Index: wp-includes/query.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/query.php	(revision 9f856e5957575f9fa032a3baedb9b92667ab4f05)
+++ wp-includes/query.php	(revision )
@@ -3444,6 +3444,9 @@
 			return true;
 
 		$cat_obj = $this->get_queried_object();
+		if ( is_null( $cat_obj ) ) {
+			return false;
+		}
 
 		$category = (array) $category;