From ccab47d59808042bdd0ab73f7f1858aea3a0bb7d Mon Sep 17 00:00:00 2001
From: Paul Marrapese <paul.marrapese@gmail.com>
Date: Sun, 5 Apr 2020 19:06:08 -0700
Subject: [PATCH 1/4] improved performance of addLayers by preallocating array

---
 src/MarkerClusterGroup.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/MarkerClusterGroup.js b/src/MarkerClusterGroup.js
index 99c56e7d..db5c3d7c 100644
--- a/src/MarkerClusterGroup.js
+++ b/src/MarkerClusterGroup.js
@@ -291,7 +291,8 @@ export var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
 
 			process();
 		} else {
-			var needsClustering = this._needsClustering;
+			var needsClustering = new Array(l - offset);	// improve performance by preallocating the maximum size of our array
+			var tail = 0;
 
 			for (; offset < l; offset++) {
 				m = layersArray[offset];
@@ -317,8 +318,11 @@ export var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
 					continue;
 				}
 
-				needsClustering.push(m);
+				needsClustering[tail++] = m;
 			}
+
+			needsClustering = needsClustering.slice(0, tail);	// truncate empty elements
+			this._needsClustering.push.apply(this._needsClustering, needsClustering);
 		}
 		return this;
 	},

From f7a510e4cb23f02d16190873dac81a8f9ff3de9b Mon Sep 17 00:00:00 2001
From: Paul Marrapese <paul.marrapese@gmail.com>
Date: Wed, 26 Oct 2022 15:07:49 -0700
Subject: [PATCH 2/4] addLayers performance: use concat instead of push

---
 src/MarkerClusterGroup.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MarkerClusterGroup.js b/src/MarkerClusterGroup.js
index c631ff3e..e2fe5ff9 100644
--- a/src/MarkerClusterGroup.js
+++ b/src/MarkerClusterGroup.js
@@ -323,7 +323,7 @@ export var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
 			}
 
 			needsClustering = needsClustering.slice(0, tail);	// truncate empty elements
-			this._needsClustering.push.apply(this._needsClustering, needsClustering);
+			this._needsClustering = this._needsClustering.concat(needsClustering);
 		}
 		return this;
 	},

From 1641cf5ba475037f15812ac5e622f8e6106cae17 Mon Sep 17 00:00:00 2001
From: maranderan <33160267+maranderan@users.noreply.github.com>
Date: Mon, 27 Apr 2020 14:55:52 -0500
Subject: [PATCH 3/4] Check for finite min and max zoom properties

In the event leaflet sends "infinity" as a max or min zoom while generating the initial clusters, the loop to set up the grid clusters will crash the browser.
---
 src/MarkerClusterGroup.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/MarkerClusterGroup.js b/src/MarkerClusterGroup.js
index e2fe5ff9..97ea55a7 100644
--- a/src/MarkerClusterGroup.js
+++ b/src/MarkerClusterGroup.js
@@ -972,6 +972,13 @@ export var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
 		this._gridUnclustered = {};
 
 		//Set up DistanceGrids for each zoom
+				
+		if (!isFinite(maxZoom) ) {
+          		throw "Map has no maxZoom specified";
+        	}
+        	if (!isFinite(minZoom)) {
+            		throw "Map has no minZoom specified";
+        	}
 		for (var zoom = maxZoom; zoom >= minZoom; zoom--) {
 			this._gridClusters[zoom] = new L.DistanceGrid(radiusFn(zoom));
 			this._gridUnclustered[zoom] = new L.DistanceGrid(radiusFn(zoom));

From ec8261dc0b18b6e9690ac7ecd02456c557a3a1fe Mon Sep 17 00:00:00 2001
From: tmiaa <95731292+tmiaa@users.noreply.github.com>
Date: Sun, 9 Jan 2022 23:46:02 +0100
Subject: [PATCH 4/4] Adding markers aria-label for accessibility

---
 src/MarkerClusterGroup.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MarkerClusterGroup.js b/src/MarkerClusterGroup.js
index 97ea55a7..042daf23 100644
--- a/src/MarkerClusterGroup.js
+++ b/src/MarkerClusterGroup.js
@@ -834,7 +834,7 @@ export var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
 			c += 'large';
 		}
 
-		return new L.DivIcon({ html: '<div><span>' + childCount + '</span></div>', className: 'marker-cluster' + c, iconSize: new L.Point(40, 40) });
+		return new L.DivIcon({ html: '<div><span>' + childCount + ' <span aria-label="markers"></span>' + '</span></div>', className: 'marker-cluster' + c, iconSize: new L.Point(40, 40) });
 	},
 
 	_bindEvents: function () {