bthome 0.04: Fix duplicate button on edit->save

apps/bthome/ChangeLog

@@ -2,3 +2,4 @@
 0.02: Fix double-button press if you press the next button within 30s (#3243)
 0.03: Cope with identical duplicate buttons (fix #3260)
       Set 'n' for buttons in Bangle.btHomeData correctly (avoids adding extra buttons on end of advertising)
+0.04: Fix duplicate button on edit->save

apps/bthome/metadata.json

@@ -1,7 +1,7 @@
 { "id": "bthome",
   "name": "BTHome",
   "shortName":"BTHome",
-  "version":"0.03",
+  "version":"0.04",
   "description": "Allow your Bangle to advertise with BTHome and send events to Home Assistant via Bluetooth",
   "icon": "icon.png",
   "type": "app",

apps/bthome/settings.js

@@ -1,7 +1,11 @@
 (function(back) {
-  var settings = require("Storage").readJSON("bthome.json",1)||{};
+  var settings;
+
+  function loadSettings() {
+    settings = require("Storage").readJSON("bthome.json",1)||{};
     if (!(settings.buttons instanceof Array))
       settings.buttons = [];
+  }
 
   function saveSettings() {
     require("Storage").writeJSON("bthome.json",settings)
@@ -15,7 +19,10 @@
     }
     var actions = ["press","double_press","triple_press","long_press","long_double_press","long_triple_press"];
     var menu = {
-      "":{title:isNew ? /*LANG*/"New Button" : /*LANG*/"Edit Button", back:showMenu},
+      "":{title:isNew ? /*LANG*/"New Button" : /*LANG*/"Edit Button", back: () => {
+        loadSettings(); // revert changes
+        showMenu();
+      }},
       /*LANG*/"Icon" : {
         value : "\0"+require("icons").getIcon(button.icon),
         onchange : () => {
@@ -49,7 +56,7 @@
         onchange : v => button.n=v
       },
       /*LANG*/"Save" : () => {
-        settings.buttons.push(button);
+        if (isNew) settings.buttons.push(button);
         saveSettings();
         showMenu();
       }
@@ -94,5 +101,7 @@
     });
     E.showMenu(menu);
   }
+
+  loadSettings();
   showMenu();
 })