+ /* 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' );