fix

Author: demoManito

callbacks/update.go

@@ -32,24 +32,37 @@ func SetupUpdateReflectValue(db *gorm.DB) {
 // BeforeUpdate before update hooks
 func BeforeUpdate(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.BeforeSave || db.Statement.Schema.BeforeUpdate) {
-		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {
-			// save a copy before executing the hook so that can find out which fields were modified after the hook is executed.
-			rv := reflect.Indirect(reflect.ValueOf(value))
-			rvClone := reflect.New(rv.Type()).Elem()
-			rvClone.Set(rv)
-
+		callMethod(db, func(value interface{}, tx *gorm.DB) bool {
+			var (
+				beforeSaveInterface   BeforeSaveInterface
+				isBeforeSaveHook      bool
+				beforeUpdateInterface BeforeUpdateInterface
+				isBeforeUpdateHook    bool
+			)
 			if db.Statement.Schema.BeforeSave {
-				if i, ok := value.(BeforeSaveInterface); ok {
-					called = true
-					db.AddError(i.BeforeSave(tx))
-				}
+				beforeSaveInterface, isBeforeSaveHook = value.(BeforeSaveInterface)
 			}
-
 			if db.Statement.Schema.BeforeUpdate {
-				if i, ok := value.(BeforeUpdateInterface); ok {
-					called = true
-					db.AddError(i.BeforeUpdate(tx))
-				}
+				beforeUpdateInterface, isBeforeUpdateHook = value.(BeforeUpdateInterface)
+			}
+
+			var (
+				called     bool
+				rv         reflect.Value
+				rvSnapshot reflect.Value
+			)
+			if isBeforeSaveHook || isBeforeUpdateHook {
+				called = true
+				// save a snapshot of the struct before the hook was called
+				rv = reflect.Indirect(reflect.ValueOf(value))
+				rvSnapshot = reflect.New(rv.Type()).Elem()
+				rvSnapshot.Set(rv)
+			}
+			if isBeforeSaveHook {
+				db.AddError(beforeSaveInterface.BeforeSave(tx))
+			}
+			if isBeforeUpdateHook {
+				db.AddError(beforeUpdateInterface.BeforeUpdate(tx))
 			}
 
 			if called {
@@ -61,8 +74,8 @@ func BeforeUpdate(db *gorm.DB) {
 					if !ok {
 						continue
 					}
-					// compare with the copy value and update the field if there is a difference
-					if !reflect.DeepEqual(rv.FieldByName(field.Name).Interface(), rvClone.FieldByName(field.Name).Interface()) {
+					// compare with the snapshot and update the field if there is a difference
+					if !reflect.DeepEqual(rv.FieldByName(field.Name).Interface(), rvSnapshot.FieldByName(field.Name).Interface()) {
 						db.Statement.SetColumn(dbFieldName, rv.FieldByName(field.Name).Interface())
 					}
 				}