Fix what information is shown about user in API. (#9115)

* Fix what information is shown about user in API.

* Use Email directly, as KeepEmailPrivate is already handled.

modules/convert/convert.go

@@ -256,6 +256,7 @@ func ToTeam(team *models.Team) *api.Team {
 }
 
 // ToUser convert models.User to api.User
+// signed shall only be set if requester is logged in. authed shall only be set if user is site admin or user himself
 func ToUser(user *models.User, signed, authed bool) *api.User {
 	result := &api.User{
 		UserName:  user.Name,
@@ -263,14 +264,13 @@ func ToUser(user *models.User, signed, authed bool) *api.User {
 		FullName:  markup.Sanitize(user.FullName),
 		Created:   user.CreatedUnix.AsTime(),
 	}
-	// hide primary email if API caller isn't user itself or an admin
+	// hide primary email if API caller is anonymous or user keep email private
-	if !signed {
+	if signed && (!user.KeepEmailPrivate || authed) {
-		result.Email = ""
-	} else if user.KeepEmailPrivate && !authed {
-		result.Email = user.GetEmail()
-	} else { // only user himself and admin could visit these information
-		result.ID = user.ID
 		result.Email = user.Email
+	}
+	// only site admin will get these information and possibly user himself
+	if authed {
+		result.ID = user.ID
 		result.IsAdmin = user.IsAdmin
 		result.LastLogin = user.LastLoginUnix.AsTime()
 	}