Allow wp.uploadFile to upload the attachment to a post. props djzone, josephscott, maxcutler. fixes #13917.

git-svn-id: http://core.svn.wordpress.org/trunk@21896 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-xmlrpc-server.php

@@ -4894,8 +4894,13 @@ class wp_xmlrpc_server extends IXR_Server {
 			return new IXR_Error(500, $errorString);
 		}
 		// Construct the attachment array
-		// attach to post_id 0
 		$post_id = 0;
+		if ( ! empty( $data['post_id'] ) ) {
+			$post_id = (int) $data['post_id'];
+
+			if ( ! current_user_can( 'edit_post', $post_id ) )
+				return new IXR_Error( 401, __( 'Sorry, you cannot edit this post.' ) );
+		}
 		$attachment = array(
 			'post_title' => $name,
 			'post_content' => '',