getLeavesFromDocumentTree can except branch now

src/jio.storage/revisionstorage.js

@@ -254,11 +254,11 @@ jIO.addStorageType('revision', function (spec, my) {
         // search method fills [result] with the winner revision
         search = function (document_tree) {
             var i;
-            if (document_tree.children.length === 0) {
-                // This node is a leaf
             if (except !== undefined && except === document_tree.rev) {
                 return;
             }
+            if (document_tree.children.length === 0) {
+                // This node is a leaf
                 result.push(document_tree.rev);
                 return;
             }