Fix crashing rule-based labeling with data-defined properties (fixes #13416)

wonder-sk · wonder-sk · commit 5b0bfc6238bf · 2015-09-29T13:23:25.000+08:00
This code has been funded by Tuscany Region (Italy) - SITA (CIG: 63526840AE) and commissioned to Gis3W s.a.s.
diff --git a/src/core/qgspallabeling.cpp b/src/core/qgspallabeling.cpp
@@ -332,6 +332,14 @@ QgsPalLayerSettings::QgsPalLayerSettings( const QgsPalLayerSettings& s )
     , showingShadowRects( false )
     , expression( NULL )
 {
+  *this = s;
+}
+
+QgsPalLayerSettings& QgsPalLayerSettings::operator=( const QgsPalLayerSettings & s )
+{
+  if ( this == &s )
+    return *this;
+
   // copy only permanent stuff
 
   enabled = s.enabled;
@@ -461,12 +469,17 @@ QgsPalLayerSettings::QgsPalLayerSettings( const QgsPalLayerSettings& s )
   shadowBlendMode = s.shadowBlendMode;
 
   // data defined
-  dataDefinedProperties = s.dataDefinedProperties;
+  QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* >::const_iterator it = s.dataDefinedProperties.constBegin();
+  for ( ; it != s.dataDefinedProperties.constEnd(); ++it )
+  {
+    dataDefinedProperties.insert( it.key(), it.value() ? new QgsDataDefined( *it.value() ) : 0 );
+  }
   mDataDefinedNames = s.mDataDefinedNames;
 
   // scale factors
   vectorScaleFactor = s.vectorScaleFactor;
   rasterCompressFactor = s.rasterCompressFactor;
+  return *this;
 }
 
 
@@ -478,7 +491,13 @@ QgsPalLayerSettings::~QgsPalLayerSettings()
   delete expression;
   delete extentGeom;
 
-  // clear pointers to QgsDataDefined objects
+  // delete all QgsDataDefined objects (which also deletes their QgsExpression object)
+  QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* >::iterator it = dataDefinedProperties.begin();
+  for ( ; it != dataDefinedProperties.constEnd(); ++it )
+  {
+    delete( it.value() );
+    it.value() = 0;
+  }
   dataDefinedProperties.clear();
 }
 
diff --git a/src/core/qgspallabeling.h b/src/core/qgspallabeling.h
@@ -67,6 +67,9 @@ class CORE_EXPORT QgsPalLayerSettings
     QgsPalLayerSettings( const QgsPalLayerSettings& s );
     ~QgsPalLayerSettings();
 
+    //! copy operator - only copies the permanent members
+    QgsPalLayerSettings &operator=( const QgsPalLayerSettings & s );
+
     //! @note added in 2.4
     static QgsPalLayerSettings fromLayer( QgsVectorLayer* layer );
 
@@ -534,6 +537,8 @@ class CORE_EXPORT QgsPalLayerSettings
     bool dataDefinedUseExpression( QgsPalLayerSettings::DataDefinedProperties p ) const;
 
     /** Map of current data defined properties
+     *
+     * Pointers to QgsDataDefined should never be null, the pointers are owned by this class
      */
     QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* > dataDefinedProperties;
 
diff --git a/src/core/qgsvectorlayerlabelprovider.cpp b/src/core/qgsvectorlayerlabelprovider.cpp
@@ -102,15 +102,6 @@ void QgsVectorLayerLabelProvider::init()
 
 QgsVectorLayerLabelProvider::~QgsVectorLayerLabelProvider()
 {
-  // delete all QgsDataDefined objects (which also deletes their QgsExpression object)
-  QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* >::iterator it = mSettings.dataDefinedProperties.begin();
-  for ( ; it != mSettings.dataDefinedProperties.constEnd(); ++it )
-  {
-    delete( it.value() );
-    it.value() = 0;
-  }
-  mSettings.dataDefinedProperties.clear();
-
   qDeleteAll( mLabels );
 
   if ( mOwnsSource )
