Fix js.

Author: csyonghe

docs/_layouts/stdlib-reference.html

@@ -316,10 +316,10 @@
     var dotLoc = pageName.lastIndexOf(".");
     if (dotLoc == -1)
     {
-      dotLoc = pageName.length;
       if (!pageName.endsWith("/"))
-        pageName += "/";
+      pageName += "/";
       pageName += "index";
+      dotLoc = pageName.length;
     }
     var currentPageID = pageName.substr(0, dotLoc);
 
@@ -350,6 +350,8 @@
         innerSpan[0].setAttribute("class", "toc_span");
       }
     }
+    if (selectedItem == null)
+      selectedItem = tocItemsArray[0];
     var curItem = selectedItem;
     while (curItem != null) {
       expandItem(curItem);