[wp-hackers] parse_query filter

[Owen Winkler]

I was looking for a plugin hook that would allow me to inject the 
query_vars with a value or two before the default posts array is 
generated.  That's when I came upon this:

if ( !empty($query) ) {
	do_action('parse_query', array(&$this));
}

Why does $query have to be empty to fire this hook?  There seems to be 
no other way to modify the query_vars on the home page from a plugin.

Owen