From 0599d13b7ddc7b0820ce6bac78085335ec14522e Mon Sep 17 00:00:00 2001
From: Neal Nelson <neal@makalumedia.com>
Date: Thu, 17 Jun 2010 16:07:52 +0200
Subject: [PATCH] Ensure step plots draw lines to the start of missing values.

---
 dygraph-canvas.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index 2eb5ce1..3988b19 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -616,6 +616,15 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
       var point = points[j];
       if (point.name == setName) {
         if (!isOK(point.canvasy)) {
+          if (stepPlot) {
+            // Draw a horizontal line to the start of the missing data
+            ctx.beginPath();
+            ctx.strokeStyle = color;
+            ctx.lineWidth = this.options.strokeWidth;
+            ctx.moveTo(prevX, prevY);
+            ctx.lineTo(point.canvasx, prevY);
+            ctx.stroke();
+          }
           // this will make us move to the next point, not draw a line to it.
           prevX = prevY = null;
         } else {
-- 
2.7.4