diff --git a/src/app/main.cpp b/src/app/main.cpp
index 65a0d579e22..5506539788f 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -226,8 +226,10 @@ static void dumpBacktrace( unsigned int depth )
   {
     int status;
     close( STDERR_FILENO );
-    if ( dup( stderr_fd ) != STDERR_FILENO )
+    int dup_stderr = dup( stderr_fd );
+    if ( dup_stderr != STDERR_FILENO )
     {
+      close( dup_stderr );
       QgsDebugMsg( "dup to stderr failed" );
     }
     close( stderr_fd );
diff --git a/src/providers/wms/qgswmsprovider.cpp b/src/providers/wms/qgswmsprovider.cpp
index dd2f84f9640..4721501ee2f 100644
--- a/src/providers/wms/qgswmsprovider.cpp
+++ b/src/providers/wms/qgswmsprovider.cpp
@@ -486,7 +486,7 @@ QImage *QgsWmsProvider::draw( QgsRectangle const &viewExtent, int pixelWidth, in
   mCachedViewWidth = pixelWidth;
   mCachedViewHeight = pixelHeight;
 
-  if ( !mSettings.mTiled && !mSettings.mMaxWidth && !mSettings.mMaxHeight )
+  if ( !mSettings.mTiled && mSettings.mMaxWidth == 0 && mSettings.mMaxHeight == 0 )
   {
     // Calculate active layers that are also visible.
 
@@ -559,7 +559,7 @@ QImage *QgsWmsProvider::draw( QgsRectangle const &viewExtent, int pixelWidth, in
     //t.start();
 
   }
-  else
+  else if ( mSettings.mMaxWidth != 0 && mSettings.mMaxHeight != 0 )
   {
     mTileReqNo++;
 
@@ -831,6 +831,10 @@ QImage *QgsWmsProvider::draw( QgsRectangle const &viewExtent, int pixelWidth, in
                       );
 #endif
   }
+  else
+  {
+    QgsDebugMsg( "empty tile size" );
+  }
 
   return mCachedImage;
 }
diff --git a/src/server/qgswfsserver.cpp b/src/server/qgswfsserver.cpp
index 6281764185c..5cb34085beb 100644
--- a/src/server/qgswfsserver.cpp
+++ b/src/server/qgswfsserver.cpp
@@ -1356,7 +1356,7 @@ QDomDocument QgsWFSServer::transaction( const QString& requestBody )
   // Store the created feature id for WFS
   QStringList insertResults;
   // Get the WFS layers id
-  QStringList wfsLayersId = mConfigParser->wfsLayers();
+  QStringList wfsLayersId = mConfigParser ? mConfigParser->wfsLayers() : QStringList();
 
   QList<QgsMapLayer*> layerList;
   QgsMapLayer* currentLayer = 0;
@@ -1373,7 +1373,7 @@ QDomDocument QgsWFSServer::transaction( const QString& requestBody )
     currentLayer = layerList.at( 0 );
 
     QgsVectorLayer* layer = qobject_cast<QgsVectorLayer*>( currentLayer );
-    // it's a vectorlayer and definy by the administrator as a WFS layer
+    // it's a vectorlayer and defined by the administrator as a WFS layer
     if ( layer && wfsLayersId.contains( layer->id() ) )
     {
       // Get the provider and it's capabilities
diff --git a/src/server/qgswmsserver.cpp b/src/server/qgswmsserver.cpp
index 7772255eb90..c3fee1d482b 100644
--- a/src/server/qgswmsserver.cpp
+++ b/src/server/qgswmsserver.cpp
@@ -1517,7 +1517,7 @@ int QgsWMSServer::getFeatureInfo( QDomDocument& result, QString version )
       else
       {
         layerElement = result.createElement( "Layer" );
-        QString layerName = mConfigParser->useLayerIDs() ? currentLayer->id() : currentLayer->name();
+        QString layerName = mConfigParser && mConfigParser->useLayerIDs() ? currentLayer->id() : currentLayer->name();
 
