Avoid updating arc targets when it's not needed - #172

c3.js

@@ -413,7 +413,10 @@
         $$.updateTargetsForLine(targets);
 
         //-- Arc --//
-        if ($$.updateTargetsForArc) { $$.updateTargetsForArc(targets); }
+        if ($$.hasArcType() && $$.updateTargetsForArc) { $$.updateTargetsForArc(targets); }
+
+        /*-- Sub --*/
+
         if ($$.updateTargetsForSubchart) { $$.updateTargetsForSubchart(targets); }
 
         /*-- Show --*/
@@ -6238,6 +6241,7 @@
         options.withTransitionForTransform = false;
         $$.transiting = false;
         $$.setTargetType(targetIds, type);
+        $$.updateTargets($$.data.targets); // this is needed when transforming to arc
         $$.updateAndRedraw(options);
     };
 

src/api.transform.js

@@ -11,5 +11,6 @@ c3_chart_internal_fn.transformTo = function (targetIds, type, optionsForRedraw)
     options.withTransitionForTransform = false;
     $$.transiting = false;
     $$.setTargetType(targetIds, type);
+    $$.updateTargets($$.data.targets); // this is needed when transforming to arc
     $$.updateAndRedraw(options);
 };

src/core.js

@@ -408,7 +408,10 @@ c3_chart_internal_fn.updateTargets = function (targets) {
     $$.updateTargetsForLine(targets);
 
     //-- Arc --//
-    if ($$.updateTargetsForArc) { $$.updateTargetsForArc(targets); }
+    if ($$.hasArcType() && $$.updateTargetsForArc) { $$.updateTargetsForArc(targets); }
+
+    /*-- Sub --*/
+
     if ($$.updateTargetsForSubchart) { $$.updateTargetsForSubchart(targets); }
 
     /*-- Show --*/