From f15e9c088a6c50d96789fbeba04bb3272a5d3d4d Mon Sep 17 00:00:00 2001
From: Shawn Pearce <spearce@spearce.org>
Date: Fri, 19 Aug 2016 11:51:40 -0700
Subject: [PATCH] DfsObjDatabase: clear PackList dirty bit if no new packs

If a reference was updated more recently than a pack was written
(typical) the PackList was perpetually dirty until the next GC
was completed for the repository.

Detect this condition by observing no changes to the PackList
membership and resetting the dirty bit.

Change-Id: Ie2133aca1f8083307c73b6a26358175864f100ef
---
 .../jgit/internal/storage/dfs/DfsObjDatabase.java | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsObjDatabase.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsObjDatabase.java
index f6e4c2391..b1d6c0dd1 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsObjDatabase.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsObjDatabase.java
@@ -67,6 +67,11 @@ boolean dirty() {
 			return true;
 		}
 
+		@Override
+		void clearDirty() {
+			// Always dirty.
+		}
+
 		@Override
 		public void markDirty() {
 			// Always dirty.
@@ -443,8 +448,10 @@ private PackList scanPacksImpl(PackList old) throws IOException {
 			p.close();
 		if (list.isEmpty())
 			return new PackListImpl(NO_PACKS.packs);
-		if (!foundNew)
+		if (!foundNew) {
+			old.clearDirty();
 			return old;
+		}
 		return new PackListImpl(list.toArray(new DfsPackFile[list.size()]));
 	}
 
@@ -514,6 +521,7 @@ public long getLastModified() {
 		}
 
 		abstract boolean dirty();
+		abstract void clearDirty();
 
 		/**
 		 * Mark pack list as dirty.
@@ -537,6 +545,11 @@ boolean dirty() {
 			return dirty;
 		}
 
+		@Override
+		void clearDirty() {
+			dirty = false;
+		}
+
 		@Override
 		public void markDirty() {
 			dirty = true;