Fix legend item width when data.names called - #775

c3.js

@@ -3766,6 +3766,9 @@
             .style('visibility', 'hidden');
     };
     var legendItemTextBox = {};
+    c3_chart_internal_fn.clearLegendItemTextBoxCache = function () {
+        legendItemTextBox = {};
+    };
     c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
         var $$ = this, config = $$.config;
         var xForLegend, xForLegendText, xForLegendRect, yForLegend, yForLegendText, yForLegendRect;
@@ -6273,6 +6276,7 @@
         return values;
     };
     c3_chart_fn.data.names = function (names) {
+        this.internal.clearLegendItemTextBoxCache();
         return this.internal.updateDataAttributes('names', names);
     };
     c3_chart_fn.data.colors = function (colors) {

src/api.data.js

@@ -16,6 +16,7 @@ c3_chart_fn.data.values = function (targetId) {
     return values;
 };
 c3_chart_fn.data.names = function (names) {
+    this.internal.clearLegendItemTextBoxCache();
     return this.internal.updateDataAttributes('names', names);
 };
 c3_chart_fn.data.colors = function (colors) {

src/legend.js

@@ -100,6 +100,9 @@ c3_chart_internal_fn.hideLegend = function (targetIds) {
         .style('visibility', 'hidden');
 };
 var legendItemTextBox = {};
+c3_chart_internal_fn.clearLegendItemTextBoxCache = function () {
+    legendItemTextBox = {};
+};
 c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
     var $$ = this, config = $$.config;
     var xForLegend, xForLegendText, xForLegendRect, yForLegend, yForLegendText, yForLegendRect;