fix

Author: yp05327

routers/api/v1/repo/issue_label.go

@@ -109,6 +109,11 @@ func AddIssueLabels(ctx *context.APIContext) {
 		return
 	}
 
+	// if permission is denied, the prepareForReplaceOrAdd function will return nil, nil, nil
+	if ctx.Written() {
+		return
+	}
+
 	if err = issue_service.AddLabels(ctx, issue, ctx.Doer, labels); err != nil {
 		ctx.Error(http.StatusInternalServerError, "AddLabels", err)
 		return