Generate unique savepoint names for nested transactions (#7174)

* Generate unique savepoint names

* Add a test for deeply nested wrapped transactions

Author: phroggyy

finisher_api.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"hash/maphash"
 	"reflect"
 	"strings"
 
@@ -623,14 +624,15 @@ func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err er
 	if committer, ok := db.Statement.ConnPool.(TxCommitter); ok && committer != nil {
 		// nested transaction
 		if !db.DisableNestedTransaction {
-			err = db.SavePoint(fmt.Sprintf("sp%p", fc)).Error
+			spID := new(maphash.Hash).Sum64()
+			err = db.SavePoint(fmt.Sprintf("sp%d", spID)).Error
 			if err != nil {
 				return
 			}
 			defer func() {
 				// Make sure to rollback when panic, Block error or Commit error
 				if panicked || err != nil {
-					db.RollbackTo(fmt.Sprintf("sp%p", fc))
+					db.RollbackTo(fmt.Sprintf("sp%d", spID))
 				}
 			}()
 		}

tests/go.mod

@@ -29,8 +29,8 @@ require (
 	github.com/microsoft/go-mssqldb v1.7.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rogpeppe/go-internal v1.12.0 // indirect
-	golang.org/x/crypto v0.24.0 // indirect
-	golang.org/x/text v0.16.0 // indirect
+	golang.org/x/crypto v0.26.0 // indirect
+	golang.org/x/text v0.17.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 

tests/transaction_test.go

@@ -297,6 +297,74 @@ func TestNestedTransactionWithBlock(t *testing.T) {
 	}
 }
 
+func TestDeeplyNestedTransactionWithBlockAndWrappedCallback(t *testing.T) {
+	transaction := func(ctx context.Context, db *gorm.DB, callback func(ctx context.Context, db *gorm.DB) error) error {
+		return db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+			return callback(ctx, tx)
+		})
+	}
+	var (
+		user  = *GetUser("transaction-nested", Config{})
+		user1 = *GetUser("transaction-nested-1", Config{})
+		user2 = *GetUser("transaction-nested-2", Config{})
+	)
+
+	if err := transaction(context.Background(), DB, func(ctx context.Context, tx *gorm.DB) error {
+		tx.Create(&user)
+
+		if err := tx.First(&User{}, "name = ?", user.Name).Error; err != nil {
+			t.Fatalf("Should find saved record")
+		}
+
+		if err := transaction(ctx, tx, func(ctx context.Context, tx1 *gorm.DB) error {
+			tx1.Create(&user1)
+
+			if err := tx1.First(&User{}, "name = ?", user1.Name).Error; err != nil {
+				t.Fatalf("Should find saved record")
+			}
+
+			if err := transaction(ctx, tx1, func(ctx context.Context, tx2 *gorm.DB) error {
+				tx2.Create(&user2)
+
+				if err := tx2.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+					t.Fatalf("Should find saved record")
+				}
+
+				return errors.New("inner rollback")
+			}); err == nil {
+				t.Fatalf("nested transaction has no error")
+			}
+
+			return errors.New("rollback")
+		}); err == nil {
+			t.Fatalf("nested transaction should returns error")
+		}
+
+		if err := tx.First(&User{}, "name = ?", user1.Name).Error; err == nil {
+			t.Fatalf("Should not find rollbacked record")
+		}
+
+		if err := tx.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+			t.Fatalf("Should find saved record")
+		}
+		return nil
+	}); err != nil {
+		t.Fatalf("no error should return, but got %v", err)
+	}
+
+	if err := DB.First(&User{}, "name = ?", user.Name).Error; err != nil {
+		t.Fatalf("Should find saved record")
+	}
+
+	if err := DB.First(&User{}, "name = ?", user1.Name).Error; err == nil {
+		t.Fatalf("Should not find rollbacked parent record")
+	}
+
+	if err := DB.First(&User{}, "name = ?", user2.Name).Error; err != nil {
+		t.Fatalf("Should not find rollbacked nested record")
+	}
+}
+
 func TestDisabledNestedTransaction(t *testing.T) {
 	var (
 		user  = *GetUser("transaction-nested", Config{})