* Don't set $IP. The entry point already sets it, so there's no point. Users can still set it if they can figure out a way to do it without breaking things.
* Don't include DefaultSettings.php. Doing that is code, not configuration, and it can easily be done in WebStart/Maintenance. Some non-standard entry points in extensions may be broken by this. That's their fault for being non-standard. Backwards compatibility is preserved thanks to require_once().
* Introduce $wgInvalidateCacheOnLocalSettingsChange, which when set, causes $wgCacheEpoch to be updated in the way that it previously was in the default LocalSettings.php.
* Don't set $wgLocalInterwiki to some nonsense value (possibly including spaces and punctuation in the new installer). It should be only for actual interwiki prefixes. Since most wikis don't have them, I set this to false by default and adjusted the referring code to accept this.
* Removed the guard for web invocation with $wgCommandLineMode set. This ancient code is redundant with modern protections in doMaintenance.php.
* In DefaultSettings.php, fixed fold terminator placement near $wgLoadScript
* Add a web entry point guard. That's one piece of code which really is necessary.
* Don't call quickUserCan('edit') unless section edit is enabled
* In DatabasePostgres and DatabaseSqlite: throw an exception on connection error
* In DatabasePostgres: don't send an invalid connection string whenever one of the fields is empty. Use quoting.
* In Database: make the captured PHP error prettier
* Display a descriptive error message when the user navigates to index.php with PHP 4, not a parse error. Check to see if the *.php5 extension works, using file_get_contents().
* The default port number for PostgreSQL is 5432, not blank.
* Better default for $wgDBname
* Wrote a tool to check the integrity of the autoloader class list, fixed some issues that came up.
* Start the autoloader before LocalSettings.php, so that when an extension writer thinks an inefficient one-file special page extension is the way to go, they don't have to use explicit includes to make the class inheritance work. Should continue to work with $IP set in LocalSettings.php as long as $IP is set before extensions are included.
The ob_start() section should preferably be removed from older
LocalSettings.php files.
* Give Content-Length header for HTTP/1.0 clients.
* Partial support for Flash cross-domain-policy filtering. Text entry points should be protected, but uploads are not.