feat: fix LDAP filter condition will return nil if error happened (casdoor#3604)

Author: dacongda

ldap/util.go

@@ -185,12 +185,9 @@ func buildUserFilterCondition(filter interface{}) (builder.Cond, error) {
 		attr := string(f.AttributeDesc())
 
 		if attr == ldapMemberOfAttr {
-			groupId := string(f.AssertionValue())
-			users, err := object.GetGroupUsers(groupId)
-			if err != nil {
-				return nil, err
-			}
 			var names []string
+			groupId := string(f.AssertionValue())
+			users := object.GetGroupUsersWithoutError(groupId)
 			for _, user := range users {
 				names = append(names, user.Name)
 			}
@@ -249,7 +246,7 @@ func buildSafeCondition(filter interface{}) builder.Cond {
 	condition, err := buildUserFilterCondition(filter)
 	if err != nil {
 		log.Printf("err = %v", err.Error())
-		return nil
+		return builder.And(builder.Expr("1 != 1"))
 	}
 	return condition
 }

object/group.go

@@ -302,7 +302,10 @@ func GetPaginationGroupUsers(groupId string, offset, limit int, field, value, so
 
 func GetGroupUsers(groupId string) ([]*User, error) {
 	users := []*User{}
-	owner, _ := util.GetOwnerAndNameFromId(groupId)
+	owner, _, err := util.GetOwnerAndNameFromIdWithError(groupId)
+	if err != nil {
+		return nil, err
+	}
 	names, err := userEnforcer.GetUserNamesByGroupName(groupId)
 	if err != nil {
 		return nil, err
@@ -314,6 +317,11 @@ func GetGroupUsers(groupId string) ([]*User, error) {
 	return users, nil
 }
 
+func GetGroupUsersWithoutError(groupId string) []*User {
+	users, _ := GetGroupUsers(groupId)
+	return users
+}
+
 func ExtendGroupWithUsers(group *Group) error {
 	if group == nil {
 		return nil