Fix coverity dereference warning

nyalldawson · nyalldawson · commit c672ce2a0521 · 2016-06-02T13:18:56.000+10:00
diff --git a/src/core/qgsaggregatecalculator.cpp b/src/core/qgsaggregatecalculator.cpp
@@ -106,7 +106,8 @@ QVariant QgsAggregateCalculator::calculate( QgsAggregateCalculator::Aggregate ag
       return QVariant();
     }
 
-    context->setFeature( f );
+    if ( context )
+      context->setFeature( f );
     QVariant v = expression->evaluate( context );
     resultType = v.type();
   }

Original file line number	Diff line number	Diff line change
`@@ -106,7 +106,8 @@ QVariant QgsAggregateCalculator::calculate( QgsAggregateCalculator::Aggregate ag`
`106`	`106`	`return QVariant();`
`107`	`107`	`}`
`108`	`108`
`109`		`- context->setFeature( f );`
	`109`	`+ if ( context )`
	`110`	`+ context->setFeature( f );`
`110`	`111`	`QVariant v = expression->evaluate( context );`
`111`	`112`	`resultType = v.type();`
`112`	`113`	`}`