Todo: Avoid issues with screwing up or screwed settings

If for some reason the todo settings are borked, do not crash/assert.
Also, avoid overwriting existing settings with default settings, if
for some reason the todo plugin is never initialized (because a
dependency fails to load).

Change-Id: Id7815b799adaff3dcdf00fedb9ade3ced01e23b9
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/todo/settings.cpp

@@ -76,6 +76,8 @@ void Settings::load(QSettings *settings)
 
     scanningScope = static_cast<ScanningScope>(settings->value(QLatin1String(Constants::SCANNING_SCOPE),
         ScanningScopeCurrentFile).toInt());
+    if (scanningScope >= ScanningScopeMax)
+        scanningScope = ScanningScopeCurrentFile;
 
     KeywordList newKeywords;
     const int keywordsSize = settings->beginReadArray(QLatin1String(Constants::KEYWORDS_LIST));

src/plugins/todo/settings.h

@@ -36,13 +36,14 @@ namespace Internal {
 enum ScanningScope {
     ScanningScopeCurrentFile,
     ScanningScopeProject,
-    ScanningScopeSubProject
+    ScanningScopeSubProject,
+    ScanningScopeMax
 };
 
 class Settings {
 public:
     KeywordList keywords;
-    ScanningScope scanningScope;
+    ScanningScope scanningScope = ScanningScopeCurrentFile;
     void save(QSettings *settings) const;
     void load(QSettings *settings);
     void setDefault();

src/plugins/todo/todoplugin.cpp

@@ -56,7 +56,6 @@ TodoPlugin::TodoPlugin() :
 
 TodoPlugin::~TodoPlugin()
 {
-    m_settings.save(Core::ICore::settings());
 }
 
 bool TodoPlugin::initialize(const QStringList& args, QString *errMsg)
@@ -80,6 +79,8 @@ bool TodoPlugin::initialize(const QStringList& args, QString *errMsg)
         return widget;
     });
     ProjectExplorer::ProjectPanelFactory::registerFactory(panelFactory);
+    connect(Core::ICore::instance(), &Core::ICore::saveSettingsRequested,
+            this, [this] { m_settings.save(Core::ICore::settings()); });
 
     return true;
 }