Fix line clipping at the chart area borders (#5321)

diff --git a/src/controllers/controller.line.js b/src/controllers/controller.line.js
index 9d9206d5cb211f385e8ed4b9e1325ae59a955abc..7aacf2d23e27bd843299ab5c5623678aec5804f2 100644 (file)
--- a/src/controllers/controller.line.js
+++ b/src/controllers/controller.line.js
@@ -283,15 +283,23 @@ module.exports = function(Chart) {
                        var points = meta.data || [];
                        var area = chart.chartArea;
                        var ilen = points.length;
+                       var halfBorderWidth;
                        var i = 0;
 
-                       helpers.canvas.clipArea(chart.ctx, area);
-
                        if (lineEnabled(me.getDataset(), chart.options)) {
+                               halfBorderWidth = (meta.dataset._model.borderWidth || 0) / 2;
+
+                               helpers.canvas.clipArea(chart.ctx, {
+                                       left: area.left,
+                                       right: area.right,
+                                       top: area.top - halfBorderWidth,
+                                       bottom: area.bottom + halfBorderWidth
+                               });
+
                                meta.dataset.draw();
-                       }
 
-                       helpers.canvas.unclipArea(chart.ctx);
+                               helpers.canvas.unclipArea(chart.ctx);
+                       }
 
                        // Draw the points
                        for (; i < ilen; ++i) {