Merge branch 'stable-7.7'

* stable-7.7:
  Ensure the SnapshottingRefDirectory shares the packedRefsRefresher

Change-Id: Ib080645b6bb4ba911710baae181c5c22a49cb40e
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
index 1b43f27..a9211fe 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
@@ -151,8 +151,7 @@ public class RefDirectory extends RefDatabase {
 	/** Immutable sorted list of packed references. */
 	final AtomicReference<PackedRefList> packedRefs = new AtomicReference<>();
 
-	private final AtomicReference<PackedRefsRefresher> packedRefsRefresher =
-			new AtomicReference<>();
+	private final AtomicReference<PackedRefsRefresher> packedRefsRefresher;
 
 	/**
 	 * Lock for coordinating operations within a single process that may contend
@@ -201,6 +200,7 @@ public class RefDirectory extends RefDatabase {
 		looseRefs.set(refDb.looseRefs.get());
 		packedRefs.set(refDb.packedRefs.get());
 		coreConfig = refDb.coreConfig;
+		packedRefsRefresher = refDb.packedRefsRefresher;
 		inProcessPackedRefsLock = refDb.inProcessPackedRefsLock;
 	}
 
@@ -217,6 +217,7 @@ public class RefDirectory extends RefDatabase {
 		looseRefs.set(RefList.<LooseRef> emptyList());
 		packedRefs.set(NO_PACKED_REFS);
 		coreConfig = db.getConfig().get(CoreConfig.KEY);
+		packedRefsRefresher = new AtomicReference<>();
 		inProcessPackedRefsLock = new ReentrantLock(true);
 	}