Further check that *is* plain object instead of simply truthy

Author: rreusser

src/plot_api/plot_api.js

@@ -2566,7 +2566,7 @@ Plotly.addFrames = function(gd, frameList, indices) {
 
     var insertions = [];
     for(i = frameList.length - 1; i >= 0; i--) {
-        if(!frameList[i]) continue;
+        if(!Lib.isPlainObject(frameList[i])) continue;
 
         var name = (_hash[frameList[i].name] || {}).name;
         var newName = frameList[i].name;

test/jasmine/tests/frame_api_test.js

@@ -43,8 +43,8 @@ describe('Test frame api', function() {
             }).catch(fail).then(done);
         });
 
-        it('compresses nulls when adding frames', function(done) {
-            Plotly.addFrames(gd, [null, {name: 'test'}, null]).then(function() {
+        it('compresses garbage when adding frames', function(done) {
+            Plotly.addFrames(gd, [null, 'garbage', 14, true, false, {name: 'test'}, null]).then(function() {
                 expect(Object.keys(h)).toEqual(['test']);
                 expect(f).toEqual([{name: 'test'}]);
             }).catch(fail).then(done);