Fix coverity uninitialized variable warnings

src/core/qgsexpression.h

@@ -518,6 +518,7 @@ class CORE_EXPORT QgsExpression
                   bool handlesNull = false,
                   bool isContextual = false )
             : mName( fnname )
+            , mParams( 0 )
             , mParameterList( params )
             , mUsesGeometry( usesGeometry )
             , mGroup( group )

src/core/qgsproject.cpp

@@ -331,6 +331,7 @@ struct QgsProject::Imp
 
   Imp()
       : title()
+      , autoTransaction( false )
       , dirty( false )
   {                             // top property node is the root
     // "properties" that contains all plug-in

src/gui/symbology-ng/qgsnullsymbolrendererwidget.cpp

@@ -26,6 +26,7 @@ QgsRendererV2Widget* QgsNullSymbolRendererWidget::create( QgsVectorLayer* layer,
 
 QgsNullSymbolRendererWidget::QgsNullSymbolRendererWidget( QgsVectorLayer* layer, QgsStyleV2* style, QgsFeatureRendererV2* renderer )
     : QgsRendererV2Widget( layer, style )
+    , mRenderer( nullptr )
 {
   if ( renderer )
   {

src/providers/db2/qgsdb2dataitems.h

@@ -118,18 +118,6 @@ class QgsDb2ConnectionItem : public QgsDataCollectionItem
 
   private:
     QString mConnInfo;
-    QString mService;
-    QString mHost;
-    QString mDriver;
-    QString mPort;
-    QString mDatabase;
-    QString mUsername;
-    QString mPassword;
-    QString mAuthcfg;
-    int     mEnvironment;
-    bool mUseGeometryColumns;
-    bool mUseEstimatedMetadata;
-    bool mAllowGeometrylessTables;
 
     void readConnectionSettings();
 };

src/providers/db2/qgsdb2geometrycolumns.cpp

@@ -23,6 +23,7 @@
 
 QgsDb2GeometryColumns::QgsDb2GeometryColumns( const QSqlDatabase db )
     : mDatabase( db )
+    , mEnvironment( ENV_LUW )
 {
   QgsDebugMsg( "constructing" );
 }
@@ -160,4 +161,4 @@ bool QgsDb2GeometryColumns::populateLayerProperty( QgsDb2LayerProperty &layer )
   }
   layer.pkColumnName = layer.pkCols.size() > 0 ? layer.pkCols.at( 0 ) : QString::null;
   return true;
-}
+}

src/providers/db2/qgsdb2provider.cpp

@@ -32,6 +32,7 @@ int QgsDb2Provider::sConnectionId = 0;
 
 QgsDb2Provider::QgsDb2Provider( QString uri )
     : QgsVectorDataProvider( uri )
+    , mNumberFeatures( 0 )
     , mEnvironment( ENV_LUW )
     , mWkbType( QGis::WKBUnknown )
 {
@@ -1754,4 +1755,4 @@ QGISEXTERN QgsVectorLayerImport::ImportError createEmptyLayer(
            uri, fields, wkbType, srs, overwrite,
            oldToNewAttrIdxMap, errorMessage, options
          );
-}
+}