         //check if the layer is given a different name for GetFeatureInfo output
         QHash<QString, QString>::const_iterator layerAliasIt = layerAliasMap.find( layerName );
@@ -2068,7 +2068,7 @@ int QgsWMSServer::featureInfoFromVectorLayer( QgsVectorLayer* layer,
     {
       bool withGeom = layer->wkbType() != QGis::WKBNoGeometry && addWktGeometry;
       int version = infoFormat.startsWith( "application/vnd.ogc.gml/3" ) ? 3 : 2;
-      QDomElement elem = createFeatureGML( &feature, layer, infoDocument, outputCrs, mConfigParser->useLayerIDs() ? layer->id() : layer->name(), withGeom, version );
+      QDomElement elem = createFeatureGML( &feature, layer, infoDocument, outputCrs, mConfigParser && mConfigParser->useLayerIDs() ? layer->id() : layer->name(), withGeom, version );
       QDomElement featureMemberElem = infoDocument.createElement( "gml:featureMember"/*wfs:FeatureMember*/ );
       featureMemberElem.appendChild( elem );
       layerElement.appendChild( featureMemberElem );
@@ -2202,7 +2202,7 @@ int QgsWMSServer::featureInfoFromRasterLayer( QgsRasterLayer* layer,
 
     QgsCoordinateReferenceSystem layerCrs = layer->crs();
     int version = infoFormat.startsWith( "application/vnd.ogc.gml/3" ) ? 3 : 2;
-    QDomElement elem = createFeatureGML( &feature, 0, infoDocument, layerCrs, mConfigParser->useLayerIDs() ? layer->id() : layer->name(), false, version );
+    QDomElement elem = createFeatureGML( &feature, 0, infoDocument, layerCrs, mConfigParser && mConfigParser->useLayerIDs() ? layer->id() : layer->name(), false, version );
     layerElement.appendChild( elem );
   }
   else
@@ -2254,7 +2254,7 @@ QStringList QgsWMSServer::layerSet( const QStringList &layersList,
       theMapLayer = layerList.at( listIndex );
       if ( theMapLayer )
       {
-        QgsDebugMsg( QString( "Checking layer: %1" ).arg( mConfigParser->useLayerIDs() ? theMapLayer->id() : theMapLayer->name() ) );
+        QgsDebugMsg( QString( "Checking layer: %1" ).arg( mConfigParser && mConfigParser->useLayerIDs() ? theMapLayer->id() : theMapLayer->name() ) );
         //test if layer is visible in requested scale
         bool useScaleConstraint = ( scaleDenominator > 0 && theMapLayer->hasScaleBasedVisibility() );
         if ( !useScaleConstraint ||
@@ -2317,7 +2317,7 @@ QMap<QString, QString> QgsWMSServer::applyRequestedLayerFilters( const QStringLi
 
       foreach ( QgsMapLayer *layer, QgsMapLayerRegistry::instance()->mapLayers() )
       {
-        if ( layer && ( mConfigParser->useLayerIDs() ? layer->id() : layer->name() ) == eqSplit.at( 0 ) )
+        if ( layer && ( mConfigParser && mConfigParser->useLayerIDs() ? layer->id() : layer->name() ) == eqSplit.at( 0 ) )
         {
           layersToFilter.push_back( layer );
         }
@@ -2542,7 +2542,7 @@ QStringList QgsWMSServer::applyFeatureSelections( const QStringList& layerList )
 
     foreach ( QgsMapLayer *layer, QgsMapLayerRegistry::instance()->mapLayers() )
     {
-      if ( layer && ( mConfigParser->useLayerIDs() ? layer->id() : layer->name() ) == layerName )
+      if ( layer && ( mConfigParser && mConfigParser->useLayerIDs() ? layer->id() : layer->name() ) == layerName )
       {
         vLayer = qobject_cast<QgsVectorLayer*>( layer );
         layersWithSelections.push_back( vLayer->id() );