Index: src/wp-includes/query.php
===================================================================
--- src/wp-includes/query.php	(revision 29743)
+++ src/wp-includes/query.php	(working copy)
@@ -4038,6 +4038,10 @@
 		$attachment = (array) $attachment;
 
 		$post_obj = $this->get_queried_object();
+		
+		if ( ! $post_obj ) {
+			return false;
+		}
 
 		if ( in_array( $post_obj->ID, $attachment ) ) {
 			return true;
@@ -4068,6 +4072,10 @@
 			return true;
 
 		$author_obj = $this->get_queried_object();
+		
+		if ( ! $author_obj ) {
+			return false;
+		}
 
 		$author = (array) $author;
 
@@ -4100,6 +4108,10 @@
 			return true;
 
 		$cat_obj = $this->get_queried_object();
+		
+		if ( ! $cat_obj ) {
+			return false;
+		}
 
 		$category = (array) $category;
 
@@ -4132,6 +4144,10 @@
 			return true;
 
 		$tag_obj = $this->get_queried_object();
+		
+		if ( ! $tag_obj ) {
+			return false;
+		}
 
 		$tag = (array) $tag;
 
@@ -4171,6 +4187,11 @@
 			return true;
 
 		$queried_object = $this->get_queried_object();
+		
+		if ( ! $queried_object ) {
+			return false;
+		}
+		
 		$tax_array = array_intersect( array_keys( $wp_taxonomies ), (array) $taxonomy );
 		$term_array = (array) $term;
 
@@ -4331,6 +4352,10 @@
 			return true;
 
 		$page_obj = $this->get_queried_object();
+		
+		if ( ! $page_obj ) {
+			return false;
+		}
 
 		$page = (array) $page;
 
@@ -4424,6 +4449,10 @@
 			return true;
 
 		$post_obj = $this->get_queried_object();
+		
+		if ( ! $post_obj ) {
+			return false;
+		}
 
 		$post = (array) $post;
 
@@ -4467,6 +4496,10 @@
 			return (bool) $this->is_singular;
 
 		$post_obj = $this->get_queried_object();
+		
+		if ( ! $post_obj ) {
+			return false;
+		}
 
 		return in_array( $post_obj->post_type, (array) $post_types );
 	}