Alwaywas return local url for users avatar (#8245)

* Always return local url for users avatar

Avoids having to wait for DNS lookups when libravatar is activated
fixing #6046

* Avoid double slash in avatar link

* Move avatar route to the correct place

routers/user/avatar.go

@@ -0,0 +1,37 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package user
+
+import (
+	"strconv"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/log"
+)
+
+// Avatar redirect browser to user avatar of requested size
+func Avatar(ctx *context.Context) {
+	userName := ctx.Params(":username")
+	size, err := strconv.Atoi(ctx.Params(":size"))
+	if err != nil {
+		ctx.ServerError("Invalid avatar size", err)
+		return
+	}
+
+	log.Debug("Asked avatar for user %v and size %v", userName, size)
+
+	user, err := models.GetUserByName(userName)
+	if err != nil {
+		if models.IsErrUserNotExist(err) {
+			ctx.ServerError("Requested avatar for invalid user", err)
+		} else {
+			ctx.ServerError("Retrieving user by name", err)
+		}
+		return
+	}
+
+	ctx.Redirect(user.RealSizedAvatarLink(size))
+}