plot_api: clear gd.data on update calls -> full data + layout replot

- so that Plotly.plot doesn't try to extend them

Author: etpinard

src/plot_api/plot_api.js

@@ -2062,9 +2062,15 @@ Plotly.update = function update(gd, traceUpdate, layoutUpdate, traces) {
     var seq = [];
 
     if(restyleFlags.fullReplot && relayoutFlags.layoutReplot) {
-        var layout = gd.layout;
+        var data = gd.data,
+            layout = gd.layout;
+
+        // clear existing data/layout on gd
+        // so that Plotly.plot doesn't try to extend them
+        gd.data = undefined;
         gd.layout = undefined;
-        seq.push(function() { return Plotly.plot(gd, gd.data, layout); });
+
+        seq.push(function() { return Plotly.plot(gd, data, layout); });
     }
     else if(restyleFlags.fullReplot) {
         seq.push(Plotly.plot);

test/jasmine/tests/plot_api_test.js

@@ -973,6 +973,26 @@ describe('Test plot api', function() {
             });
         });
 
+        it('clear calcdata on data + axis updates w/o extending current gd.data', function(done) {
+            var traceUpdate = {
+                x: [[3, 1, 3]]
+            };
+
+            var layoutUpdate = {
+                xaxis: {title: 'A', type: '-'}
+            };
+
+            Plotly.update(gd, traceUpdate, layoutUpdate).then(function() {
+                expect(data).toBe(gd.data);
+                expect(layout).toBe(gd.layout);
+                expect(calcdata).not.toBe(gd.calcdata);
+
+                expect(gd.data.length).toEqual(1);
+
+                done();
+            });
+        });
+
         it('call doLegend on legend updates', function(done) {
             expect(subroutines.doLegend).not.toHaveBeenCalled();