handle empty search note

src/public/javascripts/services/tree_builder.js

@@ -116,8 +116,19 @@ async function prepareRealBranch(parentNote) {
 
 async function prepareSearchBranch(note) {
     const fullNote = await noteDetailService.loadNote(note.noteId);
+
+    console.log("ZZZ", fullNote.noteContent.content);
+
+    if (!fullNote.noteContent.content || !fullNote.noteContent.content.trim()) {
+        return [];
+    }
+
     const json = JSON.parse(fullNote.noteContent.content);
 
+    if (!json.searchString || !json.searchString.trim()) {
+        return [];
+    }
+
     const results = (await server.get('search/' + encodeURIComponent(json.searchString)))
         .filter(res => res.noteId !== note.noteId); // this is necessary because title of the search note is often the same as the search text which would match and create circle