[JGIT PATCH 1/2] Fix the UnpackedObjectCache hash function to prevent overflow

Sometimes we got negative array indexes inside of the cache due
to WindowedFile.hash having a negative value assigned by the JVM.
We now use only the lower 8 bits as the cache is fixed to at most
256 entries.

Signed-off-by: Shawn O. Pearce <redacted>
---
 .../org/spearce/jgit/lib/UnpackedObjectCache.java  |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/UnpackedObjectCache.java b/org.spearce.jgit/src/org/spearce/jgit/lib/UnpackedObjectCache.java
index 03cf674..ee6a680 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/UnpackedObjectCache.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/UnpackedObjectCache.java

@@ -48,9 +48,9 @@
 
 	private static int hash(final WindowedFile pack, final long position) {
 		int h = pack.hash + (int) position;
-		h += h >> 16;
-		h += h >> 8;
-		return h % CACHE_SZ;
+		h += h >>> 16;
+		h += h >>> 8;
+		return h & (CACHE_SZ - 1);
 	}
 
 	private static int maxByteCount;

-- 
1.6.0.2.463.g7f0eb