Appending date & author based query vars to a permalink overrides the permalink

[dd32]

Some canonical code branches are not properly accounting for extra query variables being specified via the url.

For example, these url's are not handled properly:

/2008/?author=1 redirects to /author/admin/
/author/admin/?year=2008 redirects to /year/2008/
/category/uncategorized/?year=2008 redirects to /2008/

This happens with most date based branches, as once a higher priority canonical rule is hit, the permalink component is ignored.

The canonical code includes a branch to add any "forgotten" $_GET variables back onto the url, however this doesn't help when it's the rewritten variables are being lost.

[wonderboymusic]

This is probably happening in a million other combinations as well - here's the problem:

1) the flags for is_* are misleading because they are set to true for every present query var, regardless of rewrite structure

2) the redirection happens because redirect_canonical() says "I'm a year! and the year is in the query string when I want pretty permalinks, redirect me!" - it doesn't, however, check if the year is also the matched query or not.

3) /2012/?year=2012 and /?year=2012 should be redirected to /2012/, /{NOT_YEAR}/?year=2012 should not

My patch fixes this for this ticket's use cases - I'm sure there are other cases which could be addressed.

[nacin]

Keywords needs-unit-tests added

[boonebgorges]

Removing from trunk as per #30284