A service to get the wiki sidebar page

- getWikiSideBar: a new service to get the wiki sidebar file "_Sidebar.md".
- getFileContent: must ignore MD files which starts with "_".

src/main/scala/gitbucket/core/service/WikiService.scala

@@ -71,6 +71,20 @@ trait WikiService {
     }
   }
 
+  /**
+   * Returns the wiki sidebar page.
+   */
+  def getWikiSideBar(owner: String, repository: String): Option[WikiPageInfo] = {
+    using(Git.open(Directory.getWikiRepositoryDir(owner, repository))){ git =>
+      if(!JGitUtil.isEmpty(git)){
+        JGitUtil.getFileList(git, "master", ".").find(_.name == "_Sidebar.md").map { file =>
+          WikiPageInfo(file.name, StringUtil.convertFromByteArray(git.getRepository.open(file.id).getBytes),
+                       file.author, file.time, file.commitId)
+        }
+      } else None
+    }
+  }
+
   /**
    * Returns the content of the specified file.
    */
@@ -93,7 +107,7 @@ trait WikiService {
   def getWikiPageList(owner: String, repository: String): List[String] = {
     using(Git.open(Directory.getWikiRepositoryDir(owner, repository))){ git =>
       JGitUtil.getFileList(git, "master", ".")
-        .filter(_.name.endsWith(".md"))
+        .filter(_.name.endsWith(".md")).filterNot(_.name.startsWith("_"))
         .map(_.name.stripSuffix(".md"))
         .sortBy(x => x)
     }