avoid resorting children on every child add, fixes #1480

src/public/app/entities/note_short.js

@@ -75,14 +75,16 @@ class NoteShort {
         this.parentToBranch[parentNoteId] = branchId;
     }
 
-    addChild(childNoteId, branchId) {
+    addChild(childNoteId, branchId, sort = true) {
         if (!this.children.includes(childNoteId)) {
             this.children.push(childNoteId);
         }
 
         this.childToBranch[childNoteId] = branchId;
 
-        this.sortChildren();
+        if (sort) {
+            this.sortChildren();
+        }
     }
 
     sortChildren() {

src/public/app/services/tree_cache.js

@@ -87,6 +87,8 @@ class TreeCache {
         const branchRows = resp.branches;
         const attributeRows = resp.attributes;
 
+        const noteIdsToSort = new Set();
+
         for (const noteRow of noteRows) {
             const {noteId} = noteRow;
 
@@ -153,7 +155,9 @@ class TreeCache {
             const parentNote = this.notes[branch.parentNoteId];
 
             if (parentNote) {
-                parentNote.addChild(branch.noteId, branch.branchId);
+                parentNote.addChild(branch.noteId, branch.branchId, false);
+
+                noteIdsToSort.add(parentNote.noteId);
             }
         }
 
@@ -178,6 +182,11 @@ class TreeCache {
                 }
             }
         }
+
+        // sort all of them at once, this avoids repeated sorts (#1480)
+        for (const noteId of noteIdsToSort) {
+            this.notes[noteId].sortChildren();
+        }
     }
 
     async reloadNotes(noteIds) {

src/routes/api/tree.js

@@ -57,7 +57,7 @@ function getTree(req) {
     const noteIds = sql.getColumn(`
         WITH RECURSIVE
             treeWithDescendants(noteId, isExpanded) AS (
-                SELECT noteId, 1 FROM branches WHERE parentNoteId = ? AND isDeleted = 0
+                SELECT noteId, isExpanded FROM branches WHERE parentNoteId = ? AND isDeleted = 0
                 UNION
                 SELECT branches.noteId, branches.isExpanded FROM branches
                   JOIN treeWithDescendants ON branches.parentNoteId = treeWithDescendants.noteId