From d5cafb5db15c1c6026005bfe0b41220cf2513887 Mon Sep 17 00:00:00 2001
From: Shunsuke Otani <shun.otani@gmail.com>
Date: Thu, 12 Sep 2019 23:16:05 +0900
Subject: [PATCH] Fix CallbackProcessor.Get() for removed or replaced same name
 callback (#2548)

---
 callback.go       | 10 +++++++---
 callbacks_test.go | 48 ++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/callback.go b/callback.go
index 6f60511b..202af06e 100644
--- a/callback.go
+++ b/callback.go
@@ -135,11 +135,15 @@ func (cp *CallbackProcessor) Replace(callbackName string, callback func(scope *S
 //    db.Callback().Create().Get("gorm:create")
 func (cp *CallbackProcessor) Get(callbackName string) (callback func(scope *Scope)) {
 	for _, p := range cp.parent.processors {
-		if p.name == callbackName && p.kind == cp.kind && !cp.remove {
-			return *p.processor
+		if p.name == callbackName && p.kind == cp.kind {
+			if p.remove {
+				callback = nil
+			} else {
+				callback = *p.processor
+			}
 		}
 	}
-	return nil
+	return
 }
 
 // getRIndex get right index from string slice
diff --git a/callbacks_test.go b/callbacks_test.go
index a58913d7..c1a1d5e4 100644
--- a/callbacks_test.go
+++ b/callbacks_test.go
@@ -2,11 +2,10 @@ package gorm_test
 
 import (
 	"errors"
-
-	"github.com/jinzhu/gorm"
-
 	"reflect"
 	"testing"
+
+	"github.com/jinzhu/gorm"
 )
 
 func (s *Product) BeforeCreate() (err error) {
@@ -175,3 +174,46 @@ func TestCallbacksWithErrors(t *testing.T) {
 		t.Errorf("Record shouldn't be deleted because of an error happened in after delete callback")
 	}
 }
+
+func TestGetCallback(t *testing.T) {
+	scope := DB.NewScope(nil)
+
+	if DB.Callback().Create().Get("gorm:test_callback") != nil {
+		t.Errorf("`gorm:test_callback` should be nil")
+	}
+
+	DB.Callback().Create().Register("gorm:test_callback", func(scope *gorm.Scope) { scope.Set("gorm:test_callback_value", 1) })
+	callback := DB.Callback().Create().Get("gorm:test_callback")
+	if callback == nil {
+		t.Errorf("`gorm:test_callback` should be non-nil")
+	}
+	callback(scope)
+	if v, ok := scope.Get("gorm:test_callback_value"); !ok || v != 1 {
+		t.Errorf("`gorm:test_callback_value` should be `1, true` but `%v, %v`", v, ok)
+	}
+
+	DB.Callback().Create().Replace("gorm:test_callback", func(scope *gorm.Scope) { scope.Set("gorm:test_callback_value", 2) })
+	callback = DB.Callback().Create().Get("gorm:test_callback")
+	if callback == nil {
+		t.Errorf("`gorm:test_callback` should be non-nil")
+	}
+	callback(scope)
+	if v, ok := scope.Get("gorm:test_callback_value"); !ok || v != 2 {
+		t.Errorf("`gorm:test_callback_value` should be `2, true` but `%v, %v`", v, ok)
+	}
+
+	DB.Callback().Create().Remove("gorm:test_callback")
+	if DB.Callback().Create().Get("gorm:test_callback") != nil {
+		t.Errorf("`gorm:test_callback` should be nil")
+	}
+
+	DB.Callback().Create().Register("gorm:test_callback", func(scope *gorm.Scope) { scope.Set("gorm:test_callback_value", 3) })
+	callback = DB.Callback().Create().Get("gorm:test_callback")
+	if callback == nil {
+		t.Errorf("`gorm:test_callback` should be non-nil")
+	}
+	callback(scope)
+	if v, ok := scope.Get("gorm:test_callback_value"); !ok || v != 3 {
+		t.Errorf("`gorm:test_callback_value` should be `3, true` but `%v, %v`", v, ok)
+	}
+}