From e015025d908f827cebb566ba7b32a672802d1819 Mon Sep 17 00:00:00 2001
From: Christian Speckner <christian.speckner@mayflower.de>
Date: Sat, 4 May 2019 10:42:18 +0200
Subject: [PATCH] Minor optimization to settings I/O.

---
 src/emucore/Settings.cxx | 8 ++++----
 src/emucore/Settings.hxx | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/emucore/Settings.cxx b/src/emucore/Settings.cxx
index 289c4815b..6bddc4598 100644
--- a/src/emucore/Settings.cxx
+++ b/src/emucore/Settings.cxx
@@ -205,11 +205,11 @@ void Settings::load(const Options& options)
 {
   Options fromFile =  myRespository->load();
   for (const auto& opt: fromFile)
-    setValue(opt.first, opt.second);
+    setValue(opt.first, opt.second, false);
 
   // Apply commandline options, which override those from settings file
   for(const auto& opt: options)
-    setValue(opt.first, opt.second);
+    setValue(opt.first, opt.second, false);
 
   // Finally, validate some settings, so the rest of the codebase
   // can assume the values are valid
@@ -593,12 +593,12 @@ const Variant& Settings::value(const string& key) const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Settings::setValue(const string& key, const Variant& value)
+void Settings::setValue(const string& key, const Variant& value, bool persist)
 {
   auto it = myPermanentSettings.find(key);
   if(it != myPermanentSettings.end()) {
+    if (persist && it->second != value) myRespository->save(key, value);
     it->second = value;
-    myRespository->save(key, value);
   }
   else
     myTemporarySettings[key] = value;
diff --git a/src/emucore/Settings.hxx b/src/emucore/Settings.hxx
index 1da0d49f8..7cf1bd082 100644
--- a/src/emucore/Settings.hxx
+++ b/src/emucore/Settings.hxx
@@ -88,7 +88,7 @@ class Settings
       @param key   The key of the setting
       @param value The value to assign to the key
     */
-    void setValue(const string& key, const Variant& value);
+    void setValue(const string& key, const Variant& value, bool persist = true);
 
     /**
       Convenience methods to return specific types.