Re: [Mediawiki-l] PHP 5.3 update and MediaWiki hook return values?

On Mon, Apr 11, 2011 at 11:52 AM, Daniel Barrett danb@vistaprint.comwrote:

I updated our wiki server (1.16.2) from PHP 5.1.6 to PHP 5.3.3, and now MediaWiki is complaining about extensions not returning values in their hook functions, when they are definitely returning "true". Does this look familiar to anybody?

Example:

 $wgHooks['SkinAfterBottomScripts'][] = 'MyClass::addBottomScripts';

 class MyClass {
         static function addBottomScripts( &$sk, &$bottomScriptText ) {
                 return true;
         }
 }

See http://bugs.php.net/bug.php?id=47554 -- the hook call via call_user_func_array() can actually return null for some error cases, where the callback is invalid or uncallable for some reason like parameter validation.

In this case, it's likely failing because PHP 5.3 is much stricter about references, especially on function parameters. Your hook is declaring the $sk parameter as a reference (&$sk) but the call is not passing it as a reference:

wfRunHooks( 'SkinAfterBottomScripts', array( $this, &$bottomScriptText ) );

Your PHP or web server error log might include a warning about this; make sure you at least have warnings and errors going to a log if you've disabled PHP's display_errors setting. The use of references there probably dates back to PHP 4.x coding practices in early MediaWiki, and should be removed. (The second parameter really is a reference parameter so the string can be modified, so be sure to keep that one!)

Try removing the & reference marker on your function declaration and see if that clears it up.

-- brion