fix Makefile conflict

Makefile

@@ -66,6 +66,8 @@ frontend:
 	else \
 	haxe cagetteJs.hxml; \
 	fi
+	mkdir -p tmp
+	chown www-data:www-data tmp
 
 #update POT file from source
 i18n:	

js/ShopCart.hx

@@ -164,7 +164,13 @@ class ShopCart
 		var groups = new Map<Int,{name:String,products:Array<ProductInfo>}>();
 		var pinned = new Map<Int,{name:String,products:Array<ProductInfo>}>();
 
-		var firstCategGroup = this.categories[0].categs;
+
+		trace(this.categories);
+		var firstCategGroup = null;
+		if (this.categories.length > 0){
+			firstCategGroup = this.categories[0].categs;
+		}
+		
 
 		//trace(firstCategGroup);
 		//trace(pinnedCategories);
@@ -181,7 +187,7 @@ class ShopCart
 
 			for ( categ in p.categories){
 
-				if (Lambda.find(firstCategGroup, function(c) return c.id == categ) != null){
+				if (firstCategGroup != null && Lambda.find(firstCategGroup, function(c) return c.id == categ) != null){
 
 					//is in this category group
 					var g = groups.get(categ);