoll_dates_value < NOW()             -- HERE
                      AND d.advpoll_dates_value2 > NOW()     -- HERE
                      ORDER BY n.created DESC");

And here's the query that Drupal uses when rendering blocks (from _block_load_blocs()):

$result = $query
  ->fields('b')
    ->condition('b.theme', $theme_key)
    ->condition('b.status', 1)
    ->orderBy('b.region')
    ->orderBy('b.weight')
    ->orderBy('b.module')
    ->addTag('block_load')
    ->addTag('translatable')
    ->execute();

See the issue? The date restriction hides the blocks from one place, but they still get rendered.

This is so frustrating for a site builder to pin down, especially because both the configuration and the database look correct. It's further compounded by the fact that the block-related settings for the Advanced Polls aren't shown on the nodes after they've been created.