fix scatter fill restyle regression

... by setting trace._ownfill on every linkTraces call,
    so we don't let relinkPrivateKeys mess things up.

    Previously, the scatter fill restyle test did not fail,
    but did log a error as Drawing.fillGroupStyle logs
    in a try-catch when things go wrong instead of errorring out.

Author: etpinard

src/traces/scatter/link_traces.js

@@ -75,12 +75,11 @@ module.exports = function linkTraces(gd, plotinfo, cdscatter) {
                 }
             }
 
-            if(trace.fill && (
-                trace.fill.substr(0, 6) === 'tozero' || trace.fill === 'toself' ||
-                (trace.fill.substr(0, 2) === 'to' && !trace._prevtrace))
-            ) {
-                trace._ownfill = true;
-            }
+            trace._ownfill = (trace.fill && (
+                trace.fill.substr(0, 6) === 'tozero' ||
+                trace.fill === 'toself' ||
+                (trace.fill.substr(0, 2) === 'to' && !trace._prevtrace)
+            ));
 
             prevtraces[group] = trace;
         } else {

test/jasmine/tests/scatter_test.js

@@ -658,6 +658,10 @@ describe('end-to-end scatter tests', function() {
         // from any case to any other case.
         var indices = transitions(cases.length);
 
+        // Drawing.fillGroupStyle logs an error in a try-catch when
+        // things go wrong
+        spyOn(Lib, 'error');
+
         var p = Plotly.plot(gd, [
             {y: [1, 2], text: 'a'},
             {y: [2, 3], text: 'b'},
@@ -707,6 +711,7 @@ describe('end-to-end scatter tests', function() {
             var msg = i ? ('from ' + cases[indices[i - 1]].name + ' to ') : 'from default to ';
             msg += name;
             assertMultiNodeOrder(selectorArray, msg);
+            expect(Lib.error).not.toHaveBeenCalled();
         }; }
 
         for(i = 0; i < indices.length; i++) {