Actually, let's be a little pickier here.

diff --git a/includes/Parser.php b/includes/Parser.php
index 50324b9..bbe1fed 100644 (file)
--- a/includes/Parser.php
+++ b/includes/Parser.php
@@ -4418,7 +4418,7 @@ class Parser
                        list( $magicName, $value ) = $mwArray->matchVariableStartToEnd( $part );
                        # (bug 13436) If $value is non-numeric, assume it's a caption
                        if( isset( $paramMap[$magicName] ) &&
-                       ( !$value || is_numeric($value) ) ) {
+                       ( $value === false || is_numeric($value) ) ) {
                                list( $type, $paramName ) = $paramMap[$magicName];
                                $params[$type][$paramName] = $value;