4.4.6 upgrade fails on sites with many contacts

So, I tried the upgrade & found that I got an error creating the URL - the reason seems to be that the index creation is in the loop - so if there are lots of urls to update the index bit gets called more than once

• note the below is trying to upgrade 15002 to 20001 - ie. it has already been around the loop in function https://github.com/civicrm/civicrm-core/blob/4.4/CRM/Upgrade/Incremental/php/FourFour.php#L320 & is trying again.

Index addition could be moved to sql file. Also this query https://github.com/civicrm/civicrm-core/blob/4.4/CRM/Upgrade/Incremental/php/FourFour.php#L324 could have a conditional index_url IS NOT NULL

[Error: Upgrade image_urls (15002 => 20001)]
Error Field Error Value
Type DB_Error
Code -5
Message DB Error: already exists
Mode 16
UserInfo CREATE INDEX index_image_url ON civicrm_contact (image_url); [nativecode=1061 ** Duplicate key name 'index_image_url']
DebugInfo CREATE INDEX index_image_url ON civicrm_contact (image_url); [nativecode=1061 ** Duplicate key name 'index_image_url']