[Plugin Manager] Better cope with broken plugins

Author: borysiasty

python/utils.py

@@ -193,6 +193,7 @@ def startPlugin(packageName):
   global plugins, active_plugins, iface
 
   if packageName in active_plugins: return False
+  if packageName not in sys.modules: return False
 
   package = sys.modules[packageName]
 

src/app/pluginmanager/qgspluginmanager.cpp

@@ -484,8 +484,9 @@ void QgsPluginManager::pluginItemChanged( QStandardItem * item )
     QgsDebugMsg( " Loading plugin: " + id );
     loadPlugin( id );
   }
-  else if ( ! item->checkState() && isPluginLoaded( id ) )
+  else if ( ! item->checkState() )
   {
+    // don't test if isPluginLoaded, to allow disable also plugins taht weren't successfully loaded
     QgsDebugMsg( " Unloading plugin: " + id );
     unloadPlugin( id );
   }

src/app/qgspluginregistry.cpp

@@ -383,11 +383,12 @@ void QgsPluginRegistry::unloadPythonPlugin( QString packageName )
   if ( isLoaded( packageName ) )
   {
     mPythonUtils->unloadPlugin( packageName );
-    // add to settings
-    QSettings settings;
-    settings.setValue( "/PythonPlugins/" + packageName, false );
     QgsDebugMsg( "Python plugin successfully unloaded: " + packageName );
   }
+
+  // disable the plugin no matter if successfully loaded or not
+  QSettings settings;
+  settings.setValue( "/PythonPlugins/" + packageName, false );
 }