[JGIT PATCH 06/10 v2] Reuse the magic tOc constant for pack index headers

["Shawn O. Pearce" <spearce@spearce.org>]

We need this constant to detect version 2 index files at read time,
but we also need it to create version 2 index files.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---

 Fixed isTOC test to return true when h.length == 8, which
 is always the case as it has both the TOC and the version.

 Also rebased into my branch:
 
   repo.or.cz:/srv/git/egit/spearce.git index-v2

 With this patch in the series all tests pass again.

 .../src/org/spearce/jgit/lib/PackIndex.java        |    6 +++++-
 .../src/org/spearce/jgit/lib/PackIndexWriter.java  |    3 +++
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndex.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndex.java
index 3935d4f..c5718fa 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndex.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndex.java
@@ -104,7 +104,11 @@ public abstract class PackIndex implements Iterable<PackIndex.MutableEntry> {
 	}
 
 	private static boolean isTOC(final byte[] h) {
-		return h[0] == -1 && h[1] == 't' && h[2] == 'O' && h[3] == 'c';
+		final byte[] toc = PackIndexWriter.TOC;
+		for (int i = 0; i < toc.length; i++)
+			if (h[i] != toc[i])
+				return false;
+		return true;
 	}
 
 	/**
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
index 473e6cf..c9b27d2 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
@@ -55,6 +55,9 @@ import org.spearce.jgit.util.NB;
  * to the byte offset within the pack where the object's data can be read.
  */
 public abstract class PackIndexWriter {
+	/** Magic constant indicating post-version 1 format. */
+	protected static final byte[] TOC = { -1, 't', 'O', 'c' };
+
 	/**
 	 * Create a new writer for the oldest (most widely understood) format.
 	 * <p>
-- 
1.5.6.74.g8a5e

-- 
Shawn.