From 45fd754fd38307b18f2810f8fe944b72927dd6b7 Mon Sep 17 00:00:00 2001
From: Ben Gotow <bengotow@gmail.com>
Date: Thu, 23 Jul 2015 14:30:32 -0700
Subject: [PATCH] fix(thread-list): Cache `MailLabel` component instances to
 prevent needless rendering

---
 internal_packages/thread-list/lib/thread-list.cjsx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/internal_packages/thread-list/lib/thread-list.cjsx b/internal_packages/thread-list/lib/thread-list.cjsx
index 04acf8c3e..47c5c59a7 100644
--- a/internal_packages/thread-list/lib/thread-list.cjsx
+++ b/internal_packages/thread-list/lib/thread-list.cjsx
@@ -79,6 +79,8 @@ class ThreadList extends React.Component
         else
           <ThreadListParticipants thread={thread} />
 
+    c3LabelComponentCache = {}
+
     c3 = new ListTabular.Column
       name: "Message"
       flex: 4
@@ -92,9 +94,12 @@ class ThreadList extends React.Component
         currentCategoryId = FocusedCategoryStore.categoryId()
         allCategoryId = CategoryStore.getStandardCategory('all')?.id
         ignoredIds = [currentCategoryId, allCategoryId]
+
         for label in (thread.sortedLabels() ? [])
           continue if label.id in ignoredIds
-          labels.push <MailLabel label={label} key={label.id} />
+          if not c3LabelComponentCache[label.id]
+            c3LabelComponentCache[label.id] = <MailLabel label={label} key={label.id} />
+          labels.push c3LabelComponentCache[label.id]
 
         <span className="details">
           {labels}