Show error if admin tries to add a second authentication source of type SSPI

Author: quasoft

models/login_source.go

@@ -334,6 +334,15 @@ func LoginSources() ([]*LoginSource, error) {
 	return auths, x.Find(&auths)
 }
 
+// LoginSourcesByType returns all sources of the specified type
+func LoginSourcesByType(loginType LoginType) ([]*LoginSource, error) {
+	sources := make([]*LoginSource, 0, 1)
+	if err := x.Where("type = ?", loginType).Find(&sources); err != nil {
+		return nil, err
+	}
+	return sources, nil
+}
+
 // ActiveLoginSources returns all active sources of the specified type
 func ActiveLoginSources(loginType LoginType) ([]*LoginSource, error) {
 	sources := make([]*LoginSource, 0, 1)

options/locale/locale_en-US.ini

@@ -1849,6 +1849,7 @@ auths.delete_auth_desc = Deleting an authentication source prevents users from u
 auths.still_in_used = The authentication source is still in use. Convert or delete any users using this authentication source first.
 auths.deletion_success = The authentication source has been deleted.
 auths.login_source_exist = The authentication source '%s' already exists.
+auths.login_source_of_type_exist = An authentication source of this type already exists.
 
 config.server_config = Server Configuration
 config.app_name = Site Title

routers/admin/auths.go

@@ -233,6 +233,12 @@ func NewAuthSourcePost(ctx *context.Context, form auth.AuthenticationForm) {
 			ctx.RenderWithErr(err.Error(), tplAuthNew, form)
 			return
 		}
+		existing, err := models.LoginSourcesByType(models.LoginSSPI)
+		if err != nil || len(existing) > 0 {
+			ctx.Data["Err_Type"] = true
+			ctx.RenderWithErr(ctx.Tr("admin.auths.login_source_of_type_exist"), tplAuthNew, form)
+			return
+		}
 	default:
 		ctx.Error(400)
 		return