From 87c5a64c0521a645972b52e3a767d14548a06bc3 Mon Sep 17 00:00:00 2001
From: Dan Vanderkam <danvdk@gmail.com>
Date: Fri, 28 Nov 2014 15:50:29 -0500
Subject: [PATCH] Patch up NaN values in error bars

---
 auto_tests/tests/missing_points.js | 33 +++++++++++++++++++++++++++++++++
 dygraph-canvas.js                  | 10 +++++++---
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/auto_tests/tests/missing_points.js b/auto_tests/tests/missing_points.js
index a78e0ac..eb1c575 100644
--- a/auto_tests/tests/missing_points.js
+++ b/auto_tests/tests/missing_points.js
@@ -368,3 +368,36 @@ MissingPointsTestCase.prototype.testEmptySeries = function() {
   g.setSelection(6);
   assertEquals("1381134466: Series 2: 94", Util.getLegend(graphDiv));
 };
+
+// Regression test for issue #485
+MissingPointsTestCase.prototype.testMissingFill = function() {
+  var graphDiv = document.getElementById("graph");
+  var N = null;
+  var g = new Dygraph(
+      graphDiv,
+      [
+        [1, [8, 10, 12]],
+        [2, [3, 5,7]   ],
+        [3,     N,     ],
+        [4, [9, N, 2]  ],  // Note: nulls in arrays are not technically valid.
+        [5, [N, 2, N]  ],  // see dygraphs.com/data.html.
+        [6, [2, 3, 6]  ]
+      ],
+      {
+        customBars: true,
+        connectSeparatedPoints: false,
+        labels: [ "X", "Series1"]
+      }
+  );
+
+  // Make sure there are no 'NaN' line segments.
+  var htx = g.hidden_ctx_;
+  for (var i = 0; i < htx.calls__.length; i++) {
+    var call = htx.calls__[i];
+    if ((call.name == 'moveTo' || call.name == 'lineTo') && call.args) {
+      for (var j = 0; j < call.args.length; j++) {
+        assertFalse(isNaN(call.args[j]));
+      }
+    }
+  }
+};
diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index 4d7a7dd..6e503d9 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -599,12 +599,16 @@ DygraphCanvasRenderer._errorPlotter = function(e) {
       continue;
     }
 
+    newYs = [ point.y_bottom, point.y_top ];
     if (stepPlot) {
-      newYs = [ point.y_bottom, point.y_top ];
       prevY = point.y;
-    } else {
-      newYs = [ point.y_bottom, point.y_top ];
     }
+
+    // The documentation specifically disallows nulls inside the point arrays,
+    // but in case it happens we should do something sensible.
+    if (isNaN(newYs[0])) newYs[0] = point.y;
+    if (isNaN(newYs[1])) newYs[1] = point.y;
+
     newYs[0] = e.plotArea.h * newYs[0] + e.plotArea.y;
     newYs[1] = e.plotArea.h * newYs[1] + e.plotArea.y;
     if (!isNaN(prevX)) {
-- 
2.7.4