Fix nested Scopes, close #4196

callbacks.go

@@ -109,11 +109,13 @@ func (p *processor) Execute(db *DB) {
 	}
 
 	// call scopes
+	for len(stmt.scopes) > 0 {
 		scopes := stmt.scopes
 		stmt.scopes = nil
 		for _, scope := range scopes {
 			db = scope(db)
 		}
+	}
 
 	for _, f := range p.fns {
 		f(db)

migrator.go

@@ -8,11 +8,13 @@ import (
 // Migrator returns migrator
 func (db *DB) Migrator() Migrator {
 	// apply scopes to migrator
+	for len(db.Statement.scopes) > 0 {
 		scopes := db.Statement.scopes
 		db.Statement.scopes = nil
 		for _, scope := range scopes {
 			db = scope(db)
 		}
+	}
 
 	return db.Dialector.Migrator(db.Session(&Session{}))
 }