FdoSecrets: fix crash when enabling the plugin on a non-exposed database

src/fdosecrets/objects/Collection.h

@@ -74,6 +74,10 @@ namespace FdoSecrets
     public:
         DBusReturn<void> setProperties(const QVariantMap& properties);
 
+        bool isValid() const {
+            return backend();
+        }
+
         DBusReturn<void> removeAlias(QString alias);
         DBusReturn<void> addAlias(QString alias);
         const QSet<QString> aliases() const;
@@ -106,6 +110,7 @@ namespace FdoSecrets
     private slots:
         void onDatabaseLockChanged();
         void onDatabaseExposedGroupChanged();
+        // force reload info from backend, potentially delete self
         void reloadBackend();
 
     private:

src/fdosecrets/objects/Service.cpp

@@ -93,7 +93,24 @@ namespace FdoSecrets
 
     void Service::onDatabaseTabOpened(DatabaseWidget* dbWidget, bool emitSignal)
     {
+        // The Collection will monitor the database's exposed group.
+        // When the Collection finds that no exposed group, it will delete itself.
+        // Thus the service also needs to monitor it and recreate the collection if the user changes
+        // from no exposed to exposed something.
+        if (!dbWidget->isLocked()) {
+            monitorDatabaseExposedGroup(dbWidget);
+        }
+        connect(dbWidget, &DatabaseWidget::databaseUnlocked, this, [this, dbWidget]() {
+            monitorDatabaseExposedGroup(dbWidget);
+        });
+
         auto coll = new Collection(this, dbWidget);
+        // Creation may fail if the database is not exposed.
+        // This is okay, because we monitor the expose settings above
+        if (!coll->isValid()) {
+            coll->deleteLater();
+            return;
+        }
 
         m_collections << coll;
         m_dbToCollection[dbWidget] = coll;
@@ -127,15 +144,6 @@ namespace FdoSecrets
             emit collectionDeleted(coll);
         });
 
-        // a special case: the database changed from no expose to expose something.
-        // in this case, there is no collection out there monitoring it, so create a new collection
-        if (!dbWidget->isLocked()) {
-            monitorDatabaseExposedGroup(dbWidget);
-        }
-        connect(dbWidget, &DatabaseWidget::databaseUnlocked, this, [this, dbWidget]() {
-            monitorDatabaseExposedGroup(dbWidget);
-        });
-
         if (emitSignal) {
             emit collectionCreated(coll);
         }