From c8c503c42e57427cd4d3f2659284533552ca3fd3 Mon Sep 17 00:00:00 2001
From: Cy Rossignol <cy@rossignols.me>
Date: Tue, 20 Apr 2021 14:57:44 -0500
Subject: [PATCH] Avoid reloading redundant GUI stylesheets

This skips the application of theme stylesheets when saving the GUI
options if the user doesn't change the theme. Reloading stylesheets
can be expensive for a wallet with many transactions.
---
 src/qt/bitcoingui.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index cb4b2d54ce..bb46a4ea26 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -279,6 +279,12 @@ std::string FromQString(QString qs)
 
 void BitcoinGUI::setOptionsStyleSheet(QString qssFileName)
 {
+    // Applying a stylesheet can be rather expensive on a wallet with many
+    // transactions. Avoid reloading styles if the theme didn't change:
+    if (qssFileName == sSheet) {
+        return;
+    }
+
     // setting the style sheets for the app
     QFile qss(":/stylesheets/"+qssFileName);
     if (qss.open(QIODevice::ReadOnly)){