added check for no documents

dbhandler/mongo/servers_authorization.go

@@ -52,7 +52,6 @@ func (self *ServersAuthorizationDbHandler) AddPermissions(ctx context.Context, u
 			"server_id": serverId,
 		},
 	).Decode(&serverPermissions)
-
 	if err != nil {
 		return err
 	}
@@ -65,11 +64,12 @@ func (self *ServersAuthorizationDbHandler) AddPermissions(ctx context.Context, u
 			"username":  username,
 			"server_id": serverId,
 		},
-		bson.M{"$set": bson.M{
-			"username":    username,
-			"server_id":   serverId,
-			"permissions": newPermissions,
-		},
+		bson.M{
+			"$set": bson.M{
+				"username":    username,
+				"server_id":   serverId,
+				"permissions": newPermissions,
+			},
 		},
 		options.Update().SetUpsert(true),
 	)
@@ -86,7 +86,6 @@ func (self *ServersAuthorizationDbHandler) RemovePermissions(ctx context.Context
 			"server_id": serverId,
 		},
 	).Decode(&serverPermissions)
-
 	if err != nil {
 		return err
 	}
@@ -99,9 +98,10 @@ func (self *ServersAuthorizationDbHandler) RemovePermissions(ctx context.Context
 			"username":  username,
 			"server_id": serverId,
 		},
-		bson.M{"$set": bson.M{
-			"permissions": newPermissions,
-		},
+		bson.M{
+			"$set": bson.M{
+				"permissions": newPermissions,
+			},
 		},
 	)
 
@@ -115,9 +115,10 @@ func (self *ServersAuthorizationDbHandler) SetPermissions(ctx context.Context, u
 			"username":  username,
 			"server_id": serverId,
 		},
-		bson.M{"$set": bson.M{
-			"permissions": permissions,
-		},
+		bson.M{
+			"$set": bson.M{
+				"permissions": permissions,
+			},
 		},
 	)
 
@@ -134,8 +135,11 @@ func (self *ServersAuthorizationDbHandler) GetPermissions(ctx context.Context, u
 			"server_id": serverId,
 		},
 	).Decode(&serverPermissions)
-
 	if err != nil {
+		if err == mongo.ErrNoDocuments {
+			return 0, nil
+		}
+
 		return 0, err
 	}