Merge "Introducing pp_sortkey."

diff --cc RELEASE-NOTES-1.23
index 22520d3,58e4963..231903c
--- 1/RELEASE-NOTES-1.23
--- 2/RELEASE-NOTES-1.23
+++ b/RELEASE-NOTES-1.23
@@@ -9,11 -9,12 +9,14 @@@ MediaWiki 1.23 is an alpha-quality bran
  production.
  
  === Configuration changes in 1.23 ===
+ * Introduced $wgPagePropsHaveSortkey as a backwards-compatibility switch,
+   for using the old schema of the page_props table, in case the respective
+   schema update was not applied.
  * When $wgJobRunRate is higher that zero, jobs are now executed via an
    asynchronous HTTP request to a MediaWiki entry point. This may require
 -  increasing the number of server worker threads.
 +  increasing the number of server worker threads. $wgRunJobsAsync has been
 +  added to disable this feature if needed, falling back to executing the job
 +  on the same process but making the execution synchronously.
  * $wgDebugLogGroups values may be set to an associative array with a
    'destination' key specifying the log destination. The array may also contain
    a 'sample' key with a positive integer value N indicating that the log group

diff --cc includes/DefaultSettings.php
Simple merge

diff --cc includes/deferred/LinksUpdate.php
Simple merge

diff --cc includes/installer/PostgresUpdater.php
Simple merge

diff --cc includes/parser/ParserOutput.php
Simple merge

diff --cc tests/phpunit/includes/LinksUpdateTest.php
Simple merge