rename the error name and add detection method

Author: lunny

models/perm/access/repo_permission.go

@@ -18,14 +18,19 @@ import (
 	"code.gitea.io/gitea/modules/util"
 )
 
-type ErrNoPermission struct {
+type ErrPermissionDenied struct {
 	RepoID int64
 	Unit   unit.Type
 	Perm   perm_model.AccessMode
 }
 
-func (e ErrNoPermission) Error() string {
-	return fmt.Sprintf("no permission to access repo %d unit %s with mode %s", e.RepoID, e.Unit.LogString(), e.Perm.LogString())
+func (e ErrPermissionDenied) Error() string {
+	return fmt.Sprintf("permission denied to access repo %d unit %s with mode %s", e.RepoID, e.Unit.LogString(), e.Perm.LogString())
+}
+
+func IsErrPermissionDenied(err error) bool {
+	_, ok := err.(ErrPermissionDenied)
+	return ok
 }
 
 // Permission contains all the permissions related variables to a repository for a user

routers/web/repo/pull.go

@@ -1436,10 +1436,10 @@ func CleanUpPullRequest(ctx *context.Context) {
 	}
 
 	if err := repo_service.CanDeleteBranch(ctx, pr.HeadRepo, pr.HeadBranch, ctx.Doer); err != nil {
-		if errors.Is(err, access_model.ErrNoPermission{}) {
-			ctx.NotFound("CleanUpPullRequest", nil)
+		if access_model.IsErrPermissionDenied(err) {
+			ctx.NotFound("CanDeleteBranch", nil)
 		} else {
-			ctx.ServerError("GetUserRepoPermission", err)
+			ctx.ServerError("CanDeleteBranch", err)
 		}
 		return
 	}

services/repository/branch.go

@@ -476,7 +476,7 @@ func CanDeleteBranch(ctx context.Context, repo *repo_model.Repository, branchNam
 		return err
 	}
 	if !perm.CanWrite(unit.TypeCode) {
-		return access_model.ErrNoPermission{
+		return access_model.ErrPermissionDenied{
 			RepoID: repo.ID,
 			Unit:   unit.TypeCode,
 			Perm:   perm_model.AccessModeWrite,