From bf6b11eb2e15fff8322434629169a921410540ec Mon Sep 17 00:00:00 2001
From: johnniang <johnniang@riseup.net>
Date: Thu, 30 May 2019 14:34:11 +0800
Subject: [PATCH] Fix NPE when importing markdown files

---
 src/main/java/run/halo/app/service/TagService.java             | 1 +
 .../java/run/halo/app/service/impl/CategoryServiceImpl.java    | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main/java/run/halo/app/service/TagService.java b/src/main/java/run/halo/app/service/TagService.java
index 1992eb2ce..afd05df33 100644
--- a/src/main/java/run/halo/app/service/TagService.java
+++ b/src/main/java/run/halo/app/service/TagService.java
@@ -31,6 +31,7 @@ public interface TagService extends CrudService<Tag, Integer> {
      * @param name name
      * @return Tag
      */
+    @Nullable
     Tag getByName(@NonNull String name);
 
     /**
diff --git a/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java b/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
index 0d8b8509a..fff4aa1cc 100644
--- a/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
@@ -16,6 +16,7 @@ import run.halo.app.repository.CategoryRepository;
 import run.halo.app.service.CategoryService;
 import run.halo.app.service.PostCategoryService;
 import run.halo.app.service.base.AbstractCrudService;
+import run.halo.app.utils.ServiceUtils;
 
 import java.util.Collections;
 import java.util.LinkedList;
@@ -56,7 +57,7 @@ public class CategoryServiceImpl extends AbstractCrudService<Category, Integer>
         }
 
         // Check parent id
-        if (category.getParentId() > 0) {
+        if (!ServiceUtils.isEmptyId(category.getParentId())) {
             count = categoryRepository.countById(category.getParentId());
 
             if (count == 0) {