allow multiple parcoords dimensions with the same name

Author: monfera

src/traces/parcoords/parcoords.js

@@ -176,7 +176,7 @@ function viewModel(model) {
     viewModel.dimensions = dimensions.filter(visible).map(function(dimension, i) {
         var domainToUnit = domainToUnitScale(dimension);
         var foundKey = uniqueKeys[dimension.label];
-        uniqueKeys[dimension.label] = (foundKey ? 0 : foundKey) + 1;
+        uniqueKeys[dimension.label] = (foundKey || 0) + 1;
         var key = dimension.label + (foundKey ? '__' + foundKey : '');
         return {
             key: key,

test/jasmine/tests/parcoords_test.js

@@ -288,6 +288,23 @@ describe('parcoords', function() {
             });
         });
 
+        it('Works with duplicate dimension labels', function(done) {
+
+            var mockCopy = Lib.extendDeep({}, mock2);
+
+            mockCopy.layout.width = 320;
+            mockCopy.data[0].dimensions[1].label = mockCopy.data[0].dimensions[0].label;
+
+            var gd = createGraphDiv();
+            Plotly.plot(gd, mockCopy.data, mockCopy.layout).then(function() {
+
+                expect(gd.data.length).toEqual(1);
+                expect(gd.data[0].dimensions.length).toEqual(2);
+                expect(document.querySelectorAll('.axis').length).toEqual(2);
+                done();
+            });
+        });
+
         it('Works with a single line; also, use a longer color array than the number of lines', function(done) {
 
             var mockCopy = Lib.extendDeep({}, mock2);