Handle db upgrades and prepare work for old profiles deprecation.

app/qml/ApplicationSettings.qml

@@ -24,7 +24,9 @@ import QtQuick.Controls 1.0
 import "utils.js" as Utils
 
 QtObject{
-    property string version: "1.0.1"
+    readonly property string version: "1.0.1"
+    readonly property int profileVersion: 2
+
 
     // STATIC CONSTANTS ////////////////////////////////////////////////////////
 
@@ -109,6 +111,8 @@ QtObject{
 
     signal initializedSettings()
 
+    signal showErrorMessage(string message)
+
     property Loader fontManager: Loader{
         states: [
             State { when: rasterization == no_rasterization
@@ -331,6 +335,17 @@ QtObject{
         burnInQuality = settings.burnInQuality !== undefined ? settings.burnInQuality : burnInQuality;
     }
 
+    function userLoadProfileString(profileString) {
+        var profile = JSON.parse(profileString);
+        var version = profile.version !== undefined ? profile.version : 1;
+
+        if (version === profileVersion) {
+            loadProfileString(profileString);
+        } else {
+            showErrorMessage("This profile is not supported on this version of CRT.")
+        }
+    }
+
     function loadProfileString(profileString){
         var settings = JSON.parse(profileString);
 

app/qml/Storage.qml

@@ -23,9 +23,20 @@ import QtQuick.LocalStorage 2.0
 
 QtObject {
     property bool initialized: false
+    property string dbVersion: "1.1"
 
     function getDatabase() {
-         return LocalStorage.openDatabaseSync("coolretroterm", "1.0", "StorageDatabase", 100000);
+        try {
+            return _getDatabase(dbVersion);
+        } catch (error) {
+            console.log("Error while reading from settings database:", error);
+            updateAndResetDatabase(_getDatabase(""));
+            return _getDatabase(dbVersion);
+        }
+    }
+
+    function _getDatabase(version) {
+        return LocalStorage.openDatabaseSync("coolretroterm", version, "StorageDatabase", 100000);
     }
 
     function initialize() {
@@ -74,9 +85,22 @@ QtObject {
 
     function dropSettings(){
         var db = getDatabase();
+        dropSettingsFromDB(db);
+    }
+
+    function updateAndResetDatabase(db) {
+        console.log("Updating and resetting database.");
+        db.changeVersion(db.version, dbVersion);
+
+        try {
+            dropSettingsFromDB(db);
+        } catch (error) {}
+    }
+
+    function dropSettingsFromDB(db) {
         db.transaction(
             function(tx) {
                 tx.executeSql('DROP TABLE settings');
-          });
+        });
     }
 }