I hate Wordpress

Upgraded a client to Wordpress 2.7 and the pagination went missing.

I started echoing out all of the variables until I found out that $max_page was null.

Open wp-includes/link-template.php.

Look for the "get_next_posts_link" function and for the following line:
$max_page = $wp_query->max_num_pages;

I did a print_r() of $wp_query and found that "max_num_pages" was NULL. I tried going up-stream from there into the database code to look for any bugs but wasn't able to find any. I double-checked the database to make sure max_num_pages was set, and it was... After digging around a bit I was able to find posts_per_page under $wp_query->query_vars[].

So, here's my fix:

Replace
$max_page = $wp_query->max_num_pages;
with
$max_page = $wp_query->query_vars['posts_per_page'];

My question is this... How does this even get shipped out for download to users if it's completely broken?

If it's NOT broken for anyone else, why am I having problems? What would cause max_num_pages to be NULL?

If there is a bug or something, this is as far as I've traced it back:

Line 2266 in wp-includes/query.php:

$this->max_num_pages = ceil($this->found_posts / $q['posts_per_page']);

$this->found_posts == 0
$q['posts_per_page'] == 6 (correct)

So, I looked for found_posts:

Lines 2263 and 2264:

$found_posts_query = apply_filters( 'found_posts_query', 'SELECT FOUND_ROWS()' );
$this->found_posts = $wpdb->get_var( $found_posts_query );

$found_posts_query == 'SELECT FOUND_ROWS()'

So that calls $wpdb->get_var(SELECT FOUND_ROWS()), which, unless I'm wrong, isn't even a valid database call...