diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index 07f706c..1ba4290 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -22,6 +22,7 @@
 import org.eclipse.jgit.api.{ArchiveCommand, Git}
 import org.eclipse.jgit.archive.{TgzFormat, ZipFormat}
 import org.eclipse.jgit.dircache.DirCache
+import org.eclipse.jgit.errors.MissingObjectException
 import org.eclipse.jgit.lib._
 import org.eclipse.jgit.revwalk.RevCommit
 import org.eclipse.jgit.treewalk._
@@ -344,16 +345,21 @@
   get("/:owner/:repository/commit/:id")(referrersOnly { repository =>
     val id = params("id")
 
-    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
-      defining(JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(id))){ revCommit =>
-        JGitUtil.getDiffs(git, id) match { case (diffs, oldCommitId) =>
-          html.commit(id, new JGitUtil.CommitInfo(revCommit),
-            JGitUtil.getBranchesOfCommit(git, revCommit.getName),
-            JGitUtil.getTagsOfCommit(git, revCommit.getName),
-            getCommitComments(repository.owner, repository.name, id, false),
-            repository, diffs, oldCommitId, hasWritePermission(repository.owner, repository.name, context.loginAccount))
+    try {
+      using(Git.open(getRepositoryDir(repository.owner, repository.name))) { git =>
+        defining(JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(id))) { revCommit =>
+          JGitUtil.getDiffs(git, id) match {
+            case (diffs, oldCommitId) =>
+              html.commit(id, new JGitUtil.CommitInfo(revCommit),
+                JGitUtil.getBranchesOfCommit(git, revCommit.getName),
+                JGitUtil.getTagsOfCommit(git, revCommit.getName),
+                getCommitComments(repository.owner, repository.name, id, false),
+                repository, diffs, oldCommitId, hasWritePermission(repository.owner, repository.name, context.loginAccount))
+          }
         }
       }
+    } catch {
+      case e:MissingObjectException => NotFound
     }
   })
 
diff --git a/src/main/scala/gitbucket/core/view/LinkConverter.scala b/src/main/scala/gitbucket/core/view/LinkConverter.scala
index 639ae31..7792626 100644
--- a/src/main/scala/gitbucket/core/view/LinkConverter.scala
+++ b/src/main/scala/gitbucket/core/view/LinkConverter.scala
@@ -10,28 +10,64 @@
    * Converts issue id, username and commit id to link.
    */
   protected def convertRefsLinks(value: String, repository: RepositoryService.RepositoryInfo,
-      issueIdPrefix: String =  "#", escapeHtml: Boolean = true)(implicit context: Context): String = {
+                                 issueIdPrefix: String =  "#", escapeHtml: Boolean = true)(implicit context: Context): String = {
 
     // escape HTML tags
     val escaped = if(escapeHtml) value.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace("\"", "&quot;") else value
 
