Some const-correctness for rules

Author: m-kuhn

python/core/symbology/qgsrulebasedrenderer.sip.in

@@ -351,7 +351,7 @@ Create a rule from an XML definition
 :return: A new rule
 %End
 
-        QgsRuleBasedRenderer::RuleList &children();
+        const QgsRuleBasedRenderer::RuleList &children();
 %Docstring
 Return all children rules of this rule
 

src/core/symbology/qgsrulebasedrenderer.h

@@ -374,7 +374,7 @@ class CORE_EXPORT QgsRuleBasedRenderer : public QgsFeatureRenderer
          *
          * \returns A list of rules
          */
-        QgsRuleBasedRenderer::RuleList &children() { return mChildren; }
+        const QgsRuleBasedRenderer::RuleList &children() { return mChildren; }
 
         /**
          * Returns all children, grand-children, grand-grand-children, grand-gra... you get it

src/gui/symbology/qgsrulebasedrendererwidget.cpp

@@ -342,10 +342,10 @@ QList<QgsSymbol *> QgsRuleBasedRendererWidget::selectedSymbols()
   {
     QModelIndex parent = range.parent();
     QgsRuleBasedRenderer::Rule *parentRule = mModel->ruleForIndex( parent );
-    QgsRuleBasedRenderer::RuleList &children = parentRule->children();
+    const QgsRuleBasedRenderer::RuleList &children = parentRule->children();
     for ( int row = range.top(); row <= range.bottom(); row++ )
     {
-      symbolList.append( children[row]->symbol() );
+      symbolList.append( children.at( row )->symbol() );
     }
   }
 
@@ -360,10 +360,10 @@ QgsRuleBasedRenderer::RuleList QgsRuleBasedRendererWidget::selectedRules()
   {
     QModelIndex parent = range.parent();
     QgsRuleBasedRenderer::Rule *parentRule = mModel->ruleForIndex( parent );
-    QgsRuleBasedRenderer::RuleList &children = parentRule->children();
+    const QgsRuleBasedRenderer::RuleList &children = parentRule->children();
     for ( int row = range.top(); row <= range.bottom(); row++ )
     {
-      rl.append( children[row]->clone() );
+      rl.append( children.at( row )->clone() );
     }
   }
   return rl;