fix Map min/maxZoom not overriding TileLayer-derived min/max, close Leaflet#1848

Author: mourner

spec/suites/layer/TileLayerSpec.js

@@ -13,10 +13,11 @@ describe('TileLayer', function () {
 					minZoom = 5;
 					map.setView([0, 0], 1);
 
-					L.tileLayer(tileUrl, {
-						maxZoom: maxZoom,
-						minZoom: minZoom
-					}).addTo(map);
+				L.tileLayer(tileUrl, {
+					maxZoom: maxZoom,
+					minZoom: minZoom
+				}).addTo(map);
+
 				expect(map.getMaxZoom()).to.be(maxZoom);
 				expect(map.getMinZoom()).to.be(minZoom);
 			});

spec/suites/map/MapSpec.js

@@ -122,12 +122,15 @@ describe("Map", function () {
 
 	describe("#getMinZoom and #getMaxZoom", function () {
 		it("minZoom and maxZoom options overrides any minZoom and maxZoom set on layers", function () {
-			var c = document.createElement('div'),
-			    map = L.map(c, { minZoom: 5, maxZoom: 10 });
-			L.tileLayer("{z}{x}{y}", { minZoom:0, maxZoom: 10 }).addTo(map);
-			L.tileLayer("{z}{x}{y}", { minZoom:5, maxZoom: 15 }).addTo(map);
-			expect(map.getMinZoom()).to.be(5);
-			expect(map.getMaxZoom()).to.be(10);
+
+			var map = L.map(document.createElement('div'), {minZoom: 2, maxZoom: 20});
+
+			L.tileLayer("{z}{x}{y}", {minZoom: 4, maxZoom: 10}).addTo(map);
+			L.tileLayer("{z}{x}{y}", {minZoom: 6, maxZoom: 17}).addTo(map);
+			L.tileLayer("{z}{x}{y}", {minZoom: 0, maxZoom: 22}).addTo(map);
+
+			expect(map.getMinZoom()).to.be(2);
+			expect(map.getMaxZoom()).to.be(20);
 		});
 	});
 

src/map/Map.js

@@ -345,18 +345,15 @@ L.Map = L.Class.extend({
 	},
 
 	getMinZoom: function () {
-		var z1 = this.options.minZoom || 0,
-		    z2 = this._layersMinZoom || 0,
-		    z3 = this._boundsMinZoom || 0;
-
-		return Math.max(z1, z2, z3);
+		var z1 = this._layersMinZoom === undefined ? -Infinity : this._layersMinZoom,
+		    z2 = this._boundsMinZoom === undefined ? -Infinity : this._boundsMinZoom;
+		return this.options.minZoom === undefined ? Math.max(z1, z2) : this.options.minZoom;
 	},
 
 	getMaxZoom: function () {
-		var z1 = this.options.maxZoom === undefined ? Infinity : this.options.maxZoom,
-		    z2 = this._layersMaxZoom  === undefined ? Infinity : this._layersMaxZoom;
-
-		return Math.min(z1, z2);
+		return this.options.maxZoom === undefined ?
+			(this._layersMaxZoom === undefined ? Infinity : this._layersMaxZoom) :
+			this.options.maxZoom;
 	},
 
 	getBoundsZoom: function (bounds, inside, padding) { // (LatLngBounds[, Boolean, Point]) -> Number