From d56f77debeb3697196b9389a6f6d45335e489d7e Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@matrix.org>
Date: Mon, 28 Jan 2019 16:02:56 +0100
Subject: [PATCH] ignore updates that don't change anything

---
 src/resizer/distributors/roomsublist2.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/resizer/distributors/roomsublist2.js b/src/resizer/distributors/roomsublist2.js
index 8e9112ebb3..96ce96d4ff 100644
--- a/src/resizer/distributors/roomsublist2.js
+++ b/src/resizer/distributors/roomsublist2.js
@@ -58,11 +58,25 @@ export class Layout {
         this._applyNewSize();
     }
 
-    // [{id, count}]
     update(sections, availableHeight) {
-        if (Number.isFinite(availableHeight)) {
+        let heightChanged = false;
+
+        if (Number.isFinite(availableHeight) && availableHeight !== this._availableHeight) {
+            heightChanged = true;
             this._availableHeight = availableHeight;
         }
+
+        const sectionsChanged =
+            sections.length !== this._sections.length ||
+            sections.some((a, i) => {
+                const b = this._sections[i];
+                return a.id !== b.id || a.count !== b.count;
+            });
+
+        if (!heightChanged && !sectionsChanged) {
+            return;
+        }
+
         this._sections = sections;
         const totalHeight = this._getAvailableHeight();
         this._sections.forEach((section, i) => {