The third-party DPL (DynamicPageList) extension breaks in MediaWiki 1.26 because the "page" table no longer contains a "page_counter" column. Example:
<dpl> category=whatever addpagecounter=true </dpl>
Error message produced:
Unknown column 'wp_page.page_counter' in 'field list' (localhost)
Ideally, DPL should detect whether Extension:HitCounters is installed and use that table, or it should exit cleanly with a message that "addpagecounter" is not supported.
This patch fixes the compability issues between the HitCounters extension and DPL. Maybe it doesn't fully honor the coding guidelines (I put all changes at one place), but it works ;-)
Tested on MediaWiki 1.27.1 with and without the HitCounters extension loaded.
Thank you for making the patch. Interestingly, I filed this bug report against a different extension that's also named DynamicPageList. I found the bug in the third-party extension known as DynamicPageList2, Your patch is against the original DynamicPageList from Wikimedia.
I guess the bug was present in both extensions, coincidentally.