Add barpolar traces

src/traces/barpolar/plot.js

@@ -35,6 +35,8 @@ module.exports = function plot(gd, subplot, cdbar) {
         var bars = pointGroup.selectAll('g.point').data(Lib.identity);
 
         bars.enter().append('g')
+            .style('vector-effect', 'non-scaling-stroke')
+            .style('stroke-miterlimit', 2)
             .classed('point', true);
 
         bars.exit().remove();
@@ -82,9 +84,7 @@ module.exports = function plot(gd, subplot, cdbar) {
                 dPath = pathFn(rp0, rp1, thetag0, thetag1);
             }
 
-            Lib.ensureSingle(bar, 'path')
-                .style('vector-effect', 'non-scaling-stroke')
-                .attr('d', dPath);
+            Lib.ensureSingle(bar, 'path').attr('d', dPath);
         });
 
         // clip plotGroup, when trace layer isn't clipped

test/image/mocks/polar_bar-overlay.json

@@ -6,12 +6,15 @@
     "opacity": 0.7
   }, {
     "type": "barpolar",
-    "r": [1, 2, 3],
-    "theta": [180, 90, 360],
-    "opacity": 0.7
+    "r": [3, 3],
+    "theta": [0, 45],
+    "opacity": 0.7,
+    "marker": {
+      "line": {"width": 5}
+    }
   }],
   "layout": {
-    "polar": {"barmode": "overlay" },
+    "polar": {"barmode": "overlay"},
     "width": 500,
     "height": 500
   }