Fix session key conflict with database keyword (#28613)

This is a regression from #28220 .
`builder.Cond` will not add `` ` `` automatically but xorm method
`Get/Find` adds `` ` ``.

This PR also adds tests to prevent the method from being implemented
incorrectly. The tests are added in `integrations` to test every
database.

models/auth/session.go

@@ -41,12 +41,15 @@ func ReadSession(ctx context.Context, key string) (*Session, error) {
 	}
 	defer committer.Close()
 
-	session, exist, err := db.Get[Session](ctx, builder.Eq{"key": key})
+	session, exist, err := db.Get[Session](ctx, builder.Eq{"`key`": key})
 	if err != nil {
 		return nil, err
 	} else if !exist {
-		session.Expiry = timeutil.TimeStampNow()
-		if err := db.Insert(ctx, &session); err != nil {
+		session = &Session{
+			Key:    key,
+			Expiry: timeutil.TimeStampNow(),
+		}
+		if err := db.Insert(ctx, session); err != nil {
 			return nil, err
 		}
 	}
@@ -56,7 +59,7 @@ func ReadSession(ctx context.Context, key string) (*Session, error) {
 
 // ExistSession checks if a session exists
 func ExistSession(ctx context.Context, key string) (bool, error) {
-	return db.Exist[Session](ctx, builder.Eq{"key": key})
+	return db.Exist[Session](ctx, builder.Eq{"`key`": key})
 }
 
 // DestroySession destroys a session
@@ -75,13 +78,13 @@ func RegenerateSession(ctx context.Context, oldKey, newKey string) (*Session, er
 	}
 	defer committer.Close()
 
-	if has, err := db.Exist[Session](ctx, builder.Eq{"key": newKey}); err != nil {
+	if has, err := db.Exist[Session](ctx, builder.Eq{"`key`": newKey}); err != nil {
 		return nil, err
 	} else if has {
 		return nil, fmt.Errorf("session Key: %s already exists", newKey)
 	}
 
-	if has, err := db.Exist[Session](ctx, builder.Eq{"key": oldKey}); err != nil {
+	if has, err := db.Exist[Session](ctx, builder.Eq{"`key`": oldKey}); err != nil {
 		return nil, err
 	} else if !has {
 		if err := db.Insert(ctx, &Session{
@@ -96,7 +99,7 @@ func RegenerateSession(ctx context.Context, oldKey, newKey string) (*Session, er
 		return nil, err
 	}
 
-	s, _, err := db.Get[Session](ctx, builder.Eq{"key": newKey})
+	s, _, err := db.Get[Session](ctx, builder.Eq{"`key`": newKey})
 	if err != nil {
 		// is not exist, it should be impossible
 		return nil, err

tests/integration/session_test.go

@@ -0,0 +1,37 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_RegenerateSession(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	key := "new_key890123456"  // it must be 16 characters long
+	key2 := "new_key890123457" // it must be 16 characters
+	exist, err := auth.ExistSession(db.DefaultContext, key)
+	assert.NoError(t, err)
+	assert.False(t, exist)
+
+	sess, err := auth.RegenerateSession(db.DefaultContext, "", key)
+	assert.NoError(t, err)
+	assert.EqualValues(t, key, sess.Key)
+	assert.Len(t, sess.Data, 0)
+
+	sess, err = auth.ReadSession(db.DefaultContext, key2)
+	assert.NoError(t, err)
+	assert.EqualValues(t, key2, sess.Key)
+	assert.Len(t, sess.Data, 0)
+}