Index: wp-includes/capabilities.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/capabilities.php	(revision 32251)
+++ wp-includes/capabilities.php	(revision )
@@ -1098,7 +1098,7 @@
 		break;
 	case 'delete_post':
 	case 'delete_page':
-		$post = get_post( $args[0] );
+        $post = ( isset( $args[0] ) ) ? get_post( $args[0] ) : get_post();
 
 		if ( 'revision' == $post->post_type ) {
 			$post = get_post( $post->post_parent );
@@ -1142,7 +1142,8 @@
 		// edit_others_posts
 	case 'edit_post':
 	case 'edit_page':
-		$post = get_post( $args[0] );
+        $post = ( isset( $args[0] ) ) ? get_post( $args[0] ) : get_post();
+
 		if ( empty( $post ) )
 			break;
 
@@ -1186,9 +1187,9 @@
 		break;
 	case 'read_post':
 	case 'read_page':
-		$post = get_post( $args[0] );
+        $post = ( isset( $args[0] ) ) ? get_post( $args[0] ) : get_post();
 
-		if ( 'revision' == $post->post_type ) {
+        if ( 'revision' == $post->post_type ) {
 			$post = get_post( $post->post_parent );
 		}
 
@@ -1217,15 +1218,17 @@
 		}
 		break;
 	case 'publish_post':
-		$post = get_post( $args[0] );
+        $post = ( isset( $args[0] ) ) ? get_post( $args[0] ) : get_post();
+
-		$post_type = get_post_type_object( $post->post_type );
+        $post_type = get_post_type_object( $post->post_type );
 
 		$caps[] = $post_type->cap->publish_posts;
 		break;
 	case 'edit_post_meta':
 	case 'delete_post_meta':
 	case 'add_post_meta':
-		$post = get_post( $args[0] );
+        $post = ( isset( $args[0] ) ) ? get_post( $args[0] ) : get_post();
+
 		$caps = map_meta_cap( 'edit_post', $user_id, $post->ID );
 
 		$meta_key = isset( $args[ 1 ] ) ? $args[ 1 ] : false;