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-rw-r--r--includes/Hooks.php60
1 files changed, 51 insertions, 9 deletions
diff --git a/includes/Hooks.php b/includes/Hooks.php
index dec1c442..168f4bd9 100644
--- a/includes/Hooks.php
+++ b/includes/Hooks.php
@@ -1,6 +1,7 @@
<?php
/**
- * Hooks.php -- a tool for running hook functions
+ * A tool for running hook functions.
+ *
* Copyright 2004, 2005 Evan Prodromou <evan@wikitravel.org>.
*
* This program is free software; you can redistribute it and/or modify
@@ -24,9 +25,15 @@
/**
+ * Call hook functions defined in $wgHooks
+ *
* Because programmers assign to $wgHooks, we need to be very
* careful about its contents. So, there's a lot more error-checking
* in here than would normally be necessary.
+ *
+ * @param $event String: event name
+ * @param $args Array: parameters passed to hook functions
+ * @return Boolean
*/
function wfRunHooks($event, $args = array()) {
@@ -39,12 +46,10 @@ function wfRunHooks($event, $args = array()) {
if (!is_array($wgHooks)) {
throw new MWException("Global hooks array is not an array!\n");
- return false;
}
if (!is_array($wgHooks[$event])) {
throw new MWException("Hooks array for event '$event' is not an array!\n");
- return false;
}
foreach ($wgHooks[$event] as $index => $hook) {
@@ -55,6 +60,7 @@ function wfRunHooks($event, $args = array()) {
$data = null;
$have_data = false;
$closure = false;
+ $badhookmsg = false;
/* $hook can be: a function, an object, an array of $function and $data,
* an array of just a function, an array of object and method, or an
@@ -128,13 +134,35 @@ function wfRunHooks($event, $args = array()) {
// Run autoloader (workaround for call_user_func_array bug)
is_callable( $callback );
- /* Call the hook. */
+ /* Call the hook. The documentation of call_user_func_array clearly
+ * states that FALSE is returned on failure. However this is not
+ * case always. In some version of PHP if the function signature
+ * does not match the call signature, PHP will issue an warning:
+ * Param y in x expected to be a reference, value given.
+ *
+ * In that case the call will also return null. The following code
+ * catches that warning and provides better error message. The
+ * function documentation also says that:
+ * In other words, it does not depend on the function signature
+ * whether the parameter is passed by a value or by a reference.
+ * There is also PHP bug http://bugs.php.net/bug.php?id=47554 which
+ * is unsurprisingly marked as bogus. In short handling of failures
+ * with call_user_func_array is a failure, the documentation for that
+ * function is wrong and misleading and PHP developers don't see any
+ * problem here.
+ */
+ $retval = null;
+ set_error_handler( 'hookErrorHandler' );
wfProfileIn( $func );
- $retval = call_user_func_array( $callback, $hook_args );
+ try {
+ $retval = call_user_func_array( $callback, $hook_args );
+ } catch ( MWHookException $e ) {
+ $badhookmsg = $e->getMessage();
+ }
wfProfileOut( $func );
+ restore_error_handler();
/* String return is an error; false return means stop processing. */
-
if ( is_string( $retval ) ) {
global $wgOut;
$wgOut->showFatalError( $retval );
@@ -152,9 +180,14 @@ function wfRunHooks($event, $args = array()) {
} else {
$prettyFunc = strval( $callback );
}
- throw new MWException( "Detected bug in an extension! " .
- "Hook $prettyFunc failed to return a value; " .
- "should return true to continue hook processing or false to abort." );
+ if ( $badhookmsg ) {
+ throw new MWException( "Detected bug in an extension! " .
+ "Hook $prettyFunc has invalid call signature; " . $badhookmsg );
+ } else {
+ throw new MWException( "Detected bug in an extension! " .
+ "Hook $prettyFunc failed to return a value; " .
+ "should return true to continue hook processing or false to abort." );
+ }
} else if ( !$retval ) {
return false;
}
@@ -162,3 +195,12 @@ function wfRunHooks($event, $args = array()) {
return true;
}
+
+function hookErrorHandler( $errno, $errstr ) {
+ if ( strpos( $errstr, 'expected to be a reference, value given' ) !== false ) {
+ throw new MWHookException( $errstr );
+ }
+ return false;
+}
+
+class MWHookException extends MWException {} \ No newline at end of file