fix 500 error while use a reserved name in org rename (#17878)

fix #17876

Signed-off-by: a1012112796 <1012112796@qq.com>

models/user/user.go

@@ -10,7 +10,6 @@ import (
 	"crypto/sha256"
 	"crypto/subtle"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"net/url"
 	"os"
@@ -73,11 +72,6 @@ const (
 	EmailNotificationsDisabled = "disabled"
 )
 
-var (
-	// ErrUserNameIllegal user name contains illegal characters error
-	ErrUserNameIllegal = errors.New("User name contains illegal characters")
-)
-
 // User represents the object of individual and member of organization.
 type User struct {
 	ID        int64  `xorm:"pk autoincr"`

routers/web/org/setting.go

@@ -73,7 +73,7 @@ func SettingsPost(ctx *context.Context) {
 			ctx.RenderWithErr(ctx.Tr("form.username_been_taken"), tplSettingsOptions, &form)
 			return
 		} else if err = user_model.ChangeUserName(org.AsUser(), form.Name); err != nil {
-			if err == user_model.ErrUserNameIllegal {
+			if db.IsErrNameReserved(err) || db.IsErrNamePatternNotAllowed(err) {
 				ctx.Data["OrgName"] = true
 				ctx.RenderWithErr(ctx.Tr("form.illegal_username"), tplSettingsOptions, &form)
 			} else {