fixed setOpacity in IE7 and IE8

src/core/Browser.js

@@ -6,7 +6,6 @@
 
 	var ie = !!window.ActiveXObject,
 	    ie6 = ie && !window.XMLHttpRequest,
-	    ie7 = ie && !document.querySelector,
 
 	    // terrible browser detection to work around Safari / iOS / Android browser bugs
 	    ua = navigator.userAgent.toLowerCase(),
@@ -14,6 +13,7 @@
 	    chrome = ua.indexOf('chrome') !== -1,
 	    android = ua.indexOf('android') !== -1,
 	    android23 = ua.search('android [23]') !== -1,
+	    ie7 = ie && !document.querySelector && ua.search('msie 7') !== -1,
 
 	    mobile = typeof orientation !== undefined + '',
 	    msTouch = window.navigator && window.navigator.msPointerEnabled &&

src/dom/DomUtil.js

@@ -151,17 +151,9 @@ L.DomUtil = {
 			var filter = false,
 			    filterName = 'DXImageTransform.Microsoft.Alpha';
 
-			// filters collection throws an error if we try to retrieve a filter that doesn't exist
-			try { filter = el.filters.item(filterName); } catch (e) {}
-
 			value = Math.round(value * 100);
 
-			if (filter) {
-				filter.Enabled = (value !== 100);
-				filter.Opacity = value;
-			} else {
-				el.style.filter += ' progid:' + filterName + '(opacity=' + value + ')';
-			}
+			el.style.filter = ' progid:' + filterName + '(opacity=' + value + ')';
 		}
 	},
 

src/layer/tile/TileLayer.js

@@ -186,7 +186,9 @@ L.TileLayer = L.Class.extend({
 	},
 
 	_updateOpacity: function () {
-		L.DomUtil.setOpacity(this._container, this.options.opacity);
+		if (!L.Browser.ie7) {
+			L.DomUtil.setOpacity(this._container, this.options.opacity);
+		}
 
 		// stupid webkit hack to force redrawing of tiles
 		var i,
@@ -199,6 +201,15 @@ L.TileLayer = L.Class.extend({
 				}
 			}
 		}
+
+		if (L.Browser.ie7) {
+			for (i in tiles) {
+				if (tiles.hasOwnProperty(i)) {
+					tiles[i].style.filter = 'alpha(opacity=' + (this.options.opacity * 100) + ')';
+				}
+			}
+		}
+
 	},
 
 	_initContainer: function () {
@@ -471,6 +482,10 @@ L.TileLayer = L.Class.extend({
 	_createTile: function () {
 		var tile = this._tileImg.cloneNode(false);
 		tile.onselectstart = tile.onmousemove = L.Util.falseFn;
+		if (L.Browser.ie7 && this.options.opacity !== undefined) {
+			tile.style.filter = 'alpha(opacity=' + (this.options.opacity * 100) + ')';
+		}
+
 		return tile;
 	},