Don't call fillNullsWithZero() before graphing.
I can't remember why that was needed. If I remember, I'll put it back, but
meanwhile, various charts actually do different things with 0 vs null (ie.
you don't get a line for values that are null).
diff --git a/render.js b/render.js
index 7ef727e..957e658 100644
--- a/render.js
+++ b/render.js
@@ -754,7 +754,9 @@
var chartops = args.get('chart');
var t, datatable;
if (chartops) {
- grid = fillNullsWithZero(grid);
+ //TODO(apenwarr): something needed this, but I no longer remember what.
+ // At least line and dygraph charts are seemingly fine without it.
+ //grid = fillNullsWithZero(grid);
var el = document.getElementById('vizchart');
$(el).height(window.innerHeight).width(window.innerWidth);
var options = {};
