invalid session handling

Author: jctrotter

jbrowse/src/client/JBrowse/Browser/Browser.tsx

@@ -47,7 +47,7 @@ function View(){
         Ajax.request({
             url: ActionURL.buildURL('jbrowse', 'getSession.api'),
             method: 'GET',
-            success: function(res){ // TODO - handle empty request better
+            success: function(res){
                 setState(generateViewState(JSON.parse(res.response)));
                 console.log(res);
             },
@@ -66,7 +66,7 @@ function View(){
         return (<p>Loading...</p>)
     }
     else if (state == "invalid") {
-        return (<p>"Error fetching config. See console for more details"</p>)
+        return (<p>Error fetching config. See console for more details</p>)
     }
     return (
       <ThemeProvider theme={theme}>

jbrowse/src/org/labkey/jbrowse/JBrowseController.java

@@ -771,7 +771,7 @@ public Object execute(GetSessionForm form, BindException errors) throws Exceptio
             }
             else
             {
-                resp = null;
+                throw new FileNotFoundException("File not found.");
             }
 
             return new ApiSimpleResponse(resp);