     escaped
-      // convert issue id to link
-      .replaceBy(("(?<=(^|\\W))" + issueIdPrefix + "([0-9]+)(?=(\\W|$))").r){ m =>
-        getIssue(repository.owner, repository.name, m.group(2)) match {
-          case Some(issue) if(issue.isPullRequest)
-                       => Some(s"""<a href="${context.path}/${repository.owner}/${repository.name}/pull/${m.group(2)}">#${m.group(2)}</a>""")
-          case Some(_) => Some(s"""<a href="${context.path}/${repository.owner}/${repository.name}/issues/${m.group(2)}">#${m.group(2)}</a>""")
-          case None    => Some(s"""#${m.group(2)}""")
-        }
+      // convert username/project@SHA to link
+      .replaceBy("(?<=(^|\\W))([a-zA-Z0-9\\-_]+)/([a-zA-Z0-9\\-_\\.]+)@([a-f0-9]{40})(?=(\\W|$))".r){ m =>
+      getAccountByUserName(m.group(2)).map { _ =>
+        s"""<a href="${context.path}/${m.group(2)}/${m.group(3)}/commit/${m.group(4)}">${m.group(2)}/${m.group(3)}@${m.group(4).substring(0, 7)}</a>"""
       }
+    }
+
+      // convert username/project#Num to link
+      .replaceBy( ("(?<=(^|\\W))([a-zA-Z0-9\\-_]+)/([a-zA-Z0-9\\-_\\.]+)" + issueIdPrefix + "([0-9]+)(?=(\\W|$))").r){ m =>
+      getIssue(m.group(2), m.group(3), m.group(4)) match {
+        case Some(issue) if (issue.isPullRequest)
+        => Some( s"""<a href="${context.path}/${m.group(2)}/${m.group(3)}/pull/${m.group(4)}">${m.group(2)}/${m.group(3)}#${m.group(4)}</a>""")
+        case Some(_) => Some( s"""<a href="${context.path}/${m.group(2)}/${m.group(3)}/issues/${m.group(4)}">${m.group(2)}/${m.group(3)}#${m.group(4)}</a>""")
+        case None => Some( s"""${m.group(2)}/${m.group(3)}#${m.group(4)}""")
+      }
+    }
+
+      // convert username@SHA to link
+      .replaceBy( ("(?<=(^|\\W))([a-zA-Z0-9\\-_]+)@([a-f0-9]{40})(?=(\\W|$))").r ) { m =>
+      getAccountByUserName(m.group(2)).map { _ =>
+        s"""<a href="${context.path}/${m.group(2)}/${repository.name}/commit/${m.group(3)}">${m.group(2)}@${m.group(3).substring(0, 7)}</a>"""
+      }
+    }
+
+      // convert username#Num to link
+      .replaceBy( ("(?<=(^|\\W))([a-zA-Z0-9\\-_]+)" + issueIdPrefix + "([0-9]+)(?=(\\W|$))").r ) { m =>
+      getIssue(m.group(2), repository.name, m.group(3)) match {
+        case Some(issue) if(issue.isPullRequest)
+        => Some(s"""<a href="${context.path}/${m.group(2)}/${repository.name}/pull/${m.group(3)}">${m.group(2)}#${m.group(3)}</a>""")
+        case Some(_) => Some(s"""<a href="${context.path}/${m.group(2)}/${repository.name}/issues/${m.group(3)}">${m.group(2)}#${m.group(3)}</a>""")
+        case None    => Some(s"""${m.group(2)}#${m.group(3)}""")
+      }
+    }
+
+      // convert issue id to link
+      .replaceBy(("(?<=(^|\\W))(GH-|" + issueIdPrefix + ")([0-9]+)(?=(\\W|$))").r){ m =>
+      getIssue(repository.owner, repository.name, m.group(3)) match {
+        case Some(issue) if(issue.isPullRequest)
+        => Some(s"""<a href="${context.path}/${repository.owner}/${repository.name}/pull/${m.group(3)}">${m.group(2)}${m.group(3)}</a>""")
+        case Some(_) => Some(s"""<a href="${context.path}/${repository.owner}/${repository.name}/issues/${m.group(3)}">${m.group(2)}${m.group(3)}</a>""")
+        case None    => Some(s"""${m.group(2)}${m.group(3)}""")
+      }
+    }
+
       // convert @username to link
       .replaceBy("(?<=(^|\\W))@([a-zA-Z0-9\\-_\\.]+)(?=(\\W|$))".r){ m =>
         getAccountByUserName(m.group(2)).map { _ =>
           s"""<a href="${context.path}/${m.group(2)}">@${m.group(2)}</a>"""
         }
       }
+
       // convert commit id to link
-      .replaceAll("(?<=(^|\\W))([a-f0-9]{40})(?=(\\W|$))", s"""<a href="${context.path}/${repository.owner}/${repository.name}/commit/$$2">$$2</a>""")
+      .replaceAll("(?<=(^|[^\\w/@]))([a-f0-9]{40})(?=(\\W|$))", s"""<a href="${context.path}/${repository.owner}/${repository.name}/commit/$$2">$$2</a>""")
   }
 }