Fix zoom transition

c3.js

@@ -4266,7 +4266,7 @@ c3_chart_fn.zoom = function (domain) {
             });
         }
         if ($$.config.subchart_show) {
-            $$.brush.selectionAsValue(domain);
+            $$.brush.selectionAsValue(domain, true);
         } else {
             $$.updateXDomain(null, true, false, false, domain);
             $$.redraw({ withY: $$.config.zoom_rescale, withSubchart: false });
@@ -8307,12 +8307,16 @@ c3_chart_internal_fn.initBrush = function (scale) {
     $$.brush.selection = function () {
         return d3.brushSelection($$.context.select('.' + CLASS.brush).node());
     };
-    $$.brush.selectionAsValue = function (selectionAsValue) {
+    $$.brush.selectionAsValue = function (selectionAsValue, withTransition) {
-        var selection;
+        var selection, brush;
         if (selectionAsValue) {
             if ($$.context) {
                 selection = [this.scale(selectionAsValue[0]), this.scale(selectionAsValue[1])];
-                $$.brush.move($$.context.select('.' + CLASS.brush).transition(), selection);
+                brush = $$.context.select('.' + CLASS.brush);
+                if (withTransition) {
+                    brush = brush.transition();
+                }
+                $$.brush.move(brush, selection);
             }
             return [];
         }

src/api.zoom.js

@@ -8,7 +8,7 @@ c3_chart_fn.zoom = function (domain) {
             domain = domain.map(function (x) { return $$.parseDate(x); });
         }
         if ($$.config.subchart_show) {
-            $$.brush.selectionAsValue(domain);
+            $$.brush.selectionAsValue(domain, true);
         }
         else {
             $$.updateXDomain(null, true, false, false, domain);

src/subchart.js

@@ -39,12 +39,14 @@ c3_chart_internal_fn.initBrush = function (scale) {
     $$.brush.selection = function () {
         return d3.brushSelection($$.context.select('.' + CLASS.brush).node());
     };
-    $$.brush.selectionAsValue = function (selectionAsValue) {
+    $$.brush.selectionAsValue = function (selectionAsValue, withTransition) {
-        var selection;
+        var selection, brush;
         if (selectionAsValue) {
             if ($$.context) {
                 selection = [this.scale(selectionAsValue[0]), this.scale(selectionAsValue[1])];
-                $$.brush.move($$.context.select('.' + CLASS.brush).transition(), selection);
+                brush = $$.context.select('.' + CLASS.brush);
+                if (withTransition) { brush = brush.transition(); }
+                $$.brush.move(brush, selection);
             }
             return [];
         }