From c4d02a8f9696f547340727ce8663d9eee71ec906 Mon Sep 17 00:00:00 2001
From: Pascoual <pascoualito@gmail.com>
Date: Tue, 10 Nov 2015 00:53:08 +0100
Subject: [PATCH] Fix: no tooltips when missing data for one or more dataset

---
 src/core/core.controller.js |  6 ++++--
 src/core/core.tooltip.js    | 36 +++++++++++++++++++++---------------
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/core/core.controller.js b/src/core/core.controller.js
index 8c46fd4df..1d3e42ccb 100644
--- a/src/core/core.controller.js
+++ b/src/core/core.controller.js
@@ -439,7 +439,8 @@
 					case 'label':
 					case 'dataset':
 						for (var i = 0; i < this.lastActive.length; i++) {
-							this.data.datasets[this.lastActive[i]._datasetIndex].controller.removeHoverStyle(this.lastActive[i], this.lastActive[i]._datasetIndex, this.lastActive[i]._index);
+                            if (this.lastActive[i])
+							    this.data.datasets[this.lastActive[i]._datasetIndex].controller.removeHoverStyle(this.lastActive[i], this.lastActive[i]._datasetIndex, this.lastActive[i]._index);
 						}
 						break;
 					default:
@@ -456,7 +457,8 @@
 					case 'label':
 					case 'dataset':
 						for (var j = 0; j < this.active.length; j++) {
-							this.data.datasets[this.active[j]._datasetIndex].controller.setHoverStyle(this.active[j]);
+                            if (this.active[j])
+							    this.data.datasets[this.active[j]._datasetIndex].controller.setHoverStyle(this.active[j]);
 						}
 						break;
 					default:
diff --git a/src/core/core.tooltip.js b/src/core/core.tooltip.js
index 03b833dff..9b87df388 100644
--- a/src/core/core.tooltip.js
+++ b/src/core/core.tooltip.js
@@ -203,9 +203,11 @@
 			var yPositions = [];
 
 			helpers.each(elements, function(el){
-				var pos = el.tooltipPosition();
-				xPositions.push(pos.x);
-				yPositions.push(pos.y);
+				if(el) {
+					var pos = el.tooltipPosition();
+					xPositions.push(pos.x);
+					yPositions.push(pos.y);
+				}
 			});
 
 			var x = 0, y = 0;
@@ -249,21 +251,25 @@
 							return;
 						}
 						var currentElement = dataset.metaData[element._index];
-						var yScale = element._yScale || element._scale; // handle radar || polarArea charts
-
-						tooltipItems.push({
-							xLabel: currentElement._xScale ? currentElement._xScale.getLabelForIndex(currentElement._index, currentElement._datasetIndex) : '',
-							yLabel: yScale ? yScale.getLabelForIndex(currentElement._index, currentElement._datasetIndex) : '',
-							index: element._index,
-							datasetIndex: datasetIndex,
-						});
+						if (currentElement) {
+							var yScale = element._yScale || element._scale; // handle radar || polarArea charts
+
+							tooltipItems.push({
+								xLabel: currentElement._xScale ? currentElement._xScale.getLabelForIndex(currentElement._index, currentElement._datasetIndex) : '',
+								yLabel: yScale ? yScale.getLabelForIndex(currentElement._index, currentElement._datasetIndex) : '',
+								index: element._index,
+								datasetIndex: datasetIndex,
+							});
+						}
 					});
 
 					helpers.each(this._active, function(active, i) {
-						labelColors.push({
-							borderColor: active._view.borderColor,
-							backgroundColor: active._view.backgroundColor
-						});
+						if (active) {
+						  labelColors.push({
+						  	borderColor: active._view.borderColor,
+						  	backgroundColor: active._view.backgroundColor
+						  });
+						}
 					}, this);
 
 					tooltipPosition = this.getAveragePosition(this._active);
-- 
2.47.3