From 3463a5ed01f38b6134c0b4b1075702f328b8e7e1 Mon Sep 17 00:00:00 2001
From: Sebastian Sdorra <sebastian.sdorra@cloudogu.com>
Date: Thu, 28 Jul 2011 22:13:19 +0200
Subject: [PATCH] fix issue with git repository without HEAD ref

---
 .../scm/repository/GitChangesetViewer.java    | 22 ++++--
 .../java/sonia/scm/repository/GitUtil.java    | 69 ++++++++++++++++++-
 2 files changed, 84 insertions(+), 7 deletions(-)

diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitChangesetViewer.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitChangesetViewer.java
index ab6ea607d8..7af74596ea 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitChangesetViewer.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitChangesetViewer.java
@@ -37,6 +37,7 @@ package sonia.scm.repository;
 
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.NoHeadException;
+import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.revwalk.RevCommit;
 
 import org.slf4j.Logger;
@@ -51,6 +52,7 @@ import java.io.IOException;
 
 import java.util.ArrayList;
 import java.util.List;
+import org.eclipse.jgit.api.LogCommand;
 
 /**
  *
@@ -107,16 +109,26 @@ public class GitChangesetViewer implements ChangesetViewer
       if (!gr.getAllRefs().isEmpty())
       {
         converter = new GitChangesetConverter(gr, GitUtil.ID_LENGTH);
+
         Git git = new Git(gr);
+        ObjectId headId = GitUtil.getRepositoryHead(gr);
 
-        for (RevCommit commit : git.log().call())
+        if (headId != null)
         {
-          if ((counter >= start) && (counter < start + max))
+          for (RevCommit commit : git.log().add(headId).call())
           {
-            changesetList.add(converter.createChangeset(commit));
-          }
+            if ((counter >= start) && (counter < start + max))
+            {
+              changesetList.add(converter.createChangeset(commit));
+            }
 
-          counter++;
+            counter++;
+          }
+        }
+        else if (logger.isWarnEnabled())
+        {
+          logger.warn("could not find repository head of repository {}",
+                      repository.getName());
         }
       }
 
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
index 31658127eb..845bcf898b 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
@@ -37,12 +37,16 @@ package sonia.scm.repository;
 
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RepositoryCache;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.FS;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import sonia.scm.util.Util;
 
 //~--- JDK imports ------------------------------------------------------------
@@ -50,6 +54,8 @@ import sonia.scm.util.Util;
 import java.io.File;
 import java.io.IOException;
 
+import java.util.Map;
+
 /**
  *
  * @author Sebastian Sdorra
@@ -57,9 +63,23 @@ import java.io.IOException;
 public class GitUtil
 {
 
-    /** Field description */
+  /** Field description */
   public static final int ID_LENGTH = 20;
-  
+
+  /** Field description */
+  public static final String REF_HEAD = "HEAD";
+
+  /** Field description */
+  public static final String REF_HEAD_PREFIX = "refs/heads/";
+
+  /** Field description */
+  public static final String REF_MASTER = "master";
+
+  /** the logger for GitUtil */
+  private static final Logger logger = LoggerFactory.getLogger(GitUtil.class);
+
+  //~--- methods --------------------------------------------------------------
+
   /**
    * Method description
    *
@@ -138,6 +158,51 @@ public class GitUtil
     return date;
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param repo
+   *
+   * @return
+   */
+  public static ObjectId getRepositoryHead(org.eclipse.jgit.lib.Repository repo)
+  {
+    ObjectId id = null;
+    String head = null;
+    Map<String, Ref> refs = repo.getAllRefs();
+
+    for (Map.Entry<String, Ref> e : refs.entrySet())
+    {
+      String key = e.getKey();
+
+      if (REF_HEAD.equals(key))
+      {
+        head = REF_HEAD;
+        id = e.getValue().getObjectId();
+
+        break;
+      }
+      else if (key.startsWith(REF_HEAD_PREFIX))
+      {
+        id = e.getValue().getObjectId();
+        head = key.substring(REF_HEAD_PREFIX.length());
+
+        if (REF_MASTER.equals(head))
+        {
+          break;
+        }
+      }
+    }
+
+    if (logger.isInfoEnabled())
+    {
+      logger.info("use {}:{} as repository head", head, id);
+    }
+
+    return id;
+  }
+
   /**
    * Method description
    *